Methods and apparatus for reducing crosstalk in electrical connectors

• US 20050181676A1
• Filed: 02/10/2005
• Published: 08/18/2005
• Est. Priority Date: 02/12/2004
• Status: Active Grant

• Current Assignee: Panduit Corporation
• Original Assignee: Panduit Corporation
• Inventors: Bolouri-Saransar, Masud, Caveney, Jack E.
• Granted Patent: US 7,179,131 B2
• Time in Patent Office: Days
• US Class Current: 439/676
• CPC Class Codes: H01R 13/6461 Means for preventing cross-talk
• CPC Class Codes: H01R 13/6464 by adding capacitive elements
• CPC Class Codes: H01R 13/6466 on substrates, e.g. printed circuit boards [PCB]
• CPC Class Codes: H01R 13/66 Structural association with built-in electrical component coupling devices having concentrically or coaxially-arranged contacts H01R24/38
• CPC Class Codes: H01R 13/6658 on printed circuit board H01R13/6666 - H01R13/6691 take precedence
• CPC Class Codes: H01R 24/64 for high frequency, e.g. RJ 45
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 2201/09672 Superposed layout, i.e. in different planes
• CPC Class Codes: H05K 2201/10189 Non-printed connector
• CPC Class Codes: Y10S 439/941 Crosstalk suppression

Abstract

A communication jack having improved crosstalk compensation features is disclosed. In one embodiment, the jack is configured to receive a plug to form a communication connection, and comprises jack contacts, which may, for example, consist of metal cantilever beams, disposed in the jack, with each contact having at least a first surface and a second surface. Upon the plug being received by the jack, the plug contacts interface with the first surface of the jack contacts. The jack further includes a first capacitive coupling connected between two pairs of jack contacts to compensate for near end crosstalk, with the first capacitive coupling being connected to the pairs of jack contacts along the second surface adjacent to where the plug contacts interface with the jack contacts. A far end crosstalk compensation scheme is also set forth.

Claims

1. A communication jack configured to receive a plug to form a communication connection, comprising:

a plurality of jack contacts, which consist of metal cantilever beams, disposed in the jack, wherein each contact has at least a first surface and a second surface, wherein, upon the plug being received by the jack, a plurality of plug contacts interface with the first surface of the plurality of jack contacts; and

a first capacitive coupling connected between two pairs of the plurality of jack contacts to compensate for near end crosstalk, wherein the first capacitive coupling is connected to the pairs of jack contacts along the second surface adjacent to where the plug contacts interface with the jack contacts.

2. The communication jack of claim 1, wherein the plug has an associated plug coupling having capacitive and inductive components, and wherein, at a first frequency, the first capacitive coupling is greater in magnitude than the plug coupling, but approximately opposite in polarity.

3. The communication jack of claim 2, wherein at the first frequency the first capacitive coupling has a magnitude approximately twice that of the plug coupling.

4. The communication jack of claim 1, wherein the first capacitive coupling is connected to the jack contacts directly opposite where the plug contacts interface with the jack contacts.

5. The communication jack of claim 1, wherein the first capacitive coupling is connected between circuit paths 3:

5 and 4;

6 of the jack.

6. The communication jack of claim 1, further comprising a second capacitive coupling in electrical contact with the jack contacts.

7. The communication jack of claim 6, wherein the plug has an associated plug coupling having capacitive and inductive components, and wherein the second capacitive coupling is approximately opposite in polarity to the first capacitive coupling and approximately identical in polarity to the plug coupling.

8. The communication jack of claim 6, wherein an electrical current path from the first capacitive coupling to where the plug contacts interface with the jack contacts is shorter than an electrical current path from the second capacitive coupling to where the plug contacts interface with the jack contacts.

9. The communication jack of claim 6, wherein the first capacitive coupling is connected between circuit paths 3:

5 and 4;

6 of the jack, and the second capacitive coupling is connected between circuit paths 3;

4 and 5;

6 of the jack.

10. The communication jack of claim 6, further comprising a far end crosstalk compensation zone comprising inductive and conductive trace patterns on a printed circuit board.

11. The communication jack of claim 1, wherein the first capacitive coupling is located on a first printed circuit board attached to the jack contacts with flexible electrical conductors.

12. The communication jack of claim 11, wherein the first printed circuit board is flexible, allowing it to change shape upon insertion of the plug into the jack.

13. The communication jack of claim 11, wherein the first printed circuit board is attached to the second surface by welds.

14. The communication jack of claim 11, wherein the first printed circuit board is attached to the second surface by solder plugs.

15. The communication jack of claim 14, wherein at least a portion of the jack contacts is pre-tinned for soldering.

16. A crosstalk compensation apparatus for a communication connector consisting of a jack and a plug, comprising a printed circuit that is mechanically and electrically connected to jack contacts by flexible members, each of which is attached on the opposite side of and adjacent to an interface between a jack contact and a corresponding contact of an installed plug, wherein the jack contacts consist of metal cantilever beams.

