Enhanced wireless power transfer using magnetostatic volume modes in anisotropic magnetic metamaterials

According to the perfect lens theory, wireless power transfer (WPT) efficiency can be improved significantly by positioning a magnetic metamaterial (MM) slab with effective permeability of −1 between a transmitter and receiver. However, it is not practically preferred because the actual space between the transmitter and the receiver will be compromised by the existence of the MM slab. In this paper, we propose to place an anisotropic MM (AMM) slab to back the transmitter coil, which can enhance the WPT by modulating magnetostatic volume wave resonant modes within the slab, and more importantly avoid the obstruction of the transfer space by the slab. Both simulations and experiments verified this enhancement due to the Fabry-Perot-like (FPL) resonances of the magnetostatic volume waves (MVWs), which increases the magnetic field intensity and eventually the inductance of WPT. Influences of key variables such as the MM slab dimensions on the induction of WPT are further investigated.