Patent Publication Number: US-2023144251-A1

Title: High-speed connector

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is based on, and claims priority from, China Patent Application No. 202111324968.6, filed Nov. 10, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a high-speed connector, and more particularly to a high-speed connector which is capable of adjusting a dielectric coefficient of a peripheral structure of a terminal of the high-speed connector to improve an electromagnetic characteristic and a crosstalk interference for improving transmission quality of a high-frequency signal of the high-speed connector. 
     2. The Related Art 
     Nowadays, a high-speed connector usually includes a grounding plate and a plurality of grounding terminals. The plurality of the grounding terminals are connected to the grounding plate for reducing an insertion loss and a crosstalk interference. The grounding plate has a main body, and a plurality of elastic arms extended from the main body. The main body is a sheet shape. The plurality of the elastic arms are mostly integrally stamped with the main body in forms of cantilever beams. However, a structural strength of the grounding plate is insufficient, and the grounding plate hardly shields differential signal terminals of the high-speed connector, so it is necessary to improve the grounding plate for enhancing the structural strength and an electromagnetic characteristic of the high-speed connector. 
     A conventional high-speed connector includes a housing, an insulating core inserted into the housing, a plurality of terminals fixed to the insulating core, a shielding structure and a transmission module. The plurality of the terminals include a plurality of first conductive terminals fixed to the insulating core, and a plurality of second conductive terminals fixed to the insulating core. The plurality of the first conductive terminals are arranged along a transverse direction. The plurality of the first conductive terminals include two differential signal terminals and two grounding terminals. The two grounding terminals are adjacent to two outer sides of the two differential signal terminals. The shielding structure has a dielectric base assembled to the housing, and a metallic plating layer plated to the dielectric base. The metallic plating layer contacts with the two grounding terminals to establish an electrical connection between the two grounding terminals. The metallic plating layer is positioned at the two outer sides of the two differential signal terminals, so the metallic plating layer shields the two differential signal terminals along the transverse direction. 
     However, the above-mentioned shielding structure of the high-speed connector is fully covered with the metallic plating layer to achieve a shielding function, the high-speed connector has following disadvantages. When a signal is radiated towards the metallic plating layer, and the signal contacts with the metallic plating layer, a signal reflection is generated and an oscillation is easily caused to generate many unnecessary resonance points. When the high-speed connector transmits higher speed signals, a high-frequency characteristic of the high-speed connector becomes poorer due to the unnecessary resonance points. When high-frequency signals are transmitted among adjacent terminals, a crosstalk interference of the high-speed connector is hardly avoided. Moreover, the above-mentioned shielding structure of the high-speed connector is fully covered with the metallic plating layer to make the high-frequency characteristic poorer, so a crosstalk effect is affected. 
     Thus, it is essential to provide an innovative high-speed connector which improves an electromagnetic characteristic and a crosstalk interference of the high-speed connector by adjusting a dielectric coefficient of a peripheral structure of a terminal of the high-speed connector, so transmission quality of a high-frequency signal of the high-speed connector is improved. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a high-speed connector. The high-speed connector includes an insulating housing, a first terminal assembly received in the insulating housing, a second terminal assembly received in the insulating housing, a third terminal assembly received in the insulating housing, and a fourth terminal assembly received in the insulating housing. The second terminal assembly is opposite to the first terminal assembly along an up-down direction. The third terminal assembly is disposed between the first terminal assembly and the second terminal assembly. The fourth terminal assembly is corresponding to the third terminal assembly along the up-down direction. The fourth terminal assembly is disposed between the second terminal assembly and the third terminal assembly. The third terminal module and the fourth terminal module are positioned between the first terminal module and the second terminal module. Each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly includes a base body, a plurality of terminals and a metal plate, the plurality of the terminals include a plurality of grounding terminals and a plurality of differential signal terminals, a surface of the base body is recessed inward to form a fastening groove, the plurality of the terminals are fastened to the base body, the metal plate is fastened in the fastening groove, each terminal has a fastening portion, a contacting portion connected to a front end of the fastening portion, and a soldering portion connected to a rear end of the fastening portion, the base body surrounds the fastening portion of each terminal, the contacting portion of each terminal projects beyond a front surface of the base body, the soldering portion of each terminal is exposed to a rear of the base body, the fastening portions of the plurality of the grounding terminals and the differential signal terminals of two sides of each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly are exposed outside to the fastening groove, the metal plate electrically contacts with the fastening portions of the plurality of the grounding terminals of the two sides of each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly to form a grounding structure. Each of the third terminal assembly and the fourth terminal assembly includes a sheet structure, the sheet structure is made of a plastic material, the base body of each of the third terminal assembly and the fourth terminal assembly has a locating groove opposite to the fastening groove of each of the third terminal assembly and the fourth terminal assembly, the fastening portions of the plurality of the grounding terminals and the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are exposed to the locating groove of each of the third terminal assembly and the fourth terminal assembly, the sheet structure is located in the locating groove, the fastening portions of the plurality of the grounding terminals and the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are clamped between the metal plate and the sheet structure of each of the third terminal assembly and the fourth terminal assembly along the up-down direction, the fastening portions of the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are spaced from an inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly to form a clearance between the fastening portions of the differential signal terminals and the inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly, the fastening portions of the grounding terminals of each of the third terminal assembly and the fourth terminal assembly contact with the inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly. 
     Another object of the present invention is to provide a high-speed connector. The high-speed connector includes an insulating housing, a first terminal assembly received in the insulating housing, a second terminal assembly received in the insulating housing, a third terminal assembly received in the insulating housing, and a fourth terminal assembly received in the insulating housing. The second terminal assembly is opposite to the first terminal assembly along an up-down direction. The third terminal assembly is disposed between the first terminal assembly and the second terminal assembly. The fourth terminal assembly is corresponding to the third terminal assembly along the up-down direction. The fourth terminal assembly is disposed between the second terminal assembly and the third terminal assembly. The fourth terminal assembly includes a metal structure. Each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly includes a base body, a plurality of terminals and a metal plate. The metal structure is disposed in a front of a rear end of the base body of the fourth terminal assembly. The plurality of the terminals include a plurality of grounding terminals and a plurality of differential signal terminals. A surface of the base body is recessed inward to form a fastening groove. The plurality of the terminals are fastened to the base body. The metal plate is fastened in the fastening groove. Each terminal has a fastening portion, a contacting portion connected to a front end of the fastening portion, and a soldering portion connected to a rear end of the fastening portion. The base body surrounds the fastening portion of each terminal. The contacting portion of each terminal projects beyond a front surface of the base body. The soldering portion of each terminal is exposed to a rear of the base body. The fastening portions of the plurality of the grounding terminals and the differential signal terminals of two sides of each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly are exposed outside to the fastening groove. The metal plate electrically contacts with the fastening portions of the plurality of the grounding terminals of the two sides of each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly to form a grounding structure. Front surfaces of rear ends of the grounding terminals of the plurality of the terminals of the two sides of the fourth terminal assembly are exposed to the front of the rear end of the base body of the fourth terminal assembly. The metal structure contacts with front surfaces of rear ends of the grounding terminals of the plurality of the terminals of two sides of the fourth terminal assembly to form the grounding structure. Each of the third terminal assembly and the fourth terminal assembly includes a sheet structure. The sheet structure is made of a plastic material. The base body of each of the third terminal assembly and the fourth terminal assembly has a locating groove opposite to the fastening groove of each of the third terminal assembly and the fourth terminal assembly. The fastening portions of the plurality of the grounding terminals and the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are exposed to the locating groove of each of the third terminal assembly and the fourth terminal assembly. The sheet structure is located in the locating groove. The fastening portions of the plurality of the grounding terminals and the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are clamped between the metal plate and the sheet structure of each of the third terminal assembly and the fourth terminal assembly along the up-down direction. The fastening portions of the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are spaced from an inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly to form a clearance between the fastening portions of the differential signal terminals and the inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly. The fastening portions of the grounding terminals of each of the third terminal assembly and the fourth terminal assembly contact with the inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly. 
     Another object of the present invention is to provide a high-speed connector. The high-speed connector includes an insulating housing, a first terminal assembly received in the insulating housing, a second terminal assembly received in the insulating housing, a third terminal assembly received in the insulating housing, and a fourth terminal assembly received in the insulating housing. The second terminal assembly is opposite to the first terminal assembly along an up-down direction. The third terminal assembly is disposed between the first terminal assembly and the second terminal assembly. The fourth terminal assembly is corresponding to the third terminal assembly along the up-down direction. The third terminal module and the fourth terminal module are positioned between the first terminal module and the second terminal module. The fourth terminal assembly includes a blocking element. Each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly includes a base body, a plurality of terminals and a metal plate. The plurality of the terminals include a plurality of grounding terminals and a plurality of differential signal terminals. The blocking element is disposed in a front of a rear end of the base body of the fourth terminal assembly. A surface of the base body is recessed inward to form a fastening groove. The plurality of the terminals are fastened to the base body. The metal plate is fastened in the fastening groove. Each terminal has a fastening portion, a contacting portion connected to a front end of the fastening portion, and a soldering portion connected to a rear end of the fastening portion. The base body surrounds the fastening portion of each terminal. The contacting portion of each terminal projects beyond a front surface of the base body. The soldering portion of each terminal is exposed to a rear of the base body. The fastening portions of the plurality of the grounding terminals and the differential signal terminals of two sides of each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly are exposed outside to the fastening groove. The metal plate electrically contacts with the fastening portions of the plurality of the grounding terminals of the two sides of each of the first terminal assembly, the second terminal assembly, the third terminal assembly and the fourth terminal assembly to form a grounding structure. Front surfaces of rear ends of the grounding terminals of the plurality of the terminals of two sides of the fourth terminal assembly are exposed to the front of the rear end of the base body of the fourth terminal assembly. Each of the third terminal assembly and the fourth terminal assembly includes a sheet structure. The sheet structure is made of a plastic material. The base body of each of the third terminal assembly and the fourth terminal assembly has a locating groove opposite to the fastening groove of each of the third terminal assembly and the fourth terminal assembly. The fastening portions of the plurality of the grounding terminals and the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are exposed to the locating groove of each of the third terminal assembly and the fourth terminal assembly. The sheet structure is located in the locating groove. The fastening portions of the plurality of the grounding terminals and the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are clamped between the metal plate and the sheet structure of each of the third terminal assembly and the fourth terminal assembly along the up-down direction. The fastening portions of the differential signal terminals of each of the third terminal assembly and the fourth terminal assembly are spaced from an inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly to form a clearance between the fastening portions of the differential signal terminals and the inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly. The fastening portions of the grounding terminals of each of the third terminal assembly and the fourth terminal assembly contact with the inner surface of the sheet structure of each of the third terminal assembly and the fourth terminal assembly. The front surfaces of the rear ends of each two differential signal terminals of the two sides of the fourth terminal assembly are spaced from an inner surface of the blocking element to form an interstice. 
     As described above, a first metal plate of the first terminal assembly contacts with first grounding terminals of the first terminal assembly to form the grounding structure, a second metal plate of the second terminal assembly contacts with second grounding terminals of the second terminal assembly to form the grounding structure, a third metal plate of the third terminal assembly contacts with third grounding terminals of the third terminal assembly to form the grounding structure, and a fourth metal plate contacts with fourth grounding terminals of the fourth terminal assembly to form the grounding structure, so a signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained. Furthermore, the high-speed connector is capable of adjusting a dielectric coefficient of a peripheral structure of the terminal of the high-speed connector, a first internal space and a plurality of first gaps of a first dielectric structure, a second internal space and a plurality of second gaps of a second dielectric structure, a third internal space and a plurality of first clearances of a first sheet structure, and a fourth internal space and a plurality of second clearances of a second sheet structure are used for adjusting a dielectric coefficient of a peripheral structure of each first terminal of the first terminal assembly to improve an electromagnetic characteristic and a crosstalk interference of the high-speed connector. As a result, transmission quality of a high-frequency signal of the high-speed connector is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be apparent to those skilled in the art by reading the following description, with reference to the attached drawings, in which: 
         FIG.  1    is a perspective view of a high-speed connector in accordance with a first preferred embodiment of the present invention; 
         FIG.  2    is another perspective view of the high-speed connector of  FIG.  1   ; 
         FIG.  3    is a partially exploded view of the high-speed connector of  FIG.  1   ; 
         FIG.  4    is another partially exploded view of the high-speed connector of  FIG.  3   ; 
         FIG.  5    is a perspective view of an insulating housing of the high-speed connector of  FIG.  3   ; 
         FIG.  6    is a sectional view of the high-speed connector along a line VI-VI of  FIG.  3   ; 
         FIG.  7    is a sectional view of the high-speed connector along a line VII-VII of  FIG.  6   ; 
         FIG.  8    is a perspective view of a first terminal assembly of a terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  9    is another perspective view of the first terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  10    is an exploded view of the first terminal assembly of the terminal module of the high-speed connector of  FIG.  9   ; 
         FIG.  11    is another exploded view of the first terminal assembly of the terminal module of the high-speed connector of  FIG.  9   ; 
         FIG.  12    is an exploded view of a first dielectric structure of the first terminal assembly of the terminal module of the high-speed connector of  FIG.  9   ; 
         FIG.  13    is a sectional view of the high-speed connector along a line A-A of  FIG.  9   ; 
         FIG.  14    is an enlarged view of an encircled portion XIV of the high-speed connector of  FIG.  13   ; 
         FIG.  15    is a perspective view of a second terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  16    is another perspective view of the second terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  17    is an exploded view of the second terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  18    is another exploded view of the second terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  19    is a perspective view of a third terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  20    is another perspective view of the third terminal assembly of the terminal module of the high-speed connector of  FIG.  19   ; 
         FIG.  21    is an exploded view of the third terminal assembly of the terminal module of the high-speed connector of  FIG.  20   ; 
         FIG.  22    is another exploded view of the third terminal assembly of the terminal module of the high-speed connector of  FIG.  20   ; 
         FIG.  23    is an exploded view of a second dielectric structure of the third terminal assembly of the terminal module of the high-speed connector of  FIG.  20   ; 
         FIG.  24    is a sectional view of the high-speed connector along a line C-C of  FIG.  20   ; 
         FIG.  25    is an enlarged view of an encircled portion XXV of the high-speed connector of  FIG.  24   ; 
         FIG.  26    is a sectional view of the high-speed connector along a line B-B of  FIG.  19   ; 
         FIG.  27    is a perspective view of a fourth terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  28    is another perspective view of the fourth terminal assembly of the terminal module of the high-speed connector of  FIG.  3   ; 
         FIG.  29    is an exploded view of the fourth terminal assembly of the terminal module of the high-speed connector of  FIG.  28   ; 
         FIG.  30    is another exploded view of the fourth terminal assembly of the terminal module of the high-speed connector of  FIG.  28   ; 
         FIG.  31    is a sectional view of the high-speed connector along a line D-D of  FIG.  28   ; 
         FIG.  32    is a perspective view of the fourth terminal assembly of the terminal module of the high-speed connector in accordance with a second preferred embodiment of the present invention; 
         FIG.  33    is a partially exploded view of the fourth terminal assembly of the terminal module of the high-speed connector in accordance with the second preferred embodiment of the present invention; 
         FIG.  34    is a perspective view of the fourth terminal assembly of the terminal module of the high-speed connector in accordance with a third preferred embodiment of the present invention; and 
         FIG.  35    is a sectional view of the high-speed connector along a line E-E of  FIG.  34   . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIG.  1    and  FIG.  2   , a high-speed connector  100  in accordance with a first preferred embodiment of the present invention is shown. The high-speed connector  100  includes an insulating housing  1  and a terminal module  2 . The terminal module  2  is disposed in the insulating housing  1 . 
