Investigation of Metamaterial-based Wireless Power Transfer System at 13.56 MHz

• 作 者: JunfengChen;ShengrningWang;ZhaoyangHu;MinghaiLiu;
• 机 构: School of Electrical and Electronic Engineering,State Key Laboratory of Advanced Electromagnetic Eng
• 出 处: 2015 International Workshop of Wireless Power Transfer(2015无
• 发表日期: 2015年期

　　Magnetically coupled resonant wireless power transfer can achieve a mid-range power transfer.However, the transmission efficiency decreases fastly due to divergence of magnetic field, especially in undercoupled region.Electromagnetic metamaterial can control the direction of magnetic fields due to its negative permeability.In this paper, an ultra-thin and compact magnetic metamaterial is designed for a 13.56 MHz wireless power transfer system to enhance its efficiency.Previously reported metamaterials were too thick and large in size to increase the power transfer distance.We investigate an ultrathin and assembled planar metamaterial structure consisting of a single-sided periodic array of the capacitively loaded sprial resonators (CLSRs) by FR-4 substrate.The metamaterial design is very compact in size.In terms of wavelength at the operating frequency to unit cell ratio, the current design is about 158 while conventional split-ring resonator (SRR) is around 10.Both simulation and experiment are investigated to characterize the performance of this resonance system.Experiments show that with the proposed metamaterial slab, a maximum efficiency improvement of 41.7% is obtained at transfer distance of 30 cm.Further more, the range of efficient power transfer can be greatly extended.