A Review on High Frequency Resonant Inverter Technologies for Wireless Power Transfer using Magnetic Resonance Coupling
This paper presents a design method of the inductive coupled wireless power transfer (WPT) system with class-DE power amplifier. The class-DE amplifier can achieve high power-conversion efficiency at high frequencies because it satisfies the class-E zero-voltage switching and zero-derivative-voltage switching conditions. By using the class-DE amplifier as a driver to generate a voltage across the primary inductor, high power-delivery efficiency can be achieved in the designed WPT system. A step-by-step design example using Spice is presented. The simulation results show the overall efficiency of 32.5 % at 250 mW.