     Referring to  FIG.  3    to  FIG.  5   , the insulating housing  1  has a main portion  11 , an accommodating space  12 , a plurality of first terminal slots  13 , an insertion groove  14  and an assembling groove  15 . An inside of the main portion  11  defines the accommodating space  12 . The accommodating space  12  penetrates through a rear end of a bottom surface of the main portion  11 . Several portions of a front of the inside of the main portion  11  are recessed inward to form the plurality of the first terminal slots  13 . Two fronts of an upper inner wall and a lower inner wall of the accommodating space  12  of the main portion  11  are recessed inward to form the plurality of the first terminal slots  13 . The plurality of the first terminal slots  13  are arranged in an upper row and a lower row. Several portions of an upper portion of the front of the inside of the main portion  11  are recessed inward to form the upper row of the first terminal slots  13  penetrating through a bottom surface of the upper portion of the front of the inside of the main portion  11 . Several portions of a lower portion of the front of the inside of the main portion  11  are recessed inward to form the lower row of the first terminal slots  13  penetrating through a top surface of the lower portion of the front of the inside of the main portion  11 . The plurality of the first terminal slots  13  are located in front of the accommodating space  12 . The plurality of the first terminal slots  13  are communicated with the accommodating space  12 . 
     A middle of a front end of the main portion  11  defines the insertion groove  14 . The insertion groove  14  longitudinally penetrates through the front end of the main portion  11 . The insertion groove  14  is communicated with the plurality of the first terminal slots  13 . The insertion groove  14  is positioned between the upper row of the first terminal slots  13  and the lower row of the first terminal slots  13 . The insertion groove  14  is communicated between the upper row of the first terminal slots  13  and the lower row of the first terminal slots  13 . A rear end of the main portion  11  defines the assembling groove  15  penetrating through a rear surface of the main portion  11 . The insertion groove  14  is located in front of the accommodating space  12 . The insertion groove  14  is communicated with the accommodating space  12 . The assembling groove  15  is located behind the accommodating space  12 . The assembling groove  15  is communicated with the accommodating space  12 . 
     Referring to  FIG.  3    to  FIG.  6   , the terminal module  2  is inserted into the accommodating space  12  from the assembling groove  15  of the insulating housing  1 . The terminal module  2  includes a first terminal assembly  3 , a second terminal assembly  4 , a third terminal assembly  5  and a fourth terminal assembly  6  which are mounted in the insulating housing  1 . In a concrete implementation, the terminal module  2  is without being limited to include the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6 . The second terminal assembly  4  is corresponding to the first terminal assembly  3  along an up-down direction. The fourth terminal assembly  6  is corresponding to the third terminal assembly  5  along the up-down direction. 
     The first terminal assembly  3  is received in the insulating housing  1 . The second terminal assembly  4  is received in the insulating housing  1 . The second terminal assembly  4  is opposite to the first terminal assembly  3  along the up-down direction. The third terminal assembly  5  is received in the insulating housing  1 . The third terminal assembly  5  is disposed between the first terminal assembly  3  and the second terminal assembly  4 . The fourth terminal assembly  6  is received in the insulating housing  1 . The fourth terminal assembly  6  is disposed between the second terminal assembly  4  and the third terminal assembly  5 . The third terminal module  5  and the fourth terminal module  6  are positioned between the first terminal module  3  and the second terminal module  4 . 
     In the first preferred embodiment, the first terminal assembly  3  and the second terminal assembly  4  form a QSFP (Quad Small Form-Factor Pluggable) terminal assembly. The third terminal assembly  5  and the fourth terminal assembly  6  form another QSFP terminal assembly. In the concrete implementation, the high-speed connector  100  includes the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  to form a QSFP-DD (Quad Small Form Factor Pluggable-Double Density) high-speed connector. The high-speed connector  100  is able to include the first terminal assembly  3  and the second terminal assembly  4  to form the QSFP high-speed connector. The high-speed connector  100  is also able to include the third terminal assembly  5  and the fourth terminal assembly  6  to form the QSFP high-speed connector. 
     A top of the main portion  11  of the insulating housing  1  has at least one first aperture  111  vertically penetrating through the top of the main portion  11 . In the first preferred embodiment, the top of the main portion  11  of the insulating housing  1  has two first apertures  111  arranged transversely. The two first apertures  111  vertically penetrate through the top of the main portion  11 . A corresponding mechanism of the first terminal assembly  3  is fastened in the at least one first aperture  111  of the insulating housing  1 , so that the first terminal assembly  3  is located to the insulating housing  1 , and the first terminal assembly  3  is fastened to the insulating housing  1 . A bottom of the main portion  11  of the insulating housing  1  has at least one second aperture  112  vertically penetrating through the bottom of the main portion  11 . In the first preferred embodiment, the bottom of the main portion  11  of the insulating housing  1  has two second apertures  112  arranged transversely. The two second apertures  112  vertically penetrate through the bottom of the main portion  11 . A corresponding mechanism of the second terminal assembly  4  is fastened in the at least one second aperture  112  of the insulating housing  1 , so that the second terminal assembly  4  is located to the insulating housing  1 , and the second terminal assembly  4  is fastened to the insulating housing  1 . 
     Two upper portions of two opposite inner side surfaces of the rear end of the main portion  11  are recessed oppositely to form two first locating slots  113 . Two upper portions of two rears of two inner side walls of the accommodating space  12  of the main portion  11  are recessed oppositely to form the two first locating slots  113 . Two lower portions of the two opposite inner side surfaces of the rear end of the main portion  11  are recessed oppositely to form two second locating slots  114 . Two lower portions of the two rears of the two inner side walls of the accommodating space  12  of the main portion  11  are recessed oppositely to form the two second locating slots  114 . Two tops of two middle portions of the two opposite inner side surfaces of the rear end of the main portion  11  are recessed oppositely to form two third locating slots  115 . Two bottoms of the two middle portions of the two opposite inner side surfaces of the rear end of the main portion  11  are recessed oppositely to form two fourth locating slots  116 . Two tops of two middle portions of the two rears of the two inner side walls of the accommodating space  12  of the main portion  11  are recessed oppositely to form the two third locating slots  115 , and two bottoms of the two middle portions of the two rears of the two inner side walls of the accommodating space  12  of the main portion  11  are recessed oppositely to form the two fourth locating slots  116 . The two third locating slots  115  are above the two fourth locating slots  116 . Corresponding areas of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  of the terminal module  2  are buckled to the two first locating slots  113 , the two second locating slots  114 , the two third locating slots  115  and the two fourth locating slots  116  of the insulating housing  1 , so that the terminal module  2  is located to the insulating housing  1 , and the terminal module  2  is fastened to the insulating housing  1 . 
     Two corresponding side areas of the first terminal assembly  3  are buckled with the two first locating slots  113  and the two second locating slots  114  of the insulating housing  1 , so that the first terminal assembly  3  is located to the insulating housing  1 , and the first terminal assembly  3  is fastened to the insulating housing  1 . Two corresponding side areas of the second terminal assembly  4  and the two second locating slots  114  of the insulating housing  1  are mutually buckled to each other, so that the second terminal assembly  4  is located to the insulating housing  1 , and the second terminal assembly  4  is fastened to the insulating housing  1 . Two corresponding side areas of the third terminal assembly  5  are buckled with the two second locating slots  114  and the two third locating slots  115  of the insulating housing  1 , so the third terminal assembly  5  is located to the insulating housing  1 , and the third terminal assembly  5  is fastened to the insulating housing  1 . Two corresponding side areas of the fourth terminal assembly  6  are buckled with the two second locating slots  114  and the two fourth locating slots  116  of the insulating housing  1 , so that the fourth terminal assembly  6  is located to the insulating housing  1 , and the fourth terminal assembly  6  is fastened to the insulating housing  1 . 
     The two first locating slots  113 , the two third locating slots  115 , the two fourth locating slots  116  and the two second locating slots  114  are sequentially disposed along the up-down direction. The two lower portions of the two opposite inner side surfaces of the rear end of the main portion  11  extend towards each other to from two protruding ribs  117 . The two protruding ribs  117  are defined as two lower walls of the two second locating slots  114 . Two outer surfaces of two rears of the two corresponding side areas of the first terminal assembly  3  are recessed inward to form two first clamping slots  351 . Two outer surfaces of two rears of the two corresponding side areas of the third terminal assembly  5  are recessed inward to form two second clamping slots  551 . Two rear ends of the two protruding ribs  117  are clamped in the two first clamping slots  351  and the two second clamping slots  551 , so that the first terminal assembly  3  and the third terminal assembly  5  are located to the insulating housing  1 , and the first terminal assembly  3  and the third terminal assembly  5  are fastened to the insulating housing  1 . 
     Two sides of an inner surface of the top of the main portion  11  of insulating housing  1  extend downward to form two convex surfaces  118 . A quantity of the convex surfaces  118  of the insulating housing  1  is the same as a quantity of corresponding portions of two sides of a top of the first terminal assembly  3 . The inner surface of the top of the main portion  11  of the insulating housing  1  has a concave surface  119 . The two convex surfaces  118  are corresponding to two side positions of the top of the first terminal assembly  3 . The concave surface  119  is formed between the two convex surfaces  118 . The concave surface  119  is corresponding to a middle position of the top of the first terminal assembly  3 . 
     At least one portion of a middle of the inner surface of the top of the main portion  11  of the insulating housing  1  is recessed inward to form at least one sliding groove  16 . The at least one first aperture  111  is disposed in front of the at least one sliding groove  16 . The at least one sliding groove  16  extends longitudinally. The at least one first aperture  111  is longitudinally aligned with the at least one sliding groove  16 . The concave surface  119  is disposed among the at least one sliding groove  16  and the two convex surfaces  118 . In the first preferred embodiment, two portions of the middle of the inner surface of the top of the main portion  11  of the insulating housing  1  are recessed inward to form two abreast sliding grooves  16 . At least one corresponding section of a top of the terminal module  2  passes through the at least one sliding groove  16 , and then the at least one corresponding section of the top of the terminal module  2  is fastened in the at least one first aperture  111  of the insulating housing  1 , so that the terminal module  2  is located to the insulating housing  1 , and the terminal module  2  is fastened to the insulating housing  1 . Specifically, two corresponding sections of the top of the terminal module  2  pass through the two sliding grooves  16 , and the two corresponding sections of the top of the terminal module  2  are fastened in the two first apertures  111  of the insulating housing  1 , so that the terminal module  2  is located to the insulating housing  1 , and the terminal module  2  is fastened to the insulating housing  1 . 
     Each first aperture  111  is disposed in front of one sliding groove  16 . Each sliding groove  16  extends longitudinally. Each first aperture  111  is longitudinally aligned with the one sliding groove  16 . A rear end of each sliding groove  16  is connected with the assembling groove  15 . The rear end of each sliding groove  16  is communicated with the assembling groove  15 . A front end of each sliding groove  16  is connected with one first aperture  111 . The front end of each sliding groove  16  is communicated with the one first aperture  111 . A top surface of a top wall of each sliding groove  16  has an inclining zone  161 , a buffering zone  162  and a stopping zone  163  sequentially arranged along a rear-to-front direction. A rear end of the top surface of the top wall of each sliding groove  16  slantwise extends frontward and downward to form the inclining zone  161 . A front end of the inclining zone  161  horizontally extends frontward to form the buffering zone  162 . A front end of the buffering zone  162  protrudes downward, and then horizontally extends frontward and towards the one first aperture  111  to form the stopping zone  163 . A top surface of the inclining zone  161  is an inclined plane. A top surface of the buffering zone  162  is a flat plane. A top surface of the stopping zone  163  is another flat plane. The top surface of the stopping zone  163  and the top surface of the buffering zone  162  form a segment difference, so that a horizontal height of the top surface of the stopping zone  163  is lower than a horizontal height of the top surface of the buffering zone  162 . The concave surface  119  is disposed among the two sliding grooves  16  and the two convex surfaces  118 . 
     When the terminal module  2  is inserted into the accommodating space  12  from the assembling groove  15 , each corresponding section of the top of the terminal module  2  enters the buffering zone  162  along the inclining zone  161  of the one sliding groove  16 , each corresponding section of the top of the terminal module  2  slides along the buffering zone  162  of the one sliding groove  16 , and then each corresponding section of the top of the terminal module  2  passes through the stopping zone  163  of the one sliding groove  16 . Finally, each corresponding section of the top of the terminal module  2  is buckled to the one first aperture  111 . The two inclining zones  161  of the two sliding grooves  16  guide the two corresponding sections of the top of the terminal module  2  to enter the two sliding grooves  16 . The two inclining zones  161  of the two sliding grooves  16  prevent the two corresponding sections of the top of the terminal module  2  from being bruised. The two stopping zones  163  of the two sliding grooves  16  abut against the two corresponding sections of the top of the terminal module  2  to prevent the terminal module  2  from being slid out of the accommodating space  12 . 
     A middle of the top of the main portion  11  forms a plurality of first penetrating grooves  17  arranged transversely. Each first penetrating groove  17  penetrates through the top of the main portion  11  and extends longitudinally. The plurality of the first penetrating grooves  17  are used for regulating an electrical characteristic of the first terminal assembly  3  of the high-speed connector  100 , so that the high-speed connector  100  has a high-frequency signal stability. Positions of the plurality of the first penetrating grooves  17  are corresponding to upper positions of terminals  102  of the first terminal assembly  3  of the terminal module  2 . A front end of the bottom of the main portion  11  form a plurality of second penetrating grooves  18  arranged transversely. Each second penetrating groove  18  penetrates through the bottom of the main portion  11  and extends longitudinally. The plurality of the second penetrating grooves  18  are used for regulating an electrical characteristic of the second terminal assembly  4  of the high-speed connector  100 , so that the high-speed connector  100  has the high-frequency signal stability. Positions of the plurality of the second penetrating grooves  18  are corresponding to lower positions of the terminals  102  of the second terminal assembly  4  of the terminal module  2 . 
     Referring to  FIG.  8    to  FIG.  11   , the first terminal assembly  3  includes a first base body  32 , a plurality of first terminals  31 , a first metal plate  33 , a first dielectric structure  34  and a first holding element  35 . The plurality of the first terminals  31  are fastened to the first base body  32 . The plurality of the first terminals  31  are partially surrounded by the first base body  32 . Middles of the plurality of the first terminals  31  are surrounded by the first base body  32 . The first metal plate  33  is disposed in the first base body  32 , and the first metal plate  33  is disposed under the plurality of the first terminals  31 . The first dielectric structure  34  is disposed to rear ends of the plurality of the first terminals  31 . The rear ends of the plurality of the first terminals  31  are surrounded by the first dielectric structure  34 . The first dielectric structure  34  is used for adjusting a dielectric coefficient of a peripheral structure of each first terminal  31  to improve a crosstalk interference of the high-speed connector  100 . Lower portions of the plurality of the first terminals  31  are surrounded by the first holding element  35 . 
