Experimental investigation of 1D, 2D, and 3D metamaterials for efficiency enhancement in a 6.78MHz wireless power transfer system

In this paper, we experimentally validate the effects of different structures of metamaterial on efficiency enhancement in a four-coil magnetic resonant wireless power transfer system operating at 6.78MHz. First, we propose a concise design of magnetic metamaterials. A 6×6 planar array metamaterial slab is simulated to investigate its effect on power transmission between transmitter and receiver. The proposed metamaterials are fabricated for their application in the wireless power transfer system. Transmission and reflection coefficients of the system with 1-dimentional (including 1-slab and 2-slab), 2-dimentional, and 3-dimentional metamaterials at different positions are measured to investigate their influence on power transmission and to optimize the position of metamaterials in each case. Finally, the platform with metamaterials is utilized to light a 15W bulb to explicitly demonstrate the efficiency enhancement.