Analysis and Design of GaN Magnetic Resonant Wireless Power Transfer System

GaN field-effect transistors (FET) enables low conduction loss and low switching loss in high-frequency (>MHz) resonant wireless power transfer systems. In this work, a GaN magnetic resonant wireless power transfer (WPT) system with 75% efficiency was designed and built. Advantages of GaN magnetic resonant wireless power transfer technology are introduced and the principle of magnetic resonant wireless power transfer technology is explained. Then, LTspice is used to simulate the designed system. Moreover, a GaN based wireless power transfer testing system was built and tested, the results of which indicate that both the coil coupling coefficient k and the load of the system affect the transmission efficiency of the system. In addition, it is found that the increment of input and output power will also increase the efficiency of the system. The system is further improved according to the actual application, the system can provide power for both lamp and mobile phone.