Efficient, MHz frequency, resonant converter for sub-meter (30 cm) distance wireless power transfer

This work investigates efficient power converters for MHz frequency wireless power transfer. MHz operation is used to reduce the magnetic field strength to very low levels in the space between the coils. A design methodology is developed for the selection of the power amplifier topology along with the resonant tank compensation for the transmitting and receiving coils. The Class E power amplifier with a series-series resonant tank configuration is selected for the design of a 50 W, 30 cm air gap, 3.45 MHz wireless power transfer system with a system level peak efficiency of over 80%. The design is verified via simulation and methods for manipulating the output power are compared. A physical system is built to better understand the challenges specific to the MHz frequency power converter for wireless systems. An experimental evaluation of system performance and design limitations is presented.