Reconfigurable Intelligent Surfaces With Suppressed Quantization Lobe for Arbitrary Reflection Angles

Reconfigurable Intelligent Surfaces (RIS) have emerged as a transformative technology in wireless communication by dynamically altering electromagnetic wave propagation. These programmable surfaces, constructed using metamaterials, exhibit anomalous reflection through the manipulation of electric and magnetic properties. This paper conducts a comprehensive analysis of RIS design, emphasizing the challenge of phase quantization. Initially, we elucidate RIS principles and the significance of precise phase control for wavefront manipulation. Mathematical models are developed, accounting for incident wave direction, desired beam patterns, and phase resolution first in ID and then in 2D scenarios. The study addresses a critical issue: the appearance of undesired quantization lobes due to phase quantization. To mitigate this, a novel strategy employing random phase delays is introduced, dispersing lobes across the beam pattern. In conclusion, this paper offers a thorough investigation of RIS, introducing an innovative approach to alleviate quantization lobe effects on communication performance.