CONNECTOR WITH CROSSTALK COMPENSATION

[0001] This application claims priority to U.S. Provisional Patent Application No. 60/772,802 filed Feb. 13, 2006, entitled “Connector with Crosstalk Compensation.”

[0002] This application further incorporates by reference in their entireties the following U.S. patent applications:

[0003] a) Ser. No. 11/195,412, entitled “Wire Containment Cap,” filed Aug. 2, 2005;

[0004] b) Ser. No. 11/305,476, entitled “Wire Containment Cap with an Integral Strain Relief Clip,” filed Dec. 16, 2005;

[0005] c) Ser. No. 11/462,204, entitled “Wire Containment Cap,” filed Aug. 2, 2006; and

[0006] d) Ser. No. 11/099,110, entitled “Electrical Connector with Improved Crosstalk Compensation,” filed Apr. 5, 2005, now U.S. Pat. No. 7,153,168.

[0007] The present invention relates generally to electrical connectors, and more particularly, to a modular communication jack design with an improved wire containment cap and pair divider and crosstalk compensation.

[0008] In the communications industry, as data transmission rates have steadily increased, crosstalk due to capacitive and inductive couplings among the closely spaced parallel conductors within the jack and/or plug has become increasingly problematic. Modular connectors with improved crosstalk performance have been designed to meet the increasingly demanding standards. Many of these connectors have addressed crosstalk by compensating at the front end of the jack, i.e., the end closest to where a plug is inserted into the jack. However, the wire pairs terminated to the insulation displacement contact (“IDC”) terminals at the rear portion of a jack may also affect the performance of the jack.

[0009] One problem that exists when terminating wire pairs to the IDC terminals of a jack is the effect that termination has on the crosstalk performance of a jack. When a twisted-pair cable with four wire pairs is aligned and terminated to the IDC terminals of a jack, a wire pair may need to flip over or under another wire pair. An individual conductor of a wire pair may also be untwisted and oriented closely to a conductor from a different wire pair. Both of these conditions may result in unintended coupling in the termination area which can degrade the crosstalk performance of the jack. Thus, a solution addressing the crosstalk in the termination area of the jack would be desirable.

[0010] A second problem that exists when terminating wire pairs to the IDC terminals of a jack is variability. A technician is typically called on to properly terminate the wire pairs of a twisted pair cable to the proper IDC terminals of the jack. Each jack terminated by the technician should have similar crosstalk performance. This requires the termination to remain consistent from jack to jack. However, different installers may use slightly different techniques to separate the wire pairs and route them to their proper IDC terminals. Thus, a solution that controls the variability of terminations from jack to jack would be desirable.

[0011] A final issue that arises when terminating wire pairs to the IDC terminals of a jack is the difficulty of the termination process. Typical jacks provide little assistance to the technician, resulting in occasional misterminations (e.g., a wire being terminated at an incorrect location in the jack). Even if detailed instructions are provided with the jack, technicians may not read these instructions prior to installing the jacks. Furthermore, a jack with a difficult termination process can increase the installation time for the technician and result in a costly installation for the customer. Thus, a jack solution that simplifies the termination process and minimizes the possibility of technician error would be desirable.

[0012] It is further desirable to combine these benefits with an improved pair divider within the connector, along with crosstalk compensation, to improve overall jack performance.

[0013] The present application meets the shortcomings of the prior art by providing a wire containment cap having a first side including a plurality of wire slots with retainers for retaining wires, a second side being opposite the first side, sidewalls extending between the first side and the second side, and twisted pair holes or slots with funnel-shaped entrances between the first side and the second side.

[0014] A communication jack assembly is also described. The communication jack comprises a front portion including a retention clip, and the wire containment cap including a retention recess for securing the wire containment cap to the front portion.

[0015] Wire containment caps and communication jack assemblies according to the present invention may be provided in shielded or unshielded embodiments. Further, the second side of wire containment caps according to the present invention may be provided with a slot and other features allowing for the use of an integral strain relief clip. A metal pair divider may also be incorporated in order to provide an electrical shield between wire pairs in the communication jack.

[0016] Crosstalk compensation techniques are used to improve the communication performance of connectors in some embodiments of the present invention.

