FAR END CROSSTALK COMPENSATION

• US 20090275236A1
• Filed: 02/11/2009
• Published: 11/05/2009
• Est. Priority Date: 02/12/2008
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC GmbH (TE Connectivity Ltd. (United Kingdom))
• Inventors: Murray, David Patrick, Hammond, Bernard Harold JR.
• Granted Patent: US 7,841,909 B2
• Time in Patent Office: Days
• US Class Current: 439/620.210
• 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 13/6658 on printed circuit board H01R13/6666 - H01R13/6691 take precedence
• CPC Class Codes: H01R 13/6691 with built-in signalling means H01R13/717 takes 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 2201/09236 Parallel layout layout of balanced signal pairs H05K1/0245; superposed layout H05K2201/09672
• CPC Class Codes: H05K 2201/09672 Superposed layout, i.e. in different planes parallel traces in one plane H05K2201/09236
• CPC Class Codes: H05K 2201/10189 Non-printed connector
• CPC Class Codes: Y10S 439/941 Crosstalk suppression
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49208 by assembling plural parts
• CPC Class Codes: Y10T 29/53209 Terminal or connector

Abstract

Methods and systems for providing crosstalk compensation in a jack are disclosed. According to one method, the crosstalk compensation is adapted to compensate for undesired crosstalk generated at a capacitive coupling located at a plug inserted within the jack. The method includes positioning a first capacitive coupling a first time delay away from the capacitive coupling of the plug, the first capacitive coupling having a greater magnitude and an opposite polarity as compared to the capacitive coupling of the plug. The method also includes positioning a second capacitive coupling at a second time delay from the first capacitive coupling, the second time delay corresponding to an average time delay that optimizes near end crosstalk. The second capacitive coupling has generally the same overall magnitude but an opposite polarity as compared to the first capacitive coupling, and includes two capacitive elements spaced at different time delays from the first capacitive coupling.

Claims

1. A method for providing crosstalk compensation in a jack, the crosstalk compensation being adapted to compensate for undesired crosstalk generated at a capacitive coupling located at a plug inserted within the jack, the method comprising:

positioning a first capacitive coupling a first time delay away from the capacitive coupling of the plug, the first capacitive coupling having a greater magnitude and an opposite polarity as compared to the capacitive coupling of the plug;

positioning a second capacitive coupling at a second time delay from the first capacitive coupling, the second time delay corresponding to an average time delay that optimizes near end crosstalk, the second capacitive coupling having generally the same overall magnitude but an opposite polarity as compared to the first capacitive coupling, and including two capacitive elements spaced at different time delays from the first capacitive coupling.

2. The method of claim 1, further comprising providing a third capacitive coupling positioned a third time delay away from the second capacitive coupling, such that the third time delay is approximately the same as the first time delay.

3. The method of claim 1, wherein the two capacitive elements connect between wires of a first wire pair and a second wire pair.

4. The method of claim 3, wherein the two capacitive elements connect between different wires of the first wire pair and the second wire pair.

5. The method of claim 1, wherein different time delays of the two capacitive elements in the second capacitive coupling are centered about the average time delay.

6. The method of claim 1, wherein the first capacitive coupling exists across different wire pairs than the second capacitive coupling.

7. A telecommunications jack for use in a twisted pair system, the jack comprising:

a housing defining a port for receiving a plug;

a plurality of contact springs adapted to make electrical contact with the plug when the plug is inserted into the port of the housing;

a plurality of wire termination contacts for terminating wires to the jack;

a circuit board including conductive tracks that electrically connect the contact springs to the wire termination contacts; and

a crosstalk compensation arrangement that provides crosstalk compensation between selected tracks of the circuit board, the crosstalk compensation arrangement including a first zone of compensation a first time delay away from the capacitive coupling of the plug and a second zone of compensation at an second time delay from the first zone of compensation, the second zone of compensation including two capacitive elements spaced at different time delays from the first zone of compensation to optimize far end crosstalk and having an average time delay that optimizes near end crosstalk.

8. The telecommunications jack of claim 7, wherein the crosstalk compensation arrangement further includes a third zone of compensation that is positioned a third time delay away from the second zone of compensation, the first and third time delays being generally equal to one another.

9. The telecommunications jack of claim 7, wherein the first zone of compensation has a greater magnitude and an opposite polarity as compared to the capacitive coupling of the plug, and the second zone of compensation has generally the same overall magnitude but an opposite polarity as compared to the first zone of compensation.

