研究実績の概要 |
In FY2022, a new cascaded structure was proposed to improve the coupled KQ product (where K represents the coupling coefficient and Q represents the unloaded quality factor) and boost the power transfer efficiency (PTE) of the wireless power transfer (WPT) system. The structure consists of four small resonators that are cascaded together and fed with a single excitation, with each resonator consisting of two concentric rectangular rings. This cascaded structure is capable of achieving a maximum PTE of 89.5% at a transfer distance of 20 mm.
Subsequently, a passive relay system made of stacked metamaterial lenses is used to extend the power transfer distance and address misalignment issues. With the proposed WPT system, the transfer distance is increased to 80 mm with a PTE of 50%. This integration with metamaterials achieves a 300% improvement in the transfer distance with a reasonable PTE compared to the cascaded structure alone. An assembly of two stacked metamaterials is then utilized to further extend the transfer distance, providing an additional 200% enhancement without affecting PTE.
A thorough study of misalignment was conducted, demonstrating that the proposed system is capable of transferring power independently of the position of the receiver with a reasonable PTE. To the best of our knowledge, the proposed structure is the first to employ multiple cascaded resonators integrated with stacked metamaterials for WPT applications.
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