High efficiency midrange wireless power transfer system

Wireless power transfer systems using near-field magnetic coupling are attractive as they allow power transfer with high efficiency and do not require an unobstructed path between transmitter and receiver. In this work a two coil wireless power transmission system is analyzed, including the driving amplifier, and a demonstration system is built and characterized. The system achieves 76% efficiency for a distance of 1 meter for 40 W transferred power. The effects of changes to the geometry of the system (pitch angle of coils, separation distance) are also examined, and the effect on amplifier topologies analyzed.