High Efficiency Class-E Switched Mode Power Amplifier Design and Optimization with Random Search Algorithm

The class E switched mode power amplifier consists of a load network and a single transistor that is operated as a switch at the carrier frequency of the output signal. Main three parts of the power amplifier that specify its total efficiency are: the Q factor of output band-pass filter, the transistor on-state resistance, and the driver stage. In this paper, we design and optimize three common structures of power amplifiers using a random search algorithm. Optimized designs are simulated with HSPICE in 0.25 mm CMOS technology at the carrier frequency of 5.2GHz. The maximum efficiency for each structure is calculated, and then its bottle-neck is determined. We also achieve the total efficiency of 92.3% for the power amplifier.