Patch cord having a plug contact with a signal injection point in its middle
Patch cords are provided that include a communications cable that has at least first through fourth conductors and a plug that is attached to the cable. The plug includes a housing that receives the cable, a printed circuit board, first through fourth plug contacts, and first through fourth conductive paths that connect the first through fourth conductors to the respective first through fourth plug contacts. The first and second conductors, conductive paths, and plug contacts form a first differential transmission line, and the third and fourth conductors, conductive paths, and plug contacts form a second differential transmission line. Each of the first through fourth plug contacts has a first segment that extends longitudinally along a first surface of the printed circuit board, and the signal current injection point into the first segment of at least some of the first through fourth plug contacts is into middle portions of their respective first segments.
1. A patch cord comprising:
a communications cable that includes at least a first conductor, a second conductor, a third conductor and a fourth conductor; and
a plug that is attached to the communications cable, the plug comprising:
a housing that receives the communications cable;
a printed circuit board that is at least partly within the housing;
a first plug contact, a second plug contact, a third plug contact and a fourth plug contact that each are at least partially within the housing;
a first conductive path that connects the first conductor to the first plug contact, a second conductive path that connects the second conductor to the second plug contact, a third conductive path that connects the third conductor to the third plug contact, and a fourth conductive path that connects the fourth conductor to the fourth plug contact,
wherein the first and second conductors, the first and second conductive paths, and the first and second plug contacts form a first differential transmission line through the plug and the third and fourth conductors, the third and fourth conductive paths, and the third and fourth plug contacts form a second differential transmission line through the plug,
wherein each of the first through fourth plug contacts has a first segment that extends longitudinally along a first surface of the printed circuit board, and wherein a signal current injection point into the first segment of at least some of the first through fourth plug contacts is into middle portions of their respective first segments,
wherein the respective signal current injection points into the first and third plug contacts are aligned in a first transverse row, and the respective signal current injection points into the second and fourth plug contacts are offset from the first row, and
wherein an uppermost point of each of the first through fourth plug contacts extends no more than 60 mils above the first surface of the printed circuit board.
2. The patch cord of claim 1 , wherein the respective signal current injection points into the second and fourth plug contacts are aligned in a second transverse row.
3. The patch cord of claim 1 , wherein the printed circuit board includes a plurality of conductive vias, wherein each of the first through fourth plug contacts has a projection that is received within a respective one of the conductive vias, and wherein the conductive vias that receive the projections of the first and third plug contacts are aligned in a first row, and the conductive vias that receive the projections of the second and fourth plug contacts are offset from the first row.
4. The patch cord of claim 3 , wherein the conductive vias that receive the projections of the second and fourth plug contacts are aligned in a second row.
5. The patch cord of claim 1 , wherein the plug comprises an RJ-45 plug that further includes fifth and sixth plug contacts that are part of a third differential transmission line through the plug and seventh and eighth plug contacts that are part of a fourth differential transmission line through the plug, wherein the first, third, fifth and seventh plug contacts are mounted in respective first through fourth conductive vias that are substantially aligned in a first row and the second, fourth, sixth and eighth plug contacts are mounted in respective fifth through eighth conductive vias that are substantially aligned in a second row that is offset from the first row.
6. The patch cord of claim 1 , further comprising an offending crosstalk capacitor that injects offending crosstalk between the second conductive path and the third conductive path.
7. The patch cord of claim 6 , wherein the offending crosstalk capacitor comprises a printed circuit board capacitor that injects offending crosstalk onto the second conductive path substantially at a first interface between the second plug contact and the printed circuit board, and wherein the offending crosstalk capacitor injects offending crosstalk onto the third conductive path substantially at a second interface between the third plug contact and the printed circuit board.
8. A patch cord comprising:
a communications cable that includes at least a first conductor, a second conductor, a third conductor and a fourth conductor; and
a plug that is attached to a first end of the communications cable, the plug comprising:
a housing that receives the communications cable;
a printed circuit board within the housing, the printed circuit board including a first via, a second via, a third via and a fourth via;
a first plug contact, a second plug contact, a third plug contact and a fourth plug contact, each of which are in the respective first through fourth vias in the printed circuit board;
a first conductive path that connects the first conductor to the first plug contact, a second conductive path that connects the second conductor to the second plug contact, a third conductive path that connects the third conductor to the third plug contact, and a fourth conductive path that connects the fourth conductor to the fourth plug contact;
a fifth via that is part of the first conductive path that is located in a portion of the printed circuit board that is underneath the first through fourth plug contacts, wherein the fifth via is part of an offending crosstalk circuit; and
a sixth via that is part of the third conductive path that is located in the portion of the printed circuit board that is underneath the first through fourth plug contacts,
wherein the first and second conductors, the first and second conductive paths, and the first and second plug contacts form a first differential transmission line through the plug and the third and fourth conductors, the third and fourth conductive paths, and the third and fourth plug contacts form a second differential transmission line through the plug.
9. The patch cord of claim 8 , wherein the offending crosstalk circuit injects inductive crosstalk between the first conductive path and the fourth conductive path.
10. The patch cord of claim 9 , wherein a first trace of the printed circuit board that is part of the first conductive path is positioned to inductively couple with a second trace on the printed circuit board that is part of the fourth conductive path to provide a second offending crosstalk circuit.
11. The patch cord of claim 9 , wherein the offending crosstalk circuit is a first offending crosstalk circuit, the plug further comprising a second offending crosstalk circuit that includes the sixth via that injects inductive crosstalk between the second conductive path and the third conductive path.
12. The patch cord of claim 8 , wherein each of the first through fourth plug contacts has a first segment that extends longitudinally above a top surface of the printed circuit board, and wherein the fifth via is substantially transversely aligned with the sixth via.
13. The patch cord of claim 8 , wherein the first and third vias are transversely aligned in a first row, and the second and fourth vias are transversely aligned in a second row that is offset from a first row.
14. The patch cord of claim 13 , wherein the fifth via and the sixth via are transversely aligned with the first and third vias.
15. A patch cord comprising;
a communications cable that includes at least a first conductor, a second conductor, a third conductor and a fourth conductor; and
an RJ-45 plug that is attached to a first end of the communications cable, the plug comprising:
a printed circuit board;
a plurality of plug blades mounted on a first surface of the printed circuit board, the plug blades arranged as a plurality of differential pairs of plug blades;
wherein a first of the plug blades of a first of the differential pairs of plug blades and a first of the plug blades of a second of the differential pairs of plug blades capacitively couple more than the first of the plug blades of the first of the differential pairs of plug blades capacitively couples with a second of the plug blades of the first of the differential pairs of plug blades.
16. The patch cord of claim 15 , wherein a distal end of the first of the plug blades of the first of the differential pairs of plug blades and a distal end of the first of the plug blades of the second of the differential pairs of plug blades have respective first and second extensions that together form an offending crosstalk capacitor.
17. The patch cord of claim 16 , wherein the first and second extensions each extend along a front edge of the printed circuit board.
18. The patch cord of claim 15 , wherein the first extension has a first width in a transverse dimension of the plug that is less than a second width of the first of the plug blades of the first differential pair of plug blades.