Design methodology of Class-E power amplifier using feed inductance tuning for high-efficiency operation in wireless power transfer applications

This paper presents an iterative design methodology of the Class-E power amplifier, which assumes an RF-choke instead of a finite feed inductance to calculate the values of the initial components of the amplifier. The proposed method modified these initial values through a systematic parametric sweep of the feed inductance and the capacitor in parallel to the switch. After few iterations, the method guarantees high efficiency under the zero voltage and zero derivative voltage switching conditions. The proposed method was tested by a design study case, which specifications were based on the class 0 transmitter of the standard Qi. The simulated results have shown that the feed inductance tuning allows soft-switching operation. Furthermore, the average tuning effect on the main figures of merit of the amplifier was significant (i.e., 149.46%).