[0017] FIG. 1 is a front upper right perspective view of a communication jack having a wire containment cap in accordance with an embodiment of the present invention;

[0018] FIG. 2 is a front upper right partially exploded view of the communication jack of FIG. 1;

[0019] FIG. 3 is a front upper right perspective view of a wire containment cap in accordance with an embodiment of the present invention;

[0020] FIG. 4 is a front view of the wire containment cap of FIG. 3;

[0021] FIG. 5 is a rear upper left exploded view of a wire routing assembly comprising a wire containment cap, a metal pair divider, and a rear jack housing according to one embodiment of the present invention;

[0022] FIG. 6 is a front view of the wire routing assembly of FIG. 5;

[0023] FIG. 7 is a cross-sectional view of the wire routing assembly of FIG. 6, taken along the line A-A;

[0024] FIG. 8 is a cross-sectional view of the wire routing assembly of FIG. 6, taken along the line B-B;

[0025] FIG. 9 is a front view of a communication jack according to one embodiment of the present invention;

[0026] FIG. 10 is a cross-sectional view of the jack of FIG. 9, taken along the line C-C;

[0027] FIG. 11 is a partial exploded view of a communication jack;

[0028] FIG. 12 is an exploded view of a plug interface contact assembly and a compensation circuitry assembly;

[0029] FIG. 13 is a cross-sectional view of a flexible circuit being attached to a plug interface contact;

[0030] FIG. 13a is a detail view of the detail “D” of FIG. 13;

[0031] FIG. 14 is a cross-sectional view of a flexible circuit attached to a plug interface contact;

[0032] FIG. 14a is a detail view of the detail “E” of FIG. 14;

[0033] FIG. 15 is a cross-sectional view of an alternative embodiment of a plug interface contact;

[0034] FIG. 15a is a detail view of the detail “H” of FIG. 15;

[0035] FIG. 15b is a cross-sectional view of an alternative embodiment of a plug interface contact;

[0036] FIG. 15c is a detail view of the detail “I” of FIG. 15b;

[0037] FIG. 16 is a perspective view of a plug interface contact according to one embodiment of the present invention;

[0038] FIG. 17 is a detail view of the detail “J” of FIG. 16;

[0039] FIG. 18 is a plan view of compensation circuitry according to one embodiment of the present invention;

[0040] FIGS. 18a-18v are detail views of compensation zones of the compensation circuitry of FIG. 18;

[0041] FIG. 19 is a plan view of compensation circuitry according to another embodiment of the present invention;

[0042] FIGS. 19a-1 9f are detail views of compensation zones of the compensation circuitry of FIG. 19;

[0043] FIG. 19g is a cross-sectional view of a communication jack with the compensation circuitry of FIG. 19 installed therein;

[0044] FIG. 20 is a cross-sectional view of circuit traces for a FEXT compensation zone;

[0045] FIG. 20a illustrates adjacent circuit traces according to one embodiment of a FEXT compensation zone; and

[0046] FIG. 21 is a plan view of a circuitry zone employing FEXT compensation.

[0047] FIG. 1 is a front upper right perspective view of a communication jack 100 according to one embodiment of the present invention. The communication jack 100 includes a front jack housing 102, a rear jack housing 103, and a wire containment cap 104. The front jack housing 102 and rear jack housing 103 may house such components as plug interface contacts, a mechanism for coupling the jack to a plug, crosstalk compensation circuitry, and IDCs (insulation-displacement contacts) to provide an electrical connection between the jack and a four-twisted-pair communication cable.

[0048] FIG. 2 is a front upper right partial-exploded view of the communication jack 100 of FIG. 1. In the embodiment shown, the wire containment cap 104 is slidably mounted within the rear jack housing 103. A retention clip 106 on the rear jack housing 103 and a retention recess 108 on the wire containment cap 104 may be included to secure the wire containment cap 104 to the rear jack housing 103. A retention latch 110 is also provided in the embodiment of FIG. 2. Other mounting and securing techniques may also be used.

