Analysis and Design of kHz-Metamaterial for Wireless Power Transfer

This article proposes an optimal design of the kilohertz (kHz)-metamaterial for wireless power transfer (WPT) systems with comprehensive consideration of parameters of the metamaterial. Taking advantage of the left-handed characteristics, the transmission performance can be extensively enhanced when the resonance frequency of the WPT system coincides with the metamaterial. However, the frequency of the existing metamaterial is normally at the range of megahertz, which is not applicable to the high-power WPT system due to the frequency limitation of power switching devices. In view of this, this article carries out the quantitative analysis of the impact of key structure parameters on the frequency where the left-handed characteristic exists. In addition, a general design procedure is proposed to realize the negative permeability at the range of kHz. Finally, the simulated and experimental results are both given to verify the feasibility of the proposed design scheme and show significant meanings for the utilization of metamaterials in relatively high power-level applications, such as the in-flight wireless charging for drones.