17. The crosstalk compensation apparatus of claim 16, further comprising a Near End Crosstalk (NEXT) compensation zone.

18. The crosstalk compensation apparatus of claim 16, wherein the printed circuit provides at least a segment of a network signal path to connectors connecting the jack to a network cable.

19. The crosstalk compensation apparatus of claim 18, wherein the printed circuit provides capacitive compensation.

20. The crosstalk compensation apparatus of claim 18, wherein the printed circuit provides capacitive and inductive compensation.

21. The crosstalk compensation apparatus of claim 16, wherein the printed circuit is a flexible printed circuit.

22. A crosstalk compensation apparatus for a jack/plug combination which includes a Far End Crosstalk (FEXT) zone wherein the net inductive and capacitive couplings are approximately equal in magnitude and of opposite polarity.

23. The crosstalk compensation apparatus of claim 22, wherein the net capacitive coupling includes both distributed and remote capacitive coupling.

24. The crosstalk compensation apparatus of claim 22, wherein the phase angle displacement from a plug/jack interface to the net inductive coupling of the FEXT zone is approximately equal to the phase angle displacement from the plug/jack interface to the net capacitive coupling of the FEXT zone.

25. The crosstalk compensation apparatus of claim 22, wherein the net capacitive coupling of the FEXT zone is of the same polarity as the net capacitance associated with the plug.

26. The crosstalk compensation apparatus of claim 22, wherein the FEXT zone is symmetric with respect to conductors connected directly to the plug and conductors connected directly to the jack.

27. The crosstalk compensation apparatus of claim 26, wherein the magnitudes of the inductive and capacitive couplings are equal and the polarities are opposite to minimize the FEXT zone effect on forward and reverse near end crosstalk.

28. A crosstalk compensation apparatus for a communication connector consisting of a jack and a plug, comprising a Far End Crosstalk (FEXT) zone which has virtually no effect on Near End Crosstalk (NEXT) but which reduces Far End Crosstalk (FEXT).

29. A communication jack configured to receive a plug to form a communication connection, comprising:

a plurality of jack contacts which consist of metal cantilever beams disposed in the jack, wherein, upon the plug being received by the jack, a plurality of plug contacts interface with a first surface of the plurality of jack contacts at a plug/jack interface;

electrical conductors which are mechanically and electrically connected to a second surface of the jack contacts on the opposite side of and adjacent to the plug/jack interface; and

crosstalk compensation components connected to the electrical conductors.

30. The communication jack of claim 29, wherein the crosstalk compensation components provide capacitive coupling.

31. The communication jack of claim 30, wherein the capacitive coupling is adjacent to the jack contacts.

32. The communication jack of claim 29, wherein the electrical conductors carry the communication signal current of the plug contact to which they are electrically connected.

33. The communication jack of claim 32, wherein the electrical conductors are bent adjacent to where they are connected to the jack contacts and become oriented in a direction which is diverging from the plane that includes the jack contacts at the plug/jack interface.

34. The communication jack of claim 32, wherein the only communication signal current that is conducted by the jack contacts is approximately normal to a plane that includes the jack contacts at the plug/jack interface.

35. The communication jack of claim 32, wherein the crosstalk compensation components include both capacitive and inductive couplings.

36. The communication jack of claim 35, wherein the couplings are adjacent to where the electrical conductors connect to the jack contacts.

37. The communication jack of claim 32, wherein the electrical conductors are electrically connected to connectors to which an electrical communication cable is connected.

38. A communication jack comprising crosstalk compensation coupling which varies disproportionate to frequency compared to typical compensation couplings.

39. The communication jack of claim 38 wherein the coupling provides near end crosstalk compensation.

40. The communication jack of claim 38, wherein the coupling retards growth of crosstalk as frequency increases.

41. The communication jack of claim 40, wherein the growth of crosstalk is retarded by retarding growth of the near end crosstalk compensation as frequency increases.

42. The communication jack of claim 38, wherein the coupling consists of a capacitive coupling electrically connected to jack contacts by leads that are placed in close proximity to one another, in order to provide inductive coupling in the leads.

43. The communication jack of claim 42, wherein the leads result in a relatively high density of inductive coupling in a relatively short distance.

44. The communication jack of claim 42, wherein the leads connected to each pair of the jack contacts are all closely spaced and the leads of each pair are oriented in opposite directions to each other.

45. The communication jack of claim 44, wherein each jack contact of each pair has a polarity that is of reverse phase with respect to the other jack contact of each pair, thereby causing a resultant current in one of the leads connected to each pair to be in-phase with the other lead connected to the same pair.

46. The communication jack of claim 38, wherein the coupling is mechanically and electrically connected to jack contacts by flexible members attached on an opposite side of and adjacent to an interface of the jack contacts with contacts of an installed plug, wherein the jack contacts consist of metal cantilever beams.

47. The communication jack of claim 46, wherein the coupling and flexible members consist of a flexible printed circuit.

48. The communication jack of claim 46, wherein the flexible members are separated cantilever segments which are only as long as necessary to facilitate their connection to the jack contacts.

49. The communication jack of claim 48, wherein the crosstalk compensation coupling is located immediately adjacent to the flexible members.