[0049] FIGS. 3-5 illustrate the wire containment cap 104 in further detail. The wire containment cap 104 includes a large opening 112 in the back (shown in FIG. 5) to allow a cable to be inserted and to allow twisted pairs to separate in a short distance as they transition toward IDC terminals. The back of the wire containment cap 104 also has a strain relief guide slot 114 and strain relief latch teeth 116 to accommodate a strain relief clip as shown and described in U.S. provisional patent application Ser. No. 60/636,972, filed on Dec. 17, 2004 and entitled “Wire Containment Cap with an Integral Strain Relief Clip.” One embodiment of a strain relief 119 clip is shown in FIG. 11. Shoulders 117 are provided on the left and right along the rear of the wire containment cap 104.

[0050] The opening 112 provides easy access to two twisted-pair slots 118 having funnel-shaped slot entrances 120. A rear spine 122 separates the twisted-pair slots 118 toward the rear of the wire containment cap 104. A saddle area 126 serves as a lower support for a cable when the cable is secured by the strain relief clip.

[0051] In a preferred embodiment of the present invention, twisted wire pairs are separated and crossed over as necessary toward the rear of the wire containment cap 104, before two twisted pairs enter each of the slots 118. The saddle area 126 is sufficiently low and the rear spine 122 is sufficiently offset from the rear end of the wire containment cap 104 to provide ample space to cross over twisted pairs as necessary on the rear sides of the slots 118. One reason a crossover may be necessary is because the twisted pair layout on one end of a twisted pair cable is a mirror image of the wire pair layout on the opposite end of the twisted pair cable. Another reason this crossover may be necessary is because the Telecommunications Industry Association (“TIA”) standards allow structured cabling systems to be wired using two different wiring schemes. Finally, a crossover may occur because not all cables have the same pair layout.

[0052] The communication jack 100 also incorporates a pair divider 128. The pair divider 128 is preferably made of metal and provides an electrical shield between wire pairs in the area near the end of an installed cable. This portion of the cable typically lacks proper twist of the wires of each pair and/or lacks proper shielding of each pair. The metal pair divider therefore decreases crosstalk magnitude and variation. According to one embodiment, the pair divider 128 is made of a vacuum-metallized plastic.

[0053] In the embodiment of FIGS. 5-8, the pair divider 128 has a mounting projection 129 that is inserted into a mounting hole 131 in the rear jack housing 103. After the mounting projection 129 is inserted into the mounting hole 131, the pair divider 128 is lowered slightly so that fin restraints 133 provided on the rear jack housing 103 engage a lower fin 135 of the pair divider 128. This prevents rotation of the pair divider 128.

[0054] To complete the installation of wires in the communication jack 100, the technician need only place twisted pairs through appropriate slots 118, secure individual wires in the upper and lower wire retainers 130 and 132 having upper and lower wire restraints 134 and 136 (as shown in FIG. 3), cut off the excess wire ends, and attach the wire containment cap 104 to the rear jack housing 103 of the communication jack 100 to complete construction of the wire routing assembly 138. IDC slots 140 within the rear jack housing 103 allow IDCs 142 (as shown in FIG. 12) to pass through and contact the wires.

[0055] FIG. 9 is a front view of the communication jack 100, and FIG. 10 is a cross-sectional view of the communication jack 100 along the line C-C of FIG. 9. A flexible printed circuit (FPC) 144 makes electrical contact with plug interface contacts 146 directly below the plug-jack interface 147, where the contacts of a plug mate with the plug interface contacts 146. In the embodiment of FIG. 10, the FPC 144 is also connected to a rigid circuit portion 148, with the FPC 144 and the rigid circuit portion 148 combining to form a compensation circuitry assembly 150. The IDCs 142 are inserted into the rigid circuit portion 148 of the compensation circuitry assembly 150.

[0056] FIG. 11 is an exploded view of the communication jack 100. FIG. 12 is an exploded view of a portion of the communication jack 100 showing the plug interface contacts 146, the compensation circuitry assembly 150, and the IDCs 142. As shown in FIG. 12, the plug interface contacts 146 may be assembled in a plug interface contact assembly 152, with lower ends 154 of the plug interface contacts 146 inserted into a lower plug interface contact mount 156. Curved portions 158 of the plug interface contacts 146 are curved around curved portions 160 of an upper plug interface contact mount 162.

