Microwave power amplifiers with digitally-controlled power supply voltage for high efficiency and high linearity

A power amplifier architecture is presented which comprises a basic amplifier with an efficient, high modulation bandwidth DC-DC converter. The amplifier and the DC-DC converter are controlled by a digital signal processor that provides input signal pre-distortion, supply voltage optimization and equalization. Experimental results at 950 MHz showed ACPR values acceptable for IS-95 CDMA handset applications. With variable power supply, the overall efficiency improved by a factor of 1.4/spl times/ (when averaged over representative conditions of usage).