NEXT high frequency improvement using hybrid substrates of two materials with different dielectric constant frequency slopes

• US 7,459,640 B2
• Filed: 04/11/2007
• Issued: 12/02/2008
• Est. Priority Date: 03/21/2003
• Status: Expired

• Current Assignee: CommScope Inc. (CommScope Holding Company, Inc.)
• Original Assignee: CommScope Inc. (CommScope Holding Company, Inc.)
• Inventors: Long, Troy, Hashim, Amid, Adriaenssens, Luc
• Primary Examiner(s): Reichard; Dean A.
• Assistant Examiner(s): Semenenko; Yuriy
• Application Number:
  US11/734,263
• Publication Number:
  US 20070184724A1
• Time in Patent Office: 601 Days
• Field of Search: 174/258, 361/676, 361/404, 439/941, 439/676, 439/404, 439/418, 439/188, 333/1, 333/12, 333/35, 333/165, 333/185
• US Class Current: 174/258
• 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: 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 1/0231 Capacitors or dielectric substances
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• 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 2201/09245 Crossing layout alternating conductors H05K2201/097
• 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: H05K 3/4688 Composite multilayer circuits, i.e. comprising insulating layers having different properties having a special base or central core H05K3/4602

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 PCB substrates made of materials having different dielectric frequency characteristics.

Claims

1. A printed circuit board for providing crosstalk compensation in an electrical connector comprising:

a plurality of contacts for electrical connection with a mating connector, said plurality of contacts being mounted to said printed circuit board;

a first stage of compensation including a first capacitor having a first dielectric with a first dielectric constant that has a first rate of change with frequency;

a first conductive path electrically connecting said first capacitor to a portion of a first contact of said plurality of contacts, which portion is intended to make electrical contact with the mating connector;

a second stage of compensation including a second capacitor having a second dielectric with a second dielectric constant that has a second rate of change with frequency different than said first dielectric by at least about 0.15 across a decade of frequency; and

a second conductive path electrically connecting said second capacitor to said portion of said first contact of said plurality of contacts.

2. The printed circuit board of claim 1, wherein said plurality of contacts are spring wire contacts.

3. The printed circuit board of claim 1, wherein said first capacitor is an interdigital capacitor.

4. The printed circuit board of claim 1, wherein said first capacitor is a plate capacitor.

5. The printed circuit board of claim 1, wherein said second capacitor is a component that is surface mounted to said printed circuit board.

6. The printed circuit board of claim 1, wherein said first capacitor and said second capacitor are connected to said printed circuit board.

7. The printed circuit board of claim 6, wherein said printed circuit board includes multiple stacked substrates, and wherein said first capacitor is formed on one or more surfaces of said multiple stacked substrates.

8. The printed circuit board of claim 7, wherein said first capacitor is an interdigital capacitor.

9. The printed circuit board of claim 7, wherein said first capacitor is a plate capacitor.

10. The printed circuit board of claim 7, wherein said second capacitor is a component that is surface mounted to said printed circuit board.

11. The printed circuit board of claim 6, wherein said printed circuit board includes multiple stacked substrates, wherein a first substrate of said multiple stacked substrates serves as said first dielectric with said first dielectric constant, and wherein a second substrate of said multiple stacked substrates serves as said second dielectric with said second dielectric constant.

12. The printed circuit board of claim 11, wherein said printed circuit board includes four stacked substrates, two substrates having said first dielectric constant and two other substrates having said second dielectric constant.

13. The printed circuit board of claim 11, wherein said printed circuit board includes five stacked substrates, two substrates having said first dielectric constant and two other substrates having said second dielectric constant, and a fifth substrate having a first portion with said first dielectric constant and a second portion with said second dielectric constant.

14. The printed circuit board of claim 1, wherein said printed circuit board is includes a first circuit board portion and a separate second circuit board portion, wherein said first capacitor is connected to said first circuit board portion and wherein said second capacitor is connected to said second circuit board portion.

15. The printed circuit board of claim 14, wherein said first circuit board portion includes multiple stacked first substrates, wherein at least one of said stacked first substrates serves as said first dielectric with said first dielectric constant, wherein said second circuit board portion includes multiple stacked second substrates, and wherein at least one of said stacked second substrates serves as said second dielectric with said second dielectric constant.

16. The printed circuit board of claim 1, wherein said plurality of contacts extend away from said printed circuit board, and include at least one crossover, where an ordering of said plurality of contacts is changed prior to free ends of said plurality of contacts.

17. The printed circuit board of claim 1, wherein said plurality of contacts have fixed ends mounted to said printed circuit board and free ends opposite said fixed ends, and wherein said first conductive path passes through said free end of said first contact of said plurality of contacts.

18. The printed circuit board of claim 17, wherein said second conductive path passes through said fixed end of said first contact of said plurality of contacts.

19. The printed circuit board of claim 1, further comprising:

a modular jack housing for housing at least a portion of said plurality of contacts, said modular jack housing having an opening for receiving the mating connector.

20. The printed circuit board of claim 1, wherein said second dielectric is lower in rate of decline with frequency than said first dielectric.

21. The printed circuit board of claim 1 wherein said first dielectric constant is about 4.0 at 1 MHz with a rate of decline being about 0.4 per decade of frequency between 1 MHz and 1 GHz.

22. The printed circuit board of claim 21, wherein said second dielectric constant is about 4.0 at 1 MHz and remains constant across a frequency range of 1 MHz to 1 GHz.

23. The printed circuit board of claim 1, wherein said second dielectric constant is about 4.0 at 1 MHz and remains constant across a frequency range of 1 MHz to 1 GHz.

24. The printed circuit board of claim 1, wherein said first dielectric constant is in the range of 3.0 to 5.0 at 1 MHz with a rate of decline being about 0.4 per decade of frequency between 1 MHz and 1 GHz.