[0057] FIGS. 13-17 illustrate how the FPC 144 is attached to the plug interface contacts 146 by a welding process. FIGS. 13-17 illustrate connection to a single plug interface contact 146, but the FPC 144 is preferably attached to multiple plug interface contacts 146 simultaneously. As shown in FIGS. 13 and 13a, the FPC 144 is inserted between a mounting end 164 of the plug interface contact 146 and an opposing connecting surface 166 of the plug interface contact 146. The mounting end 164 is positioned opposite the opposing connecting surface 166 by the formation of a bend 167 in the plug interface contact. Upper and lower welder electrodes 168 and 170 are positioned above and below a welding region 172 of the plug interface contact 146. The welding region 172 may include upper and lower weld concentrator pivots 174 and 176 formed in the plug interface contact 146.

[0058] Next, as shown in FIGS. 14 and 14a, force at the outer edge of the electrodes 168 and 170 causes the mounting end 164 of the plug interface contact to rotate inwardly around the weld concentrator pivots 174 and 176 towards the FPC 144 as shown by the arrow “F.” This causes a high spring force, indicated by the arrows “G,” which electrically connects the FPC 144 to the plug interface contact 146 and clamps the FPC 144, retaining the FPC 144 in connection with the plug interface contact 146. A weld 177 holds the upper and lower weld concentrator pivots 174 and 176 together.

[0059] FIGS. 15 and 15a show an alternative embodiment of a plug interface contact 146 having only a lower weld concentrator pivot 176 with no upper weld concentrator pivot.

[0060] FIGS. 15b and 15c show another alternative embodiment of a plug interface contact 146 that is formed without any concentrator pivots.

[0061] FIGS. 16 and 17 are perspective views of a plug interface contact 146 showing the locations of the upper and lower weld concentrator pivots 174 and 176.

[0062] Turning now to FIG. 18, a trace diagram of conductive traces 178 on the FPC 144 and the rigid circuit portion 148 of the compensation circuitry assembly 150 is shown. The conductive traces consist of two layers: an upper layer that is shown by solid lines in FIG. 18 and a lower level that is shown in dotted lines. Zones A-F and Z are shown in FIGS. 18-18v. These zones generally act as follows: Zone A is a transition zone from the connection to the plug interface contacts to the NEXT (Near-End CrossTalk) compensation zone; Zone B is the NEXT compensation zone; Zone C is a transition zone from the NEXT compensation zone to the NEXT crosstalk zone; Zone D is a compensation zone to compensate for the plug interface contacts; Zone E is the NEXT crosstalk zone; Zone F is a neutral zone that connects the NEXT crosstalk zone to sockets for the IDCs; and Zone Z is an impedance compensation zone that ensures that the combined impedance of the communication jack and plug matches the impedance of other network elements.

[0063] The conductive traces 178 illustrated in FIGS. 18-18v extend from plug interface contact points 180 that contact the plug interface contacts 146 to IDC sockets 182 into which IDCs 142 are inserted. The traces may pass between the upper and lower layers through vias 184. FIG. 18 illustrates the locations of zones according to one embodiment, and FIGS. 18a through 18v illustrate conductive traces within individual zones. Numbers one through eight shown in FIGS. 18a-18u correspond to the first through eighth conductors in a four-pair embodiment.

[0064] FIG. 18a shows traces in Zone A. FIG. 18b shows the conductive traces that are on the top layer in Zone A and FIG. 18c shows the conductive traces that are on the bottom layer in Zone A.

[0065] FIG. 18d shows traces in Zone B. FIG. 18e shows the conductive traces that are on the top layer in Zone B and FIG. 18f shows the conductive traces that are on the bottom layer in Zone B.

[0066] FIG. 18g shows traces in Zone C. FIG. 18h shows the conductive traces that are on the top layer in Zone C and FIG. 18i shows the conductive traces that are on the bottom layer in Zone C.

[0067] FIG. 18j shows traces in Zone D corresponding to conductors 3,4, 5, and 6. Zone D is positioned in the middle part of Zone B in the plan view of FIG. 18. FIG. 18k shows the conductive traces corresponding to these conductors that are on the top layer in Zone D and FIG. 18l shows the conductive traces corresponding to these conductors that are on the bottom layer in Zone D.

[0068] FIG. 18m shows traces in Zone D corresponding to conductors 1, 3, 6, and 8. FIG. 18n shows the conductive traces corresponding to these conductors that are on the top layer in Zone D and FIG. 18o shows the conductive traces corresponding to these conductors that are on the bottom layer in Zone D.

