Low-Profile Transmissive Metasurface for Generating The Butterfly-Shaped Beam

A low-profile transmissive metasurface is proposed for generating the butterfly-shaped beam. The metasurface is composed of the single-layer dielectric unit cell with vias. The metal on the upper and lower surfaces of the unit cell is consistent, and the shape of each metal layer is extremely simple, consisting of three rectangular patches. The phase distribution of metasurfaces includes two parts: the focusing phase and the periodic phase. The simulation results show that the proposed metasurface can generate a butterfly-shaped beam with a gain of 19.4 dBi.