Filter circuit

Abstract

A filter for use in a coaxial cable network includes a printed circuit board having first and second opposed major surfaces, and first and second opposing sides. The opposed major surfaces are substantially parallel to a single plane, and are bisected by a longitudinal axis. The first and second opposing sides are substantially parallel to the longitudinal axis. The filter further includes an input terminal and an output terminal connected to the printed circuit board. The input terminal and the output terminal have an axis extending substantially parallel to the longitudinal axis. A signal path is disposed on the printed circuit board and extends from the input terminal toward the output terminal. The filter further includes a plurality of resonator elements fabricated upon the first opposed major surface. In one embodiment, the inductor elements are arranged in series along the signal path defining a footprint of less than 540 square millimeters. The filter passes a first range of frequencies in a provider bandwidth and attenuates a second range of frequencies in a personal data network bandwidth. In one embodiment, the resonator elements are parallel inductor elements and capacitor elements, the inductor elements being etched spiral inductors.

I claim: 
     
       1. A filter circuit assembly comprising:
 a printed circuit board having first and second opposed major surfaces and first and second opposing sides, the opposed major surfaces being substantially parallel to a single plane and being bisected by a longitudinal axis, the first and second opposing sides being substantially parallel to the longitudinal axis; 
 an input terminal connected to the printed circuit board, the input terminal having an axis extending substantially parallel to the longitudinal axis; 
 an output terminal connected to the printed circuit board, the output terminal having an axis extending substantially parallel to the longitudinal axis; 
 a signal path disposed on the printed circuit board, the signal path extending from the input terminal toward the output terminal; 
 a plurality of resonator elements being fabricated upon at least one of the major surfaces, the resonator elements arranged in series along the signal path and defining a footprint being less than 540 square millimeters; and 
 a spark gap element disposed on one of the opposing major surfaces, 
 wherein the filter passes a first range of frequencies in a provider bandwidth and attenuates a second range of frequencies in a personal data network bandwidth. 
 
     
     
       2. The filter circuit assembly of  claim 1 , wherein the first range of frequencies in the provider bandwidth is between 5 megahertz and 1002 megahertz, and the second range of frequencies in the personal data network bandwidth is between 1125 megahertz and 1525 megahertz. 
     
     
       3. The filter circuit assembly of  claim 1 , wherein the filter has an insertion loss characteristic of more than 30 decibels in the personal data network bandwidth. 
     
     
       4. The filter circuit assembly of  claim 1 , wherein the filter has an insertion loss of less than 3 decibels in the provider bandwidth. 
     
     
       5. The filter circuit assembly of  claim 1 , further comprising a spark gap element disposed on one of the major opposing surfaces. 
     
     
       6. The filter circuit assembly of  claim 1  wherein the resonator elements define a footprint, and wherein the footprint has an area that is less than 250 square millimeters. 
     
     
       7. The filter circuit assembly of  claim 6  wherein the footprint has an area that is less than 190 square millimeters. 
     
     
       8. The filter circuit assembly of  claim 1  wherein the resonator elements comprise parallel inductor and capacitor elements. 
     
     
       9. The filter circuit assembly of  claim 8  wherein the inductor elements are disposed on one major surface and the capacitor elements are disposed on another major surface, the inductor elements and capacitor elements being in electrical communication by a via. 
     
     
       10. The filter circuit assembly of  claim 8  further comprising a tuning element bridging an intermediate portion of at least one of the inductor elements to the signal path. 
     
     
       11. The filter circuit assembly of  claim 8  wherein the inductor elements are spiral etched inductor elements. 
     
     
       12. The filter circuit assembly of  claim 11  further comprising a tuning element bridging an intermediate portion of at least one of the spiral etched inductor elements to a via. 
     
     
       13. A filter circuit comprising:
 a first plurality of resonator elements; 
 a second plurality of shunt capacitor elements; and 
 a spark gap element disposed on a major surface of a printed circuit board; 
 the filter circuit having a frequency response, the frequency response comprising: 
 a signal path extending from an input to an output and having a conductor and a ground; 
 a low-pass portion having a first frequency spectrum in a provider bandwidth; 
 an attenuated portion having a second frequency spectrum in a personal data network bandwidth, the attenuated portion causing a uniform insertion loss of greater than 30 decibels; 
 a transition portion between the low pass portion and the attenuated portion; and wherein a topology of the filter circuit comprises a the first plurality of resonator elements arranged in series along the a signal path, and a the second plurality of shunt capacitor elements disposed between the first plurality of resonator elements, the second plurality of shunt capacitor elements in electrical communication with the a ground. 
 
