Systems and methods for biasing amplifiers using adaptive closed-loop control and adaptive predistortion
View Patent ↗Various embodiments described herein provide systems and methods for improved performance for power amplifiers, particularly GaN power amplifiers. According to some embodiments, a power amplifier (e.g., GaN power amplifier) utilizes adaptive predistortion and adaptive closed-loop control of the drain current of the power amplifier to achieve improved power amplifier performance.
1. A method comprising:
determining an optimized quiescent drain current value for a drain current of a power amplifier while the power amplifier is operating under an operational parameter and while a power amplifier input signal received by the power amplifier is based on a first non-predistorted signal;
storing the optimized quiescent drain current value as saved drain current data;
determining a set of calibrated drain current values for the drain current, the set of calibrated drain current values being calibrated for a set of power levels for a power amplifier output signal while the power amplifier is operating under the operational parameter and while the power amplifier input signal received by the power amplifier is based on a second non-predistorted signal;
storing the set of calibrated drain current values in the saved drain current data;
comparing a present drain current value of the drain current to a particular drain current value in the saved drain current data while the power amplifier input signal received by the power amplifier is based on a predistorted signal;
determining whether the comparing the present drain current value to the particular drain current value satisfies a condition; and
adjusting the drain current based on the particular drain current value if the condition is determined to be satisfied.
2. The method of claim 1 , wherein the predistorted signal is generated by a predistorter module configured to detect existing distortion in an initial signal and to generate the predistorted signal based on the detected existing distortion.
3. The method of claim 1 , wherein the first non-predistorted signal or the second non-predistorted signal is generated by disabling generation of the predistorted signal by a predistorter module.
4. The method of claim 3 , further comprising disabling generation of the predistorted signal by the predistorter module.
5. The method of claim 3 , further comprising enabling generation of the predistorted signal by the predistorter module.
6. The method of claim 1 , wherein the power amplifier is a GaN power amplifier.
7. The method of claim 1 , wherein the operational parameter comprises a plurality of operational parameters.
8. The method of claim 1 , wherein the operational parameter comprises a frequency of the power amplifier input signal, a phase of the power amplifier input signal, a power level of the power amplifier input signal, or a temperature of the power amplifier.
9. The method of claim 1 , wherein storing the optimized quiescent drain current value comprises storing the optimized quiescent drain current value in association with the operational parameter.
10. The method of claim 1 , wherein storing the set of calibrated drain current values comprises storing the set of calibrated drain current values in association with the operational parameter or the set of power levels.
11. The method of claim 1 , wherein the condition is that a difference between the present drain current value and the particular drain current value in the saved drain current data is less than, equal to, or larger than a predetermined value.
12. The method of claim 1 , wherein adjusting the drain current based on the particular drain current value comprises adjusting the drain current to match or substantially match the particular drain current value in the saved drain current data.
13. The method of claim 1 , wherein adjusting the drain current based on the particular drain current value comprises adjusting a voltage bias of the power amplifier such that the drain current matches or substantially matches the particular drain current value in the saved drain current data.
14. A system comprising:
means for determining an optimized quiescent drain current value for a drain current of a power amplifier while the power amplifier is operating under an operational parameter and while a power amplifier input signal received by the power amplifier is based on a first non-predistorted signal;
means for storing the optimized quiescent drain current value as saved drain current data;
means for determining a set of calibrated drain current values for the drain current, the set of calibrated drain current values being calibrated for a set of power levels for a power amplifier output signal while the power amplifier is operating under the operational parameter and while the power amplifier input signal received by the power amplifier is based on a second non-predistorted signal;
means for storing the set of calibrated drain current values in the saved drain current data;
means for comparing a present drain current value of the drain current to a particular drain current value in the saved drain current data while the power amplifier input signal received by the power amplifier is based on a predistorted signal;
means for determining whether the comparing the present drain current value to the particular drain current value satisfies a condition; and
means for adjusting the drain current based on the particular drain current value if the condition is determined to be satisfied.
15. A system comprising:
a power amplifier having a power amplifier input signal, a power amplifier output signal and a drain current;
a power amplifier calibration module configured to determine an optimized quiescent drain current value for the drain current while the power amplifier is operating under an operational parameter and while the power amplifier input signal received by the power amplifier is based on a first non-predistorted signal, and to determine a set of calibrated drain current values for the drain current, the set of calibrated drain current values being calibrated for a set of power levels for the power amplifier output signal while the power amplifier is operating under the operational parameter and while the power amplifier input signal received by the power amplifier is based on a second non-predistorted signal;
a storage module configured to store the optimized quiescent drain current value and the set of calibrated drain current values as saved drain current data; and
a power amplifier operation module configured to compare a present drain current value of the drain current to a particular drain current value in the saved drain current data while the power amplifier input signal received by the power amplifier is based on a predistorted signal, determine whether the comparing the present drain current value to the particular drain current value satisfies a condition, and adjust the drain current based on the particular drain current value if the condition is determined to be satisfied.
16. The system of claim 15 , wherein the predistorted signal is generated by a predistorter module configured to detect existing distortion in an initial signal and to generate the predistorted signal based on the detected existing distortion.
17. The system of claim 15 , wherein the first non-predistorted signal or the second non-predistorted signal is generated by disabling generation of the predistorted signal by a predistorter module.
18. The system of claim 17 , further comprising a predistorter control module configured to disable generation of the predistorted signal by the predistorter module.
19. The system of claim 17 , further comprising a predistorter control module configured to enable generation of the predistorted signal by the predistorter module.
20. The system of claim 15 , wherein the power amplifier is a GaN power amplifier.
21. The system of claim 15 , wherein the operational parameter comprises a plurality of operational parameters.
22. The system of claim 15 , wherein the operational parameter comprises a frequency of the power amplifier input signal, a phase of the power amplifier input signal, a power level of the power amplifier input signal, or a temperature of the power amplifier.
23. The system of claim 15 , wherein storing the optimized quiescent drain current value comprises storing the optimized quiescent drain current value in association with the operational parameter.
24. The system of claim 15 , wherein storing the set of calibrated drain current values comprises storing the set of calibrated drain current values in association with the operational parameter or the set of power levels.
25. The system of claim 15 , wherein the condition is that a difference between the present drain current value and the particular drain current value in the saved drain current data is less than, equal to, or larger than a predetermined value.
26. The system of claim 15 , wherein adjusting the drain current based on the particular drain current value comprises adjusting the drain current to match or substantially match the particular drain current value in the saved drain current data.
27. The system of claim 15 , wherein adjusting the drain current based on the drain current value comprises adjusting a voltage bias of the power amplifier such that the drain current matches or substantially matches the particular drain current value in the saved drain current data.