An analytical study of wireless power transmission system with metamaterials

Abstract Computation of transmission system efficiency of electromagnetic radiation becomes inaccurate when Friis formula is used in Fresnel zone (near-field zone) of wireless power transmission (WPT). A novel methodology has been proposed in this paper for estimation of the power density, received power and transmission system efficiency at a particular operating frequency in the near-field zone. The power transfer and transmission system efficiency need to be maximized for minimal dimensions of transmitter and receiver. Utilization of negative refractive index metamaterials (MM) between transmitter and receiver is proposed to achieve maximum power transfer. In the present paper, variation of received power and system efficiency with respect to transmitting distance is computed and compared for WPT system with and without metamaterials. The variation of system efficiency is studied for varied location of metamaterial from transmitter by assuming metamaterial diameter at a given location is greater than or equal to the beam diameter at that location. Different configurations with varied input power and transmitting distances from shorter to longer range are considered in the study to analyse parameters that affect system efficiency. The approach for identifying optimal number of metamaterials and their placement between transmitter and receiver for maximum power transfer has also been discussed.