Novel and compact design of capacitively loaded C-shaped DGS resonators for dual band wireless power transfer (DB-WPT) systems

Abstract

This paper proposes a new dual band coupled resonators band pass filter that employs two C-shaped defected ground structures (DGSs) loaded with lumped capacitors for dual band wireless power transfer (DB-WPT) applications. The proposed resonators produce two independent frequency bands for dual band operations of the WPT system. When the two C-shaped DGS are coupled back-to-back, it transfers to a dual band pass filter leading to compact and efficient WPT system working at 0.3 GHz and 0.9 GHz. The system has been analyzed using the J-inverter method for verification. A compact prototype with a size of 20 mm × 20 mm is fabricated, tested, and measured. The fabricated prototype achieves coupling efficiencies of 99% and 91% at a transmission distance of 10 mm for both operating bands at 0.3 and 0.91 GHz, respectively. Good agreements between the equivalent circuit model (ECM) and the measurements have been achieved.