Furukawa Electric Review No.56Development of an RF Power Supply for Wireless Charging Systems and Efforts for Its Implementation in the Society

Yuichiro Karakawa, Takashi Kinoshita, Hiroyuki Yamazaki, Naoki Tsurutani, Hiroto Takeuchi, Yoshifumi Azuma, Daiki Obara

This paper reports on the development of the Radio Frequency (RF) power supply technology and results of demonstration experiments aimed at the implementation in the society of an electric field coupling-type wireless charging system developed for the micro-mobility. When using existing MHz-band RF power supplies for the Wireless Power Transfer (WPT), large size and low conversion efficiency are issues. In particular, when applying to the low power consumption of about a few hundred watts, a small and highly efficient RF power supply is required. Therefore, as a solution, we developed a class E inverter technology using GaN devices and achieved a high conversion efficiency. Also, we summarized the direction of its institutionalization for the implementation in the society and conducted demonstration experiments to show the usefulness of an electric micro-mobility and the wireless charging. We are reporting these activities.