Method and apparatus for controlling a power amplifier supply voltage

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

determining a power ratio, wherein the power ratio is a percentage utilization of a peak power capability of the PA;

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 V 1 =(P R ) 1/2 *V 2 , where V 1 is the constant voltage, V 2 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, wherein the power ratio is a percentage utilization of a peak power capability of the PA;

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 farther 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 farther 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 comprising at least a compression level of the PA;

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 further comprises a power ratio, wherein the power ratio is a percentage utilization of a peak power capability of the PA.

19. The method of claim 18 , 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.