     
     
       14. The filter circuit of  claim 13  wherein the a frequency range in the provider bandwidth is 5 megahertz to 1002 megahertz. 
     
     
       15. The filter circuit of  claim 13  wherein the attenuated portion causes a uniform insertion loss of greater than 50 decibels. 
     
     
       16. The filter circuit of  claim 13  wherein the resonator elements comprise parallel inductor elements and capacitor elements. 
     
     
       17. The filter circuit of  claim 13  wherein the transition portion has a frequency range of less than 150 megahertz. 
     
     
       18. The filter circuit of  claim 13  wherein the a range of frequencies in the personal data network bandwidth is 1125 megahertz to 1525 megahertz. 
     
     
       19. The filter circuit of  claim 18  wherein the frequency range of frequencies in the personal data network bandwidth is greater than 1125 megahertz and less than 1525 megahertz. 
     
     
       20. The filter circuit of  claim 19  wherein the attenuated portion causinges a uniform insertion loss of greater than 40 decibels. 
     
     
       21. The filter circuit of  claim 13  wherein the topology is an elliptic filter. 
     
     
       22. The filter circuit of  claim 21  wherein the elliptic filter is a Chebyshev elliptic filter. 
     
     
       23. The filter circuit of  claim 22  wherein the elliptic filter is a ninth order Chebyshev elliptic filter. 
     
     
       24. A filter circuit assembly for use in television provider services, the circuit assembly comprising:
 a printed circuit board having a first and a second opposed major surfaces and first and second opposing sides, the opposed major surfaces being substantially parallel to a single plane and being bisected by a longitudinal axis, the first and second opposing sides being substantially parallel to the longitudinal axis, the printed circuit board being comprised of a substrate having dielectric properties; 
 a signal path disposed on the substrate, the signal path extending from an input port toward an output port; 
 at least three etched spiral inductor elements fabricated upon the first opposed major surface and arranged in series along the signal path, the arrangement of the inductor elements defining a footprint, wherein the footprint being less than 250 square millimeters has an area; 
 a plurality of capacitor elements in electrical communication with the etched inductor elements to form a plurality of resonator elements, the capacitor elements being fabricated upon the second opposed major surface and being connected to the inductor elements by a via; and 
 a spark gap element disposed on one of the first and the second opposed major surfaces, 
 wherein the filter passes a first range of frequencies between 5 megahertz and 1002 megahertz and attenuates a second range of frequencies between 1125 megahertz and 1525 megahertz, the second range of frequencies having an insertion loss of more than 30 decibels. 
 
     
     
       25. The filter circuit assembly of  claim 24  wherein the area of the footprint is less than 190 square millimeters. 
     
     
       26. The filter circuit assembly of  claim 24  wherein the inductor element comprises a conductive trace, the filter further comprising a tuning element bridging intermediate portions of the conductive trace to the via. 
     
     
       27. The filter circuit assembly of  claim 26  wherein the tuning element is a conductive trace etched into the opposed major surface. 
     
     
       28. A coaxial cable ground block assembly comprising:
 a housing having a thru bore, the housing adapted for electrical contact with a source to electrical ground; 
 a first connector body coupled to one end of the thru bore of the housing; 
 a first coaxial cable terminal coupled to the first connector body; 
 a second connector body coupled to the other end of the thru bore of the housing; 
 a second coaxial cable terminal coupled to the second connector body; and 
 a printed circuit board sealed contained within the housing, the circuit board having an input in electrical contact with the first terminal, an output in electrical contact with the second terminal, a ground plane in electrical contact with the housing, a signal path extending from the input toward the output, a spark gap element disposed on a major surface of the printed circuit board and a filter circuit disposed on the signal path, the filter circuit passing a provider bandwidth and attenuating a personal data network bandwidth. 
 
     
     
       29. The coaxial cable ground block assembly of  claim 28  wherein the filter circuit comprises a plurality of resonator elements arranged in series along the signal path. 
     
     
       30. The connectorcoaxial cable ground block assembly of  claim 29  wherein the resonator elements comprise parallel inductor and capacitor elements, the inductor elements comprising spiral etched inductor elements. 
     
     
       31. The coaxial cable ground block assembly of  claim 29  wherein resonator elements define a footprint being less than 540 square millimeters. 
     
