Communications connectors including low impedance transmission line segments that improve return loss and related methods

Patent metadata

Field	Value
Publication number	US-9318848-B2
Application number	US-201414449383-A
Country	US
Kind code	B2
Filing date	Aug 1, 2014
Priority date	Aug 1, 2014
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A communications connector includes a printed circuit board having a first internal conductive layer and first and second external conductive layers that are stacked with dielectric layers therebetween. The printed circuit board has input terminals, output terminals and signal current carrying conductive paths which electrically connect respective ones of the input and output terminals. The signal current carrying conductive paths are arranged in pairs to form differential transmission lines. The first signal current carrying conductive path includes a first segment that is on the first internal conductive layer which is routed in a vertically stacked arrangement with a second segment of the second signal current carrying conductive path, the first and second signal current carrying conductive paths being part of the same differential transmission line.

First claim

That which is claimed is:

1. A communications connector comprising:
a printed circuit board having a first internal conductive layer, a first external conductive layer and a second external conductive layer, the first and second external conductive layers and the first internal conductive layer stacked along a vertical axis with dielectric layers therebetween;
wherein the printed circuit board includes a plurality of input terminals, a plurality of output terminals and a plurality of signal current carrying conductive paths, each of which electrically connects a respective one of the input terminals to a respective one of the output terminals, the signal current carrying conductive paths arranged in pairs to form a plurality of differential transmission lines, and
wherein a first signal current carrying conductive path includes a first segment that is on the first internal conductive layer of the printed circuit board which is routed in a vertically stacked arrangement with a second segment of a second signal current carrying conductive path, the first and second signal current carrying conductive paths being part of the same one of the differential transmission lines.

2. The communications connector of claim 1 , wherein the communications connector is an RJ-45 plug, the plurality of input terminals comprise first through eighth input terminals that are electrically connected to respective first through eighth plug blades, the plurality of output terminals comprise first through eighth output terminals that are electrically connected to respective first through eighth conductors of a communications cable, the plurality of signal current carrying conductive paths comprise first through eighth signal current carrying conductive paths, and the plurality of differential transmission lines comprise first through fourth differential transmission lines.

3. The communications connector of claim 1 , wherein the communications connector is an RJ-45 jack that includes first through eighth jackwire contacts that are electrically connected to respective ones of the plurality of input terminals and first through eighth wire connection terminals that are electrically connected to respective ones of the plurality of output terminals, the plurality of signal current carrying conductive paths comprise first through eighth signal current carrying conductive paths, and the plurality of differential transmission lines comprising first through fourth differential transmission lines.

4. The communications connector of claim 3 , wherein the first signal current carrying conductive path includes a first inductive self-coupling section and the second signal current carrying conductive path includes a second inductive self-coupling section.

5. The communications connector of claim 3 , wherein the first segment has a first average width that exceeds the average width of the entirety of the first signal current carrying conductive path and/or the second segment has a second average width that exceeds the average width of the entirety of the second signal current carrying conductive path.

6. The communications connector of claim 3 , wherein at least one of the signal current carrying conductive paths of the differential transmission line that includes the first and second signal current carrying conductive paths further includes an inductive self coupling section.

7. The communications connector of claim 6 , wherein the location and/or magnitude of at least one of the vertically stacked first and second segments or the inductive self-coupling section is selected to provide a local maximum in the return loss spectrum of the differential transmission line that includes the first and second signal current carrying conductive paths, where the maximum in the return loss spectrum is between a first frequency that is half a maximum specified operating frequency for the RJ-45 jack and 1.5 times the maximum specified operating frequency for the RJ-45 jack.

8. A communications connector comprising:
a printed circuit board;
wherein the printed circuit hoard includes a plurality of input terminals, a plurality of output terminals, and a plurality of signal current carrying conductive paths, each of which electrically connects a respective one of the input terminals to a respective one of the output terminals, the signal current carrying conductive paths arranged in pairs to form a plurality of differential transmission lines, the plurality of differential transmission lines including a first differential transmission line; and
wherein the first and second signal current carrying conductive paths form the first differential transmission line,
wherein the first differential transmission line includes a first section in which a first segment of the first signal current carrying path is routed on a first layer of the printed circuit board and is positioned to capacitively and inductively couple with a second segment of the second signal current carrying path that is routed on a second layer of the printed circuit board that is different than the first layer,
wherein the first section of the first differential transmission line has a characteristic impedance that is at least twenty percent below a pre-selected impedance, and
wherein the first differential transmission line includes a second section that has a second characteristic impedance that is at least twenty percent greater than the pre-selected impedance.

9. The communications connector of claim 8 , wherein the locations and/or characteristic impedances of the first and second sections of the first differential transmission line are selected to provide a local maximum in the return loss spectrum for the first differential transmission line that is between a first frequency that is half a maximum specified operating frequency for the communications connector and 1.5 times the maximum specified operating frequency for the communications connector.

10. The communications connector of claim 8 , wherein the second section is directly connected to the first section by a third section having an impedance within twenty percent of the pre-selected impedance.

11. The communications connector of claim 8 , wherein the pre-selected impedance is 100 ohms.

12. The communications connector of claim 8 , wherein the first section is between the second section and the output terminals that are electrically connected to the first differential transmission line.

13. The communications connector of claim 12 , wherein the first section comprises a first segment of the first signal current carrying conductive path that is routed in a vertically stacked arrangement with a second segment of the second signal current carrying conductive path, and wherein at least one of the first segment and the second segment is on an internal layer of the printed circuit board.

14. The communications connector of claim 12 , wherein the communications connector is an RJ-45 jack, the plurality of input terminals comprise first through eighth input terminals, the plurality of output terminals comprise first through eighth output terminals, the plurality of signal current carrying conductive paths comprise first through eighth signal current carrying conductive paths, and the plurality of differential transmission lines comprise the first differential transmission line and second through fourth differential transmission lines.

15. The communications connector of claim 14 , wherein at least one of the first and second signal current carrying conductive paths includes an inductive self-coupling section between the first and second sections.

16.

Assignees

• Commscope Inc

Inventors

• Hashim Amid I

Classifications

• H01R24/64

  for high frequency, e.g. RJ 45 · CPC title

• H01R13/6466 Primary

  on substrates, e.g. printed circuit boards [PCB] · CPC title

• H05K2201/10189

  Non-printed connector · CPC title

• H05K1/0253

  Impedance adaptations of transmission lines by special lay-out of power planes, e.g. providing openings (H05K1/0251 takes precedence) · CPC title

• H05K1/162

  incorporating printed capacitors · CPC title