A 30W and 95% Efficiency Class-E Wireless Power Transfer Transmitter with Vector Algorithm Control

Abstract

This paper proposes a vector algorithm control (VAC) method for class-E power amplifier (PA) to compensate the variation of load resistance based on an introduced mathematical model. In contrast to the conventional Class-E PA adaptive control method with impedance matching, which introduces additional power loss, the proposed VAC loop directly adjusts the core parameters of the Class-E PA, thus enhances the system efficiency. A transmitter applicable to wireless power transfer (WPT) systems is implemented to verify the proposed VAC loop. Simulation results show that the system achieves a peak output power of 30W and a very high peak efficiency of 95% with wide variable loads.