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

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.

A communications connector comprising:

• a printed circuit board having a first internal conductive layer, first and second external conductive layers, and first and second dielectric layers, the first dielectric layer between the first external conductive layer and the first internal conductive layer and the second dielectric layer between the first internal conductive layer and the second external conductive layer, the first and second external conductive layers, the first internal conductive layer and the first and second dielectric layers stacked along a vertical axis,
• wherein the printed circuit board includes first through eighth input terminals, first through eighth output terminals, and first through eighth signal current carrying conductive paths, each of which electrically connecting a respective one of the input terminals to a respective one of the output terminals, the first through eighth signal current carrying conductive paths arranged in pairs to form first through fourth differential transmission lines, with the first and second signal current carrying conductive paths forming the first differential transmission line,
• wherein a return loss compensation circuit is formed in the first differential transmission line that includes a high impedance section in series with a tow-impedance section, where the impedances of the high and low impedance sections and the distance between the high and low impedance sections are selected to improve the return loss performance of the first differential transmission line at a maximum operating frequency of the communications connector, and
• wherein the low impedance section comprises a first segment of the first signal carrying conductive path that is on a first layer of the printed circuit board that runs in generally the same direction as a second segment of the second signal current carrying conductive path that is on a second internal layer of the printed circuit board that is different than the first layer, the first and second segments positioned to have a capacitive reactance therebetween that exceeds their inductive reactance.