Experiments With a Compact Wireless Power Transfer System Using Strongly Coupled Magnetic Resonance and Metamaterials

Abstract

The technology for inductive wireless power transfer (IWPT) by using strongly coupled magnetic resonance has been applied successfully to supply energy to several applications such as biomedical implants, radio frequency identification systems, Internet-of-Things sensors, and battery chargers for personal devices. In order to attain high values of efficiency and reach, the technology requires the employment of coils with high values of quality factor. However, this feature can only be found by using large wire coils. A compact IWPT system composed of printed coils, which typically have low values of quality factor, is proposed in this paper. An evolutionary algorithm is used to optimize the printed coil geometry so that it presents the greatest value of quality factor possible, according to the imposed restrictions. With the aim to improve the system efficiency and reach, the effect of metamaterial surfaces inclusion is investigated. In addition, in order to increase the amount of power processed by the system, a low-cost self-oscillating electronic converter is proposed to power it.