Dual Band Coupled Resonators System with Fixed Low Band and Tunable High Band for Wireless Power Transfer (WPT) Applications
This work proposes a design of compact dual band coupled resonators system with fixed and frequency-agile bands for wireless power transfer (WPT) systems. The coupled resonators are realized by etching an interlaced hairpin defected ground structure (IH-DGS) in the ground plane and loaded with lumped varactor for miniaturization and for achieving the reconfiguration operation. The proposed structure is designed to operate at a fixed low frequency of 0.5GHz and a tunable high frequency band from 0.65 to 1.38GHz. A reconfigurable range of 0.73 GHz from 0.65 to 1.38 GHz is attained for the high band by changing the capacitance of the SMV 2023 varactor from 9.9 to 1.09 pF, respectively. These quasi-lumped component resonators can efficiently transfer power using electromagnetic (EM) resonant coupling for a short range of 10 mm at the desired dual frequency bands. The prototype has a compact size of 13.5 mm × 25 mm. The proposed coupled resonators are simulated and testedto verify the performance of the proposed design. The proposed design has highest efficiencies at a capacitance of 1.54 pF. The design achieves coupling efficiencies of about 98 % and 99.4 % at the two operating bands of 0.5 and 1.1GHz, respectively, with a transmission distance of 10 mm at a capacitance of 1.54 pF. The proposed design achieves proper efficiencies at all tunable bands. The proposed design is suitable for tunable and multiband WPT applications.