GaN-based wireless charging system with self-driven rectifier

This paper presents the analysis and the experimental validation of an innovative high efficiency GaN-based wireless charging system for mobile phones, suitable in the automotive environment. The peculiarities of the power conversion system reside in the monolithic nature of the GaN full-bridge, on the transmitter side, and in the implementation of a hybrid self-driven rectifier, on the receiver side. Thanks to the new emerging technology, characterized by very low RDSon, an optimized converter with negligible conduction and switching losses is presented. The rectification block is realized by replacing two diodes of a traditional single-phase full-wave uncontrolled rectifier with two power switches and by implementing a self-driven structure. The proposed solution leads to a notable increase in the system power transfer efficiency with zero additional costs.