25. The printed circuit board of claim 24, wherein said second dielectric constant is in the range of 3.0 to 5.0 at 1 MHz and remains constant across a frequency range of 1 MHz to 1 GHz.

26. The printed circuit board of claim 1, wherein said second dielectric constant is in the range of 3.0 to 5.0 at 1 MHz and remains constant across a frequency range of 1 MHz to 1 GHz.

27. The printed circuit board of claim 1, wherein the difference in the decline rate of said first dielectric and said second dielectric is in the range of 0.15 to 0.45 per decade of frequency.

28. The printed circuit board of claim 1, wherein said first stage of compensation further includes a third capacitor having said first dielectric with said first dielectric constant, and said second stage of compensation includes a fourth capacitor having said second dielectric with said second dielectric constant, further comprising:

a third conductive path electrically connecting said third capacitor to a portion of a second contact of said plurality of contacts, which portion is intended to make electrical contact with the mating connector; and

a fourth conductive path electrically connecting said fourth capacitor to said portion of said second contact of said plurality of contacts, wherein said fourth conductive path is longer than said third conductive path.

29. The printed circuit board of claim 28, wherein said plurality of contacts have fixed ends mounted to said printed circuit board and free ends opposite said fixed ends, and wherein said third conductive path passes through said free end of said second contact of said plurality of contacts.

30. The printed circuit board of claim 29, wherein said fourth conductive path passes through said fixed end of said second contact of said plurality of contacts.

31. The printed circuit board of claim 28, further comprising:

a fifth conductive path electrically connecting said first capacitor to a portion of a third contact of said plurality of contacts, which portion is intended to make electrical contact with the mating connector; and

a sixth conductive path electrically connecting said second capacitor to said portion of said third contact of said plurality of contacts, wherein said sixth conductive path is longer than said fifth conductive path;

a seventh conductive path electrically connecting said third capacitor to a portion of a fourth contact of said plurality of contacts, which portion is intended to make electrical contact with the mating connector; and

a eighth conductive path electrically connecting said fourth capacitor to said portion of said fourth contact of said plurality of contacts, wherein said eighth conductive path is longer than said seventh conductive path.

32. The printed circuit board of claim 31, wherein said plurality of contacts have fixed ends mounted to said printed circuit board and free ends opposite said fixed ends, wherein said first conductive path passes through said free end of said first contact of said plurality of contacts, wherein said third conductive path passes through said free end of said second contact of said plurality of contacts, wherein said fifth conductive path passes through said free end of said third contact of said plurality of contacts, and wherein said seventh conductive path passes through said free end of said fourth contact of said plurality of contacts.

33. The printed circuit board of claim 32, wherein said second conductive path passes through said fixed end of said first contact of said plurality of contacts, wherein said fourth conductive path passes through said fixed end of said second contact of said plurality of contacts, wherein said sixth conductive path passes through said fixed end of said third contact of said plurality of contacts, and wherein said eighth conductive path passes through said fixed end of said fourth contact of said plurality of contacts.

34. The printed circuit board of claim 1, wherein said second conductive path is longer than said first conductive path.

35. A printed circuit board for providing crosstalk compensation in an electrical connector, the printed circuit board comprising:

a plurality of conductors;

a first capacitor electrically connected to a first of the conductors and providing crosstalk compensation to a signal communicated on the first of the conductors, the first capacitor having a first dielectric with a first dielectric constant slope; and

a second capacitor electrically connected to the first of the conductors and providing crosstalk compensation to the signal communicated on the first of the conductors, the second capacitor having a second dielectric with a second dielectric constant slope, different than the first dielectric constant slope.

36. The printed circuit board of claim 35, wherein the first dielectric constant slope or the second dielectric constant slope is substantially constant across the frequency range of about 1 MHz to about 1 GHz.

37. The printed circuit board of claim 35, wherein the first dielectric constant slope is about 0.2 per decade of frequency across the frequency range of 1 MHz to 1 GHz.

38. The printed circuit board of claim 35, wherein the first dielectric constant slope is about 0.4 per decade of frequency across the frequency range of 1 MHz to 1 GHz.

39. A printed circuit board comprising:

a plurality of conductive paths that extend from a plurality of respective inputs of said printed circuit board to a plurality of respective outputs of said printed circuit board;

a first compensation stage for capacitively coupling crosstalk compensation having a first polarity onto a first path of said plurality of conductive paths, said first compensation stage including at least one first capacitive element that includes a first dielectric constant material that has a first rate of change with frequency; and

a second compensation stage for capacitively coupling crosstalk compensation having a polarity opposite the first polarity onto said first path of said plurality of conductive paths, said second compensation stage including at least one second capacitive element that includes a second dielectric constant material that has a second rate of change with frequency, different than the first rate of change with frequency.

40. The printed circuit board of claim 39, wherein the first rate of change is about 0.2 per decade of frequency across the frequency range of 1 MHz to 1 GHz.

41. The printed circuit board of claim 39, wherein the first rate of change is about 0.4 per decade of frequency across the frequency range of 1 MHz to 1 GHz.

42. The printed circuit board of claim 39, wherein the second rate of change is substantially flat with frequency across the frequency range of 1 MHz to 1 GHz.

43. The printed circuit board of claim 39, wherein the first and second rates of change are pre-selected to reduce the near-end crosstalk on said first path of said plurality of conductive paths in the 1 MHz to 100 MHz frequency range when a high crosstalk plug is electrically connected to said plurality of respective inputs, and to reduce the near-end crosstalk on said first path of said plurality of conductive paths at frequencies above 250 MHz when a low crosstalk plug is electrically connected to said plurality of respective inputs.