Designs of Dual-band Metamaterials for Near-field Wireless Power Transmission

Within the ever-changing environment of Wireless Power Transmission (WPT), the goal of increased efficiency and charging range has gained significant interest. A significant difficulty is the inherent reduction in energy transmission with increasing distance and decreasing coupling coefficients. Metamaterials (MTMs), designed objects with remarkable electromagnetic characteristics, represent a possible option for overcoming these restrictions through magnetic field manipulation. Recent research has focused on multiband WPT systems, namely dual-band metamaterial (DB-MTM) that can optimize power transfer efficiency at two different frequencies at the same time. This study presents a complete overview of recent advances in DB-MTM for WPT applications. It investigates the structural complexities of these metamaterials before conducting a comparative examination of previously described DB-MTM-based WPT systems across a range of performance criteria.

I. Introduction

Materials can be categorized according to their permeability (µ) and permittivity (ε) values [1]. Metamaterials (MTM) are materials that exhibit epsilon-negative (ENG), mu-negative (MNG), and double-negative (DNG) properties depicted in Figure 1. The basic characteristics of metamaterials include transmission through a slab, refraction, and focusing [2]. A single-band wireless power transmission (WPT) system employing MTM is described in [3]. Recently, there has been considerable interest in multiband WPT systems. The dual-band WPT system offers several advantages over its single-band counterpart, including increased power transmission, reduced charging time [4], and the ability to charge multiple devices for various applications [5]. The DB-MTM can improve power transfer efficiency at two frequencies.