Design of a reflective metasurface with a transmit lens using near-field beam focusing

In this paper, a design of a reflective metasurface with a transmit lens is proposed to mechanically adjust a focal point of wireless power transmission using near-field beam focusing. The metasurface with 10 by 10 unit cells is modeled to provide an incident semi-planewave toward the transmission lens. The transmit lens can then focus the electric field at the focal point to increase the WPT efficiency, and the location of the lens can be mechanically adjusted to easily change the beam focusing point. The resulting electric field intensities are 26.4 dBV/m, 23.8 dBV/m, and 23.4 dBV/m at focusing points of 140 mm, 235.8 mm, and 342 mm, respectively, when the transmit lens is located at heights of 50 mm, 100 mm, and 150 mm along the bore-sight direction.