A High Misalignment-Tolerant Hybrid Coupler for Unmanned Aerial Vehicle WPT Charging Systems

Coupling attenuation and resonance loss due to imprecise transmitter/receiver alignment are critical challenges for reliable wireless drone charging. This paper introduces a novel, structurally simple hybrid coupler that effectively mitigates coupling fluctuations due to physical offsets without requiring additional control. The impact of magnetic core structure on the misalignment characteristics of the distributed-turn winding coil is investigated. The hybrid coupler structure that integrates a ferrite array with the distributed-turn winding coil is proposed. Besides, the design and optimization algorithm of the proposed coupler is further identified and outlined. The findings are substantiated through both simulation and experimental results, demonstrating the coupler's efficacy. Notably, the coupler achieves a circular anti-offset region that covers 100% receiver coil radius, in which mutual inductance fluctuations are maintained below 2%. Compared with existing anti-misalignment couplers, the proposed coupler is at an advanced level in terms of anti-misalignment performance and coupling strength with simpler structure and requiring no additional control.