An Ultra-Thin Self-Resonant Coupler With Nanocrystalline Flake Ribbons for Wireless Power Transfer System

This article introduces an ultra-thin self-resonant coupler using nanocrystalline flake ribbon (NFR) material for wireless power transfer (WPT). The self-resonant coupler has garnered certain attention in the industry due to its ability to eliminate the compensating capacitor, resulting in a notable increase in power density. However, most research endeavors have primarily focused on WPT systems operating at megahertz frequencies with low power levels. Nanocrystalline materials exhibit high magnetic saturation and lower core loss in comparison to conventional MnZn materials. In addition, NFR materials offer ultra-thin profiles and flexibility, enabling the creation of compact WPT systems. In this study, the self-resonant coupler is fabricated with a double-D (DD) structured, flexible printed circuit (FPC) pad and integrated NFR core. This configuration achieves a power output of 400 W at 32 kHz, rendering it suitable for flexible surface WPT charging systems within a thickness of 0.54 mm.