Method and system for LNA adjustment to compensate for dynamic impedance matching

• US 7,933,574 B2
• Filed: 11/16/2007
• Issued: 04/26/2011
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Broadcom Corporation (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Maryam, Rofougaran, Ahmadreza
• Primary Examiner(s): Nguyen; Lee
• Application Number:
  US11/941,241
• Publication Number:
  US 20090130991A1
• Time in Patent Office: 1,257 Days
• Field of Search: 455/232.1, 4552341-2342, 455/248.1, 455/280, 455/193.1, 333/17.3, 333/32, 333/124, 333/129, 343/822, 343/852, 343860-861
• US Class Current: 455/248.1
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 1/18 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

Abstract

Aspects of a method and system for LNA adjustment to compensate for dynamic impedance matching are provided. In this regard, an antenna matching network may be configured to maximize received signal strength for a determined frequency and an amplifier gain may be adjusted based on the maximized signal strength such that output levels of the amplifier are between specified limits. The antenna matching network may be programmatically controlled via one or more switching elements. The amplifier gain may be programmatically controlled via one or more bias points. The antenna matching network may be configured for a plurality of frequencies in a frequency band, such as an FM broadcast band, and a configuration for each frequency may be stored. Accordingly, when the receiver is tuned to a frequency, a corresponding configuration may be retrieved from memory.

Claims

1. A method for signal processing, the method comprising:

performing, by one or more processors and/circuits;

configuring an antenna matching network in a receiver to maximize received signal strength for a determined frequency; and

adjusting a gain of an amplifier within said receiver based on said maximized signal strength such that output levels of said amplifier are between specified limits.

2. The method according to claim 1, comprising programmatically controlling said antenna matching network by one or more signals that control one or more switching elements.

3. The method according to claim 1, comprising programmatically adjusting said gain of said amplifier by controlling one or more bias points.

4. The method according to claim 1, comprising configuring said antenna matching network for a plurality of frequencies in a frequency band.

5. The method according to claim 4, comprising storing a result of said configuring for each of said plurality of frequencies.

6. The method according to claim 5, comprising retrieving said stored result for a frequency when tuning to said frequency.

7. The method according to claim 1, comprising retrieving stored configuration data from a memory to configure said antenna matching network.

8. The method according to claim 1, wherein said determined frequency is within an FM broadcast band.

9. A machine-readable storage having stored thereon, a computer program having at least one code section for signal processing, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

configuring an antenna matching network in a receiver to maximize received signal strength for a determined frequency; and

adjusting a gain of an amplifier within said receiver based on said maximized signal strength such that output levels of said amplifier are between specified limits.

10. The machine-readable storage according to claim 9, wherein said at least one code section comprises code that programmatically controls said antenna matching network by one or more signals that control one or more switching elements.

11. The machine-readable storage according to claim 9, wherein said at least one code section comprises code that programmatically adjusts said gain of said amplifier by controlling one or more bias points.

12. The machine-readable storage according to claim 9, wherein said at least one code section comprises code that configures said antenna matching network for a plurality of frequencies in a frequency band.

13. The machine-readable storage according to claim 12, wherein said at least one code section comprises code that stores a result of said configuring for each of said plurality of frequencies.

14. The machine-readable storage according to claim 13, wherein said at least one code section comprises code that retrieves said stored result for a frequency when tuning to said frequency.

15. The machine-readable storage according to claim 9, wherein said at least one code section comprises code that retrieves stored configuration data from a memory to configure said antenna matching network.

16. The machine-readable storage according to claim 9, wherein said determined frequency is within an FM broadcast band.

17. A system for signal processing, the system comprising:

one or more circuits that;

configure an antenna matching network in a receiver to maximize received signal strength for a determined frequency; and

adjust a gain of an amplifier within said receiver based on said maximized signal strength such that output levels of said amplifier are between specified limits.

18. The system according to claim 17, wherein said one or more circuits programmatically control said antenna matching network by one or more signals that control one or more switching elements.

19. The system according to claim 17, wherein said one or more circuits programmatically adjust said gain of said amplifier by controlling one or more bias points.

20. The system according to claim 17, wherein said one or more circuits configuring said antenna matching network for a plurality of frequencies in a frequency band.

21. The system according to claim 20, wherein said one or more circuits comprises a memory that stores a result of said configuring for each of said plurality of frequencies.

22. The system according to claim 21, wherein said one or more circuits retrieve said stored result from said memory for a frequency when tuning to said frequency.

23. The system according to claim 17, wherein said one or more circuits retrieve stored configuration data from a memory to configure said antenna matching network.

24. The system according to claim 17, wherein said determined frequency is within an FM broadcast band.