Class Phi2 Amplifier using GaN HEMTs at 13.56MHz with Tuned Transformer for Wireless Power Transfer

This paper discusses a design procedure of a wireless power transfer system at a RF switching frequency of 13.56MHz. The wireless power transfer amplifier uses GaN HEMTs in a Class ϕ2 topology and is designed in order to achieve high efficiency and high power density. A design method for the load over a certain bandwidth is presented for a transformer with its tuning network.