Method and System for Enhancing Efficiency by Modulating Power Amplifier Gain

• US 20120063545A1
• Filed: 11/28/2011
• Published: 03/15/2012
• 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: Afashi, Ali, Magoon, Vikram, Behzad, Arya
• Granted Patent: US 8,346,185 B2
• Time in Patent Office: Days
• US Class Current: 375/298
• CPC Class Codes: H03F 1/0277 Selecting one or more amplifiers from a plurality of amplifiers
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/21145 Output signals are combined by switching a plurality of paralleled power amplifiers to a common output
• CPC Class Codes: H03F 2203/45396 the AAC comprising one or more switches
• CPC Class Codes: H03F 2203/45481 the CSC comprising only a direct connection to the supply voltage, no other components being present
• CPC Class Codes: H03F 2203/45638 the LC comprising one or more coils
• CPC Class Codes: H03F 2203/7236 the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers by (a ) switch(es)
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/45188 Non-folded cascode stages
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• 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 enhancing efficiency by modulating power amplifier (PA) gain are presented. Aspects of the system may comprise a PA gain modulator that enables modification of an amplitude of a digital baseband signal. A baseband processor may enable computation of a first gain value based on the modification. The baseband processor may enable computation of a second gain value based on the first gain value. A PA may enable generation of an RF output signal based on the modified digital baseband signal and the second gain value.

Claims

1. A method performed in a baseband processor, comprising the steps of:

generating a baseband signal;

generating a modulated baseband signal based at least upon the baseband signal;

generating an intermediate baseband signal based at least upon the baseband signal;

calculating a dynamic gain level based at least upon an amplitude of the modulated baseband signal and the intermediate baseband signal;

generating an RF output signal based at least upon the modulated baseband signal, the intermediate baseband signal, and the dynamic gain level.

2. The method according to claim 1, wherein the modulated baseband signal is associated with a time varying amplitude.

3. The method according to claim 1, wherein the amplitude of the intermediate baseband signal is constant.

4. The method according to claim 1, further comprising the step of generating quadrature baseband signals based at least upon the modulated baseband signal.

5. The method according to claim 4, further comprising the steps of:

generating an input RF signal based at least upon the quadrature baseband signals, wherein the output RF signal is based at least upon the input RF signal.

6. The method according to claim 5, further comprising the step of generating the input RF signal based at least upon on the intermediate baseband signal, the modulated baseband signal, and a first gain value.

7. The method according to claim 6, wherein an amplitude of said generated input RF signal is constant.

8. The method according to claim 1, wherein the dynamic gain level is based at least upon an amplitude of the modulated baseband signal.

9. The method according to claim 1, further comprising the step of generating at least one control signal based upon the dynamic gain level, wherein a gain associated with the RF output signal is based at least upon the at least one control signal.

10. A system, comprising:

a baseband processor configured to generate a baseband signal, the baseband processor further configured to generate a modulated baseband signal based at least upon the baseband signal and an intermediate baseband signal based at least upon the baseband signal;

an RF transmitter configured to calculate a dynamic gain level based at least upon an amplitude of the modulated baseband signal and the intermediate baseband signal, the RF transmitter further configured to generate an RF output signal based at least upon the modulated baseband signal, the intermediate baseband signal, and the dynamic gain level.

11. The system of claim 10, wherein the modulated baseband signal is associated with a time varying amplitude.

12. The system of claim 10, wherein the amplitude of the intermediate baseband signal is constant.

13. The system of claim 10, wherein the baseband processor is further configured to generate quadrature baseband signals based at least upon the modulated baseband signal.

14. The system of claim 13, wherein the RF transmitter is further configured to generate an input RF signal based at least upon the quadrature baseband signals, wherein the output RF signal is based at least upon the input RF signal.

15. The system of claim 14, wherein the RF transmitter is further configured to generate the input RF signal based at least upon on the intermediate baseband signal, the modulated baseband signal, and a first gain value.

16. The system of claim 15, wherein an amplitude of said generated input RF signal is constant.

17. The system of claim 10, wherein the dynamic gain level is based at least upon an amplitude of the modulated baseband signal.

18. The system of claim 10, wherein the baseband processor is configured to generate at least one control signal based upon the dynamic gain level.

19. The system of claim 18, wherein a gain associated with the RF output signal is based at least upon the at least one control signal.

20. A system, comprising:

means for generating a baseband signal;

means for generating a modulated baseband signal based at least upon the baseband signal;

means for generating an intermediate baseband signal based at least upon the baseband signal;

means for calculating a dynamic gain level based at least upon an amplitude of the modulated baseband signal and the intermediate baseband signal;

means for generating an RF output signal based at least upon the modulated baseband signal, the intermediate baseband signal, and the dynamic gain level.