Multipath mitigation circuit for home network

• US 9,979,373 B2
• Filed: 02/22/2016
• Issued: 05/22/2018
• Est. Priority Date: 02/01/2010
• Status: Active Grant

• Current Assignee: PPC Broadband Incorporated (Belden Inc.)
• Original Assignee: PPC Broadband Incorporated (Belden Inc.)
• Inventors: Alkan, Erdogan, Palinkas, Raymond W.
• Primary Examiner(s): LEE, BENNY T
• Assistant Examiner(s): Rahman, Hafizur
• Application Number:
  US15/049,805
• Publication Number:
  US 20160173054A1
• Time in Patent Office: 820 Days
• Field of Search: 333167, 333168, 333175, 333176, 333 81 A, 333100, 333129, 333132, 455296, 455307
• CPC Class Codes: H03H 7/01 Frequency selective two-port networks
• CPC Class Codes: H03H 7/0138 Electrical filters or coupling circuits
• CPC Class Codes: H03H 7/0161 Bandpass filters H03H7/12 takes precedence
• CPC Class Codes: H03H 7/06 including resistors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H03H 7/1741 Comprising typical LC combinations, irrespective of presence and location of additional resistors when resistors are present, also classify in H03H7/06 - H03H7/07
• CPC Class Codes: H03H 7/1758 Series LC in shunt or branch path H03H7/1791 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence

Abstract

A filter circuit is provided having multipath interference mitigation. The filter includes a signal path extending from an input to an output. The signal path includes a conductive path and a ground. A pass band filter is disposed along the signal path between the input and the output. The pass band filter passes a first frequency spectrum in a provider bandwidth, and attenuates a second frequency spectrum in a home network bandwidth. The filter circuit further includes a multipath interference mitigation leg operatively branched from the signal path. The multipath interference mitigation leg increases a return loss of the home network bandwidth. A frequency response of the filter circuit is characterized by an insertion loss characteristic between the input and the output being less than 3 dB in the provider bandwidth, and more than 20 dB in the home network bandwidth.

Claims

1. A filter circuit, comprising:

a pass band filter portion disposed along a signal path between a provider-side port and a user-side port, the pass band filter portion configured to pass a first frequency spectrum in a provider bandwidth and attenuate a second frequency spectrum in a home network bandwidth; and

a multipath interference mitigation leg operatively branched in parallel from the pass band filter portion, the multipath interference mitigation leg configured to decrease multipath distortions by improving a return loss characteristic of the home network bandwidth,

wherein a frequency response of the filter circuit comprises a respective insertion loss characteristic in the provider bandwidth and in the home network bandwidth between the provider-side port and the user-side port, the insertion loss characteristic being less in the provider bandwidth than in the home network bandwidth, the frequency response further characterized by a return loss characteristic at the user-side port, and

wherein the second frequency spectrum in the home network bandwidth is distinct from and higher than the first frequency spectrum in the provider bandwidth.

2. The filter circuit of claim 1, wherein the frequency response further comprises the return loss characteristic in the home network bandwidth being more than 20 dB.

3. The filter circuit of claim 2, wherein the multipath interference mitigation leg further comprises a shunt resistor.

4. The filter circuit of claim 3, wherein the provider bandwidth has a characteristic impedance of 75 ohms, and the shunt resistor has a resistance value of about 75 ohms.

5. The filter circuit of claim 1, wherein the pass band filter portion comprises an inductor/capacitor arrangement having tank elements.

6. The filter circuit of claim 1 wherein the multipath interference mitigation leg comprises an attenuator portion.

7. The filter circuit of claim 6, wherein the attenuator portion comprises a Tee-type resistive attenuator.

8. The filter circuit of claim 1, wherein the frequency response is further characterized by the return loss at an output and an input being more than 20 dB in the provider bandwidth and home network bandwidth.

9. The filter circuit of claim 1, wherein the first frequency spectrum comprises a spectrum of frequencies carrying media content and the second frequency spectrum comprises an open spectrum of frequencies carrying personal data content.

10. The filter circuit of claim 1, wherein the respective insertion loss characteristic is less than 3 dB in the provider bandwidth and more than 20 dB in the home network bandwidth.

11. The filter circuit of claim 1, wherein a return loss characteristic in the provider bandwidth is more than 10 dB, and the return loss characteristic in the home network bandwidth is more than 10 dB.

12. A filter circuit, comprising:

a pass band filter portion disposed along a signal path between a provider-side port and a user-side port, the pass band filter portion configured to pass a provider bandwidth received at the provider-side port and attenuate a home network bandwidth received at the user-side port; and

a multipath interference mitigation leg operatively branched in parallel from the signal path, the multipath interference mitigation leg configured to decrease interference related to transmissions of downstream and upstream signals along the signal path,

wherein a frequency spectrum of the home network bandwidth is distinct from and higher than a frequency spectrum of the provider bandwidth.

