High frequency magnetic resonant coupling wireless power transfer system for middle power charging applications

This paper presents the design and implementation of a high frequency magnetic resonant coupling wireless power transfer (WPT) for middle power charging applications. The size and efficiency of resonator are depending on the resonant coupling frequency in the WPT system with magnetic resonant coupling. To improve the WPT efficiency, power capacity and resonator size, a high resonant coupling frequency is commonly desirable. However, the silicon based high frequency switching devices for middle power converter are limited. Also, power amplifier converter at high frequency has low efficiency. Therefore, this paper proposes a high frequency full-bridge inverter using Gallium Nitride (GaN) transistors for less than hundred watt charging applications. In order to verify the proposed system efficiency, simulation and experiments has been carried out.