Independently Polarization Manipulable Liquid- Crystal -Based Reflective Metasurface for 5G Reflectarray and Reconfigurable Intelligent Surface

This study presents a new class of independently polarization manipulable liquid-crystal (LC)-based reflective metasurface (RMS) antenna. To the best of the authors’ knowledge, this study first introduces independent polarization controllability of the LC-based RMS in mmWave. Two LC layers are embedded into the proposed structure for independent manipulation of the polarization. Isolation topologies, such as rectangular patch shape and metal strip ground, are used to enhance polarization purity, achieving compact bias configuration. The independent polarization controllability and antenna performance, such as aperture efficiency, sidelobe level (SSL), and beam coverage, are validated as a reflectarray. The proposed antenna has a maximum aperture efficiency of 22.5% and beam coverage of over 120°. In addition, the proposed metasurface is used to achieve link connectivity as a reconfigurable intelligent surface (RIS) at millimeter-wave (mmWave) 5G. The demonstration confirms a small-aperture RIS concept, considering spillover and taper efficiencies.