Wireless Power Transfer through Resonance Coupling

Efficient and compact wireless power transfer (WPT) systems are proposed and designed for charging small importable devices such as mobile, laptops and sensor networks. They use the magnetic resonance coupling scheme to transfer power over a relatively large distance. The receiver resonator coil and the load loop are designed in correspondence to size restriction of devices. The dimensions of the coils are optimized and effective values of the lumped capacitors are investigated and fine-tuned for efficiency enhancement. The design configurations of the WPT system, consisting of two coils the transmitter and the receiver, are designed and fabricated. The transfer efficiency is measured over different transmission distances and with different orientation angles of the receiver coils. The measurement results show good agreements with the simulations and illustrate that the proposed WPT systems exhibit nearly Omni directional radiation performance. Furthermore, the receiver coils are implanted inside of a biological object to show the power can be transferred effectively