Metamaterial-inspired dual-function loop antenna for wireless power transfer and wireless communications

This paper first presents a metamaterial-inspired dual-function loop antenna for wireless power transfer and wireless communication which operates at 6.78 MHz (AirFuel Alliance standard frequency) and 2.4 GHz. The proposed metamaterial slab with a dimension of 33.6 mm × 33.6 mm is integrated on top of the single-turn loop antenna. The demonstrated metamaterial slab has an enhanced dual-band property for WPT and wireless communications with electromagnetic wave focusing capability. A prototype metamaterial-inspired dual-function loop antenna for simultaneous WPT and wireless communications is designed, fabricated and characterized. It shows a size reduction of 50 % compared to a device consisting of a separate WPT coil and a separate wireless communication antenna, a WPT efficiency improvement of 28.07 % (a factor of 4.19 improvement) at a distance of 100 mm compared with a device without a metamaterial slab, and an antenna gain improvement of 1.89 dB compared with a device without a metamaterial slab.