Communications jack having a flexible printed circuit board with conductive paths on two opposite sides of the board with the paths inductively and capacitively coupled
Communications jacks include a housing having a plug aperture that is configured to receive a mating RJ-45 plug along a longitudinal axis and eight jackwire contacts that are arranged as four differential pairs of jackwire contacts, each of the jackwire contacts including a plug contact region that extends into the plug aperture. A first of the jackwire contacts is configured to engage a longitudinally extending surface of a first blade of a mating RJ-45 plug when the mating RJ-45 plug is fully received within the plug aperture.
1. An RJ-45 communications jack having a longitudinal axis, comprising:
a housing having a plug aperture that is configured to receive a mating RJ-45 plug along the longitudinal axis;
a flexible printed circuit board having a first conductive path and a second conductive path that form a first differential pair of conductive paths and a third conductive path and a fourth conductive path that form a second differential pair of conductive paths;
a first jackwire contact that is electrically connected to the first conductive path;
a second jackwire contact that is electrically connected to the second conductive path;
a third jackwire contact that is electrically connected to the third conductive path;
a fourth jackwire contact that is electrically connected to the fourth conductive path;
wherein a section of the first conductive path is on a first side of the flexible printed circuit board and a section of the third conductive path is on a second side of the flexible printed circuit board that is opposite the first side, and
wherein the section of the first conductive path and the section of the third conductive path are configured to form a coupling section in which the first and third conductive paths both inductively and capacitively couple.
2. The communications jack of claim 1 , wherein the section of the first conductive path and the section of the third conductive path that form the coupling section partially overlap but do not completely overlap.
3. The communications jack of claim 2 , wherein an amount of capacitive coupling between the section of the first conductive path and the section of the third conductive path is at least half an amount of inductive coupling between the section of the first conductive path and the section of the third conductive path.
4. The communications jack of claim 1 , wherein the coupling section is configured so that the capacitive coupling has a first polarity and the inductive coupling has a second polarity that is opposite the first polarity.
5. The communications jack of claim 1 , wherein a first amount of capacitive coupling that the coupling section is configured to generate is substantially equal to a second amount of capacitive coupling that the coupling section is configured to generate.
6. The communications jack of claim 1 , wherein the first conductive path is a tip conductive path and the third conductive path is a ring conductive path.
7. The communications jack of claim 1 , wherein the coupling section is configured so that the magnitude of the capacitive coupling per unit length is substantially equal to the magnitude of the inductive coupling per unit length.
8. The communications jack of claim 1 , wherein at least a portion of the first conductive path that is in the coupling section is widened as compared to the remainder of the first conductive path.
9. A communications jack, comprising:
a flexible printed circuit board;
a first conductive path electrically connecting a first input of the jack and a first output of the jack;
a second conductive path electrically connecting a second input of the jack and a second output of the jack, wherein the first and second conductive paths comprise a first differential pair of conductive paths for transmitting a first information signal;
a third conductive path electrically connecting a third input of the jack and a third output of the jack;
a fourth conductive path electrically connecting a fourth input of the jack and a fourth output of the jack, wherein the third and fourth conductive paths comprise a second differential pair of conductive paths for transmitting a second information signal; and
a return loss improvement circuit that comprises a first section of the first conductive path and a second section of the second conductive path that have substantially the same instantaneous current directions, wherein the first section and the second section are positioned to both capacitively and inductively couple with each other,
wherein the first section of the first conductive path is on a first side of the flexible printed circuit board and the second section of the second conductive path is on a second side of the flexible printed circuit board that is opposite the first side.
10. The communications jack of claim 9 , wherein the ratio of the capacitive coupling to the inductive coupling in the return loss improvement circuit is selected to provide a local maximum in a return loss spectrum.