Push-Pull Class- ${\rm E}_{\rm M}$ Power Amplifier for Low Harmonic-Contents and High Output-Power Applications

This paper introduces a push-pull class-E_M power amplifier for achieving low harmonic contents and high output power. By applying the push-pull configuration of the class-E_M power amplifier, the proposed amplifier achieves an extremely lower total harmonic distortion (THD) and about four times higher output power than the conventional single class-E_M power amplifier. Design curves of the proposed amplifiers for satisfying the class-E_M ZVS/ZDVS/ZCS/ZDCS conditions are given. A design example is shown along with the PSpice-simulation and experimental waveforms for 1-MHz amplifier, considering the MOSFET drain-to-source nonlinear parasitic capacitances, MOSFET switch-on resistances, and equivalent series resistance of the inductors. The waveforms from the PSpice simulation and circuit experiment satisfied all the switching conditions, which has shown the accuracy of the design curves given in this paper and validated the effectiveness of the push-pull class-E_M power amplifier.