Abstract:
An electrical connector assembly, comprising: a housing with an interior section, a front and a rear; a plurality of first contacts, and a plurality of second contacts. The first contacts have mating sections extending into the interior section and directed towards the rear of the housing. The second contacts have mating sections extending into the interior section and directed towards the front of the housing. The second contacts occupy three of the eight positions in the housing. In a modular jack arrangement, the second contacts occupy positions  3  and  5 , and either position  1  or position  7 . Cross-talk between the contacts is thereby reduced.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 09/024,588, filed on Feb. 17, 1998, which is a continuation of U.S. patent application Ser. No. 08/643,241, filed on May 02, 1996 and now U.S. Pat. No. 5,759,070, which is a continuation-in-part of U.S. patent application Ser. No. 08/346,640, filed on Nov. 30, 1994 and now U.S. Pat. No. 5,599,209, each herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical connectors and more particularly to modular jacks for use in telecommunications equipment. 
     2. Brief Description of Earlier Developments 
     Modular jacks are used in two broad categories of signal transmission: analog (voice) and digital (data) transmission. These categories can overlap somewhat since digital systems are used for voice transmission as well. Nevertheless, there is a significant difference in the amount of data transmitted by a system per second. A low speed system would ordinarily transmit from about 10 to 16 megabits per second (Mbps), while a high speed system should be able to handle 155 Mbps or even higher data transfer speeds. Often, high speed installations are based on asynchronous transfer mode transmission and utilize shielded and unshielded twisted pair cables. 
     With recent increases in the speed of data transmission, requirements have become important for electrical connectors, in particular, with regard to the reduction or elimination of crosstalk. Crosstalk is a phenomena in which a part of the electromagnetic energy transmitted through one of multiple conductors in a connector causes electrical currents in the other conductors. 
     Another problem is common mode electromagnetic interference or noise. Such common mode interference is often most severe in conductors of the same length, when a parasitic signal induced by ESD, lightning or simultaneous switching of semiconductor gates arrives in an adjacent electrical node through multiple conductors at the same time. 
     Another factor which must be considered is that the telecommunications industry has reached a high degree of standardization in modular jack design. Outlines and contact areas are essentially fixed and have to be interchangeable with other designs. It is, therefore, important that any novel modular jack allow with only minor modification, the use of conventional parts or tooling in its production. 
     There is, therefore, a need for a modular jack which will reduce or eliminate crosstalk in telecommunications equipment. 
     There is also a need for a modular jack which will reduce or eliminate common mode electromagnetic interference in telecommunications equipment. 
     There is also a need for such a modular jack which can reduce or eliminate crosstalk and common mode interference which is interchangeable with prior art modular jacks and which may be manufactured using conventional parts and tooling. 
     SUMMARY OF THE INVENTION 
     The present invention reduces, or eliminates, cross-talk and common mode electromagnetic interference by means of the following factors: 
     (a) the conductors are separated into two groups and each of these groups is positioned in a distinct separate area in the modular jack; 
     (b) the distance between adjacent conductors is increased; 
     (c) the common length between adjacent conductors is reduced; and 
     (d) adjacent conductors of significantly different lengths are used. 
     The present invention could be achieved by an electrical connector assembly, comprising: a housing with an interior section, a front and a rear; a plurality of first contacts, and a plurality of second contacts. The contacts occupy eight positions in the housing. The first contacts have mating sections extending into the interior section and directed towards the rear of the housing. The second contacts have mating sections extending into the interior section and directed towards the front of the housing. The second contacts occupy three of the eight positions. 
     The present invention could also be achieved by an electrical connector assembly, comprising: a housing with an interior section, a front and a rear; a plurality of first contacts; and a plurality of second contacts. The first contacts have mating sections extending into the interior section and directed towards the rear of the housing. The second contacts have mating sections extending into the interior section and directed towards the front of the housing. The first contacts and the second contacts occupy positions in the housing designated  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  and  8  across the housing. The second contacts occupy positions  3  and  5 , and either position  1  or position  7 . 
