Efficiency Improvement of Dual-Band Wireless Power Transfer (DB-WPT) System with U-shape Resonator and Capacitively Loaded E-shape Defected Ground Structure (DGS)

This paper suggests a design for dual-band wireless power transfer systems that use E-shape defected ground structure resonator loaded with a 1.5 pF capacitor and U-shape resonator at the top layer. When the two resonators of the proposed design are coupled back-to-back, it transfers to a dual band-pass filter leading to an efficient WPT system working at 0.9 GHz and 1.4 GHz. A compact size of 20 mm × 20 mm is fabricated achieving a WPT efficiency of more than 97% at a distance of 16 mm for both bands. Good concurrences among the equivalent circuit model (ECM), the theoretical studies, and the measurements have been attained.