High Efficiency Wireless Power Transfer System using a Two-stack Hybrid Metamaterial Slab

In this paper, we proposed a two-stack hybrid metamaterial slab to enhance the power transfer efficiency in wireless power transfer (WPT) system. A hybrid metamaterial is consist of zero magnetic permeability unit cells and negative magnetic permeability unit cells. Previous research shows that a hybrid metamaterial slab slightly enhances power transfer efficiency of WPT system. We first used a two-stack hybrid metamaterial slab and it shows considerably the enhanced power transfer efficiency compared to one hybrid metamaterial case. We verified the power transfer efficiency with S-parameter measurement. Thus, we finally achieved maximum 25.4% efficiency enhancement when the distance between Tx and Rx coils is 15 cm, and in overall distance variation cases, the proposed two-stack hybrid metamaterial slab make the power transfer efficiency increase.