A Circularly Polarized Transmissive Metasurface with Pancharatnam-Berry Phases

In this paper, a transmissive metasurface with high efficiency and 2-bit compensation phases is proposed for circularly polarized applications. The proposed structure consists of three identical metallic layers separated by two identical dielectric slabs. By using the Pancharatnam-Berry phase theory, four different unit cells are designed to provide four transmissive phases with a consistent step of 90°. Simulations demonstrate their validation. The transmission efficiency higher than 0.9 is from 11.9 GHz to 12.75 GHz, about 7.2%, and the 3-dB axial ratio bandwidth is 11.5-12.7 GHz. about 9.6%.