Low-Profile Full-Space Transmission-Reflection-Integrated Multiple Focused and OAM Beams Metasurface for Indoor Communication

A low-profile full-space multiple focused and orbital angular momentum (OAM) beams metasurface is proposed for the indoor environment. The proposed full-space metasurface consists of two groups of meta-atoms: the transmissive unit cell (UC) and the total reflective UC, where the transmissive UC employs vias to enhance the transmissive magnitude and phase shift range. All transmissive UCs form the transmissive aperture to generate multiple high-gain focused beams, and its phase distribution consists of focused and periodic phases. The phase distribution of the reflective aperture is formed by focused, periodic, and OAM phases, and it can generate multiple high-gain OAM beams. A feed patch and two full-space metasurface prototypes are fabricated for measurement verification. The measurement results show that the two full-space metasurfaces can generate a transmissive dual-focused beam and reflective dual-OAM beam and a transmissive tri-focused beam and reflective tri-OAM beam, respectively. The excellent agreement between all measurement and simulation results proves the feasibility of the proposed method. The demonstrated full-space multibeam metasurfaces could be potentially applied to multiple wireless devices in indoor communication systems for wireless power and information transmission applications.