     
       32. The connector coaxial cable ground block assembly of  claim 31  wherein the footprint is less than 250 square millimeters. 
     
     
       33. The connector coaxial cable ground block assembly of  claim 32  wherein the footprint is less than 190 square millimeters. 
     
     
       34. A coaxial cable connector assembly comprising:
 a printed circuit board having a signal path and a ground plane thereon, the printed circuit board having first and second opposed major surfaces and first and second opposing sides, the opposed major surfaces being substantially parallel to a single plane and being bisected by a longitudinal axis, the first and second opposing sides being substantially parallel to the longitudinal axis, the signal path having an input, an output, and a filter circuit disposed therebetween, the filter circuit passing a provider bandwidth and attenuating a personal data network bandwidth, the filter circuit having a plurality of resonator elements arranged in series along the signal path and defining a footprint being less than 540 square millimeters and a spark gap element disposed on a first major surface of the printed circuit board ; 
 a body that receives the printed circuit board, the body having a first end and a second end opposite the first end, the first end and second end shaped so as to receive a first cable connector and a second cable connector respectively; 
 a first terminal disposed within the body in electrical contact with the input of the signal path; 
 a second terminal disposed within the body in electrical contact with the output of the signal path; 
 a first insulator disposed in surrounding relation to the first terminal; and  
 a second insulator disposed in surrounding relation to the second terminal; and 
 at least one seal located entirely within the body to protect the circuit board from environmental elements. 
 
     
     
       35. The coaxial cable connector assembly of  claim 34  wherein the filter circuit has an insertion loss characteristic of more than 30 decibels in the personal data network bandwidth. 
     
     
       36. The coaxial cable connector assembly of  claim 34  wherein the resonator elements comprise parallel inductor and capacitor elements, the inductor elements comprising spiral etched inductor elements. 
     
     
       37. The coaxial cable connector assembly of  claim 34  wherein the resonator elements define a footprint having an area, and wherein the area of the footprint is less than 250 square millimeters. 
     
     
       38. The coaxial cable connector assembly of  claim 37  wherein the area of the footprint is less than 190 square millimeters. 
     
     
       39. The filter circuit assembly of claim 1, wherein the opposed major surfaces are substantially parallel to a single plane and are bisected by a longitudinal axis, and wherein the first and second opposing sides are substantially parallel to the longitudinal axis. 
     
     
       40. The filter circuit assembly of claim 1, wherein the plurality of resonator elements define a footprint having an area, and wherein the area of the footprint is less than 540 square millimeters. 
     
     
       41. The filter circuit assembly of claim 39, wherein the input terminal has an axis extending substantially parallel to the longitudinal axis. 
     
     
       42. The filter circuit assembly of claim 39, wherein the output terminal has an axis extending substantially parallel to the longitudinal axis. 
     
     
       43. The filter circuit assembly of claim 39, wherein the input terminal has an axis extending substantially parallel to the longitudinal axis, and wherein the output terminal has an axis extending substantially parallel to the longitudinal axis. 
     
     
       44. The filter circuit of claim 13, wherein the signal path extends from an input to an output and comprises a conductor and the ground. 
     
     
       45. The filter circuit assembly of claim 24, wherein the first and the second opposed major surface are substantially parallel to a single plane and are bisected by a longitudinal axis. 
     
     
       46. The filter circuit assembly of claim 45, wherein the printed circuit board further comprises a first and a second opposing side, wherein the first and the second opposing sides are each parallel to the longitudinal axis. 
     
     
       47. The filter circuit assembly of claim 24, wherein the area of the footprint is less than 250 square millimeters. 
     
     
       48. The coaxial cable ground block assembly of claim 28, wherein the printed circuit board is sealed within the housing. 
     
     
       49. The coaxial cable connector assembly of claim 34, wherein the filter circuit defines a footprint, wherein the footprint has an area less than 540 square millimeters. 
     
     
       50. The coaxial cable connector assembly of claim 34, wherein the printed circuit board further comprises a second major surface opposed to the first major surface and a first and a second opposing side, wherein the first and the second major surfaces are substantially parallel to a single plane and are bisected by a longitudinal axis, and
 wherein the first and the second opposing sides are substantially parallel to the longitudinal axis.   
     
     
       51. The coaxial cable connector assembly of claim 34, further comprising at least one seal located entirely within the body to protect the circuit board from environmental elements.