10. The telecommunications jack of claim 7, wherein the second zone of compensation is positioned such that the second time delay is greater than the first time delay.

11. The telecommunications jack of claim 7, wherein the second zone of compensation is positioned such that the second time delay is less than the first time delay.

12. A crosstalk compensation system within a telecommunications jack, the system comprising:

a circuit board;

a plurality of contact springs mounted on the circuit board, the contact springs including first, second, third, fourth, fifth, sixth, seventh and eighth consecutively arranged contact springs;

a plurality of wire termination contacts mounted on the circuit board, the wire termination contents including first, second, third, fourth, fifth, sixth, seventh and eighth wire termination contacts for terminating wires to the jack;

a plurality of tracks on the circuit board, the tracks including first, second, third, fourth, fifth, sixth, seventh and eighth tracks that respectively electrically connect the first, second, third, fourth, fifth, sixth, seventh and eighth contact springs to the first, second, third, fourth, fifth, sixth, seventh and eighth wire termination contacts;

a crosstalk compensation arrangement that provides crosstalk compensation between the tracks of the circuit board, the crosstalk compensation arrangement including a first zone of compensation a first time delay away from the contact springs and a second zone of compensation at an second time delay from the first zone of compensation, the second zone of compensation including two capacitive elements spaced at different time delays from the first capacitive coupling and having an average time delay that that optimizes near end crosstalk.

13. The system of claim 12, wherein the second zone of compensation includes a capacitive element connected between the third track and the fourth track.

14. The system of claim 13, wherein the second zone of compensation includes a second capacitive element connected between the fifth track and the sixth track.

15. The system of claim 14, wherein the capacitive element is placed at a time delay further away from the first zone of compensation than the second capacitive element.

16. The system of claim 12, wherein the first zone of compensation includes a capacitive element connected between the third track and the fifth track.

17. The system of claim 12, wherein the first zone of compensation includes a capacitive element connected between the fourth track and the sixth track.

18. The system of claim 12, wherein the crosstalk compensation arrangement includes a third zone of compensation that is positioned a third time delay away from the second zone of compensation, the first and third time delays being generally equal to one another.

19. A method for determining the positions of first and second zones of crosstalk compensation in a jack, the first and second zones of crosstalk compensation being adapted to compensate for undesired crosstalk caused by an undesired capacitive coupling located at a plug inserted within the jack, the first zone of crosstalk compensation including a first capacitive coupling positioned a first time delay away from the undesired capacitive coupling of the plug, the first capacitive coupling having a greater magnitude and an opposite polarity as compared to the undesired capacitive coupling of the plug, the second zone of crosstalk compensation including a second capacitive coupling having two capacitive elements positioned, on average, a second time delay away from the first capacitive coupling, the second capacitive coupling having generally the same magnitude but an opposite polarity as compared to the first capacitive coupling, the method comprising:

positioning the first and second capacitive couplings in initial positions in which the first and second time delays are generally equal to one another;

adjusting the position of the second capacitive coupling from the initial position to an adjusted position to provide improved near end crosstalk compensation;

adjusting the position of the first and second capacitive elements to different lengths to provide improved far end crosstalk compensation while maintaining the adjusted position of the second capacitive coupling as the average position of the first and second capacitive elements.

20. The method of claim 19, further comprising positioning a third zone of compensation a third time delay away from the second zone of compensation, the first and third time delays being generally equal to one another.

21. A method of designing a crosstalk compensation system for a telecommunications jack, the method comprising:

positioning a first zone of crosstalk compensation across at least a first wire pair and a second wire pair on a circuit board within a telecommunications jack, the first zone of crosstalk compensation placed at a first distance from contact springs associated with the first wire pair and the second wire pair;

positioning a second zone of crosstalk compensation across the at least first and second wire pairs at a second distance from the first zone of crosstalk compensation, the second zone of crosstalk compensation including a first capacitive coupling and a second capacitive coupling;

altering the position of the capacitive couplings to establish a distance between the first capacitive coupling and the second capacitive coupling while maintaining the second distance as an average distance from the first zone of crosstalk compensation;

wherein altering the position of the capacitive couplings provides improved far end crosstalk compensation.

22. The method of claim 21, wherein the first and second capacitive couplings connect between different wires of the first wire pair and the second wire pair.