Next High Frequency Improvement by Using Frequency Dependent Effective Capacitance

• US 20080268710A1
• Filed: 07/07/2008
• Published: 10/30/2008
• Est. Priority Date: 05/14/2004
• Status: Active Grant

• Current Assignee: Amid Hashim, Julian Robert Pharney
• Original Assignee: Amid Hashim, Julian Robert Pharney
• Inventors: Hashim, Amid, Pharney, Julian Robert
• Granted Patent: US 7,677,930 B2
• Time in Patent Office: Days
• US Class Current: 439/620.21
• CPC Class Codes: H01R 13/6464 by adding capacitive elements
• CPC Class Codes: H01R 13/6469 on substrates
• 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 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/09236 Parallel layout
• CPC Class Codes: H05K 2201/10189 Non-printed connector
• CPC Class Codes: Y10S 439/941 Crosstalk suppression

Abstract

A connector is provided for simultaneously improving both the NEXT high frequency performance when low crosstalk plugs are used and the NEXT low frequency performance when high crosstalk plugs are used. The connector includes a first compensation structure provided on an inner metalized layer of the PCB at a first stage area of the PCB, and a second compensation structure, provided at a second stage area of the PCB, for increasing compensation capacitance with increasing frequency.

Claims

1. An electrical connector, comprising

a plurality of input terminals;

a plurality of output terminals;

a plurality of conductive paths connecting respective of the plurality of input terminals with respective of the plurality of output terminals and

a first compensation structure that couples a first compensating crosstalk signal from a first of the plurality of conductive paths to a second of the plurality of conductive paths; and

a second compensation structure that couples a second compensating crosstalk signal from a third of the plurality of conductive paths to the second of the plurality of conductive paths,

wherein the second compensation structure comprises a capacitor and an inductor that is connected to the capacitor in series.

2. The electrical connector of claim 1, wherein the inductor comprises a conductive path that includes one or more self-coupling sections.

3. The electrical connector of claim 2, wherein the first compensating crosstalk signal has a first polarity and the second compensating crosstalk signal has a second polarity that is generally opposite the first polarity.

4. The electrical connector of claim 2, wherein the conductive path that includes one or more self-coupling sections comprises a conductive path in the general shape of a spiral.

5. The electrical connector of claim 1, wherein the electrical connector comprises an RJ-45 style jack, and wherein a signal input onto the second conductive path from an RJ-45 style plug that mates with the RJ-45 style jack reaches the first compensation structure before the signal reaches the second compensation structure.

6. A printed circuit board for an RJ-45 style electrical connector, the printed circuit board comprising:

a plurality of input terminals;

a plurality of output terminals;

a plurality of conductive paths connecting respective of the plurality of input terminals with respective of the plurality of output terminals; and

a first conductive trace branching off of a first of the plurality of conductive paths, the first conductive trace including a self-inductive section and a first electrode of a capacitor;

a second conductive trace branching off of a second of the plurality of conductive paths, the second conductive trace including a second electrode of the capacitor.

7. The printed circuit board of claim 6, further comprising a first compensation structure that couples a first compensating crosstalk signal from the first of the plurality of conductive paths to a third of the plurality of conductive paths.

8. The printed circuit board of claim 7, further comprising a second compensation structure that couples a second compensating crosstalk signal from the second of the plurality of conductive paths to the first of the plurality of conductive paths, wherein the second compensation stage includes the capacitor.

9. The printed circuit board of claim 8, wherein the first compensating crosstalk signal has a first polarity and the second compensating crosstalk signal has a second polarity that is generally opposite the first polarity.

10. The printed circuit board of claim 6, wherein the self-inductive section of the first conductive trace comprises a spiral section of the first conductive trace.

11. The connector of claim 6, wherein the capacitor comprises a parallel plate capacitor.

12. The connector of claim 6, wherein the capacitor comprises an interdigital capacitor.

13. A method of reducing near end crosstalk in an electrical connector that includes a plurality of pairs of conductors, the method comprising:

providing a first compensation structure that couples a first compensating crosstalk signal from a first conductor of a first of the pairs of conductors to a first conductor of a second of the pairs of conductors;

providing a second compensation structure that couples a second compensating crosstalk signal from the first conductor of the first of the pairs of conductors to a second conductor of the second of the pairs of conductors;

wherein the second compensation structure includes a series inductor-capacitor circuit.

14. The method of claim 13, wherein the inductor in the series inductor-capacitor circuit comprises a conductive path that includes one or more self-coupling sections.

15. The method of claim 14, wherein the conductive path that includes one or more self-coupling sections comprises a conductive path in the general shape of a spiral.

16. The method of claim 15, wherein the first compensating crosstalk signal has a first polarity and the second compensating crosstalk signal has a second polarity that is generally opposite the first polarity.

17. An electrical connector, comprising

a first conductor;

a second conductor; and

a circuit that is configured to couple energy between the first and second conductors;

wherein the circuit comprises a capacitor and an inductor that is connected in series to the capacitor.

18. The electrical connector of claim 17, wherein the first conductor is part of a first differential pair of conductors and the second conductor is part of a second differential pair of conductors.

19. The electrical connector of claim 18, wherein the inductor comprises a conductive trace on a printed circuit board that include self-coupling sections.

20. The electrical connector of claim 19, wherein the conductive trace that includes the self-coupling sections comprises a conductive trace that is in the general shape of a spiral.