Analysis of inductive power link for efficient wireless power transfer

In this paper, we address the problem of choosing the right topology for a wireless power transfer (WPT) application to obtain maximum power transfer efficiency. We analyze the series and parallel resonant topologies used in inductively coupled links, derive the efficiency expressions and verify them experimentally using planar inductors built on a PCB. We compare and contrast the two topologies and arrive at the frequency boundary that separates them. The results are verified experimentally and corroborated using simulation results from HFSS.