Efficiency comparison between resonant coil and metamaterial sheet for wireless power transfer

Resonant coils and metamaterials are useful to increase the effective range of a wireless power transfer system. We experimentally compared the characteristics of a resonant coil and a metamaterial with similar sizes. The resonant coil had higher Q and higher coupling ability with a loop than did the metamaterial. The transmission coefficient with the resonant coil system averaged 3.6 times higher than that with the metamaterial system.