     The present invention could also be achieved by a modular jack assembly that receives another connecting element having contacts for signal transmission so as to reduce crosstalk during such signal transmission. The assembly includes: an outer insulative housing; a first plurality of generally parallel contacts; a second plurality of generally parallel contacts; and an insulative insert. The outer insulative housing has top and bottom walls and opposed lateral walls all defining an interior section. The housing also has front and rear open ends. The first plurality of generally parallel contacts extend from the bottom wall of the insulative housing across the rear end to the top wall and then toward the front end in a common plane then toward the rear end in a common oblique plane. The second plurality of generally parallel contacts extend from the bottom wall of the insulative housing across only a part of the rear end in a common plane and then angularly toward the front end in a common oblique plane. The portions of both of said first and second pluralities of contacts that are located in said oblique planes are positioned for engaging the contacts of said other connecting element when said other connecting element is inserted into the front open end of the housing for signal transmission. The first plurality of contacts are at least partially positioned in the insulative insert. The insert has an upper section having base and upper sides and rear and terminal ends and is positioned so that its base side is superimposed over the rear open end of the insulative housing and its upper end is adjacent the top side of the insulative housing such that its terminal end extends into the interior section of the insulative housing. The insulative insert has opposed lateral sides and the contacts are arranged in a numerical sequence from one of said lateral sides to the other of said lateral sides in a plurality of positions designated  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  and  8  and the first plurality of contacts are in positions  1 ,  2 ,  4 ,  5 ,  6  and  8  and the second plurality of contacts are in positions  3 ,  5  and  7 . Cross-talk between the contacts is thereby reduced. 
     Another modular jack which may be used to practice the method of this invention has an outer insulated housing having top and bottom walls and opposed lateral walls and front and rear open ends. A first plurality of conductive means extend in a common vertical plane from the bottom wall of the housing across the open rear end to the top wall and then extend horizontally forward and then angularly downwardly and rearwardly back toward the rear open end. A second plurality of conductive means extends first in a common vertical plane from the bottom wall across only a part of the rear open end and then extends obliquely, horizontally and upwardly toward the open front end. The downwardly extending oblique plane of the first plurality of conductive means and upwardly extending oblique plane of the second plurality of conductive means have a common length but that common length is small preferably being between 0.8 inch to 1.0 inch while the length of the horizontal section of the first group of conductive means is relatively much longer being preferably 0.6 inch to 2.0 inch. 
     Also encompassed within the invention is an insert for a modular jack assembly comprising an insulative member comprising a lower section having a base side and opposed front and rear sides and an upper section. The upper section has an upper side, a lower side and a terminal end interposed between said upper and said lower side. The upper section is superimposed over said lower section and extends from the lower side perpendicularly to said terminal ends. A first wire extends from adjacent the base side of the lower section longitudinally through the lower section and transversely through the upper section. It then extends perpendicularly adjacent the upper side of the upper section. A second wire extends from adjacent the base side of the lower section longitudinally through only part of the lower section and then angularly through the front side of the lower section. A third wire extends from adjacent the base side of the lower section longitudinally through the lower section and transversely across the upper section. It then extends perpendicularly adjacent the upper side of the upper section wherein said third conductive means at least at some point extends angularly away from said first wire. Surprisingly and unexpectedly low cross talk is achieved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other uses and advantages of the present invention will become apparent to those skilled in the art upon reference to the specification and the drawings, in which: 
     FIG. 1 is a front end view of the preferred embodiment of the modular jack assembly of the present invention; 
     FIG. 2 is a rear end view of the modular jack assembly shown in FIG. 1; 
     FIG. 3 is a cross sectional view taken through line III—III in FIG. 5; 
     FIG. 4 is a top plan view of the modular jack assembly shown in FIG. 1; 
     FIG. 5 is a bottom plan view of the modular jack assembly shown in FIG. 1; 
     FIG. 6 is a perspective view of the insulated insert element of the modular jack assembly shown in FIG. 1; 
     FIG. 7 is a perspective view of the wire retaining element of the modular jack assembly shown in FIG. 1; 
     FIG. 8 is a perspective view of the grounding strip element of the modular jack assembly shown in FIG. 1; 
     FIG. 9 is the schematic view of the modular jack assembly similar to FIG. 3 in which common planes of the groups are illustrated; 
     FIG. 10 is a side elevational view of an insulated insert representing another preferred embodiment of the present invention; 
     FIG. 11 is a top plan view of the part of the insulated insert shown in FIG. 10; 
     FIG. 12 is a bottom plan view of the insulated insert shown in FIG. 10; 
     FIG. 13 is a front view of the insulated insert shown in FIG. 10; and 