     Each first terminal  31  has a first fastening portion  311 , a first stepping portion  312 , a first contacting portion  313 , a first extending portion  314 , a first bending portion  315 , and a first soldering portion  316 . The plurality of the first terminals  31  include a plurality of first grounding terminals  317  and a plurality of first differential signal terminals  318 . Each first differential signal terminal  318  is used for transmitting a signal. In the first preferred embodiment, the plurality of the first terminals  31  includes seven first grounding terminals  317  and twelve first differential signal terminals  318 . Each two adjacent first differential signal terminals  318  are located between two first grounding terminals  317 . The first fastening portion  311  of one first grounding terminal  317  and the first fastening portions  311  of four first differential signal terminals  318  are surrounded by a middle of the first base body  32 . 
     The first fastening portions  311  of the plurality of the first terminals  31  which are located at two sides of the first base body  32  of the first terminal assembly  3  are corresponding to the positions of the plurality of the first penetrating grooves  17  of the main portion  11  of the insulating housing  1 . The front end of the first fastening portion  311  slantwise extends frontward and downward to form the first stepping portion  312 . A front end of the first stepping portion  312  extends frontward and then is arched downward to form the first contacting portion  313 . The first stepping portions  312  and rear ends of the first contacting portions  313  of the first terminals  31  of two sides of the first terminal assembly  3  are exposed to two sides of a front end of the first base body  32 . A front end of the first contacting portion  313  of each first terminal  31  projects beyond a front surface of the first base body  32 . The first contacting portions  313  of the plurality of the first terminals  31  are disposed in the upper row of the first terminal slots  13 . Bottom surfaces of the first contacting portions  313  of the plurality of the first terminals  31  are exposed out of the upper row of the first terminal slots  13 , and the bottom surfaces of the first contacting portions  313  of the plurality of the first terminals  31  project into the insertion groove  14 . 
     A rear end of the first fastening portion  311  slantwise extends rearward and downward to form the first extending portion  314 . A rear end of the first extending portion  314  is bent downward to form the first bending portion  315 . A bottom end of the first bending portion  315  is bent rearward to form the first soldering portion  316 . The rear end of the first fastening portion  311 , the first extending portion  314 , the first bending portion  315  and the first soldering portion  316  of each first terminal  31  project beyond a rear surface of the first base body  32 . The first dielectric structure  34  is fastened to the first extending portions  314  of the plurality of the first terminals  31 . Tail ends of the first bending portions  315  of the plurality of the first terminals  31  are surrounded by the first holding element  35 . Two opposite sides of the front end of each first fastening portion  311 , two opposite sides of the rear end of each first fastening portion  311  and two opposite sides of the rear end of each first contacting portion  313  are recessed inward to form a plurality of first lacking grooves  319 . Corresponding formations of the first base body  32  are engaged with the first lacking grooves  319  of the plurality of the first terminals  31  by a plastic injection molding technology. 
     The first fastening portions  311 , the first stepping portions  312  and the rear ends of the first contacting portions  313  of the first terminals  31  of a middle of the first terminal assembly  3  are surrounded by the middle of the first base body  32 . The first base body  32  has a first surrounding portion  320 , at least one first protruding block  321 , a plurality of first protruding portions  322 , a first fastening groove  323 , a plurality of first openings  324 , a plurality of first contact surfaces  325 , a first location hole  326 , a plurality of first restricting holes  327  and a plurality of first connecting portions  328 . 
     In the first preferred embodiment, the first base body  32  has two first protruding blocks  321 , two first protruding portions  322 , the first fastening groove  323 , four first openings  324 , the plurality of the first contact surfaces  325 , the first location hole  326 , the plurality of the first restricting holes  327  and the plurality of the first connecting portions  328 . The first surrounding portion  320  is disposed to the middle of the first base body  32 , and the first surrounding portion  320  is connected between the front end of the first base body  32  and a rear end of the first base body  32 . The first fastening portion  311  of the one first grounding terminal  317  and the first fastening portions  311  of the four first differential signal terminals  318  are surrounded by the first surrounding portion  320 . The first surrounding portion  320  of the first base body  32  of the first terminal assembly  3  is corresponding to the concave surface  119  of the insulating housing  1 . 
     At least one portion of a rear end of a top surface of the first surrounding portion  320  of the first base body  32  protrudes upward to form the at least one first protruding block  321 . In the first preferred embodiment, two sides of the rear end of the top surface of the first surrounding portion  320  of the first base body  32  protrude upward to form the two first protruding blocks  321 . A quantity of the at least one first protruding block  321  of the first base body  32  is the same as a quantity of the at least one first aperture  111  of the insulating housing  1 . After each first protruding block  321  passes through the one sliding groove  16 , each first protruding block  321  is fastened in the one first aperture  111  of the insulating housing  1 , so that the first terminal assembly  3  is located to the insulating housing  1 , and the first terminal assembly  3  is fastened to the insulating housing  1 . 
     When the terminal module  2  is inserted into the accommodating space  12  from the assembling groove  15 , each first protruding block  321  of the first base body  32  of the terminal module  2  enters the buffering zone  162  along the inclining zone  161  of the one sliding groove  16 , each first protruding block  321  of the first base body  32  of the terminal module  2  slides along the buffering zone  162  of the one sliding groove  16 , and then each first protruding block  321  of the first base body  32  of the terminal module  2  passes through the stopping zone  163  of the one sliding groove  16 . Finally, each first protruding block  321  of the first base body  32  of the terminal module  2  is buckled to the one first aperture  111 . The two inclining zones  161  of the two sliding grooves  16  guide the two first protruding blocks  321  of the first terminal assembly  3  of the terminal module  2  to enter the two sliding grooves  16 . The two inclining zones  161  of the two sliding grooves  16  prevent the two first protruding blocks  321  of the first terminal assembly  3  of the terminal module  2  from being bruised. The two stopping zones  163  of the two sliding grooves  16  abut against the two first protruding blocks  321  of the first terminal assembly  3  of the terminal module  2  to prevent the first terminal assembly  3  of the terminal module  2  from being slid out of the accommodating space  12 . 
     In the first preferred embodiment, two opposite sides of the first base body  32  extend outward to form the two first protruding portions  322 . A middle of a bottom surface of the rear end of the first base body  32  is recessed inward to form the first fastening groove  323 . The front end of the first base body  32  has two first openings  324 , and the rear end of the first base body  32  has the other two first openings  324 . The two first openings  324  of the front end of the first base body  32  penetrate through two sides of a top surface and two sides of a bottom surface of the front end of the first base body  32 . Two tops of two sides of the first fastening groove  323  extend upward to form the other two first openings  324  penetrating through two sides of a top surface of the rear end of the first base body  32 . A front end of the first surrounding portion  320  is located between the two first openings  324  of the front end of the first base body  32 . A rear end of the first surrounding portion  320  is located between the other two first openings  324  of the rear end of the first base body  32 . The two first protruding portions  322  of the first base body  32  are buckled in two front ends of the two first locating slots  113  of the insulating housing  1 , so that the first terminal assembly  3  is located to the insulating housing  1 , and the first terminal assembly  3  is fastened to the insulating housing  1 . The first fastening portions  311  of the plurality of the first grounding terminals  317  and the first differential signal terminals  318  of the two sides of the first terminal assembly  3  are exposed to the two first openings  324  of the rear end of the first base body  32 . The rear ends of the first contacting portions  313  and the first stepping portions  312  of the plurality of the first grounding terminals  317  and the first differential signal terminals  318  of the two sides of the first terminal assembly  3  are exposed to the two first openings  324  of the front end of the first base body  32 . The first metal plate  33  is disposed in the first fastening groove  323  of the first base body  32 . The first fastening portions  311  of the plurality of the first grounding terminals  317  and the first differential signal terminals  318  of the two sides of the first terminal assembly  3  are exposed to the first fastening groove  323  from the two first openings  324  of the rear end of the first base body  32 . 
     In the first preferred embodiment, the first openings  324  of the first base body  32  are formed to two sides of the first surrounding portion  320 . A quantity of the first openings  324  of the rear end of the first base body  32  of the first terminal assembly  3  is the same as a quantity of the convex surfaces  118  of insulating housing  1 . The two first openings  324  of the rear end of the first base body  32  of the first terminal assembly  3  are corresponding to the two convex surfaces  118  of the insulating housing  1 . 
     A middle of a bottom surface of the first surrounding portion  320  of first base body  32  extends downward to form a supporting block  301 . Several portions of a rear surface and a front surface of the supporting block  301  are arched oppositely to form the plurality of the first contact surfaces  325 . The plurality of the first contact surfaces  325  are used for fastening the first metal plate  33 . A middle of a bottom surface of the supporting block  301  of the first surrounding portion  320  of first base body  32  is recessed inward to from the first location hole  326 . A corresponding mechanism of the third terminal assembly  5  is fastened in the first location hole  326 , so that the third terminal assembly  5  is located to the first terminal assembly  3 , and the third terminal assembly  5  is fastened to the first terminal assembly  3 . The plurality of the first restricting holes  327  penetrate through the top surface and the bottom surface of the two opposite sides of the first base body  32 . Corresponding mechanisms of the first metal plate  33  are disposed in the plurality of the first restricting holes  327 , so that the first metal plate  33  is located to the first base body  32 , and the first metal plate  33  is fastened to the first base body  32 . 
     An upper surface of the first base body  32  has the plurality of the first connecting portions  328 . The plurality of the first connecting portions  328  are longitudinally arranged in three rows. Each first connecting portion  328  is disposed between two adjacent first terminals  31 . The plurality of the first connecting portions  328  are used to simplify a mold manufacturing process. The plurality of the first connecting portions  328  are embedded into the plurality of the first lacking grooves  319  of the plurality of the first fastening portions  311  and the plurality of the first contacting portions  313 . A lower surface of the first base body  32  has a transverse row of second terminal slots  329 . Corresponding parts of the third terminal assembly  5  are disposed to the transverse row of the second terminal slots  329 . During an assembling process of the high-speed connector  100 , the transverse row of the second terminal slots  329  are used for preventing the corresponding parts of the third terminal assembly  5  from tilting. 
     The first metal plate  33  is fastened in the first fastening groove  323  of the first base body  32 . The first metal plate  33  is located under the plurality of the first terminals  31 . The first metal plate  33  has a first main sheet  331 , a limiting hole  332 , a plurality of first inclining sheets  333 , a plurality of first contact sheets  334 , a plurality of first covering sheets  336  and a plurality of first restricting portions  337 . 
     A position of the first main sheet  331  is corresponding to a position of the first surrounding portion  320  of the first base body  32 . The limiting hole  332  is formed at a middle of the first main sheet  331 . The first main sheet  331  is a rectangular frame shape. The plurality of the first contact surfaces  325  abut against a front inner wall and a rear inner wall of the limiting hole  332  of the first main sheet  331 . In the concrete implementation, the first main sheet  331  is fastened to the bottom surface of the first surrounding portion  320  of the first base body  32 . Two opposite sides of the first main sheet  331  meander oppositely to form two first flank sheets  335 . Each first flank sheet  335  is shown as a wave shape. Each first flank sheet  335  includes the plurality of the first inclining sheets  333 , the plurality of the first contact sheets  334  and the plurality of the first covering sheets  336 . 
     The two opposite sides of the first main sheet  331  slantwise extend outward and upward to form two of the plurality of the first inclining sheets  333 . The two of the plurality of the first inclining sheets  333  are corresponding to two outer surfaces of the first surrounding portion  320  of the first base body  32 . The two of the plurality of the first inclining sheets  333  are covered to the two outer surfaces of the first surrounding portion  320 . Two sides of the limiting hole  332  extend to middles of the two of the plurality of the first inclining sheets  333 . Two outer edges of the two of the plurality of the first inclining sheets  333  horizontally extend to form two first contact sheets  334 . Each first contact sheet  334  and the first main sheet  331  are horizontally disposed. Each first contact sheet  334  is parallel to the first main sheet  331 . Two outer edges of the two first contact sheets  334  slantwise extend outward and downward to form another two of the plurality of the first inclining sheets  333 . The another two of the plurality of the first inclining sheets  333  of two opposite sides of the two first contact sheets  334  are opposite to each other. Two outer edges of the another two of the plurality of the first inclining sheets  333  horizontally extend outward to form two first covering sheets  336 . Each first covering sheet  336  and the first main sheet  331  are horizontally disposed. Each first covering sheet  336  and the first main sheet  331  are disposed at the same level. Two outer edges of the two first covering sheets  336  slantwise extend upward and outward to form two extra first inclining sheets  333 . Two outer edges of the two extra first inclining sheets  333  horizontally extend oppositely to form another two first contact sheets  334 . Two outer edges of the another two first contact sheets  334  slantwise extend outward and downward to form two additional first inclining sheets  333 . Two outer edges of the two additional first inclining sheets  333  horizontally extend outward to form another two first covering sheets  336 . Two outer edges of the another two first covering sheets  336  slantwise extend outward and upward to form two other first inclining sheets  333 . Two outer edges of the two other first inclining sheets  333  horizontally extend outward to form two outermost first contact sheets  334 . 
     The two opposite sides of the first main sheet  331  meander outward to form the first inclining sheets  333 , the first contact sheets  334  and the first covering sheets  336  of the two first flank sheets  335  according to a quantity of the plurality of the first terminals  31 . In the first preferred embodiment, each first flank sheet  335  has five first inclining sheets  333 , three first contact sheets  334  and two first covering sheets  336 , so the first metal plate  33  has the first main sheet  331 , one limiting hole  332 , ten first inclining sheets  333 , six first contact sheets  334  and four first covering sheets  336 . Two opposite side edges of each first covering sheet  336  slantwise extend upward and sideward to form the two first inclining sheets  333 . The two first inclining sheets  333  of each first covering sheet  336  are connected with two of the plurality of the first contact sheets  334 . The two first inclining sheets  333  of each first covering sheet  336  are opposite to each other. Each two first inclining sheets  333  of the first metal plate  33  are opposite to each other. 
     From an inner side of each first flank sheet  335  to an outer side of each first flank sheet  335 , each first flank sheet  335  sequentially has the first inclining sheet  333  connected with one side of the first main sheet  331 , the first contact sheet  334  connected with the outer edge of the first inclining sheet  333  which is connected with the one side of the first main sheet  331 , the first inclining sheet  333  connected with the outer edge of the first contact sheet  334 , the first covering sheet  336  connected with the outer edge of the first inclining sheet  333  which is connected with the outer edge of the first contact sheet  334 , the first inclining sheet  333  connected with an outer edge of the first covering sheet  336 , the first contact sheet  334  connected with the outer edge of the first inclining sheet  333  which is connected with the outer edge of the first covering sheet  336 , the first inclining sheet  333  connected with the outer edge of the first contact sheet  334 , the first covering sheet  336  connected with the outer edge of the first inclining sheet  333  which is connected with the outer edge of the first contact sheet  334 , the first inclining sheet  333  connected with the outer edge of the first covering sheet  336 , and the first contact sheet  334  connected with the outer edge of the first inclining sheet  333 . 
     Referring to  FIG.  7    to  FIG.  10   , the first contact sheets  334  of the first metal plate  33  contact with the first fastening portions  311  of the plurality of the first grounding terminals  317  of the two sides of the first terminal assembly  3  to form a grounding structure  90 . In this way, a signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained for improving transmission quality of the high-frequency signal. The first covering sheets  336  of the first metal plate  33  keep distances from the first fastening portions  311  of the first differential signal terminals  318  of the first terminal assembly  3 . 
