Axial Magnetic Quadrupole Mode of Dielectric Resonator for Omnidirectional Wireless Power Transfer

TL;DR

This paper introduces a novel omnidirectional wireless power transfer system using a dielectric resonator operating at axial magnetic quadrupole mode, achieving high efficiency and safety for multiple receivers.

Contribution

Develops a dielectric disk resonator-based system for omnidirectional wireless power transfer, demonstrating high efficiency and multi-receiver charging capabilities.

Findings

Achieved 88% power transfer efficiency at 157 MHz over 3 cm distance.

Demonstrated 90% total efficiency with two receivers regardless of angular position.

Observed reduced electromagnetic exposure, enhancing safety for higher power transfer.

Abstract

To achieve omnidirectional wireless power transfer with high efficiency, a high Q-factor transmitter generating homogeneous magnetic field is crucial. Traditionally, orthogonal coils of different shapes are used to realize transmitters. In this paper, we develop an omnidirectional magnetic resonant wireless power transfer system based on a dielectric disk resonator with colossal permittivity and low loss operating at axial magnetic quadrupole mode. The constant power transfer efficiency of 88% at the frequency of 157 MHz over the transfer distance of 3 cm for all angular positions of a receiver is experimentally demonstrated. The possibility of multi-receivers charging is also studied demonstrating a total efficiency of 90% regardless of angular position between two receivers with respect to the transmitting disk resonator. The minimized exposure of biological tissues to the electric and magnetic fields as well as a low specific absorption rate is observed that makes the WPT system safer for charging with higher input power.