Abstract:
An electrical connector includes an insulating housing and a plurality of contacts. The contacts include a plurality of signal contacts arranged in differential signal pairs and a plurality of ground contacts. Differential signal pairs are separated by signal contacts. A first ground bar connects each ground contact to form a first electrical connection. A second ground bar connects each ground contact to form a second electrical connection. The first ground bar is electrically connected to the second ground bar through at least a bridge.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an electrical connector, especially to a high-frequency electrical connector. 
         [0003]    2. Description of the Prior Art 
         [0004]    US Pat. No. US2009/0221165 discloses a high-frequency connector up to 6 Gbps, which comprises a housing loading a plurality of electrical contacts. The electrical contacts include a plurality of signal contacts and a plurality of ground contacts. A shieldless ground coupling assembly places at least a portion of the ground contacts in electrical communication with each other. The only one ground bar fails to meet a high-frequency performance up to 12 Gbps. 
         [0005]    Hence, an electrical connector of a high-frequency performance is desired. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    Accordingly, an object of the present invention is to provide an electrical connector with a high-frequency performance. 
         [0007]    To achieve the above object, an electrical connector comprises an insulating housing and a plurality of contacts. The contacts include a plurality of signal contacts arranged in differential signal pairs and a plurality of ground contacts. Every two adjacent differential signal pairs is separated by a ground contact. A first ground bar connects each ground contact to form a first electrical connection. A second ground bar connects each ground contact to form a second electrical connection. The first ground bar is electrically connected to the second ground bar through at least a bridge. 
         [0008]    Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of an electrical connector assembly in accordance with a preferred embodiment of the present invention; 
           [0010]      FIG. 2  is an exploded perspective view of a first electrical connector of the assembly as shown in  FIG. 1 ; 
           [0011]      FIG. 3  is a perspective view of contacts and two ground bars of the first electrical connector in  FIG. 2 ; 
           [0012]      FIG. 4  is a perspective view of the ground bars; 
           [0013]      FIG. 5  is a cross sectional view of the first electrical connector taken along lines  5 - 5  in  FIG. 1 ; 
           [0014]      FIG. 6  is a partially exploded view of the second electrical connector; and 
           [0015]      FIG. 7  is a cross sectional view of the second electrical connector taken along lines  7 - 7  in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    Reference will now be made to the drawing figures to describe the preferred embodiment of the present invention in details.  FIG. 1  illustrates an electrical connector assembly  1000  to transmit high frequency signals, which comprises a first electrical connector  100  in a plug connector type and a second electrical connector  200  in a receptacle connector type, mating with each other along a mating direction. The first electrical connector  100  comprises an insulating housing  10  and several plug contacts  20  loaded in the insulating housing  10 . The second electrical connector  200  comprises an insulating housing  30  and a plurality of receptacle contacts  40  loaded in the insulating housing  30 . The first electrical connector  100  defines a mating tongue  11  intending to be inserted into a mating slot  31  defined by the second electrical connector  200 . A pair of guiding posts  32  of the second electrical connector  200  is guided into a corresponding pair of U shaped guiding recesses  12  of the first electrical connector  100 . 
         [0017]    Referring to  FIG. 2  to  FIG. 3 , the mating tongue  11  extends from a base  13  of the insulating housing  10  along the mating direction and a lengthwise direction perpendicular to the mating direction. The mating tongue  11  defines an upper face  111 , an opposite lower face  112  and a protrusion  113  on the upper face  111 . The upper face  111  is divided into a first area  111   a  and a second area  111   b  by said protrusion  113 . The plug contacts  20  are of plate form, each has a contacting portion  21  embedded in the mating tongue  11 , a retaining portion  22  retained in the mating tongue or/and base  13  and a leg portion  23  extending out of a rear face of the base  13 . The retaining portion  22  joints the contacting portion  21  and the soldering portion  23 . The first contacts  20  are arranged into three groups  20   a,    20   b,    20   c  along the mating tongue  11 . The contacting portions  21   a,    21   b  of the first and second groups  20   a,    20   b  of the contacts are located at the first and second areas  111   a,    111   b  of the upper face  111 . The contacting portions  21   c  of the third group  20   c  of contacts are located at the lower face  112  and corresponding to the protrusion  113 . The first and third groups of contacts  20   a,    20   c  are used to transmit data signals while the second group of contacts  20   b  is used to transmit power signals. 
         [0018]    Each of the first and third groups  20   a,    20   c  of contacts includes two pairs of differential signal pair  241  and three individual ground contacts  242  separating two pairs of the signal pair. Combination with  FIGS. 3 and 4 , a first ground bar  25  and a second ground bar  26  are provided to connect the individual ground contacts  241 , the first ground bar  25  includes a beam  251  and a plurality of first elastic arms  252   a  and second elastic arms  252   b.  The second ground bar  26  includes a beam  261  and a plurality of first elastic arms  262   a  and second elastic arms  262   b.  The first and second ground bars are retained in the insulating housing, the first ground bar  25  is loaded in the mating tongue  11  and the second ground bar  26  is retained in the base  13 . The first elastic arms  252   a,    262   a  of the first and second ground bars  25 ,  26  touch the contacting portions  21   a,    21   c  of the contacts  20   a,    20   c.  The second elastic arms  252   b,    262   b  of the first and second ground bars  25 ,  26  touch the retaining portions  22   a,    22   c  of the contacts  20   a,    20   c.  The first elastic arms  252   a,    262   a  each defines a downward opening  253  while the second elastic arms  252   b,    262   b  each defines an upward opening  263 . The elastic arms  252   a,    252   b  of the first ground bar  25  are symmetric to the elastic arms  262   a,    262   b  of the second ground bar  26  with respect to an invisible line. The first ground bar  25  is also symmetric to the second ground bar  26  with respect to said invisible line. 
         [0019]    The first ground bar  25  is electrically connected to the second ground bar  26  via two bridges  24  so as to form a closed circuit. The closed circuit can decrease voltage distribution among the elastic arms or among ground contacts. The crosstalk between the differential pairs will be reduced because of little voltage distribution. The two bridges are parallel to each other. One bridge is also acceptable and the high-frequency performance may be little worse than two bridges. Please mention that the bridges won&#39;t align with the third group  20   c  of contacts from a top-to-bottom view for little pitch between adjacent contacts. 
         [0020]    A spacer  27  is provided to used to retain the soldering portions of the first series of contacts  20   a.  The retaining elements  28  are attached to a PCB after being assembled to the insulating housing  10 . 
         [0021]    The second electrical connector  200  comprises insulating housing  30 , contacts  40  assembled on the insulating housing. A first ground bar  50  includes several elastic arms connecting retaining portions of the ground contacts of a group of contacts  40   c.  A second ground bar  60  includes several plate-shaped bridges  61  connecting the first ground bar  50 . When the first electrical connector  100  mates with the electrical second connector  200 , the contacting portions  41  c of the second electrical connector will be deformed by the contacting portions  21  c of the first electrical connector and touch the bridges  61 . It is noted that the housing  30  is composed of two opposite side walls sandwiching the mating slot  31  therebetween wherein one of the side walls defines a cutout without the contacts  40  therein while the other of the side walls has the contact  40  located only vertically in alignment with the cutout. In addition, the side wall having the cutout defines an outwardly protruding region on an exterior surface in alignment with the cutout along the vertical direction while the side wall without said cutout defines an even exterior surface thereof 
         [0022]    While preferred embodiments in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as defined in the appended claims.