     Several portions of two opposite outer sides of the two outermost first contact sheets  334  of the first metal plate  33  slantwise extend downward and outward, and then are bent outward to form the plurality of the first restricting portions  337 . A quantity of the plurality of the first restricting portions  337  is the same as a quantity of the plurality of the first restricting holes  327  of the first base body  32 . The plurality of the first restricting portions  337  are restricted in the plurality of the first restricting holes  327 , so the first metal plate  33  is fastened in the first base body  32 . 
     Referring to  FIG.  12    to  FIG.  14   , the first dielectric structure  34  has two first covers  341  and a first fastening structure  342 . The first fastening structure  342  is disposed between the two first covers  341 . In one condition, structures of the two first covers  341  are the same. In another condition, the two first covers  341  are symmetrical. The two first covers  341  are disposed opposite to each other. The two first covers  341  and the first fastening structure  342  are buckled in a whole. The two first covers  341  are buckled by the first fastening structure  342  to form an entirety. 
     Each first cover  341  has a first extending foot  3411 , a first notch  3412 , a plurality of first attaching surfaces  3413  and a first internal space  3414 . One side of each first cover  341  protrudes inward and perpendicular to each first cover  341  to form the first extending foot  3411 . The other side of each first cover  341  has the first notch  3412  penetrating through an outer surface, an inner surface and the other side surface of each first cover  341 . In the first preferred embodiment, each first cover  341  has two first extending feet  3411 , two first notches  3412 , the plurality of the first attaching surfaces  3413  and the first internal space  3414 . Two portions of the one side of each first cover  341  protrude inward and perpendicular to each first cover  341  to form the two first extending feet  3411 . The other side of each first cover  341  has the two first notches  3412  penetrating through the outer surface, the inner surface and the other side surface of each first cover  341 . The two first extending feet  3411  of one first cover  341  are disposed corresponding to the two first notches  3412  of the other first cover  341 . The first extending feet  3411  of the two first covers  341  are buckled with the first notches  3412  of the two first covers  341 . 
     Two sides of the inner surface of each first cover  341  has the plurality of the first attaching surfaces  3413  protruded beyond the inner surface of each first cover  341 . The first attaching surfaces  3413  of the two first covers  341  are corresponding to the first extending portions  314  of the first grounding terminals  317  of the two sides of the first terminal assembly  3 . The first attaching surfaces  3413  of the two first covers  341  clamp the first extending portions  314  of the first grounding terminals  317  of the two sides of the first terminal assembly  3 . The first attaching surfaces  3413  of the one first cover  341  are corresponding to upper surfaces of the first extending portions  314  of the first grounding terminals  317  of the two sides of the first terminal assembly  3 , and the first attaching surfaces  3413  of the other first cover  341  are corresponding to lower surfaces of the first extending portions  314  of the first grounding terminals  317  of the two sides of the first terminal assembly  3 . The first attaching surfaces  3413  of the one first cover  341  contact with the upper surfaces of the first extending portions  314  of the first grounding terminals  317  of the two sides of the first terminal assembly  3 , and the first attaching surfaces  3413  of the other first cover  341  contact with the lower surfaces of the first extending portions  314  of the first grounding terminals  317  of the two sides of the first terminal assembly  3 . 
     The first attaching surfaces  3413  of the one first cover  341  face the first attaching surfaces  3413  of the other first cover  341 . The first attaching surfaces  3413  of the two first covers  341  are spaced to form the first internal space  3414 . The first extending portions  314  of the first differential signal terminals  318  of the two sides of the first terminal assembly  3  pass through the first internal space  3414 . The upper surfaces and the lower surfaces of the first extending portions  314  of the first differential signal terminals  318  of the two sides of the first terminal assembly  3  are spaced from the two inner surfaces of the two first covers  341  to form two first gaps  3415 . A plurality of the first gaps  3415  are formed among the first terminal assembly  3  and the two inner surfaces of the two first covers  341 . The first internal space  3414  and the plurality of the first gaps  3415  of the first dielectric structure  34  are used for adjusting the dielectric coefficient of the peripheral structure of each first terminal  31  to improve an electromagnetic characteristic and the crosstalk interference of the high-speed connector  100 . 
     A middle of the inner surface of each first cover  341  is recessed inward to from a first sunken portion  3416 . The first sunken portion  3416  is used for receiving the first fastening structure  342 . The first sunken portion  3416  of each first cover  341  has at least one first perforation  3417  penetrating through the inner surface and an outer surface of each first cover  341 . In the first preferred embodiment, the first sunken portion  3416  of each first cover  341  has two first perforations  3417 . The two first perforations  3417  penetrate through the two inner surfaces and the two outer surfaces of the two first covers  341 . Corresponding hooks of the first fastening structure  342  are disposed to the first perforations  3417  of the two first covers  341 , and the corresponding hooks of the first fastening structure  342  are buckled to the two outer surfaces of the two first covers  341 , so that the first fastening structure  342  is located between the two first covers  341 , and the first fastening structure  342  is fastened between the two first covers  341 . 
     Each side of the first fastening structure  342  has at least one first buckling hook  3421 . In the first preferred embodiment, the first fastening structure  342  has four first buckling hooks  3421 . Each side of the first fastening structure  342  has two first buckling hooks  3421 . The two first buckling hooks  3421  of each side of the first fastening structure  342  oppositely extend towards the two first covers  341 , and then protrude outward to form the two first buckling hooks  3421 . A quantity of the first buckling hooks  3421  of the first fastening structure  342  is the same as a quantity of the first perforations  3417  of the two first covers  341 . The first buckling hooks  3421  of the first fastening structure  342  are buckled in the first perforations  3417  of the two first covers  341 , and the first buckling hooks  3421  of the first fastening structure  342  hook the two outer surfaces of the two first covers  341 , so that the first fastening structure  342  is located between the two first covers  341 , and the first fastening structure  342  is fastened between the two first covers  341 . The first extending portions  314  of the first terminals  31  of the middle of the first terminal assembly  3  longitudinally pass through a middle of the first fastening structure  342 . 
     Bottom ends of the plurality of the first terminals  31  are surrounded by the first holding element  35 . Two opposite sides of the first holding element  35  are recessed inward to form the two first clamping slots  351 . The two rear ends of the two protruding ribs  117  of the insulating housing  1  are clamped in the two first clamping slots  351  of the first terminal assembly  3 , so that the first terminal assembly  3  is located to the insulating housing  1 , and the first terminal assembly  3  is fastened to the insulating housing  1 . Each first clamping slot  351  is shown as a horn shape, and a front of each first clamping slot  351  is wider than a rear of each first clamping slot  351 , so that the two protruding ribs  117  of the insulating housing  1  are buckled in the two first clamping slots  351  conveniently. 
     Referring to  FIG.  3    to  FIG.  18   , the second terminal assembly  4  is corresponding to the first terminal assembly  3  along the up-down direction. The second terminal assembly  4  includes a plurality of second terminals  41 , a second base body  42  and a second metal plate  43 . The plurality of the second terminals  41  are fastened to the second base body  42 . The plurality of the second terminals  41  are partially surrounded by the second base body  42 . The second metal plate  43  is disposed to the second base body  42 . 
     Each second terminal  41  has a second fastening portion  411 , a second stepping portion  412 , a second contacting portion  413  and a second soldering portion  414 . The plurality of the second terminals  41  include a plurality of second grounding terminals  415  and a plurality of second differential signal terminals  416 . In the first preferred embodiment, the plurality of the second terminals  41  includes seven second grounding terminals  415  and twelve second differential signal terminals  416 . Each two adjacent second differential signal terminals  416  are located between two second grounding terminals  415 . Each second differential signal terminal  416  is used for transmitting the signal. The second fastening portion  411  of one second grounding terminal  415  and the second fastening portions  411  of four second differential signal terminals  416  are surrounded by a middle of the second base body  42 . 
     A front end of the second fastening portion  411  slantwise extends upward and frontward to form the second stepping portion  412 . A front end of the second stepping portion  412  extends frontward and then is arched upward to form the second contacting portion  413 . A rear end of the second fastening portion  411  is bent downward and then extends rearward to form the second soldering portion  414 . Two sides of the front end of the second fastening portion  411 , two sides of the rear end of the second fastening portion  411  and two sides of a rear end of the second contacting portion  413  are recessed inward to form a plurality of second lacking grooves  417 . 
     The second stepping portions  412  and the rear ends of the second contacting portions  413  of the second terminals  41  of two sides of the second terminal assembly  4  are exposed to two sides of a front end of the second base body  42 . The second contacting portions  413  of the plurality of the second terminals  41  project beyond a front surface of the second base body  42 . The second contacting portions  413  of the plurality of the second terminals  41  are disposed in the lower row of the first terminal slots  13 . Top surfaces of the second contacting portions  413  of the plurality of the second terminals  41  are exposed out of the lower row of the first terminal slots  13 . The top surfaces of the second contacting portions  413  of the plurality of the second terminals  41  project into the insertion groove  14 . The second contacting portions  413  of the plurality of the second terminals  41  of the two sides of the second terminal assembly  4  are corresponding to the plurality of the second penetrating grooves  18  of the insulating housing  1 . Corresponding formations of the second base body  42  are engaged with the plurality of the second lacking grooves  417  of the second fastening portions  411  and the second contacting portions  413  of the plurality of the second terminals  41  by the plastic injection molding technology. 
     The second fastening portions  411 , the second stepping portions  412  and the rear ends of the second contacting portions  413  of the second terminals  41  of a middle of the second terminal assembly  4  are surrounded by the middle of the second base body  42 . The second base body  42  has a second surrounding portion  420 , at least one second protruding block  421 , two second protruding portions  422 , a second fastening groove  423 , a plurality of second openings  424 , a plurality of second contact surfaces  425 , a supporting portion  426 , two second restricting holes  427 , a plurality of second connecting portions  428  and a plurality of third terminal slots  429 . In the first preferred embodiment, the second base body  42  includes two second protruding blocks  421 . 
     The second surrounding portion  420  is disposed to the middle of the second base body  42 . The second surrounding portion  420  is connected between the front end of the second base body  42  and a rear end of the second base body  42 . The second fastening portion  411  of one second grounding terminal  415  and the second fastening portions  411  of four second differential signal terminals  416  are surrounded by the second surrounding portion  420 . A rear end of a bottom surface of the second surrounding portion  420  of the second base body  42  extends downward to form the at least one second protruding block  421 . In the first preferred embodiment, two sides of the rear end of the bottom surface of the second surrounding portion  420  of the second base body  42  extend downward to form the two second protruding blocks  421 . A quantity of the at least one second protruding block  421  of the second base body  42  is the same as a quantity of the at least one second aperture  112  of the insulating housing  1 . The two second protruding blocks  421  are fastened in the two second apertures  112  of the insulating housing  1 , so that the second terminal assembly  4  is located to the insulating housing  1 , and the second terminal assembly  4  is fastened to the insulating housing  1 . 
     In the first preferred embodiment, two opposite sides of the second base body  42  extend outward to form the two second protruding portions  422 . The two second protruding portions  422  are buckled in the two second locating slots  114  of the insulating housing  1 , so that the second terminal assembly  4  is located to the insulating housing  1 , and the second terminal assembly  4  is fastened to the insulating housing  1 . A middle of a top surface of the rear end of the second base body  42  is recessed downward to form the second fastening groove  423 . The second metal plate  43  is disposed in the second fastening groove  423  of the second base body  42 . The second base body  42  has four second openings  424  formed to two sides of the second surrounding portion  420 . The front end of the second base body  42  has two second openings  424  arranged transversely, and the rear end of the second base body  42  has the other two second openings  424  arranged transversely. The two second openings  424  of the front end of the second base body  42  penetrate through two sides of a top surface and two sides of a bottom surface of the front end of the second base body  42 . Two bottoms of two sides of the second fastening groove  423  extend downward to form the other two second openings  424  penetrating through two sides of a bottom surface of the rear end of the second base body  42 . A front end of the second surrounding portion  420  is located between the two second openings  424  of the front end of the second base body  42 . A rear end of the second surrounding portion  420  is located between the other two second openings  424  of the rear end of the second base body  42 . The second fastening portions  411  of the plurality of the second grounding terminals  415  and the second differential signal terminals  416  of the two sides of the second terminal assembly  4  are exposed to the other two second openings  424  of the rear end of the second base body  42 . The second fastening portions  411  of the plurality of the second grounding terminals  415  and the second differential signal terminals  416  of the two sides of the second terminal assembly  4  are exposed to the second fastening groove  423  from the other two second openings  424  of the rear end of the second base body  42 . 
     Several portions of an upper surface of the second surrounding portion  420  of the second base body  42  extend upward to form the plurality of the second contact surfaces  425 . The plurality of the second contact surfaces  425  are connected with the front end of the second base body  42  and the rear end of the second base body  42 . The second contact surfaces  425  of the front end of the second base body  42  and the second contact surfaces  425  of the rear end of the second base body  42  are arched face to face. The plurality of the second contact surfaces  425  are used for fastening the second metal plate  43 . A rear end of the second base body  42  is formed as the supporting portion  426 . In the first preferred embodiment, a front end of a corresponding location of the fourth terminal assembly  6  abuts against the supporting portion  426 . The two second restricting holes  427  penetrate through two sides of the top surface and two sides of the bottom surface of the second base body  42 . Two second restricting portions  436  of the second metal plate  43  are restricted in the two second restricting holes  427 , so that the second metal plate  43  is located to the second base body  42 , and the second metal plate  43  is fastened to the second base body  42 . 
     A lower surface of the second base body  42  has the plurality of the second connecting portions  428 . Each second connecting portion  428  is disposed between two adjacent second terminals  41 . Each second connecting portion  428  is used to simplify the mold manufacturing process. The plurality of the second connecting portions  428  are longitudinally arranged in three rows. In the first preferred embodiment, the plurality of the second connecting portions  428  are embedded in the plurality of the second lacking grooves  417  of the second fastening portions  411  and the second contacting portions  413  of the plurality of the second terminals  41 . An upper surface of the second base body  42  has a row of third terminal slots  429 . Front ends of a plurality of fourth terminals  61  of the fourth terminal assembly  6  are disposed to the row of the third terminal slots  429 . During the assembling process of the high-speed connector  100 , the row of the third terminal slots  429  are used for preventing the plurality of the fourth terminals  61  of fourth terminal assembly  6  from tilting. The upper surface of the second surrounding portion  420  of the second base body  42  extends upward to from a first fastening pillar  4201 . The first fastening pillar  4201  is used for fastening the second metal plate  43 . The first fastening pillar  4201  is corresponding to a corresponding second perforation  437  of the second metal plate  43 . 
     The second metal plate  43  is disposed in the second fastening groove  423  of the second base body  42 . The second metal plate  43  is disposed to top surfaces of the plurality of the second terminals  41 . The second metal plate  43  has a rectangular second main sheet  431 , a plurality of second inclining sheets  432 , a plurality of second contact sheets  433 , a plurality of second covering sheets  435  and the two second restricting portions  436 . 
     A position of the second main sheet  431  is corresponding to a position of the second surrounding portion  420  of the second base body  42 . The second main sheet  431  is covered to the upper surface of the second surrounding portion  420 . The plurality of the second contact surfaces  425  abut against a front edge and a rear edge of the second main sheet  431 . In the concrete implementation, the second main sheet  431  is directly fastened to the second surrounding portion  420  of the second base body  42 . Two opposite sides of the second main sheet  431  form two second flank sheets  434 . Each second flank sheet  434  is wavy. Each second flank sheet  434  has the plurality of the second inclining sheets  432 , the plurality of the second contact sheets  433  and the plurality of the second covering sheets  435 . 
