High efficiency microwave amplifier

1. An electromagnetic signal amplifier, comprising:

a gain stage electrically disposed between a supply rail and a return rail, wherein the gain stage includes an input and an output;

a rail voltage controller operably coupled to at least one of the supply rail and the return rail, the rail voltage controller being configured to provide a rail voltage responsive to a rail voltage control signal;

a drive controller operably coupled to the gain stage input and configured to provide an input signal thereto responsive to a drive control signal;

at least one sensor configured to sense an operational parameter of the amplifier and to provide a sensor signal corresponding thereto; and

an amplifier controller adapted to receive the at least one sensor signal and in response thereto provide at least one of a rail voltage control signal to the rail voltage controller and a drive control signal to the drive controller.

2. The electromagnetic signal amplifier in accordance with claim 1 , wherein the amplifier controller is adapted to receive an input corresponding to a target output level.

3. The electromagnetic signal amplifier in accordance with claim 1 , wherein the gain stage comprises at least two gain elements arranged in a push-pull configuration.

4. The electromagnetic signal amplifier in accordance with claim 3 , wherein the at least two gain elements are selected from the group consisting of transistors, field-effect transistors, and laterally diffused metal oxide semiconductors.

5. The electromagnetic signal amplifier in accordance with claim 1 , wherein the sensor is configured to sense an output voltage.

6. The electromagnetic signal amplifier in accordance with claim 1 , wherein the sensor is configured to sense a bias current.

7. The electromagnetic signal amplifier in accordance with claim 6 , wherein:

the gain stage includes a bias circuit;

the electromagnetic signal amplifier further comprises a bias controller operably coupled to the bias circuit and configured to provide a bias voltage thereto responsive to a bias control signal and wherein the amplifier controller provides a bias control signal to the bias controller in response to the at least one sensor signal.

8. The electromagnetic signal amplifier in accordance with claim 7 , wherein the amplifier controller:

sets the rail voltage to an initial value;

measures a rail current;

determines whether the rail current meets a target criteria;

increases a bias voltage in response to a determination that the rail current does not meet a target criteria;

stores the bias voltage in response to a determination that the rail current meets a target criteria; and

increases the rail voltage.

9. The electromagnetic signal amplifier in accordance with claim 1 , wherein the amplifier controller:

sets a rail voltage to a minimum value;

sets a drive signal to a minimum amplitude;

measures an output signal;

determines whether the output signal meets a predetermined criteria;

responds to a determination the output signal does not meet the predetermined criteria by determining whether the drive signal is set to a maximum value;

responds to a determination the drive signal is not set to a maximum value by increasing the drive signal; and

responds to a determination the drive signal is set to a maximum value by increasing the rail voltage.

10. A method of controlling an electromagnetic signal amplifier, comprising:

setting a rail voltage to a minimum value;

setting a drive signal to a minimum amplitude;

measuring an output signal;

determining whether the output signal meets a predetermined criteria;

responding to a determination the output signal does not meet the predetermined criteria by determining whether the drive signal is set to a maximum value;

responding to a determination the drive signal is not set to a maximum value by increasing the drive signal; and

responding to a determination the drive signal is set to a maximum value by increasing the rail voltage.

11. The method in accordance with claim 10 , wherein the predetermined criteria is determined in response to a user input.

12. The method in accordance with claim 10 , wherein the minimum rail voltage value is in a range of about 0 volts to about 30 volts.

13. The method in accordance with claim 10 , wherein the minimum rail voltage value is about 14 volts.

14. The method in accordance with claim 10 , wherein the output criteria is an output power.

15. The method in accordance with claim 10 , wherein the output signal is evaluated by at least one of a root-mean-square, peak-to-peak, and moving average measurement.

16. A method of controlling an electromagnetic signal amplifier, comprising:

setting a rail voltage to an initial value;

measuring a rail current;

determining whether the rail current meets a target criteria;

increasing a bias voltage in response to a determination that the rail current does not meet a target criteria;

storing the bias voltage in response to a determination that the rail current meets a target criteria; and

increasing the rail voltage.

17. The method in accordance with claim 16 , wherein the initial rail voltage value is in a range of about 0 volts to about 30 volts.

18. The method in accordance with claim 16 , wherein the initial rail voltage value is about 14 volts.

19. The method in accordance with claim 16 , wherein the target criteria includes operating a gain element substantially outside of a linear operating region thereof.

20. The method in accordance with claim 19 , wherein the initial rail voltage value is determined in accordance with an output capacitance characteristic of the gain element.

21. The method in accordance with claim 16 , wherein the target criteria corresponds to a rail current of about 0.1 amperes.