A multi-coil wireless power transfer system utilizing dynamic matching for in-vivo and biomedical applications

Typically, single coil wireless power transfer (WPT) systems which are potential utilized for in-vivo device powering are limited by the total available power at the antenna. To overcome this limitation, a multi-coil system is presented which can greatly increase the power available to the receiver coil by as much as 80% while still remaining within the regulatory limits for total available power from an individual antenna. The effects of matching based on coil separation are presented which demonstrate the dependence of the self-resonant frequency of the WPT system, and a dynamic matching solution is proposed which allows for maximum power transfer efficiency independent of coil separation or changes in body impedance.