The Design and Analysis of Electronically Reconfigurable Liquid Crystal-Based Reflectarray Metasurface for 6G Beamforming, Beamsteering, and Beamsplitting

Reconfigurable intelligent surfaces (RISs) are becoming increasingly popular in the field of wireless communications, given their potential to ameliorate the challenges faced in millimeter-wave wireless communications. Specifically, liquid crystal (LC)-based RISs have demonstrated numerous advantages over other types of RISs in terms of cost, complexity, and radiation efficiency in the high-frequency regime. This paper presents the design, algorithms, implementation routines, and simulation of a novel reconfigurable LC-based reflectarray metasurface operating at 108 GHz. The scanning range of the proposed device is +/- 40 degrees (azimuthally and horizontally), with an average scanning beamwidth of 8.6 degrees. We present semi-analytical findings on the scalability and phase continuity of our design, showing how key performance indicators (KPIs) are affected by dimension and phase degree-of-freedom changes. We demonstrate agreement between our semi-analytical models and full-wave analysis, focusing on genetic algorithm (GA)-optimized beam manipulations. Our results present a feasible workflow that enables dynamic beamforming, beamsteering, and multibeams at 108 GHz, and is easily scalable for applications in other 6G and beyond frequency spectra.