GENERATION OF ULTRA-WIDEBAND MULTI-MODE VORTEX WAVES BASED ON MONOLAYER REFLECTIVE METASURFACE

In this paper, a monolayer metasurface that can simultaneously generate multi-mode vortex waves in ultra-wideband is proposed. Smooth phase variation is obtained by properly assigning the arm lengths of arrow-shaped metal on the top of the reflective metasurface unit cell. Different reflective cells are arranged in different sectors to form a phase-shifted surface that can convert a linearly polarized plane wave into a vortex wave. The full-wave simulations show that the designed reflective metasurface can generate vortex wave with multi-mode in ultra-wideband from 18 GHz to 42 GHz, which is in good agreement with the theoretical analysis. The proposed reflective metasurface paves an effective approach to generate vortex wave with multi-mode in ultra-wideband for OAM-based systems. Compared to the traditional ways of generating vortex waves, our design has the advantage of wide bandwidth.