     The two opposite sides of the second main sheet  431  slantwise extend outward and upward to form two of the plurality of the second inclining sheets  432 . The two of the plurality of the second inclining sheets  432  are corresponding to two outer surfaces of the second surrounding portion  420  of the second base body  42 . The two of the plurality of the second inclining sheets  432  are covered to the two outer surfaces of the second surrounding portion  420 . Two outer edges of the two of the plurality of the second inclining sheets  432  horizontally extend to form two second contact sheets  433 . Each second contact sheet  433  and the second main sheet  431  are horizontally disposed. Each second contact sheet  433  is parallel to the second main sheet  431 . Two outer edges of the two second contact sheets  433  slantwise extend outward and downward to form another two of the plurality of the second inclining sheets  432 . The another two of the plurality of the second inclining sheets  432  of the two outer edges of the two second contact sheets  433  are opposite to each other. Two outer edges of the another two of the plurality of the second inclining sheets  432  horizontally extend outward to form two second covering sheets  435 . Each second covering sheet  435  and the second main sheet  431  are horizontally disposed. Each second covering sheet  435  and the second main sheet  431  are disposed at the same level. Two outer edges of the two second covering sheets  435  extend outward and downward to form two extra second inclining sheets  432 . Two outer edges of the two extra second inclining sheets  432  horizontally extend oppositely to form another two second contact sheets  433 . Two outer edges of the another two second contact sheets  433  slantwise extend outward and upward to form two additional second inclining sheets  432 . Two outer edges of the two additional second inclining sheets  432  horizontally extend outward to form another two second covering sheets  435 . Two outer edges of the another two second covering sheets  435  slantwise extend outward and downward to form two other second inclining sheets  432 . Two outer edges of the two other second inclining sheets  432  horizontally extend outward to form two outermost second contact sheets  433 . 
     The two opposite sides of the second main sheet  431  meander outward to form the second inclining sheets  432 , the second contact sheets  433  and the second covering sheets  435  of the two second flank sheets  434  according to a quantity of the plurality of the second terminals  41 . In the first preferred embodiment, each second flank sheet  434  of the second metal plate  43  has five second inclining sheets  432 , three second contact sheets  433  and two second covering sheets  435 , so the second metal plate  43  has one second main sheet  431 , ten second inclining sheets  432 , six second contact sheets  433  and four second covering sheets  435 . Two opposite side edges of each second covering sheet  435  slantwise extend downward and sideward to form the two second inclining sheets  432 . The two second inclining sheets  432  of each second covering sheet  435  are connected with two of the plurality of the second contact sheets  433 . The two second inclining sheets  432  of each second covering sheet  435  are opposite to each other. Each two second inclining sheets  432  of the second metal plate  43  are opposite to each other. 
     From an inner side of each second flank sheet  434  to an outer side of each second flank sheet  434 , each second flank sheet  434  sequentially has the second inclining sheet  432  connected with one side of the second main sheet  431 , the second contact sheet  433  connected with the outer edge of the second inclining sheet  432  which is connected with the one side of the second main sheet  431 , the second inclining sheet  432  connected with the outer edge of the second contact sheet  433 , the second covering sheet  435  connected with the outer edge of the second inclining sheet  432  which is connected with the outer edge of the second contact sheet  433 , the second inclining sheet  432  connected with the outer edge of the second covering sheet  435 , the second contact sheet  433  connected with the outer edge of the second inclining sheet  432  which is connected with the outer edge of the second covering sheet  435 , the second inclining sheet  432  connected with the outer edge of the second contact sheet  433 , the second covering sheet  435  connected with the outer edge of the second inclining sheet  432  which is connected with the outer edge of the second contact sheet  433 , the second inclining sheet  432  connected with the outer edge of the second covering sheet  435 , and the second contact sheet  433  connected with the outer edge of the second inclining sheet  432 . 
     Referring to  FIG.  7    and  FIG.  17   , the second contact sheets  433  of the second metal plate  43  contact with the second fastening portions  411  of the second grounding terminals  415  of the two sides of the second terminal assembly  4  to form the grounding structure  90 . In this way, the signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained for improving the transmission quality of the high-frequency signal. The second covering sheets  435  of the second metal plate  43  keep distances from the second fastening portions  411  of the second differential signal terminals  416  of the second terminal assembly  4 . 
     Two middles of two opposite outer sides of the two outermost second contact sheets  433  of the second metal plate  43  slantwise extend upward and outward, and then are bent outward to form the two second restricting portions  436 . A quantity of the second restricting portions  436  of the second metal plate  43  is the same as a quantity of the second restricting holes  427  of the second base body  42 . The two second restricting portions  436  are buckled in the two second restricting holes  427 , so the second metal plate  43  is fastened in the second base body  42 . The second main sheet  431  of the second metal plate  43  has the second perforation  437  vertically penetrating through a top surface and a bottom surface of the second main sheet  431 . The first fastening pillar  4201  of the second surrounding portion  420  of the second base body  42  is fastened in the second perforation  437 , so that the second metal plate  43  is located to the second base body  42 , and the second metal plate  43  is fastened to the second base body  42 . 
     Referring to  FIG.  10    to  FIG.  26   , the third terminal assembly  5  includes a plurality of third terminals  51 , a third base body  52 , a third metal plate  53 , a second dielectric structure  54 , a second holding element  55  and a first sheet structure  56 . The plurality of the third terminals  51  are disposed between the third metal plate  53  and the first sheet structure  56 . The third metal plate  53  is disposed in the third base body  52 , and the third metal plate  53  is disposed under the plurality of the third terminals  51 . The plurality of the third terminals  51  are fastened to the third base body  52 . The plurality of the third terminals  51  are partially surrounded by the third base body  52 . 
     Rear ends of the plurality of the third terminals  51  are surrounded by the second dielectric structure  54 . The second dielectric structure  54  is used for adjusting a dielectric coefficient of a peripheral structure of each third terminal  51  to improve the crosstalk interference of the high-speed connector  100 . Lower portions of the plurality of the third terminals  51  are surrounded by the second holding element  55 . The first sheet structure  56  is disposed in the third base body  52 , and the first sheet structure  56  is disposed on the plurality of the third terminals  51 . The first sheet structure  56  is opposite to the third metal plate  53 . The first sheet structure  56  is used for adjusting the dielectric coefficient of the peripheral structure of each third terminal  51  to improve the crosstalk interference of the high-speed connector  100 . A position of the first sheet structure  56  is corresponding to a position of the rear end of the first base body  32 . The first sheet structure  56  is mounted under the rear end of the first base body  32 . 
     Each third terminal  51  has a third fastening portion  511 , a third contacting portion  512 , a second extending portion  513 , a second bending portion  514  and a third soldering portion  515 . The plurality of the third terminals  51  include a plurality of third grounding terminals  516  and a plurality of third differential signal terminals  517 . Each two adjacent third differential signal terminals  517  are disposed between two third grounding terminals  516 . In the first preferred embodiment, the plurality of the third terminals  51  include seven third grounding terminals  516  and twelve third differential signal terminals  517 . Each third differential signal terminal  517  is used for transmitting the signal. The third fastening portion  511  of one third grounding terminal  516  and the third fastening portions  511  of four third differential signal terminals  517  are surrounded by a middle of the third base body  52 . 
     A front end of the third fastening portion  511  extends frontward, and then is arched downward to form the third contacting portion  512 . A rear end of the third fastening portion  511  slantwise extends rearward and downward to form the second extending portion  513 . A rear end of the second extending portion  513  is bent downward to form the second bending portion  514 . A tail end of the second bending portion  514  is bent rearward to form the third soldering portion  515 . The third fastening portions  511  of the plurality of the third terminals  51  are fastened to the third base body  52 . The third contacting portions  512  of the plurality of the third terminals  51  project beyond a front surface of the third base body  52 . The third contacting portions  512  of the plurality of the third terminals  51  are disposed in the plurality of the second terminal slots  329  of the first terminal assembly  3 . During the assembling process of the high-speed connector  100 , the plurality of the second terminal slots  329  are used for preventing the third contacting portions  512  of third terminal assembly  5  from tilting. The second extending portions  513  of the plurality of the third terminals  51  project beyond a rear surface of the third base body  52 . The second dielectric structure  54  is fastened to the second extending portions  513  of the plurality of the third terminals  51 . Tail ends of the plurality of the second bending portions  514  of the plurality of the third terminals  51  are surrounded by the second holding element  55 . Two opposite sides of the front end of each third fastening portion  511 , two opposite sides of the rear end of each third fastening portion  511  and two opposite sides of each second bending portion  514  are recessed inward to form a plurality of third lacking grooves  518 . Corresponding formations of the third base body  52  are embedded into the plurality of the third lacking grooves  518  of the third fastening portions  511  and the second bending portions  514  of the plurality of the third terminals  51 . 
     The third base body  52  has a third surrounding portion  520 , a first locating pillar  521 , two third protruding portions  522 , a third fastening groove  523 , two third openings  524 , a plurality of third contact surfaces  525 , a second location hole  526 , two third restricting holes  527  and a plurality of third connecting portions  528 . The third surrounding portion  520  is disposed at the middle of the third base body  52 , and the third surrounding portion  520  is connected between a front end of the third base body  52  and a rear end of the third base body  52 . The third fastening portion  511  of the one third grounding terminal  516  and the third fastening portions  511  of the four third differential signal terminals  517  are surrounded by the third surrounding portion  520 . A front end of a top surface of the third surrounding portion  520  of the third base body  52  extends upward to form the first locating pillar  521 . The first locating pillar  521  is fastened in the first location hole  326  of the first base body  32  of the first terminal assembly  3 , so that the third terminal assembly  5  is located to the first terminal assembly  3 , and the third terminal assembly  5  is fastened to the first terminal assembly  3 . 
     In the first preferred embodiment, two opposite sides of the third base body  52  extend outward to form the two third protruding portions  522 . The two third protruding portions  522  are buckled in the two third locating slots  115  of the insulating housing  1 , so that the third terminal assembly  5  is located to the insulating housing  1 , and the third terminal assembly  5  is fastened to the insulating housing  1 . A middle of a bottom surface of the third base body  52  is recessed inward to form the third fastening groove  523 . A middle of a top surface of the third base body  52  is recessed inward to form a first locating groove  204 . The third metal plate  53  is disposed in the third fastening groove  523  of the third base body  52 . Two tops of two sides of the third fastening groove  523  extend upward to form the two third openings  524  penetrating through two sides of the top surface of the third base body  52 . The two third openings  524  are formed to two sides of the third surrounding portion  520 . The plurality of the third fastening portions  511  of the plurality of the third grounding terminals  516  and the plurality of the third fastening portions  511  of the plurality of the third differential signal terminals  517  of two sides of the third terminal assembly  5  are exposed to the two third openings  524  of the third base body  52 . The plurality of the third fastening portions  511  of the plurality of the third grounding terminals  516  and the plurality of the third fastening portions  511  of the plurality of the third differential signal terminals  517  of the two sides of the third terminal assembly  5  are exposed to the third fastening groove  523  from the two third openings  524  of the third base body  52 . 
     Several portions of a lower surface of the third surrounding portion  520  of third base body  52  extend downward to form the plurality of the third contact surfaces  525 . The plurality of the third contact surfaces  525  are connected with the front end of the third base body  52  and the rear end of the third base body  52 . The third contact surfaces  525  of the front end of the third base body  52  and the third contact surfaces  525  of the rear end of the third base body  52  are arched face to face. The plurality of the third contact surfaces  525  are used for fastening the third metal plate  53 . A rear end of a bottom surface of the third surrounding portion  520  of third base body  52  is recessed inward to form the second location hole  526 . A corresponding mechanism of the fourth terminal assembly  6  is fastened in the second location hole  526  of the third base body  52 , so that the fourth terminal assembly  6  is located to the third terminal assembly  5 , and the fourth terminal assembly  6  is fastened to the third terminal assembly  5 . The two third restricting holes  527  penetrate through the top surface and the bottom surface of the two opposite sides of the third base body  52 . Two third restricting portions  536  of the third metal plate  53  are disposed in the two third restricting holes  527 , so that the third metal plate  53  is located to the third base body  52 , and the third metal plate  53  is fastened to the third base body  52 . 
     An upper surface of the third base body  52  and an upper surface of the second holding element  55  have the plurality of the third connecting portions  528 . The plurality of the third connecting portions  528  are longitudinally arranged in three rows. Each third connecting portion  528  is disposed between two third terminals  51 . Each third connecting portion  528  is used to simplify the mold manufacturing process. In the first preferred embodiment, the plurality of the third connecting portions  528  are embedded into the third lacking grooves  518  of the third fastening portions  511  and the second bending portions  514  of the plurality of the third terminals  51 . A middle of the lower surface of the third surrounding portion  520  of the third base body  52  extends downward to from a second fastening pillar  5201 . The second fastening pillar  5201  is used for fastening the third metal plate  53 . The second fastening pillar  5201  is corresponding to a corresponding third perforation  537  of the third metal plate  53 . 
     The third metal plate  53  is disposed in the third fastening groove  523  of the third base body  52 , and the third metal plate  53  is disposed under the plurality of the third terminals  51 . The third metal plate  53  has a rectangular third main sheet  531 , a plurality of third inclining sheets  532 , a plurality of third contact sheets  533 , a plurality of third covering sheets  535  and two third restricting portions  536 . 
     A position of the third main sheet  531  is corresponding to a position of the third surrounding portion  520  of the third base body  52 . The third main sheet  531  is covered to the lower surface of the third surrounding portion  520 . The plurality of the third contact surfaces  525  abut against a front edge and a rear edge of the third main sheet  531 . In the concrete implementation, the third main sheet  531  is directly fastened to the third surrounding portion  520  of the third base body  52 . Two opposite sides of the third main sheet  531  form two third flank sheets  534 . Each third flank sheet  534  is wavy. Each third flank sheet  534  has the plurality of the third inclining sheets  532 , the plurality of the third contact sheets  533  and the plurality of the third covering sheets  535 . 
     The two opposite sides of the third main sheet  531  slantwise extend outward and upward to form two of the plurality of the third inclining sheets  532 . The two of the plurality of the third inclining sheets  532  are corresponding to two outer surfaces of the third surrounding portion  520  of the third base body  52 . The two of the plurality of the third inclining sheets  532  are covered to the two outer surfaces of the third surrounding portion  520  of the third base body  52 . Two outer edges of the two of the plurality of the third inclining sheets  532  horizontally extend outward to form two third contact sheets  533 . Each third contact sheet  533  and the third main sheet  531  are horizontally disposed. Each third contact sheet  533  is parallel to the third main sheet  531 . Two outer edges of the two third contact sheets  533  slantwise extend outward and downward to form another two of the plurality of the third inclining sheets  532 . The another two of the plurality of third inclining sheets  532  of the two outer edges of the two third contact sheets  533  are opposite to each other. Two outer edges of the another two of the plurality of the third inclining sheets  532  horizontally extend outward to form two third covering sheets  535 . Each third covering sheet  535  and the third main sheet  531  are horizontally disposed. Each third covering sheet  535  and the third main sheet  531  are disposed at the same level. Two outer edges of the two third covering sheets  535  slantwise extend outward and upward to form two extra third inclining sheets  532 . Two outer edges of the two extra third inclining sheets  532  horizontally extend oppositely to form another two third contact sheets  533 . Two outer edges of the another two third contact sheets  533  slantwise extend outward and downward to form two additional third inclining sheets  532 . Two outer edges of the two additional third inclining sheets  532  horizontally extend outward to form another two third covering sheets  535 . Two outer edges of the another two third covering sheets  535  slantwise extend outward and upward to form two other third inclining sheets  532 . Two outer edges of the two other third inclining sheets  532  horizontally extend outward to form two outermost third contact sheets  533 . 
