Characterization and Modeling of Dual-Single-Layer PCB Resonators for Megahertz Hybrid Inductive and Capacitive Wireless Power Transfer

Recent advancements in the dual-single-layer printed-circuit-board (DSL-PCB) resonators open a door to designing megahertz (MHz) wireless power transfer (WPT) systems characterized by high-quality factor, energy efficiency, and suitability for mass production. This article introduces a novel procedure to characterize the DSL-PCB resonator structure and derive the parameters for an equivalent circuit model capable of addressing both capacitive and inductive WPT for a wide-frequency range. The proposed DSL-PCB resonator circuit model is practically evaluated using various dielectric materials in the gap between the two single-layer PCBs. Then, two resonator models are used to form the transmitter and receiver resonators in a hybrid inductive and capacitive WPT system. A new mathematical proof is included to confirm that the coupling coefficient of hybrid WPT is always higher than those of the inductive WPT and capacitive WPT. Theoretical predictions and experimental validations of the system are conducted within the MHz frequency range. The predicted performance characteristics of the WPT system based on DSL-PCB resonators align closely with experimental measurements. The proposed resonator model, along with its corresponding WPT framework, establishes a solid theoretical foundation for future research into MHz WPT systems leveraging DSL-PCB resonators.