High efficiency magnetic resonance wireless power transfer system and charging IC for mobile devices

In this paper, we propose enhanced wireless power transfer system based on magnetic resonance for portable electronic device charging. Resonators are designed and fabricated for efficiency improvement and miniaturization through electromagnetic simulation tools. Impedance matching technique is utilized to improve the transmission power efficiency by modulating the impedance at the transmitter end to match the load impedance. The fabricated receiver IC consists of rectifier, DC-DC converter and charging control circuit designed to reduce the power loss in the power conversion stages. This chip is implemented in 0.35μm BCD technology. A maximum overall efficiency of 73.8% was determined for the system.