Affiliations: [a] College of Electronics and Information, Hangzhou Dianzi University, Hangzhou, 310037, China
Correspondence:
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Corresponding author: Yuhua Cheng, College of Electronics and Information, Hangzhou Dianzi University, Hangzhou, 310037, China. E-mail: chengyh@hdu.edu.cn
Abstract: Inserting metamaterials into the path of wireless power transfer (WPT) is an effective way to improve the power transfer efficiency (PTE) or extend the power transfer distance. The resonant frequency f0 of the metamaterial is a critical parameter to distinguish the positive or negative permeability regions, which should be determined accurately. A new method to measure f0 is developed and validated in theory and simulation. The paramagnetic region (where the effective permeability is positive) is a frequency band below f0, and is used as the operating region of WPT with insertion of the metamaterial. According to experiments, the PTE is improved by comparison to the case without metamaterial. More interestingly, the PTE improvement effects at different operating regions are compared. It is shown that the region, where the forced-resonant frequency fRS is close to f0, has better effect than the other regions where fRS is lower or higher than f0.
Keywords: Wireless power transfer, resonator, metamaterial
