A 25.6 W 13.56 MHz wireless power transfer system with a 94% efficiency GaN Class-E power amplifier

In this work, we propose the design and implementation of a 13.56 MHz GaN Class-E power amplifier, which takes into account transistor parasitic effects. The design uses the parasitic capacitance of the transistor to replace the charging capacitance, simplifying the circuit structure and obtaining a 93.6% efficiency at output power of 26.8 W. In addition, a wireless power transfer system using the proposed Class-E amplifier is demonstrated, achieving a 73.4% system efficiency when the power delivered to the load is 25.6 W.