Low crosstalk printed circuit board based communications plugs and patch cords including such plugs

Abstract

Patch cords include a cable having eight conductors that are twisted together to form four differential pairs of conductors and a plug that is attached to the cable. The plug includes a housing, a printed circuit board, and respective first through eighth plug contacts that are electrically connected to the respective first through eighth conductors via respective first through eighth conductive paths on the printed circuit board. The plug contacts are arranged in a row in numerical order. The plug includes a wire guide that has a top shelf that extends above the printed circuit board and a bottom shelf that extends below the printed circuit board. Two of the differential pairs are routed into respective first and second channels in the top shelf and the other two of the differential pairs are routed into respective third and fourth channels in the bottom shelf.

That which is claimed is: 
     
         1 . A communications connector, comprising:
 a housing;   a printed circuit board mounted at least partially within the housing, the printed circuit board including first through eighth metal-plated vias;   first through eighth contacts mounted in the first through eighth metal-plated vias, respectively, the first through eighth contacts configured as first to fourth differential pairs of contacts; and   a first conductive trace having a first curved segment that forms a first annular ring-to-via capacitor with the first metal-plated via.   
     
     
         2 . The communications connector of  claim 1 , further comprising a second conductive trace having a second curved segment that forms a second annular ring-to-via capacitor with the second metal-plated via. 
     
     
         3 . The communications connector of  claim 2 , wherein the communications connector is an RJ-45 plug, and the first through eighth contacts comprise first through eighth plug blades. 
     
     
         4 . The communications connector of  claim 3 , wherein the first curved segment extends at least halfway around the first metal-plated via. 
     
     
         5 . The communications connector of  claim 3 , wherein the printed circuit board extends in a longitudinal direction, a transverse direction and a vertical direction that are perpendicular to each other, wherein each of the first through eighth metal-plated vias extend through the printed circuit board in the vertical direction, wherein each of the first through eighth plug blades extends in the longitudinal direction, and wherein the first through eighth metal-plated vias are aligned in at least two transverse rows. 
     
     
         6 . The communications connector of  claim 5 , wherein the first through eighth plug blades are transversely aligned in numerical order, and wherein the first conductive trace is electrically connected to the sixth metal-plated via, and the second conductive trace is electrically connected to the third metal-plated via. 
     
     
         7 . The communications connector of  claim 3 , wherein each of the first through eighth plug blades includes a blade portion having a bottom surface that extends along a top surface of the printed circuit board, a downwardly extending projection that is received within a respective one of the first through eighth metal-plated vias, and wherein at least one of the plug blades includes an air gap between at least some portion of the bottom surface thereof and a top surface of the printed circuit board when the plug blade is mounted on the printed circuit board. 
     
     
         8 . The communications connector of  claim 1 , wherein the first annular ring-to-via capacitor comprises an offending crosstalk capacitor. 
     
     
         9 . The communications connector of  claim 1 , wherein a first end of the first conductive trace is directly connected to one of the first through eighth metal-plated vias. 
     
     
         10 . A communications plug, comprising:
 a housing;   a printed circuit board mounted at least partly within the housing;   a wire guide having a top shelf that extends onto a top surface of the printed circuit board and a bottom shelf that extends onto a bottom surface of the printed circuit board, the wire guide further including a rearwardly extending member that forms a crosstail, wherein the rearwardly extending member includes at least one slot that is configured to receive a portion of a separator of a communications cable.   
     
     
         11 . The communications plug of  claim 10 , wherein the wire guide further includes first and second spaced-apart, longitudinally extending channels in the top shelf and third and fourth spaced-apart, longitudinally extending channels in the bottom shelf. 
     
     
         12 . The communications plug of  claim 11 , wherein each of the first through fourth longitudinally extending channels includes a twist terminator. 
     
     
         13 . The communications plug of  claim 12 , wherein a first air gap is provided in the wire guide between the first and second spaced-apart, longitudinally extending channels and a second air gap is provided in the wire guide between the third and fourth spaced-apart, longitudinally extending channels. 
     
     
         14 . The communications plug of  claim 10 , wherein the rearwardly extending member includes a vertical member and first and second horizontal members that are on either side of the vertical member, and wherein the at least one slot comprises a first slot that is between the vertical member and the first horizontal member and a second slot that is between the vertical member and the second horizontal member. 
     
     
         15 . The communications plug of  claim 10 , wherein the at least one slot comprises a vertically-extending slot and a horizontally-extending slot, and wherein the rearwardly extending member includes first and second vertical members that are separated by the vertically-extending slot and first and second horizontal members that are separated by the horizontally-extending slot. 
     
     
         16 . The communications plug of  claim 15 , wherein the horizontally-extending slot extends through the vertically-extending slot. 
     
     
         17 . An RJ-45 plug, comprising:
 a housing that receives a communications cable having first through eighth conductors;   a printed circuit board that is at least partly within the housing; and   first through eighth plug blades that are electrically connected to the respective first through eighth conductors of the communications cable,   wherein each plug blade includes a blade portion having a bottom surface that extends along a top surface of the printed circuit board, a downwardly extending projection that is received within a respective one of the first through eighth metal-plated vias, and wherein the bottom surface of the first plug blade includes a recessed region that forms an air gap between a portion of the bottom surface of the first plug blade and a top surface of the printed circuit board when the first plug blade is mounted on the printed circuit board.   
     
     
         18 . The RJ-45 plug of  claim 17 , wherein bottom surfaces of the second through eighth plug blades each includes a respective recessed region that forms a respective air gap between a portion of the bottom surface of the respective plug blade and the top surface of the printed circuit board when the respective plug blades are mounted on the printed circuit board.