Distance Detection System for Digital Transmitter Coil Achieving Distance-Variation-Tolerant Wireless Power Transfer

Abstract

In this paper, a distance detection system that only processes the information in the transmitter (TX) side is proposed. By using the distance detection system, the radius of the digital TX coil can change automatically depending on the distance and thus achieve the maximum efficiency tracking. A wireless power transfer (WPT) prototype is fabricated and experimental results demonstrate that, compared with using the conventional TX coil with a constant radius, the efficiency is improved from 12% to 20% at the distance of 4 times the RX coil radius.