13. The filter circuit of claim 12, wherein a frequency response of the filter circuit results in attenuation between the provider-side port and the user-side port, the attenuation being higher in the home network bandwidth than in the provider bandwidth, and the frequency response further results in a decrease in energy reflection at the user-side port.

14. The filter circuit of claim 12, wherein the multipath interference mitigation leg comprises an absorptive portion.

15. The filter circuit of claim 14, wherein the absorptive portion comprises at least one lumped element comprising two capacitors in series, with an inductor/capacitor series connection shunted to ground from a node between the two capacitors.

16. The filter circuit of claim 14, wherein the multipath interference mitigation leg comprises a termination resistor configured to match an impedance of a line load of the signal path.

17. A filter circuit, comprising:

a pass band filter portion disposed along a signal path between a provider-side port and a user-side port, the pass band filter portion configured to pass a provider bandwidth and attenuate a home network bandwidth; and

a multipath interference mitigation leg operatively branched from the signal path, the multipath interference mitigation leg configured to decrease reflections due to an impedance mismatch, wherein a frequency response of the filter circuit results in an attenuation between the provider-side port and the user-side port, the attenuation being less in the provider bandwidth than in the home network bandwidth, and the frequency response further results in a decrease in reflection of energy at the user-side port,

wherein a frequency spectrum of the home network bandwidth is distinct from and higher than a frequency spectrum of the provider bandwidth.

18. The filter circuit of claim 17, wherein the filter circuit is a point-of-entry filter in a cable television network.

19. The filter circuit of claim 17, wherein the multipath interference mitigation leg comprises at least two lumped elements, each lumped element comprising two capacitors in series and an inductor/capacitor series connection, the inductor/capacitor series connection being shunted to ground from a node between the two capacitors.

20. A filter circuit, comprising:

a pass band filter portion disposed along a signal path between a provider-side port and a user-side port, the pass band filter portion configured to pass a provider bandwidth comprising a spectrum of frequencies carrying media content, and attenuate a home network bandwidth comprising an open spectrum of frequencies carrying personal data content; and

a multipath interference mitigation leg operatively branched in parallel from the pass band filter portion, the multipath interference mitigation leg configured to decrease multipath distortions in the home network bandwidth by improving a return loss characteristic at the user-side port,

wherein a frequency response of the filter circuit comprises a respective insertion loss characteristic in the provider bandwidth and in the home network bandwidth between the provider-side port and the user-side port, the insertion loss characteristic being less in the provider bandwidth than in the home network bandwidth,

wherein the frequency response further comprises the return loss characteristic at the user-side port being more than 10 dB in the home network bandwidth, and

wherein the open spectrum of frequencies in the home network bandwidth is distinct from and higher than the spectrum of frequencies in the provider bandwidth.

21. A filter circuit for decreasing impedance mismatch reflections and lowering attenuation in a home network bandwidth relative to attenuation in a provider bandwidth, comprising:

an impedance mismatch mitigation and attenuation device configured to decrease impedance mismatch reflections in a home network and selectively attenuate a frequency response between a provider-side port and a user-side port so as to generate a first attenuation level of a provider bandwidth that is less than a second attenuation level of a home network bandwidth; and

wherein the home network bandwidth has a first frequency spectrum, and the provider bandwidth has a second frequency spectrum that is less than the first frequency spectrum of the home network bandwidth.

22. The filter circuit of claim 21, wherein the impedance mismatch mitigation and attenuation device comprises a pass band filter portion disposed along a signal path between the provider-side port and the user-side port, the pass band filter portion being configured to pass the provider bandwidth and attenuate the home network bandwidth.

23. The filter circuit of claim 22, wherein the pass band filter portion comprises a low pass filter comprising a parallel inductor/capacitor arrangement.

24. The filter circuit of claim 23, wherein the impedance mismatch mitigation and attenuation device comprises a multipath interference mitigation leg branched from a signal path between the provider-side port and the use-side port, wherein the multipath interference mitigation leg is configured to decrease the impedance mismatch reflections in the home network.

25. The filter circuit of claim 24, wherein the impedance mismatch mitigation and attenuation device comprises a high pass filter portion and an attenuator portion, wherein the attenuator portion comprises a Tee-type resistive attenuator.

26. The filter circuit of claim 24, wherein the multipath interference mitigation leg comprises at least two lumped elements, each lumped element comprising two capacitors in series and an inductor/capacitor series connection, the inductor/capacitor series connection being shunted to ground from a node between the two capacitors.