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 40W 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.