Investigation of hybrid metamaterial for enhancing efficiency of wireless power transfer systems

Abstract

With the drastic attention of the wireless power transfer (WPT) system for the electronic devices, applying the metamaterial mechanism into the WPT system is one of the potential methods for improving the power transfer efficiency (PTE).Different from the conventional metamaterial slab with single negative permeability, the WPT with hybrid negative permeability (HNP) metamaterial slab has higher PTE. In this thesis, we investigate the parameters of HNP slab at different position between WPT coils. The results show that the optimal parameters of HNP slab for high PTE is dependent on the metamaterial position. After adopting an appropriate HNP slab, the higher PTE can be obtained at required arrangement of WPT coil module with the metamaterial slab, e.g, increasing the effective transfer distance from 5 cm to 8 cm, the efficiency has remained at 32 %. Furthermore, with the HNP slab, the PTE has improved from 23.4 % to 55 % in the same transferred distance of 10cm.We not only investigate the WPT system with HNP slab, but also discuss the parameter extraction method of the metamaterial in the near-field. Instead of the full-wave parameter extraction method, the metamaterial in the condition of near-field will be considered, so will the oblique incident condition.