New Printed-Circuit-Board Resonators With High Quality Factor and Transmission Efficiency for Mega-Hertz Wireless Power Transfer Applications

Abstract

This article presents a new printed-circuit-board (PCB) resonator structure suitable for mega-hertz wireless power transfer (WPT) applications. Unlike previous PCB resonators that can form only parallel resonant structures, the new designs can easily be configurated as either parallel or series resonators. The novelty of the resonator structure involves the replacement of the PCB material with an airgap in the main magnetic flux path of the resonator structure and adoption of air-trenches between adjacent turns, therefore greatly reducing the inter and intracapacitance of the two printed windings and its associated PCB dielectric power loss. The natural resonant frequency can easily be tuned for mega-hertz operation. A comparative study is conducted between conventional and new designs. The quality factor, resonant frequency, transmission efficiency, and ac resistance of the new designs are significantly improved by over 435%, 236%, 137%, and 41%, respectively, over those of the conventional designs. An accurate distributed-circuit model of the new PCB resonator structures is also included and used in domino WPT system simulation. PCB resonators of the conventional and new designs are constructed to form domino WPT systems for practical evaluation Both simulation and practical results are included to confirm the accuracy of the PCB resonator model and the advantages of the new resonator structure.