Electromagnetic Design and Simulation-Based Validation of a Finite X-Band Reconfigurable Intelligent Surface for Beam Steering Applications

Abstract

The problems in achieving accurate beam steering in existing finite reconfigurable intelligent surface (RIS) designs include small surface size, mutual coupling, phase quantization limits, and high X-band sidelobe levels. In real-world wireless scenarios, these constraints can decrease coverage, beamforming capabilities and communication reliability. The authors present a framework for validating and designing a finite X-band RIS (Reconfigurable Intelligent Surface) operating around 10 GHz for adaptive beam steering based on electromagnetic design and simulation. The design consists of a finite array of reconfigurable unit cells with optimized phase configuration, controlling the reflected electromagnetic wave and directing the reflected beam to desired directions. Full-wave electromagnetic simulations evaluate the design, and the available DeepMIMO dataset provides complementary beam- and channel-level validation. The frame provides accurate phase control, stable reflection characteristics, and good beam directionality. The simulation results show a reflection magnitude of 0.93 and phase tuning up to 348°, with a maximum realized gain of 18.6 dBi at 10 GHz and an S11 of -22.4 dB at 10 GHz. The proposed RIS meets the 1.8 ° beam-steering error requirement, and the sidelobe level is below −13.7 dB within the beam-steering range. The proposed design achieves a directional gain improvement of around 15.4% compared with a traditional fixed-phase surface.