LC filtering with auto tuning

Patent metadata

Field	Value
Publication number	US-11716443-B2
Application number	US-202117208718-A
Country	US
Kind code	B2
Filing date	Mar 22, 2021
Priority date	Mar 23, 2020
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

A radio-frequency amplifier for a cable network includes a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of the cable network and a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of the cable network. An out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to the cable receiver of the cable network and a notch filter configured to reject the amplified digitally protected video signal having the frequency in the range between 70 MHz and 130 MHz from being amplified by the return amplifier.

First claim

We claim:

1. A radio-frequency amplifier for a cable network comprising:
(a) a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of said cable network;
(b) a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of said cable network;
(c) an out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to said cable receiver of said cable network;
(d) a notch filter configured to reject said amplified said digitally protected video signal having said frequency in said range between 70 MHz and 130 MHz from being amplified by said return amplifier;
(e) said radio-frequency amplifier providing said high frequency range of signals together with said amplified digitally protected video signal to said cable receiver; and
(f) said radio-frequency amplifier providing said low frequency range of signals without said frequencies rejected by said notch filter to said head end of said cable network, wherein said notch filter has a rejection range of no more than 24 MHz wide with at least 50 dB rejection for said digitally protected video signal.

2. The radio-frequency amplifier for said cable network of claim 1 wherein said digitally protected video signal includes 104 MHz.

3. The radio-frequency amplifier for said cable network of claim 1 wherein said high frequency range of signals includes 102 MHz to at least 750 MHz.

4. The radio-frequency amplifier for said cable network of claim 1 wherein said high frequency range of signals includes 258 MHz to at least 750 MHz.

5. The radio-frequency amplifier for said cable network of claim 1 wherein said low frequency range of signals includes 5 MHz to no more than 85 MHz.

6. The radio-frequency amplifier for said cable network of claim 1 wherein said low frequency range of signals includes 5 MHz to no more than 204 MHz.

7. The radio-frequency amplifier for said cable network of claim 1 wherein said digitally protected video signal includes 104 MHz, said high frequency range of signals includes 258 MHz to at least 750 MHz, and said low frequency range of signals includes 5 MHz to no more than 204 MHz.

8. The radio-frequency amplifier for said cable network of claim 1 wherein said notch filter includes no more than 2 dB insertion loss for a passband signal through said notch filter.

9. The radio-frequency amplifier for said cable network of claim 1 wherein said notch filter includes a plurality of inductor-capacitor resonators.

10. The radio-frequency amplifier for said cable network of claim 9 wherein a first one of said inductor-capacitor resonators includes a series inductor-capacitor resonator including a first inductor and a first capacitor, wherein a second one of said inductor-capacitor resonators includes a parallel inductor-capacitor resonator including a second inductor and a second capacitor.

11. The radio-frequency amplifier for said cable network of claim 10 wherein said first inductor of said series inductor-capacitor resonator has an inductance of at least 1 uH.

12. The radio-frequency amplifier for said cable network of claim 11 wherein said first inductor of said series inductor-capacitor resonator is a surface mounted device with a ceramic core.

13. The radio-frequency amplifier for said cable network of claim 10 wherein said second inductor of said parallel inductor-capacitor resonator has an inductance of less than 100 nH.

14. The radio-frequency amplifier for said cable network of claim 13 wherein said second inductor of said parallel inductor-capacitor resonator is a surface mounted device with an air coil.

15. The radio-frequency amplifier for said cable network of claim 10 wherein said first capacitor of said series inductor-capacitor resonator is a first varactor having a voltage-controlled capacitance.

16. The radio-frequency amplifier for said cable network of claim 15 wherein said second capacitor of said parallel inductor-capacitor resonator is a second varactor having a voltage-controlled capacitance.

17. The radio-frequency amplifier for said cable network of claim 10 wherein said first inductor of said series inductor-capacitor resonator has an inductance of at least 1 uH, wherein said second inductor of said parallel inductor-capacitor resonator has an inductance of less than 100 nH, wherein said first capacitor of said series inductor-capacitor resonator is a first varactor having a voltage controlled capacitance, wherein said second capacitor of said parallel inductor-capacitor resonator is a second varactor having a voltage controlled capacitance.

18. The radio-frequency amplifier for said cable network of claim 17 further comprising a processor providing a first signal to control a first voltage to be applied to said first varactor and a second signal to control a second voltage be applied to said second varactor.

19. The radio-frequency amplifier for said cable network of claim 18 further comprising a temperature sensor sensing an ambient temperature and said processor modifying said first voltage and said second voltage in response to a signal from said temperature sensor.

20. A radio-frequency amplifier for a cable network comprising:
(a) a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of said cable network;
(b) a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of said cable network;
(c) an out-of-band forward amplifier configured to amplify a digitally protected video signal having a frequency in a range between 70 MHz and 130 MHz that are provided downstream to said cable receiver of said cable network;
(d) a notch filter configured to reject said amplified said digitally protected video signal having said frequency in said range between 70 MHz and 130 MHz from being amplified by said return amplifier;
(e) said radio-frequency amplifier providing said high frequency range of signals together with said amplified digitally protected video signal to said cable receiver; and
(f) said radio-frequency amplifier providing said low frequency range of signals without said frequencies rejected by said notch filter to said head end of said cable network, wherein said digitally protected video signal includes 104 MHz.

21. The radio-frequency amplifier for said cable network of claim 20 wherein said high frequency range of signals includes 102 MHz to at least 750 MHz.

22. The radio-frequency amplifier for said cable network of claim 20 wherein said high frequency range of signals includes 258 MHz to at least 750 MHz.

23. The radio-frequency amplifier for said cable network of claim 20 wherein said low frequency range of signals includes 5 MHz to no more than 85 MHz.

24. The radio-frequency amplifier for said cable network of claim 20 wherein said low frequency range of signals includes 5 MHz to no more than 204 MHz.

25. A radio-frequency amplifier for a cable network comprising:
(a) a forward amplifier configured to amplify a high frequency range of signals that are provided downstream to a cable receiver of said cable network;
(b) a return amplifier configured to amplify a low frequency range of signals that are provided upstream to a head end of said cabl

Assignees

• Arris Entpr Llc

Inventors

• Schemmann Marcel Franz Christian
• Maricevic Zoran
• Sun Zhijian
• Cormier Eric Joseph

Classifications

• H04N7/102 Primary

  Circuits therefor, e.g. noise reducers, equalisers, amplifiers (H04N7/108 takes precedence) · CPC title

• H03F1/32

  Modifications of amplifiers to reduce non-linear distortion (by negative feedback H03F1/34) · CPC title

• H03F1/565

  using inductive elements · CPC title

• H04B1/18 Primary

  Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) · CPC title

• H04H60/96

  CATV systems (for accessing the Internet H04H60/86) · CPC title