     FIG. 14 is a cross sectional view through XIV—XIV in FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings FIGS. 1-9, the outer insulative housing is shown generally at numeral  10 . This housing includes a top wall  12 , a bottom wall  14  and a pair of opposed lateral walls  16  and  18 . The material from which the housing is constructed is a thermoplastic polymer having suitable insulative properties. Within these walls is an interior section  20  which has a rear open end  22  and a forward open end  24 . Projecting upwardly from the bottom wall in this interior section there is a medial wall generally shown at numeral  26  which has a rear side  28 , a front side  30  and an inclined top side  32  which slopes upwardly and forwardly from its rear side toward its front side. Adjacent to the lateral walls, the medial lateral extensions  34  and  36  which serve as projections to retain other elements as will be hereafter explained. Interposed between these lateral extensions there are a plurality of wire separation extensions as at  38 ,  40  and  42  and between these wire separation extensions there are plurality of slots at  44  and  46 . 
     Extending downwardly from the bottom wall there are a pair of pins  48  and  49  and a pair of stand-offs  50  and  51 . In the bottom wall of the insulative housing there is also a front slot  52 . The lateral wall  16  includes a lower shoulder  54 , another shoulder  56 , a lower main wall  58 , an upper main wall  60  and a recessed wall  62  interposed between the lower and upper main wall. It will be seen that the lateral wall  18  has substantially identical features as lateral wall  16 . Referring particularly to FIGS. 3 and 6, the insulative insert shown generally at numeral  64  may be considered to be comprised of an upper section  66  and a lower section  68 . Although the embodiment shown in FIG. 3 displays these sections making up one integral insert, it will be understood that the insert may comprise two separate upper and lower sections or only an upper section may be used as shown in FIG.  6 . The upper section includes a base side  70 , an upper side  72 , a rear end  74  and a terminal end  76 . On the upper side there are a plurality of upper side grooves as at  78  and at the terminal end there are terminal end grooves as at  80 . The lower section includes a bottom end  82  a top end  84  a front side  86  and a rear side  88 . On this rear side there are a plurality of vertical grooves as at  90  which adjoin the grooves on the upper side of the upper section. The insulated insert is superimposed over a conductive wire retaining element  92  which engages one group of wires as is explained hereafter. Another group of wires is engaged by a grounding strip  94  having a grounding tab  96  as is also explained hereafter. 
     In a first common plane there is a first group of wires  98 ,  100 ,  102  and  104 . There is also a second group of wires in a common plane which is made up of wires  106 ,  108 ,  110  and  112 . It will be seen that the first group of wires are in a common first plane shown generally at  114 . In this first plane there is a vertical section  116  in which the wires extend upwardly from a point beneath the bottom wall of the insulated housing and from that bottom wall to the top wall of the insulated housing from where they extend horizontally toward the front end of the housing in horizontal section  118  of the plane and then extend rearwardly and downwardly toward the rear end of the housing in angular oblique section of the plane  120 . It will be noted that there is an angle al between the horizontal and oblique sections of the plane and that the horizontal section has a distance L. It will also be observed that the angular oblique section of the plane ends in terminal edge  122 . The second group of wires is in a second plane shown generally at numeral  124 . In this plane the wires extend first upwardly from below the bottom wall of the housing in a common vertical section of the plane  126 . Before reaching the top wall of the housing and preferably at a point medially between the bottom and top wall, the wires in the second plane extend forwardly and upwardly into the interior of the housing in angular oblique section  128  of the second plane. This oblique section ends in a terminal edge  130 . This common plane includes wires  106 ,  108 ,  110  and  112 . It will be noted that there is an angle a 2  between the vertical section and the oblique section of the second plane. It will also be noted that there is a distance g which is the longitudinal distance between the terminal edges of the first plane and the second plane. It will also be noted that in both the first plane and the second plane there is uniform distance between adjacent wires in the first group and the second group of wires which is shown, for example, as d 1  in the first group of wires and d 2  in the second group of wires. The distance between the vertical sections of the first and second planes is shown as d 3 . The distance between the oblique sections of the first and second planes is shown as d 4 . Preferably, the distance L is from 0.2 inch to 2.0 inch and the distance g is from 0.2 inch to 1.0 inch while the distances d 1  and d 2  are from 0.040 inch to 0.250 inch, d 3  is from 0.040 inch to 0.200 inch, and d 4 is from  0.0 inch to 0.3 inch. Angle a 1  will preferably be from 15° to 70°, and angle a 2  will preferably be 105° to 160°. The wires will preferably be from 0.01 inch to 0.05 inch in diameter. The overall lengths of the wires in the first plane will be from 1.0 inch to 3.0 inch, and the overall lengths of the wires in the second plane will be from 0.5 inch to 1.5 inch. 
     EXAMPLE 
     Four modular jacks were manufactured according to the following description. The overall lengths of the wires in the first group was 1.75 inch. The overall lengths of the wires in the second group was 0.75 inch. Eight wires were arranged in substantially the same pattern as is shown in FIG.  5 . For the purpose of this description the positions shown in FIG. 5 will be referred to as shown in the following Table 1. 
     