     The two opposite sides of the third main sheet  531  meander outward to form the third inclining sheets  532 , the third contact sheets  533  and the third covering sheets  535  of the two third flank sheets  534  according to a quantity of the plurality of the third terminals  51 . In the first preferred embodiment, each third flank sheet  534  of the third metal plate  53  has five third inclining sheets  532 , three third contact sheets  533  and two third covering sheets  535 , so the third metal plate  53  has one third main sheet  531 , ten third inclining sheets  532 , six third contact sheets  533  and four third covering sheets  535 . Two opposite side edges of each third covering sheet  535  slantwise extend upward and sideward to form the two third inclining sheets  532 . The two third inclining sheets  532  of each third covering sheet  535  are connected with two of the plurality of the third contact sheets  533 . The two third inclining sheets  532  of each third covering sheet  535  are opposite to each other. Each two third inclining sheets  532  of the third metal plate  53  are opposite to each other. 
     From an inner side of each third flank sheet  534  to an outer side of each third flank sheet  534 , each third flank sheet  534  sequentially has the third inclining sheet  532  connected with one side of the third main sheet  531 , the third contact sheet  533  connected with the outer edge of the third inclining sheet  532  which is connected with the one side of the third main sheet  531 , the third inclining sheet  532  connected with the outer edge of the third contact sheet  533 , the third covering sheet  535  connected with the outer edge of the third inclining sheet  532  which is connected with the outer edge of the third contact sheet  533 , the third inclining sheet  532  connected with the outer edge of the third covering sheet  535 , the third contact sheet  533  connected with the outer edge of the third inclining sheet  532  which is connected with the outer edge of the third covering sheet  535 , the third inclining sheet  532  connected with the outer edge of the third contact sheet  533 , the third covering sheet  535  connected with the outer edge of the third inclining sheet  532  which is connected with the outer edge of the third contact sheet  533 , the third inclining sheet  532  connected with the outer edge of the third covering sheet  535 , and the third contact sheet  533  connected with the outer edge of the third inclining sheet  532 . 
     Referring to  FIG.  7    and  FIG.  21   , the third contact sheets  533  of the third metal plate  53  contact with the third fastening portions  511  of the third grounding terminals  516  the two sides of the third terminal assembly  5  to form the grounding structure  90 . In this way, the signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained for improving the transmission quality of the high-frequency signal. The third covering sheets  535  of the third metal plate  53  keep distances from the third fastening portions  511  of the third differential signal terminals  517  of the third terminal assembly  5 . 
     Two middles of two opposite outer sides of the two outermost third contact sheets  533  of the third metal plate  53  slantwise extend outward and downward, and then are bent outward to form the two third restricting portions  536 . A quantity of the third restricting portions  536  of the third metal plate  53  is the same as a quantity of the third restricting holes  527  of the third base body  52 . The two third restricting portions  536  are buckled in the two third restricting holes  527 , so the third metal plate  53  is fastened in the third base body  52 . A middle of the third main sheet  531  of the third metal plate  53  has the third perforation  537  vertically penetrating through a top surface and a bottom surface of the third main sheet  531 . The second fastening pillar  5201  of the third surrounding portion  520  of the third base body  52  is fastened in the third perforation  537 , so that the third metal plate  53  is located to the third base body  52 , and the third metal plate  53  is fastened to the third base body  52 . 
     Referring to  FIG.  23    to  FIG.  25   , the second dielectric structure  54  includes two second covers  541  and a second fastening structure  542 . In one condition, structures of the two second covers  541  are the same. In another condition, the two second covers  541  are symmetrical. The two second covers  541  are disposed opposite to each other. The second fastening structure  542  is disposed between the two second covers  541 . Two sides of the second fastening structure  542  penetrate through the two second covers  541 . The two second covers  541  and the second fastening structure  542  are buckled in a whole. The two second covers  541  are buckled by the second fastening structure  542  to form another entirety. 
     Each second cover  541  has a second extending foot  5411 , a second notch  5412 , a plurality of second attaching surfaces  5413  and a second internal space  5414 . One side of each second cover  541  protrudes inward and perpendicular to each second cover  541  to form the second extending foot  5411 . The other side of each second cover  541  has the second notch  5412  penetrating through an outer surface, an inner surface and the other side surface of each second cover  541 . Each second extending foot  5411  is disposed corresponding to one second notch  5412 . The two second extending feet  5411  of the two second covers  541  are buckled with the two second notches  5412  of the two second covers  541 . 
     Two sides of the inner surface of each second cover  541  has the plurality of the second attaching surfaces  5413  protruded beyond the inner surface of each second cover  541 . The second attaching surfaces  5413  of one second cover  541  face the second attaching surfaces  5413  of the other second cover  541 . The second attaching surfaces  5413  of the two second covers  541  are spaced to form the second internal space  5414 . The second extending portions  513  of the plurality of the third differential signal terminals  517  pass through the second internal space  5414 . The second attaching surfaces  5413  of the two second covers  541  are corresponding to the second extending portions  513  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 . The second attaching surfaces  5413  of the two second covers  541  clamp the second extending portions  513  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 . The second attaching surfaces  5413  of the one second cover  541  are corresponding to upper surfaces of the second extending portions  513  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 , and the second attaching surfaces  5413  of the other second cover  541  are corresponding to lower surfaces of the second extending portions  513  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 . The second attaching surfaces  5413  of the one second cover  541  contact with the upper surfaces of the second extending portions  513  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 , and the second attaching surfaces  5413  of the other second cover  541  contact with the lower surfaces of the second extending portions  513  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 . 
     The upper surfaces and the lower surfaces of the second extending portions  513  of the third differential signal terminals  517  of the two sides of the third terminal assembly  5  are spaced from the two inner surfaces of the two second covers  541  to form two second gaps  5415 . A plurality of the second gaps  5415  are formed among the third terminal assembly  5  and the two inner surfaces of the two second covers  541 . The second internal space  5414  and the plurality of the second gaps  5415  of the second dielectric structure  54  are used for adjusting the dielectric coefficient of the peripheral structure of each third terminal  51  to improve an electromagnetic characteristic and the crosstalk interference of the high-speed connector  100 . 
     A middle of the inner surface of each second cover  541  is recessed inward to from a second sunken portion  5416 . The second sunken portion  5416  is used for receiving the second fastening structure  542 . The second sunken portion  5416  of each second cover  541  has a second perforation  5417  penetrating through the inner surface and the outer surface of each second cover  541 . Corresponding hooks of the second fastening structure  542  are disposed to the second perforations  5417  of the two second covers  541 , and the corresponding hooks of the second fastening structure  542  are buckled to the two outer surfaces of the two second covers  541 , so that the second fastening structure  542  is located between the two second covers  541 , and the second fastening structure  542  is fastened between the two second covers  541 . 
     One side of the second fastening structure  542  has a second buckling hook  5421 . In the first preferred embodiment, two opposite sides of the second fastening structure  542  extend oppositely and then protrude oppositely to form two second buckling hooks  5421 . A quantity of the second buckling hooks  5421  of the second fastening structure  542  is the same as a quantity of the second perforations  5417  of the two second covers  541 . The second buckling hooks  5421  of the second fastening structure  542  are buckled in the second perforations  5417  of the two second covers  541 , and the second buckling hooks  5421  of the second fastening structure  542  hook the two outer surfaces of the two second covers  541 , so that the second fastening structure  542  is located between the two second covers  541 , and the second fastening structure  542  is fastened between the two second covers  541 . The second extending portions  513  of the third terminals  51  of a middle of the third terminal assembly  5  longitudinally pass through a middle of the second fastening structure  542 . 
     Bottom ends of the plurality of the third terminals  51  are surrounded by the second holding element  55 . The tail ends of the plurality of the second bending portions  514  of the plurality of the third terminals  51  are surrounded by the second holding element  55 . Two opposite sides of the second holding element  55  are recessed inward to form the two second clamping slots  551 . The two rear ends of the two protruding ribs  117  of the insulating housing  1  are clamped in the two second clamping slots  551  of the third terminal assembly  5 , so that the third terminal assembly  5  is located to the insulating housing  1 , and the third terminal assembly  5  is fastened to the insulating housing  1 . Each second clamping slot  551  is shown as the horn shape, so that the two protruding ribs  117  of the insulating housing  1  are buckled in the two second clamping slots  551  conveniently. 
     When the terminal module  2  is assembled, the second holding element  55  is disposed in front of the first holding element  35 , and the two second clamping slots  551  of the second holding element  55  are disposed in front of the two first clamping slots  351  of the first holding element  35 . The two second clamping slots  551  of the second holding element  55  and the two first clamping slots  351  of the first holding element  35  are longitudinally aligned. Two rear ends of the two second clamping slots  551  of the second holding element  55  are connected with two front ends of the two first clamping slots  351  of the first holding element  35 . 
     Referring to  FIG.  26   , the first sheet structure  56  is formed by the plastic injection molding technology. The first sheet structure  56  is located in the first locating groove  204 . An inner surface of the first sheet structure  56  has a plurality of third attaching surfaces  561 . Several portions of two sides of a bottom surface of the first sheet structure  56  protrude downward to form the plurality of the third attaching surfaces  561 . In the first preferred embodiment, the plurality of the third attaching surfaces  561  are corresponding to top surfaces of the third fastening portions  511  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 . The plurality of the third attaching surfaces  561  contact with the top surfaces of the third fastening portions  511  of the third grounding terminals  516  of the two sides of the third terminal assembly  5 . 
     The first sheet structure  56  is spaced from the third metal plate  53 . The third covering sheets  535  of the third metal plate  53  are spaced from the inner surface of the first sheet structure  56  to form a plurality of third internal spaces  562 . Each third internal space  562  is formed between the first sheet structure  56  and one third covering sheet  535  of the third metal plate  53 . The third contact sheets  533  of the third metal plate  53  are corresponding to the plurality of the third attaching surfaces  561  of the first sheet structure  56 . The third fastening portions  511  of each two third differential signal terminals  517  of the two sides of the third terminal assembly  5  pass through one third internal space  562 . Top surfaces of the third fastening portions  511  of each two third differential signal terminals  517  of the two sides of the third terminal assembly  5  are spaced from the inner surface of the first sheet structure  56  to form a first clearance  563 . A plurality of the first clearances  563  are formed between the third terminal assembly  5  and the inner surface of the first sheet structure  56 . The third internal space  562  and the plurality of the first clearances  563  of the first sheet structure  56  are used for adjusting the dielectric coefficient of the peripheral structure of each third terminal  51  of the high-speed connector  100  to improve the electromagnetic characteristic and the crosstalk interference of the high-speed connector  100 . 
     In the concrete implementation, according to a whole structure adjustment of the third terminal assembly  5 , a size of the first clearance  563  is changed, and the first clearance  563  is even canceled. An outer surface of the first sheet structure  56  extends outward to form a first strengthening structure  564 . The first strengthening structure  564  is used for reinforcing a structural strength of the first sheet structure  56 . In the first preferred embodiment, two sides of the first strengthening structure  564  are shown as two cross structures from a vertical view to reinforce the structural strength of the first sheet structure  56 . 
     Referring to  FIG.  3    to  FIG.  30   , the fourth terminal assembly  6  is corresponding to the third terminal assembly  5  along the up-down direction. The fourth terminal assembly  6  is mounted under the third terminal assembly  5 . The fourth terminal assembly  6  includes the plurality of the fourth terminals  61 , a fourth base body  62 , a fourth metal plate  63  and a second sheet structure  64 . The plurality of the fourth terminals  61  are disposed between the fourth metal plate  63  and the second sheet structure  64 . The plurality of the fourth terminals  61  are fastened to the fourth base body  62 , and the plurality of the fourth terminals  61  are partially surrounded by the fourth base body  62 . The fourth metal plate  63  is disposed in the fourth base body  62 , and the fourth metal plate  63  is disposed under the plurality of the fourth terminals  61 . The second sheet structure  64  is disposed in the fourth base body  62 , and the plurality of the fourth terminals  61  are mounted under the second sheet structure  64 . The second sheet structure  64  is used for adjusting the dielectric coefficient of a peripheral structure of each fourth terminal  61  to improve the crosstalk interference of the high-speed connector  100 . A position of the second sheet structure  64  is corresponding to positions of the second soldering portions  414  of the plurality of the second terminals  41  of the second terminal assembly  4 . A distance between a front of the second sheet structure  64  and the first terminal slots  13  of the insulating housing  1  is smaller than a distance between a front of the first sheet structure  56  and the first terminal slots  13  of the insulating housing  1  along a front-to-rear direction. 
     Each fourth terminal  61  has a fourth fastening portion  611 , a fourth contacting portion  612 , a third bending portion  613  and a fourth soldering portion  614 . The plurality of the fourth terminals  61  include a plurality of fourth grounding terminals  615  and a plurality of fourth differential signal terminals  616 . In the first preferred embodiment, the plurality of the fourth terminals  61  includes seven fourth grounding terminals  615  and twelve fourth differential signal terminals  616 . Each two adjacent fourth differential signal terminals  616  are located between two fourth grounding terminals  615 . Each fourth differential signal terminal  616  is used for transmitting the signal. The fourth fastening portion  611  of one fourth grounding terminal  615  and the fourth fastening portions  611  of four fourth differential signal terminals  616  are surrounded by a middle of the fourth base body  62 . 
     A front end of the fourth fastening portion  611  extends frontward and then is arched upward to form the fourth contacting portion  612 . A rear end of the fourth fastening portion  611  is bent downward to form the third bending portion  613 . A tail end of the third bending portion  613  is bent rearward to form the fourth soldering portion  614 . The fourth fastening portions  611  of the plurality of the fourth terminals  61  are fastened to the fourth base body  62 . The fourth contacting portions  612  of the plurality of the fourth terminals  61  project beyond a front surface of the fourth base body  62 . The fourth contacting portions  612  of the plurality of the fourth terminals  61  of the fourth terminal assembly  6  are disposed in the row of the third terminal slots  429  of the second terminal assembly  4 . During the assembling process of the high-speed connector  100 , the row of the third terminal slots  429  are used for preventing the fourth contacting portions  612  of the fourth terminal assembly  6  from tilting. The third bending portions  613  of the plurality of the fourth terminals  61  project beyond a rear surface of the fourth base body  62 . Two opposite sides of the front end of each fourth fastening portion  611 , two opposite sides of the rear end of each fourth fastening portion  611  and two opposite sides of each third bending portion  613  are recessed inward to from a plurality of fourth lacking grooves  617 . Corresponding portions of the fourth base body  62  are fastened in the plurality of the fourth lacking grooves  617  of the fourth fastening portions  611  and the third bending portions  613  of the plurality of the fourth terminals  61 . 
