Experimental verification of rectifiers with SiC/GaN for wireless power transfer using a magnetic resonance coupling

This paper demonstrates that SiC and GaN diode rectifiers are used in a magnetic resonant coupling (MRC) for wireless power transfer system. The size of the resonance coils, which are used in the wireless power transfer using a MRC, depends on the transmission frequency. So, the MRC is desired to operate at a high frequency in the Industry Science Medical (ISM) band such as 13.56 MHz. In the receiving side, a rectifier which converts to the DC voltage from high frequency AC voltage is necessary to supply the power to the applications such as a battery charger for EV and home appliances. The experimental results show the maximum efficiency from a Radio Frequency (RF) power supply to DC outputs is 75.2% when the transmission distance is 150 mm. In addition, A power loss separation method of the wireless power transfer system is discussed in this paper. The experimental results verify the reflected power of the resonance coil which dominates the largest amount of the loss in the total loss. Therefore, the suppression of the reflected power is important for the wireless power transfer system using a MRC.