       
         
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
             
               
                   
                 WIRE I 
                 - 
                 106 
               
               
                   
                 WIRE 2 
                 - 
                  98 
               
               
                   
                 WIRE 3 
                 - 
                 108 
               
               
                   
                 WIRE 4 
                 - 
                 100 
               
               
                   
                 WIRE 5 
                 - 
                 110 
               
               
                   
                 WIRE 6 
                 - 
                 102 
               
               
                   
                 WIRE 7 
                 - 
                 112 
               
               
                   
                 WIRE 8 
                 - 
                 104 
               
               
                   
                   
               
             
          
         
       
     
     One jack (JACK  1 ) was manufactured in the conventional manner so that all the wires extended vertically from the bottom wall of the housing then horizontally forward then downwardly and rearwardly back toward the rear open end. In the other three jacks, made within the scope of this invention, two to four wires were positioned generally as described above in the second plane as at numeral  124  in FIG.  9 . The other wires extended upwardly, horizontally then downwardly and rearwardly generally as in the first plane  114  in FIG. 9 or in a plane parallel to such a plane. The specific positioning of the wires is shown according to the following Table 2. 
     
       
         
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                 WIRES IN 
                   
               
               
                   
                 FIRST PLANE OR 
                 WIRES IN 
               
               
                 JACK 
                 PARALLEL TO 
                 SECOND PLANE 
               
               
                   
               
             
             
               
                 1 
                 1-8 
                 NONE 
               
               
                 2 
                 1, 3, 5, 7    
                 2, 4, 6, 8 
               
               
                 3 
                 1, 2, 4, 6, 7, 8 
                 3, 5    
               
               
                 4 
                 1, 2, 4, 6, 8   
                 3, 5, 7   
               
               
                   
               
             
          
         
       
     
     In all the jacks the length L was 0.6 inch, and angle al was 30°. In JACKS  2 ,  3  and  4  the length g was 0.4 inch and angle a 2  was 120°. The distances between wires in each row (d 1  and d 2 ) was 0.100 inch in all the jacks. The distance between the rows (d 3 ) was 0.100 inch in all the jacks. The transverse distance between the oblique planes of wires (d 4 ) in JACK  2 , JACK  3  and JACK  4  was 0.020 inch. In all the jacks the wires were 0.020 inch in diameter and had an overall length of about 1.75 inch for wires positioned in the first plane and about 0.75 inch for wires positioned in the insulative housing. The insulative housing and insulative insert were a polyester resin. The following test was performed on these modular jacks. 
     COMPARATIVE TEST 
     Transmission performance of connecting hardware for UTP cabling (without cross-connect jumpers or patch cords) was determined by evaluating its impact upon measurements of attenuation, NEXT loss and return loss for a pair of 100Ω balanced 24 AWG (0.02 inch) test leads. After calibration, reference sweeps were performed, the test leads and impedance matching terminations were connected to the test sample and connector transmission performance data was collected for each parameter. With the network analyzer calibrated to factor out the combined attenuation of the baluns and test leads; 100Ω resistors were connected across each of the two balanced outputs of the test baluns. In order to minimize inductive effects, the resistor leads were kept as short as possible (0.2 inch or less per side). The cable pairs were positioned such that they are sequenced  1 &amp; 2 ,  3 &amp; 6 ,  4 &amp; 5  and  7 &amp; 8  respectively. To prevent physical invasion between pairs under the jacket when the plug was crimped, the side-by-side orientation of the test leads extended into the jacket a distance of at least 0.3 inch, creating a flat portion. The flat, jacketed portion of the test leads appeared to be oblong in cross-section. To measure a telecommunications outlet/connector, the plug was then mated with the test jack and NEXT loss measurements were performed. Results of this test were shown in the attached Table 3. 
     
