Analysis of class EM amplifier with considering non-zero current fall time of drain current

The class EM amplifier is composed of class E amplifier and auxiliary circuit output harmonic. The class EM amplifier achieves jumpless current and voltage waveforms, so class EM amplifier keeps high efficiency operation with long turnoff switching time in comparision with the class E amplifier. However, the analysis of the conventional class EM amplifier, switch current jump is not taken into account in the auxiliary circuit. Since the current fall time is present, the power loss occurs as there is overlap of switch voltage and switch current. Therefore, in order to obtain a more stringent power efficiency, it is important to take into account the current fall time in the auxiliary circuit. In this paper, we propose analysis and design of class EM amplifier that takes into account the current fall time in the auxiliary circuit. By this analysis, we can carry out more stringent design of the EM amplifier, including the impact of the current fall time in the auxiliary circuit. Moreover, by carrying out the laboratory experiments, we show the validity of the analysis in this paper.