     The fourth base body  62  has a fourth surrounding portion  620 , a second locating pillar  621 , a plurality of fourth protruding portions  622 , a fourth fastening groove  623 , a plurality of fourth openings  624 , a plurality of fourth contact surfaces  625 , two fourth restricting holes  626  and a plurality of fourth connecting portions  627 . The fourth surrounding portion  620  is disposed to the middle of the fourth base body  62 , and the fourth surrounding portion  620  is connected between a front end and a rear end of the fourth base body  62 . The fourth fastening portion  611  of the one fourth grounding terminal  615  and the fourth fastening portions  611  of the four fourth differential signal terminals  616  are surrounded by the fourth surrounding portion  620 . A top surface of the fourth surrounding portion  620  of the fourth base body  62  extends upward to form the second locating pillar  621 . The second locating pillar  621  of the fourth surrounding portion  620  of the fourth base body  62  is fastened in the second location hole  526  of the third base body  52  of the third terminal assembly  5 , so that the fourth terminal assembly  6  is located to third terminal assembly  5 , and the fourth terminal assembly  6  is fastened to third terminal assembly  5 . 
     In the first preferred embodiment, several portions of two opposite sides of the fourth base body  62  extend outward to form the plurality of the fourth protruding portions  622 . The plurality of the fourth protruding portions  622  are arranged in two rows along the front-to-rear direction. A front row of the fourth protruding portions  622  are located above a rear row of the fourth protruding portions  622 . The fourth protruding portions  622  of the fourth base body  62  are buckled in the two second locating slots  114  and the two fourth locating slots  116  of the insulating housing  1 , so that the fourth terminal assembly  6  is located to the insulating housing  1 , and the fourth terminal assembly  6  is fastened to the insulating housing  1 . A middle of a top surface of the front end of the fourth base body  62  is recessed downward to form the fourth fastening groove  623 . A middle of a bottom surface of the front end of the fourth base body  62  is recessed inward to form a second locating groove  205 . The fourth metal plate  63  is disposed in the fourth fastening groove  623  of the fourth base body  62 . The fourth base body  62  has four fourth openings  624 . The front end of the fourth base body  62  has two fourth openings  624 , and the rear end of the fourth base body  62  has the other two fourth openings  624 . Two bottoms of two sides of the fourth fastening groove  623  extend downward to form the two fourth openings  624  penetrating through two sides of the bottom surface of the front end of the fourth base body  62 . The other two fourth openings  624  of the rear end of the fourth base body  62  penetrate through two sides of a top surface and two sides of a bottom surface of the rear end of the fourth base body  62 . The fourth fastening portions  611  of the plurality of the fourth grounding terminals  615  and the fourth differential signal terminals  616  of two sides of the fourth terminal assembly  6  are exposed to the two fourth openings  624  of the front end of the fourth base body  62 . The fourth fastening portions  611  of the plurality of the fourth grounding terminals  615  and the fourth differential signal terminals  616  of the two sides of the fourth terminal assembly  6  are exposed to the fourth fastening groove  623  from the two fourth openings  624  of the front end of the fourth base body  62 . The third bending portions  613  of the plurality of the fourth grounding terminals  615  and the fourth differential signal terminals  616  are exposed to the two fourth openings  624  of the rear end of the fourth base body  62 . 
     A front end of the fourth surrounding portion  620  is located between the two fourth openings  624  of the front end of the fourth base body  62 . A rear end of the fourth surrounding portion  620  is located between the other two fourth openings  624  of the rear end of the fourth base body  62 . In the first preferred embodiment, the four fourth openings  624  of the fourth base body  62  are formed to two sides of the fourth surrounding portion  620 . A front of the bottom surface of the front end of the fourth base body  62  of the fourth terminal assembly  6  abuts against the supporting portion  426  of the second base body  42 . 
     Several portions of a front end and a rear end of an upper surface of the fourth surrounding portion  620  of the fourth base body  62  extend upward to form the plurality of the fourth contact surfaces  625 . The plurality of the fourth contact surfaces  625  are connected with the front end and the rear end of the fourth base body  62 . The fourth contact surfaces  625  of the front end of the fourth base body  62  and the fourth contact surfaces  625  of the rear end of the fourth base body  62  are arched face to face. The plurality of the fourth contact surfaces  625  are used for fastening the fourth metal plate  63 . The two fourth restricting holes  626  vertically penetrate through two sides of the top surface and the two sides of the bottom surface of the front end of the fourth base body  62 . Two fourth restricting portions  636  of the fourth metal plate  63  are disposed in the two fourth restricting holes  626 , so that the fourth metal plate  63  is located to the fourth base body  62 , and the fourth metal plate  63  is fastened to the fourth base body  62 . 
     A lower portion of the fourth base body  62  has the plurality of the fourth connecting portions  627 . The plurality of the fourth connecting portions  627  are longitudinally arranged in three rows. Each row of the fourth connecting portions  627  are arranged transversely. Each fourth connecting portion  627  is disposed between two fourth terminals  61 . The plurality of the fourth connecting portions  627  are used to simplify the mold manufacturing process. In the first preferred embodiment, the plurality of the fourth connecting portions  627  are embedded in the fourth lacking grooves  617  of the fourth fastening portions  611  and the third bending portions  613  of the plurality of the fourth terminals  61 . A middle of the top surface of the fourth surrounding portion  620  of the fourth base body  62  extends upward to from a third fastening pillar  6201 . The third fastening pillar  6201  is used for fastening the fourth metal plate  63 . The third fastening pillar  6201  is corresponding to a corresponding fifth perforation  637  of the fourth metal plate  63 . 
     The fourth metal plate  63  is disposed in the fourth fastening groove  623  of the fourth base body  62 . The plurality of the fourth terminals  61  are mounted under the fourth metal plate  63 . The fourth metal plate  63  has a rectangular fourth main sheet  631 , a plurality of fourth inclining sheets  632 , a plurality of fourth contact sheets  633 , a plurality of fourth covering sheets  635  and two fourth restricting portions  636 . 
     A position of the fourth main sheet  631  is corresponding to a position of the fourth surrounding portion  620  of the fourth base body  62 . The plurality of the fourth contact surfaces  625  abut against a front edge and a rear edge of the fourth main sheet  631 . In the concrete implementation, the fourth main sheet  631  is directly fastened to the fourth surrounding portion  620  of the fourth base body  62 . Two opposite sides of the fourth main sheet  631  form two fourth flank sheets  634 . Each fourth flank sheet  634  is wavy. Each fourth flank sheet  634  has the plurality of the fourth inclining sheets  632 , the plurality of the fourth contact sheets  633  and the plurality of the fourth covering sheets  635 . 
     The two opposite sides of the fourth main sheet  631  slantwise extend outward and downward to form two of the plurality of the fourth inclining sheets  632 . The two of the plurality of the fourth inclining sheets  632  are corresponding to two outer surfaces of the fourth surrounding portion  620  of the fourth base body  62 . The two of the plurality of the fourth inclining sheets  632  are covered to the two outer surfaces of the fourth surrounding portion  620  of the fourth base body  62 . Two outer edges of the two of the plurality of the fourth inclining sheets  632  horizontally extend outward to form two fourth contact sheets  633 . Each fourth contact sheet  633  and the fourth main sheet  631  are horizontally disposed. Each fourth contact sheet  633  is parallel to the fourth main sheet  631 . Two outer edges of the two fourth contact sheets  633  slantwise extend outward and upward to form another two of the plurality of the fourth inclining sheets  632 . The another two of the plurality of the fourth inclining sheets  632  of the two outer edges of the two fourth contact sheets  633  are opposite to each other. Two outer edges of the another two of the plurality of the fourth inclining sheets  632  horizontally extend outward to form two fourth covering sheets  635 . Each fourth covering sheet  635  and the fourth main sheet  631  are horizontally disposed. Each fourth covering sheet  635  and the fourth main sheet  631  are disposed at the same level. Two outer edges of the two fourth covering sheets  635  slantwise extend outward and downward to form two extra fourth inclining sheets  632 . Two outer edges of the two extra fourth inclining sheets  632  horizontally extend oppositely to form another two fourth contact sheets  633 . Two outer edges of the another two fourth contact sheets  633  slantwise extend outward and upward to form two additional fourth inclining sheets  632 . Two outer edges of the two additional fourth inclining sheets  632  horizontally extend outward to form another two fourth covering sheets  635 . Two outer edges of the another two fourth covering sheets  635  slantwise extend outward and downward to form two other fourth inclining sheets  632 . Two outer edges of the two other fourth inclining sheets  632  horizontally extend outward to form two outermost fourth contact sheets  633 . 
     The two opposite sides of the fourth main sheet  631  meander outward to form the fourth inclining sheets  632 , the fourth contact sheets  633  and the fourth covering sheets  635  of the two fourth flank sheets  634  according to a quantity of the plurality of the fourth terminals  61 . In the first preferred embodiment, each fourth flank sheet  634  of the fourth metal plate  63  has five fourth inclining sheets  632 , three fourth contact sheets  633  and two fourth covering sheets  635 , so the fourth metal plate  63  has one fourth main sheet  631 , ten fourth inclining sheets  632 , six fourth contact sheets  633  and four fourth covering sheets  635 . Two opposite side edges of each fourth covering sheet  635  slantwise extend downward and sideward to form the two fourth inclining sheets  632 . The two fourth inclining sheets  632  of each fourth covering sheet  635  are connected with two of the plurality of the fourth contact sheets  633 . The two fourth inclining sheets  632  of each fourth covering sheet  635  are opposite to each other. Each two fourth inclining sheets  632  of the fourth metal plate  63  are opposite to each other. 
     From an inner side of each fourth flank sheet  634  to an outer side of each fourth flank sheet  634 , each fourth flank sheet  634  sequentially has the fourth inclining sheet  632  connected with one side of the fourth main sheet  631 , the fourth contact sheet  633  connected with the outer edge of the fourth inclining sheet  632  which is connected with the one side of the fourth main sheet  631 , the fourth inclining sheet  632  connected with the outer edge of the fourth contact sheet  633 , the fourth covering sheet  635  connected with the outer edge of the fourth inclining sheet  632  which is connected with the outer edge of the fourth contact sheet  633 , the fourth inclining sheet  632  connected with the outer edge of the fourth covering sheet  635 , the fourth contact sheet  633  connected with the outer edge of the fourth inclining sheet  632  which is connected with the outer edge of the fourth covering sheet  635 , the fourth inclining sheet  632  connected with the outer edge of the fourth contact sheet  633 , the fourth covering sheet  635  connected with the outer edge of the fourth inclining sheet  632  which is connected with the outer edge of the fourth contact sheet  633 , the fourth inclining sheet  632  connected with the outer edge of the fourth covering sheet  635 , and the fourth contact sheet  633  connected with the outer edge of the fourth inclining sheet  632 . 
     Referring to  FIG.  7    and  FIG.  29   , the fourth contact sheets  633  of the fourth metal plate  63  contact with the fourth fastening portions  611  of the plurality of the fourth grounding terminals  615  of the plurality of the fourth terminals  61  of the two sides of the fourth terminal assembly  6  to form the grounding structure  90 . In this way, the signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained for improving the transmission quality of the high-frequency signal. The fourth covering sheets  635  of the fourth metal plate  63  keep distances from the fourth fastening portions  611  of the fourth differential signal terminals  616  of the fourth terminal assembly  6 . 
     Two middles of two opposite outer sides of the two outermost fourth contact sheets  633  of the fourth metal plate  63  slantwise extend outward and upward, and then are bent outward to form the two fourth restricting portions  636 . A quantity of the fourth restricting portions  636  of the fourth metal plate  63  are the same as a quantity of the fourth restricting holes  626  of the fourth base body  62 . The two fourth restricting portions  636  are buckled in the two fourth restricting holes  626 , so the fourth metal plate  63  is fastened in the fourth base body  62 . A middle of the fourth main sheet  631  of the fourth metal plate  63  has the fifth perforation  637  vertically penetrating through a top surface and a bottom surface of the fourth main sheet  631 . The third fastening pillar  6201  of the fourth surrounding portion  620  of the fourth base body  62  is fastened in the fifth perforation  637 , so that the fourth metal plate  63  is located to the fourth base body  62 , and the fourth metal plate  63  is fastened to the fourth base body  62 . 
     Referring to  FIG.  27    to  FIG.  31   , the second sheet structure  64  is formed by the plastic injection molding technology. The second sheet structure  64  is located in the second locating groove  205 . An inner surface of the second sheet structure  64  has a plurality of fourth attaching surfaces  641 . Several portions of two sides of a top surface of the second sheet structure  64  protrude upward to form the plurality of the fourth attaching surfaces  641 . In the first preferred embodiment, the plurality of the fourth attaching surfaces  641  are corresponding to bottom surfaces of the fourth fastening portions  611  of the fourth grounding terminals  615  of the two sides of the fourth terminal assembly  6 . The plurality of the fourth attaching surfaces  641  contact with the bottom surfaces of the fourth fastening portions  611  of the fourth grounding terminals  615  of the two sides of the fourth terminal assembly  6 . 
     The second sheet structure  64  is spaced from the fourth metal plate  63 . The fourth covering sheets  635  of the fourth metal plate  63  are spaced from the inner surface of the second sheet structure  64  to form a plurality of fourth internal spaces  642 . Each fourth internal space  642  is formed between the second sheet structure  64  and one fourth covering sheet  635  of the fourth metal plate  63 . The fourth contact sheets  633  of the fourth metal plate  63  are corresponding to the plurality of the fourth attaching surfaces  641  of the second sheet structure  64 . The fourth fastening portions  611  of each two fourth differential signal terminals  616  of the two sides of the fourth terminal assembly  6  pass through one fourth internal space  642 . Bottom surfaces of the fourth fastening portions  611  of each two fourth differential signal terminals  616  of the two sides of the fourth terminal assembly  6  are spaced from the inner surface of the second sheet structure  64  to form a second clearance  643 . A plurality of the second clearances  643  are formed between the fourth terminal assembly  6  and the inner surface of the second sheet structure  64 . The fourth internal space  642  and the plurality of the second clearances  643  of the second sheet structure  64  are used for adjusting the dielectric coefficient of a peripheral structure of each fourth terminal  61  of the high-speed connector  100  to improve the electromagnetic characteristic and the crosstalk interference of the high-speed connector  100 . 
     In the concrete implementation, according to a whole structure adjustment of the fourth terminal assembly  6 , a size of the second clearance  643  is changed, and the second clearance  643  is even canceled. An outer surface of the second sheet structure  64  extends outward to form a second strengthening structure  644 . The second strengthening structure  644  is used for reinforcing a structural strength of the second sheet structure  64 . In the first preferred embodiment, two sides of the second strengthening structure  644  are shown as the two cross structures from an upward view to reinforce the structural strength of the second sheet structure  64 . 
     Referring to  FIG.  3    to  FIG.  31   , in the first preferred embodiment, the first holding element  35  of the first terminal assembly  3  abuts against a rear end of the second holding element  55  of the third terminal assembly  5 . The rear end of the fourth base body  62  abuts against a front end of the second holding element  55  of the third terminal assembly  5 . The bottom surface of the third base body  52  of the third terminal assembly  5  abuts against the top surface of the front end of the fourth base body  62  of the fourth terminal assembly  6 . The bottom surface of the front end of the fourth base body  62  of the fourth terminal assembly  6  abuts against a top surface of the rear end of the second base body  42  of the second terminal assembly  4 . 