       
         
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 CROSSTALK BETWEEN WIRES (dB) 
               
             
          
           
               
                 JACK 
                 1 &amp; 2 
                 1 &amp; 3 
                 1 &amp; 4 
                 2 &amp; 3 
                 2 &amp; 4 
                 3 &amp; 4 
               
               
                   
               
               
                 1 
                 −32.9 
                 −43.0 
                 −47.0 
                 −42.0 
                 −41.7 
                 −52.0 
               
               
                 2 
                 −40.5 
                 −41.7 
                 −41.2 
                 −50.4 
                 −44.6 
                 −52.3 
               
               
                 3 
                 −40.8 
                 −41.7 
                 −50.8 
                 −52.0 
                 −42.5 
                 −80.4 
               
               
                 4 
                 −40.6 
                 −48.4 
                 −46.6 
                 −44.6 
                 −54.0 
                 −80.6 
               
               
                   
               
             
          
         
       
     
     From the foregoing Example and Comparative Test, it will be appreciated that it may be advantageous to construct a jack of the present invention so that at least one wire may extend vertically through the lower vertical section of the second plane and continue to extend vertically to the top wall and then extend horizontally adjacent the top wall and then downwardly and rearwardly toward the rear open end. Examples of such wires would be wires  1  and  7  in JACK  3  and wire  1  in JACK  4 . 
     Referring to FIGS. 10-14 an insulative insert shown generally at numeral  200  which represents another preferred embodiment of this invention. This insert may be used with a housing as was described above or with any other suitable housing of which those skilled in the art will be aware. This insert includes wires  201 - 208  which are in pos.  1 -pos. 8  as is particularly shown in FIG.  12 . In addition to the conductive members as described above the insulative insert includes an insulative member shown generally at numeral  210 . This insulative member is generally comprised of a lower section  212  and an upper section  214 . The lower section has a base side  216 , a front side  218  and a rear side  220 . The upper section has an upper side  222 , a lower side  224  and a terminal end  226  interposed between the upper and lower sides. 
     There is also a cutaway area  228  on the rear side of the insulative member. At the base of this cutaway area there is an exposed section  230  and opposed outwardly sloping sides  232  and  234 . Because of this cutaway, section wires  202  and  204  are exposed and diverge from one another in a common vertical plane in sections  236  and  238 . It will be understood that below exposed area  230  that these wires extend in a common vertical plane in essentially parallel relation. 
     On reaching the upper side of the upper section  214 . wires  202  and  204  enter, respectively, grooves  240  and  242  and follow an outwardly bowed arcuate path in sections  244  and  245  and then a converging path in sections  248  and  250 . Along with the other wires on the upper surface of the upper section they pass through weld  252  and at the terminal end of the upper section they extending downward oblique extensions as at  254  (FIG. 14) toward the front side of the lower section. It will be appreciated that wires  202 ,  204 ,  206  and  208  extend first vertically in a common vertical plane then horizontally in a common horizontal plane, and wire  207  extends vertically in a separate vertical plane and then horizontally in said common horizontal plane. 
     Wires  201 ,  203  and  205  extend from the base of the lower section in a common vertical plane longitudinally through only part of the lower section at which point they extend angularly through the front side of the lower section toward the lower side of the upper section. The vertical plane of wires  201 ,  203  and  205  is spaced from and parallel to the vertical plane of wires  202 ,  204 ,  206  and  208 . The wires  201 ,  203  and  205  do not touch this lower side of the upper section or the wires  202 ,  204 ,  206 ,  207  and  208  extending downwardly from the upper side of the upper section, but they do overlap these downwardly extending section as at  254  in upward extensions as at  256  (FIG. 14) which extend toward the lower side of the upper section  214 . 
     It will also be seen that wires  201 ,  203  and  205  are positioned in a removable insert  258 . The insulative insert also includes housing engagement projections  260 ,  262 ,  264  and  266  which are used to engage the insulative housing in a conventional manner. 
     It will be appreciated that there has been described a method of reducing or eliminating crosstalk as well as common mode electromagnetic interference and a modular jack for use therein. It will also be appreciated that this modular jack is interchangeable with conventional modular jacks and can be manufactured easily and inexpensively with conventional parts and tooling. 
     While the present invention has been described in connection with the referred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.