Method and apparatus for controlling a power amplifier supply voltage

• US 20070024372A1
• Filed: 07/14/2005
• Published: 02/01/2007
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hagen, Rodney
• Granted Patent: US 7,443,244 B2
• Time in Patent Office: Days
• US Class Current: 330/297
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/0238 using supply converters
• CPC Class Codes: H03F 2200/516 Some amplifier stages of an amplifier use supply voltages of different value
• CPC Class Codes: H03F 3/24 of transmitter output stages

Abstract

A method for controlling a supply voltage for a radio frequency power amplifier, that includes the steps of: determining (210) at least one parameter; determining (220) a constant voltage based on the at least one parameter; and automatically adjusting (230) the supply voltage to the constant voltage.

Claims

1. A method for controlling a supply voltage for a radio frequency power amplifier (PA), comprising the steps of:

determining a power ratio;

determining a constant voltage based on the power ratio using a predetermined function; and

automatically adjusting the supply voltage to the constant voltage.

2. The method of claim 1 further comprising the steps of:

receiving an indication of a fault in the PA;

determining a second constant voltage based on the indication of a fault; and

automatically adjusting the supply voltage to the second constant voltage.

3. The method of claim 1, wherein the predetermined function comprises a scalar that is modulation independent for adjusting the supply voltage.

4. The method of claim 1, wherein the predetermined function comprises a scalar that is modulation dependent for adjusting the supply voltage.

5. The method of claim 1, wherein the power ratio is determined without using feedback from the PA.

6. The method of claim 1, wherein the power ratio is determined by using feedback from the PA.

7. The method of claim 1, wherein the predetermined function is implemented in one of software and hardware.

8. The method of claim 1, wherein the predetermined function is V₁=(P_R)^1/2*V₂, where V₁ is the constant voltage, V₂ is an input voltage and P_R is the power ratio.

9. Apparatus comprising:

transceiver apparatus comprising a radio frequency power amplifier (PA);

a converter device; and

a controller that controls the converter device to generate and provide a supply voltage to the PA, the controller executing the steps of;

determining a power ratio;

determining a constant voltage based on the power ratio using a predetermined function; and

automatically adjusting the supply voltage to the constant voltage.

10. The apparatus of claim 9, wherein the converter device comprises one of a buck converter. a boost converter and a flyback converter.

11. The apparatus of claim 9, wherein the PA is one of a linear PA and a non-linear PA.

12. The apparatus of claim 9 wherein the PA is a multi-stage PA.

13. The apparatus of claim 12, wherein the supply voltage is provided to at least a final stage of the PA.

14. The apparatus of claim 13 further comprising a compensation circuit that adjusts at least one of a phase and an amplitude of an input signal into the PA using an input from one of the controller and the converter device.

15. The apparatus of claim 9 further comprising:

a detector circuit for detecting a RF signal at one of an input and an output of the power amplifier for sampling the RF signal and detecting a peak amplitude of the RF signal, wherein the controller further executes the step of determining the power ratio based on the detected peak amplitude.

16. The apparatus of claim 9, wherein the apparatus comprises a base radio.

17. A method for controlling a supply voltage for a radio frequency power amplifier (PA), comprising the steps of:

determining at least one parameter;

determining a constant voltage based on the at least one parameter; and

automatically adjusting the supply voltage to the constant voltage.

18. The method of claim 17, wherein the at least one parameter comprises a compression level of the PA.

19. The method of claim 18, wherein the at least one parameter further comprises a power ratio.

20. The method of claim 19, further comprising the steps of:

determining an initial constant voltage based on the power ratio using a predetermined function;

automatically adjusting the supply voltage to the initial voltage;

determining a subsequent constant voltage based on the compression level of the PA; and

automatically adjusting the supply voltage to the subsequent constant voltage.