     Referring to  FIG.  1   ,  FIG.  32    and  FIG.  33   , a high-speed connector  200  in accordance with a second preferred embodiment of the present invention is shown. Differences between the high-speed connector  100  in accordance with the first preferred embodiment and the high-speed connector  200  in accordance with the second preferred embodiment are described as follows. 
     In the second preferred embodiment, the fourth terminal assembly  6  further includes a metal structure  65 . The metal structure  65  is disposed in a front of the rear end of the fourth base body  62 . The metal structure  65  is disposed in front of the third bending portions  613  of the plurality of the fourth terminals  61 . The metal structure  65  has a main plate  651 , a plurality of inclining plates  652 , a plurality of contacting plates  653 , a plurality of covering plates  655  and a locating plate  656 . Specifically, the metal structure  65  has two locating plates  656 . 
     The main plate  651  is disposed corresponding to the third bending portions  613  of the fourth terminals  61  of a middle of the fourth terminal assembly  6 . The main plate  651  is located in front of the third bending portions  613  of the fourth terminals  61  of the middle of the fourth terminal assembly  6 . Two opposite sides of the main plate  651  form two lateral plates  654 . Each lateral plate  654  is wavy. Each lateral plate  654  has the plurality of the inclining plates  652 , the plurality of the contacting plates  653  and the plurality of the covering plates  655 . 
     The two opposite sides of the main plate  651  slantwise extend outward and rearward to form two of the plurality of the inclining plates  652 . Two outer edges of the two of the plurality of the inclining plates  652  horizontally extend outward to form two contacting plates  653 . Each contacting plate  653  and the main plate  651  are horizontally disposed. Each contacting plate  653  is parallel to the main plate  651 . Two outer edges of the two contacting plates  653  slantwise extend outward and frontward to form another two of the plurality of the inclining plates  652 . The another two of the plurality of the inclining plates  652  of the two outer edges of the two contacting plates  653  are opposite to each other. Two outer edges of the another two of the plurality of the inclining plates  652  horizontally extend outward to form two covering plates  655 . Each covering plate  655  and the main plate  651  are horizontally disposed. Each covering plate  655  and the main plate  651  are disposed at the same level. Two outer edges of the two covering plates  655  slantwise extend outward and rearward to form two extra inclining plates  652 . Two outer edges of the two extra inclining plates  652  horizontally extend oppositely to form another two contacting plates  653 . Two outer edges of the another two contacting plates  653  slantwise extend outward and frontward to form two additional inclining plates  652 . Two outer edges of the two additional inclining plates  652  horizontally extend outward to form another two covering plates  655 . Two outer edges of the another two covering plates  655  slantwise extend outward and rearward to form two other inclining plates  652 . Two outer edges of the two other inclining plates  652  horizontally extend outward to form two outermost contacting plates  653 . 
     The two opposite sides of the main plate  651  meander outward to form the inclining plates  652 , the contacting plates  653  and the covering plates  655  of the two lateral plates  654  according to a quantity of the plurality of the fourth terminals  61 . In the second preferred embodiment, each lateral plate  654  of the fifth metal plate  65  has five inclining plates  652 , three contacting plates  653  and two covering plates  655 , so the metal structure  65  has one main plate  651 , ten inclining plates  652 , six contacting plates  653  and four covering plates  655 . Two opposite side edges of each covering plate  655  slantwise extend sideward and rearward to form the two inclining plates  652 . The two inclining plates  652  of each covering plate  655  are connected with two of the plurality of the contacting plates  653 . The two inclining plates  652  of each covering plate  655  are opposite to each other. Each two inclining plates  652  of the metal structure  65  are opposite to each other. 
     From an inner side of each lateral plate  654  to an outer side of each lateral plate  654 , each lateral plate  654  sequentially has the inclining plate  652  connected with one side of the main plate  651 , the contacting plate  653  connected with the outer edge of the inclining plate  652  which is connected with the one side of the main plate  651 , the inclining plate  652  connected with the outer edge of the contacting plate  653 , the covering plate  655  connected with the outer edge of the inclining plate  652  which is connected with the outer edge of the contacting plate  653 , the inclining plate  652  connected with the outer edge of the covering plate  655 , the contacting plate  653  connected with the outer edge of the inclining plate  652  which is connected with the outer edge of the covering plate  655 , the inclining plate  652  connected with the outer edge of the contacting plate  653 , the covering plate  655  connected with the outer edge of the inclining plate  652  which is connected with the outer edge of the contacting plate  653 , the inclining plate  652  connected with the outer edge of the covering plate  655 , and the contacting plate  653  connected with the outer edge of the inclining plate  652 . 
     The contacting plates  653  of the metal structure  65  are connected with front surfaces of the third bending portions  613  of the fourth grounding terminals  615  of the plurality of the fourth terminals  61  of the two sides of the fourth terminal assembly  6  to form the grounding structure  90 . In this way, the signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained for improving the transmission quality of the high-frequency signal. The covering plates  655  of the metal structure  65  keep distances from the third bending portions  613  of the fourth differential signal terminals  616  of the fourth terminal assembly  6 . A top end of the main plate  651  has the locating plate  656 . The front of the rear end of the fourth base body  62  has a third location hole  628  penetrating through a bottom surface of the front of the rear end of the fourth base body  62 . The locating plate  656  is fastened in the third location hole  628 . 
     Specifically, the metal structure  65  has two locating plates  656 , and the fourth base body  62  has two third location holes  628 . The two locating plates  656  are fastened in the two third location holes  628 . 
     Referring to  FIG.  3    to  FIG.  35   , a high-speed connector  300  in accordance with a third preferred embodiment of the present invention is shown. Differences between the high-speed connector  100  in accordance with the first preferred embodiment and the high-speed connector  300  in accordance with the third preferred embodiment are described as follows. 
     In the third preferred embodiment, the fourth terminal assembly  6  further includes a blocking element  66 . The blocking element  66  is disposed in the front of the rear end of the fourth base body  62 . The blocking element  66  is disposed in front of the third bending portions  613  of the plurality of the fourth terminals  61 . An inner surface of the blocking element  66  has a plurality of abutting surfaces  661 . Several portions of two sides of the inner surface of the blocking element  66  protrude rearward to form the plurality of the abutting surfaces  661 . The plurality of the abutting surfaces  661  are corresponding to the front surfaces of the third bending portions  613  of the fourth grounding terminals  615  of the two sides of the fourth terminal assembly  6 . The plurality of the abutting surfaces  661  contact with the front surfaces of the third bending portions  613  of the fourth grounding terminals  615  of the two sides of the fourth terminal assembly  6 . 
     The front surfaces of the third bending portions  613  of each two fourth differential signal terminals  616  of the two sides of the fourth terminal assembly  6  are spaced from the inner surface of the blocking element  66  to form an interstice  662 . A plurality of the interstices  662  are formed between the fourth terminal assembly  6  and the inner surface of the blocking element  66 . The plurality of the interstices  662  are used for adjusting the dielectric coefficient of the peripheral structure of each fourth terminal  61  of the high-speed connector  300  to improve the electromagnetic characteristic and the crosstalk interference of the high-speed connector  300 . An outer surface of the blocking element  66  extends outward to form a third strengthening structure  663 . The third strengthening structure  663  is used for reinforcing a structural strength of the blocking element  66 . In the third preferred embodiment, two sides of the third strengthening structure  663  are shown as two cross structures from a front view to reinforce the structural strength of the blocking element  66 . A distance between the front of the second sheet structure  64  and a front end of the insulating housing  1  is smaller than a distance between the front of the first sheet structure  56  and the front end of the insulating housing  1  along the front-to-rear direction. 
     Referring to  FIG.  1    to  FIG.  35   , in summary, each of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  includes a base body  101 , the plurality of the terminals  102  and a metal plate  103 , the plurality of the terminals  102  include a plurality of grounding terminals  104  and a plurality of differential signal terminals  105 . A surface of the base body  101  is recessed inward to form a fastening groove  106 , the plurality of the terminals  102  are fastened to the base body  101 , the metal plate  103  is fastened in the fastening groove  106 , each terminal  102  has a fastening portion  107 , a contacting portion  108  connected to a front end of the fastening portion  107 , and a soldering portion  109  connected to a rear end of the fastening portion  107 , the base body  101  surrounds the fastening portion  107  of each terminal  102 , the contacting portion  108  of each terminal  102  projects beyond a front surface of the base body  101 , the soldering portion  109  of each terminal  102  is exposed to a rear of the base body  101 , the fastening portions  107  of the plurality of the grounding terminals  104  and the differential signal terminals  105  of two sides of each of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  are exposed outside to the fastening groove  106 , the metal plate  103  electrically contacts with the fastening portions  107  of the plurality of the grounding terminals  104  of the two sides of each of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  to form the grounding structure  90 . 
     Each of the third terminal assembly  5  and the fourth terminal assembly  6  includes a sheet structure  201 , the sheet structure  201  is made of a plastic material, the base body  101  of each of the third terminal assembly  5  and the fourth terminal assembly  6  has a locating groove  202  opposite to the fastening groove  106  of each of the third terminal assembly  5  and the fourth terminal assembly  6 , the fastening portions  107  of the plurality of the grounding terminals  104  and the differential signal terminals  105  of each of the third terminal assembly  5  and the fourth terminal assembly  6  are exposed to the locating groove  202  of each of the third terminal assembly  5  and the fourth terminal assembly  6 , the sheet structure  201  is located in the locating groove  202 , the fastening portions  107  of the plurality of the grounding terminals  104  and the differential signal terminals  105  of each of the third terminal assembly  5  and the fourth terminal assembly  6  are clamped between the metal plate  103  and the sheet structure  201  of each of the third terminal assembly  5  and the fourth terminal assembly  6  along the up-down direction, the fastening portions  107  of the differential signal terminals  105  of each of the third terminal assembly  5  and the fourth terminal assembly  6  are spaced from an inner surface of the sheet structure  201  of each of the third terminal assembly  5  and the fourth terminal assembly  6  to form a clearance  203  between the fastening portions  107  of the differential signal terminals  105  and the inner surface of the sheet structure  201  of each of the third terminal assembly  5  and the fourth terminal assembly  6 , the fastening portions  107  of the grounding terminals  104  of each of the third terminal assembly  5  and the fourth terminal assembly  6  contact with the inner surface of the sheet structure  201  of each of the third terminal assembly  5  and the fourth terminal assembly  6 . 
     The base bodies  101  of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  include the first base body  32 , the second base body  42 , the third base body  52  and the fourth base body  62 . The plurality of the terminals  102  include the plurality of the first terminals  31  of the first terminal assembly  3 , the plurality of the second terminals  41  of the second terminal assembly  4 , the plurality of the third terminals  51  of the third terminal assembly  5  and the plurality of the fourth terminals  61  of the fourth terminal assembly  6 . The metal plates  103  of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  include the first metal plate  33 , the second metal plate  43 , the third metal plate  53  and the fourth metal plate  63 . The plurality of the grounding terminals  104  include the plurality of the first grounding terminals  317 , the second grounding terminals  415 , the third grounding terminals  516  and the fourth grounding terminals  615 . The plurality of the differential signal terminals  105  include the plurality of the first differential signal terminals  318 , the second differential signal terminals  416 , the third differential signal terminals  517  and the fourth differential signal terminals  616 . The fastening grooves  106  of the first terminal assembly  3 , the second terminal assembly  4 , the third terminal assembly  5  and the fourth terminal assembly  6  include the first fastening groove  323 , the second fastening groove  423 , the third fastening groove  523  and the fourth fastening groove  623 . The fastening portions  107  of the plurality of the terminals  102  include the first fastening portions  311  of the plurality of the first terminals  31 , the second fastening portions  411  of the plurality of the second terminals  41 , the third fastening portions  511  of the plurality of the third terminals  51  and the fourth fastening portions  611  of the plurality of the fourth terminals  61 . The contacting portions  108  of the plurality of the terminals  102  include the first contacting portions  313  of the plurality of the first terminals  31 , the second contacting portions  413  of the plurality of the second terminals  41 , the third contacting portions  512  of the plurality of the third terminals  51  and the fourth contacting portions  612  of the plurality of the fourth terminals  61 . The soldering portions  109  of the plurality of the terminals  102  include the first soldering portions  316  of the plurality of the first terminals  31 , the second soldering portions  414  of the plurality of the second terminals  41 , the third soldering portions  515  of the plurality of the third terminals  51  and the fourth soldering portions  614  of the plurality of the fourth terminals  61 . The sheet structures  201  of the third terminal assembly  5  and the fourth terminal assembly  6  include the first sheet structure  56  and the second sheet structure  64 . The locating grooves  202  of the third terminal assembly  5  and the fourth terminal assembly  6  include a first locating groove  204  and a second locating groove  205 . The clearances  203  of the third terminal assembly  5  and the fourth terminal assembly  6  include the first clearance  563  and the second clearance  643 . 
     In the second preferred embodiment, the metal structure  65  is disposed in a front of a rear end of the base body  101  of the fourth terminal assembly  6 . Front surfaces of rear ends of the grounding terminals  104  of the plurality of the terminals  102  of the two sides of the fourth terminal assembly  6  are exposed to the front of the rear end of the base body  101  of the fourth terminal assembly  6 . The contacting plates  653  of the metal structure  65  contact with the front surfaces of the rear ends of the grounding terminals  104  of the plurality of the terminals  102  of the two sides of the fourth terminal assembly  6  to form the grounding structure  90 . 
     In the third preferred embodiment, the blocking element  66  is disposed in the front of the rear end of the base body  101  of the fourth terminal assembly  6 . The front surfaces of the rear ends of the grounding terminals  104  of the plurality of the terminals  102  of the two sides of the fourth terminal assembly  6  are exposed to the front of the rear end of the base body  101  of the fourth terminal assembly  6 . The front surfaces of the rear ends of each two differential signal terminals  105  of the two sides of the fourth terminal assembly  6  are spaced from the inner surface of the blocking element  66  to form the interstice  662 . 
     As described above, the first metal plate  33  of the first terminal assembly  3  contacts with the first grounding terminals  317  of the first terminal assembly  3  to form the grounding structure  90 , the second metal plate  43  of the second terminal assembly  4  contacts with the second grounding terminals  415  of the second terminal assembly  4  to form the grounding structure  90 , the third metal plate  53  of the third terminal assembly  5  contacts with the third grounding terminals  516  of the third terminal assembly  5  to form the grounding structure  90 , and the fourth metal plate  63  of the fourth terminal assembly  6  contacts with the fourth grounding terminals  615  of the fourth terminal assembly  6  to form the grounding structure  90 , so the signal noise is able to be effectively absorbed and the signal noise is able to be effectively restrained. Furthermore, the high-speed connector  100  is capable of adjusting a dielectric coefficient of a peripheral structure of the terminal  102  of the high-speed connector  100 , the first internal space  3414  and the plurality of the first gaps  3415  of the first dielectric structure  34 , the second internal space  5414  and the plurality of the second gaps  5415  of the second dielectric structure  54 , the third internal space  562  and the plurality of the first clearances  563  of the first sheet structure  56 , and the fourth internal space  642  and the plurality of the second clearances  643  of the second sheet structure  64  are used for adjusting the dielectric coefficient of the peripheral structure of each first terminal  31  of the first terminal assembly  3  to improve the electromagnetic characteristic and the crosstalk interference of the high-speed connector  100 . As a result, the transmission quality of the high-frequency signal of the high-speed connector  100  is improved.