Wireless Power Transfer

Abstract

This chapter introduces the fundamentals of wireless power transfer with an emphasis on implant powering. Firstly, an overview of implant powering solutions is introduced, and then, the decision of using wireless power transfer is justified. Next, among possible wireless power transfer methods, it is explained that why magnetic coupling befits the best for the target application and its specifications. In this book, a recent inductive link topology which employs 4 coils at resonance is employed in order to realize magnetic coupling. This approach has brought two main advantages: higher power transfer efficiency and less dependence of power transfer efficiency on load impedance. Detailed explanation of the 4-coil resonant inductive link is followed by the design of electronic circuits utilized to create a reliable power supply in the implant. This unit consists of an active half-wave rectifier and a low drop-out voltage regulator.