부산대학교 도서관

The adoption of wireless charging technologies for consumer and industrial applications is inhibited by concerns over reliability culminating from the fluctuating output power, low transmit power, and power transfer efficiency (PTE) of these systems. Besides, the inherently high radio and microwave resonant frequency of existing Metamaterial (MTM) designs imposes high switching stress on power switches and passive components, leading to significant power loss and enormously high degradation in system performance. This manuscript presents a compact, low-frequency MTM-based Wireless Power Transfer (WPT) structure coupled with a comprehensive investigation of the effect of physical parameters on the resonant frequency where left-handed characteristics occur. Model design and simulation were conducted in ANSYS High-Frequency Structure Simulator (HFSS) to extract the transmission coefficient and reflection coefficient while realizing negative permeability at a resonant frequency ( $f_{o}$ ) of 1.2MHz. To further mitigate the resonant frequency of the MTM, a metaheuristic-based parameter optimization algorithm was implemented to achieve negative permeability and evanescent wave amplification at a resonant frequency of 750kHz, making it suitable for high-power WPT applications. A prototype MTM sample is fabricated for experimental measurement of power transfer efficiency and medium parameters, using the Keysight ENA5061 Vector Network Analyzer (VNA), effectively confirming the validity of the proposed design. The excellent efficiency enhancement and mutual coupling make the design an attractive solution for WPT applications. A close agreement between the experimental results and numerical simulation validates the accuracy of the optimization results.