Inhomogeneous electromagnetic metamaterial design method for improving efficiency and range of wireless power transfer

In the past few years, the limitation of homogeneous electromagnetic metamaterial (EMMM) in magnetic field modulation had been proved by many researches. The introduction of inhomogeneous EMMM (IEMMM) provided a significant progress in improving the range and efficiency of the wireless power transfer system (WPTS). An IEMMM with three kinds of effective permeability came up here. By analysing the effective permeability characteristics of the circular, square, and '8'-shaped coil unit cell and the modulated regulation of magnetic field by negative permeability medium, a two-dimensional IEMMM with combinations of square and '8'-shaped coil unit cell were studied. The finite element simulation results of WPTS with IEMMM proved an improvement in magnetic field modulation and flux leakage control. In the WPTS, the designed IEMMM is able to improve the power transmission efficiency by up to 28%.