[0069] FIG. 18p shows traces in Zone E. FIG. 18q shows the conductive traces that are on the top layer in Zone E and FIG. 18r shows the conductive traces that are on the bottom layer in Zone E.

[0070] FIG. 18s shows traces in Zone F. FIG. 18t shows the conductive traces that are on the top layer in Zone F and FIG. 18u shows the conductive traces that are on the bottom layer in Zone F.

[0071] FIG. 18v shows the conductive traces that are in Zone Z. Zone Z is located above Zone D in the plan view of FIG. 18.

[0072] FIG. 19 shows a portion of a flexible circuit board 186 according to another embodiment of the present invention. The flexible circuit board 186 has Zone D provided on a fold-over portion 188, such that the fold-over portion 188 can be folded around a folding pivot 190. The flexible circuit board 186 also includes a “Zone G” compensation section. Zone G is a zone in which compensation changes as frequency increases. Such compensation is further shown and described in U.S. patent application Ser. No. 11/099,110, Publication No. 2005/0277339, which is incorporated herein by reference in its entirety.

[0073] FIG. 19a shows conductive traces in Zone D of the embodiment of FIG. 19. FIG. 19b shows the conductive traces that are on the top layer in Zone D and FIG. 19c shows the conductive traces that are on the bottom layer in Zone D.

[0074] FIG. 19d shows conductive traces in Zone G of the embodiment of FIG. 19. FIG. 19e shows the conductive traces that are on the top layer in Zone G and FIG. 19f shows the conductive traces that are on the bottom layer in Zone G.

[0075] FIG. 19g is a cross-sectional view of part of a communication jack 189 with the flexible circuit board 186 installed. The flexible circuit board 186 makes electrical contact with the plug interface contacts 146 directly below the plug-jack interface 147. The fold-over portion 188 is shown in its folded configuration.

[0076] It is beneficial to include far-end crosstalk (FEXT) compensation in some embodiments of communication jacks. The location of distributed capacitive and/or inductive crosstalk or compensation does not affect FEXT, because signals generated by distributed couplings all arrive at the extremity of the connector at the same time. However, when negative-polarity capacitive (−C) and positive-polarity inductive (+L) compensation is added in a FEXT zone, ideally it is distributed, and the capacitive and inductive compensation disposed in the same location to make their effect on NEXT=0.

[0077] FEXT compensation may be used in connectors with balanced NEXT but net capacitive coupling greater than net inductive coupling.

[0078] The procedure to determine the magnitude of −C and +L in a FEXT compensation zone is as follows:
FEXT=C_T−L_T

[0079] C_T=Total net capacitance of connector including the FEXT zone

[0080] L_T=Total net inductance of connector including the FEXT zone

[0081] C_F=Capacitance of FEXT compensation zone

[0082] L_F=Inductance of FEXT compensation zone
C_T=C_R+C_F
L_T=L_R+L_F

[0083] C_R=Total net capacitance of connector without the FEXT zone

[0084] L_R=Total net inductance of connector without the FEXT zone.

[0085] C_F and L_F are designed to be equal in magnitude and their magnitude is designed to make C_T equal to L_T and therefore FEXT=0.

[0086] FIGS. 20 and 20a show examples of conductive traces for conductors 3, 4, 5, and 6 of a connector in which a distributed FEXT zone is used to result in substantially no FEXT. As shown in FIG. 20, a fifth conductive trace overlies a sixth conductive trace and a fourth conductive trace overlies a third conductive trace. As shown in FIG. 20a, the lengths of the traces are chosen as required to result in zero FEXT for the connector. The arrows in FIG. 20a show the direction of signal current through the conductive traces.

[0087] FIG. 21 shows conductive traces in one embodiment of a circuit board in which FEXT compensation is incorporated into Zone F. Solid lines in FIG. 21 indicate traces on an upper layer and dotted lines represent traces on a lower layer. In sections where the traces on the upper and lower layers overlap, number designations are used to show the overlapping traces. For example, in a section labeled “6/3,” a conductive trace corresponding to the sixth conductor is overlapping a conductive trace corresponding to the third conductor. IDC sockets 182 and vias 184 are also illustrated in FIG. 21.

[0088] While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.