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

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.

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. 
     
     
       44. A printed circuit board comprising:
 a plurality of conductors;   a first compensation structure that is configured to provide a first compensating crosstalk having a first magnitude to a first of the plurality of conductors; and   a second compensation structure that is configured to provide a second compensating crosstalk having a second magnitude to the first of the plurality of conductors;   wherein a ratio of the first magnitude to the second magnitude varies with frequency.   
     
     
       45. The printed circuit board of claim 44, wherein the printed circuit board includes a first printed circuit board portion and a second printed circuit board portion that is separate from the first printed circuit board portion, and wherein the first printed circuit board portion includes the first compensation structure and the second printed circuit board portion includes the second compensation structure. 
     
     
       46. The printed circuit board of claim 45, wherein the first compensation structure is at a first delay from a point where the conductors of the electrical connector intercept conductors of a mating plug connector and the second compensation structure is at a second delay from the point where the conductors of the electrical connector intercept conductors of the mating plug connector, where the first delay is less than the second delay. 
     
     
       47. The printed circuit board of claim 46, wherein the first compensation structure includes a parallel plate capacitor. 
     
     
       48. The printed circuit board of claim 47, wherein the first printed circuit board portion includes a first dielectric material that has a first dielectric constant that has a first rate of change with frequency, and the second printed circuit board portion includes a second dielectric material that has a second dielectric constant that has a second rate of change with frequency that is different than the first rate of change with frequency. 
     
     
       49. The printed circuit board of claim 48, wherein the first rate of change with frequency is higher than the second rate of change with frequency. 
     
     
       50. The printed circuit board of claim 1, wherein the printed circuit board includes a first printed circuit board portion and a separate second printed circuit board portion, and wherein the first printed circuit board portion includes the first stage of compensation and the second printed circuit board portion includes the second stage of compensation. 
     
     
       51. The printed circuit board of claim 35, wherein the printed circuit board includes a first printed circuit board portion and a separate second printed circuit board portion, and wherein the first printed circuit board portion includes the first capacitor and the second printed circuit board portion includes the second capacitor. 
     
     
       52. The printed circuit board of claim 44, wherein the printed circuit board comprises a unitary printed circuit board structure and the first compensation structure and the second compensation structure are both on the unitary printed circuit board structure.