Comparative Analysis of Inductive and Capacitive Feeding of Magnetic Resonance Wireless Power Transfer

One of the most challenging issues in a magnetic resonance wireless power transfer (WPT) system is to maintain high efficiency at various distances between the transmitter and the receiver. One way to achieve the desired efficiency is to use matching network between the source and the resonating coils. In this paper, we present a comparison between capacitive and inductive impedance matching techniques, which are widely exploited to overcome the efficiency drop. This study includes circuit analysis and verification of these via simulation. During this research, key concepts within WPT such critical coupling and trade-off between efficiency and distance are discussed as well. We show through Simulation that it is possible to achieve a maximum power transfer efficiency (PTE) with both methods at 60 cm distance between the coils (coupling coefficient 0.01) in an ideal case.