Parallel Resonant Inductive Wireless Power Transfer

This paper presents a parallel resonant inductive wireless power transfer system for medical implant applications. The aim of the transcutaneous charging system is to address a larger range of implant depth compared to the current state of the art technology. The impact on amplifier load impedance and with that, -design and -modeling, is shown from an analytical stand-point. The obtained model provides insight into component tolerance impact as well. An objective simulation comparison approach for rectifier topologies further ensures an efficient design. With a 0.5 W transmitter output power, a transferred current of 100 mA is measured over an implant depth of 10 to 50 mm and fitting well both a time- and frequency domain simulation model. The latter enabling complex analyses like class- $\mathrm{D}$ amplifier load pull combined with component tuning.