1.06 FoM and Compact Wireless Power Transfer System Using Rectangular Defected Ground Structure Resonators

This letter proposes a wireless power transfer (WPT) system using coplanar waveguide fed rectangular defected ground structure (DGS) resonators. One of the advantages of rectangular DGS resonator is that it has higher quality (Q-) and coupling (K-) factor compared to the H-shape or semi-H-shape DGS resonators. When two DGS resonators are coupled back-to-back, it transforms to a bandpass filter with tight coupling, resulting in the transfer of power wirelessly. The fabricated WPT system of size 35.8~mm × 20 mm achieves, for the first time, a figure of merit of more than one at a WPT distance from 40 to 44 mm.