Near-Field Focusing Conformal Magnetic Metasurface for Wireless Power Transfer

Abstract

This paper proposes a conformal magnetic metasurface whose response can be opportunely controlled to obtain an efficient near-field focusing for resonant inductive Wireless Power Transfer applications. In particular, an analytical model is employed, allowing a proper control of the metasurface response so that a the magnetic near-field focusing can be achieved. A numerical Wireless Power Transfer set-up, working at 13.56 MHz, is designed to demonstrate the validity of the proposed approach. The results obtained through full-wave simulations prove that the magnetic field can be focused in the desired spatial spot, although the low frequency herein employed and overcoming the effects of metasurface conformal shape. In addition, the power transfer efficiency has been tested by positioning the receiver in two distinct spatial regions, respectively coaxial to and far from the focalized location. The results demonstrate that the WPT efficiency is effectively enhanced only when the receiver is positioned above the magnetic field focalized spot. Several WPT technologies, including charging pads, biomedical implants, and automotive applications, may advantageously exploit these features to precisely power multiple receivers, to achieve reconfigurability, and to realize conformal devices.