Method and system for enhancement of power amplifier efficiency through controlled variation of gain in a power Amplifier Driver

• US 7,538,610 B2
• Filed: 12/31/2006
• Issued: 05/26/2009
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Behzad, Arya, Afashi, Ali, Magoon, Vikram
• Primary Examiner(s): Pascal; Robert
• Assistant Examiner(s): Nguyen; Khiem D
• Application Number:
  US11/618,864
• Publication Number:
  US 20080136515A1
• Time in Patent Office: 877 Days
• Field of Search: 330/136, 330/133
• US Class Current: 330/136
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04

Abstract

Aspects of a method and system for enhancement of power amplifier (PA) efficiency through controlled variation of gain in a power amplifier driver are presented. Aspects of the system may comprise an envelope detector that enables detection of an amplitude of an analog input signal. The envelope detector may enable computation of a first gain value based on the detection. A second gain value may be computed based on the first gain value. A PA may enable generation of an analog output signal based on the analog input signal, the first gain value and the second gain value.

Claims

1. A method for controlling gain in an amplifier circuit, the method comprising:

detecting an amplitude of an analog input signal;

determining a gain value based in said detecting;

determining at least one subsequent gain value based on said gain value;

generating an intermediate analog signal based on said analog input signal and said gain value, wherein an amplitude of said intermediate analog signal is constant; and

generating an analog output signal based on said analog input signal, said gain value and said at least one subsequent gain value.

2. The method according to claim 1, wherein a multiplicative product of said gain value and said at least one subsequent gain value is a constant value.

3. The method according to claim 1, comprising generating said analog output signal based on said intermediate analog signal and said at least one subsequent gain value.

4. The method according to claim 1, comprising dynamically adjusting said gain value based on a detected change in said amplitude of said analog input signal.

5. The method according to claim 4, comprising dynamically adjusting at least a portion of said at least one subsequent gain value in response to said dynamically adjusted gain value.

6. The method according to claim 5, wherein a multiplicative product of said gain value and said at least one subsequent gain value is approximately equal to a multiplicative product of said dynamically adjusted gain value, said dynamically adjusted at least a portion of said at least one gain value and a remainder of said at least one subsequent gain value.

7. The method according to claim 1, wherein a ratio of said detected amplitude of said analog input signal and an amplitude of said generated analog output signal is a constant value.

15. The method according to claim 1, comprising generating a control signal based on said gain value.

16. The method according to claim 15, comprising configuring a plurality of gain stages based on said control signal.

17. The method according to claim 1, comprising generating a corresponding control signal for each of said at least one subsequent gain value.

18. The method according to claim 17, comprising configuring a corresponding subsequent plurality of gain stages based on each said corresponding control signal.

8. A system for controlling gain in an amplifier circuit, the system comprising:

one or more circuits that are operable to detect an amplitude of an analog input signal;

said one or more circuits are operable to determine a gain value based on said detecting;

said one or more circuits are operable to determine at least one subsequent gain value based on said gain value;

said one or more circuits are operable to generate an intermediate analog signal based on said analog input signal and said gain value, wherein an amplitude of said intermediate analog signal is constant;

and

said one or more circuits are operable to generate an analog output signal based on said analog input signal, said gain value and said at least one subsequent gain value.

9. The system according to claim 8, wherein a multiplicative product of said gain value and said at least one subsequent gain value is a constant value.

10. The system according to claim 8, wherein said one or more circuits are operable to generate said analog output signal based on said intermediate analog signal and said at least one subsequent gain value.

11. The system according to claim 8, wherein said one or more circuits are operable to dynamically adjust said gain value based on a detected change in said amplitude of said analog input signal.

12. The system according to claim 11, wherein said one or more circuits are operable to dynamically adjust at least a portion of said at least one subsequent gain value in response to said dynamically adjusted gain value.

13. The system according to claim 12, wherein a multiplicative product of said gain value and said at least one subsequent gain value is approximately equal to a multiplicative product of said dynamically adjusted gain value, said dynamically adjusted at least a portion of said at least one gain value and a remainder of said at least one subsequent gain value.

14. The system according to claim 8, wherein a ratio of said detected amplitude of said analog input signal and an amplitude of said generated analog output signal is a constant value.

19. The system according to claim 8, wherein said one or more circuits are operable to generate a control signal based on said gain value.

20. The system according to claim 19, wherein said one or more circuits are operable to configure a plurality of gain stages based on said control signal.

21. The system according to claim 8, wherein said one or more circuits are operable to generate a corresponding control signal for each of said at least one subsequent gain value.

22. The system according to claim 21, wherein said one or more circuits are operable to configure a corresponding subsequent plurality of gain stages based on each said corresponding control signal.