A Mode-Matching Approach to the Design of RIS-Aided Communications

TL;DR

This paper introduces a mode-matching approach for designing RIS-aided wireless communications, optimizing reflected power directionality and minimizing reradiation, with a focus on electromagnetic consistency and performance tradeoffs.

Contribution

It presents a novel mode-matching and Floquets expansion method for RIS design, enabling optimized anomalous reflection with improved electromagnetic consistency.

Findings

Enhanced power reflection towards desired directions

Reduced undesired reradiation

Tradeoff analysis between performance and complexity

Abstract

Reconfigurable intelligent surface (RIS) is an emerging technology for application to wireless communications. In this paper, we consider the problem of anomalous reflection and model the RIS as a periodic surface impedance boundary. We utilize the mode matching method and Floquets expansion representation to compute the field reflected from a spatially periodic RIS, and evaluate the performance versus implementation complexity tradeoffs of RIS aided communications based on the global design criterion. This allows us to maximize the power reflected towards the intended direction of propagation, while minimizing the power reradiated towards undesired directions of propagation. In addition, we discuss the advantages of the proposed electromagnetically consistent approach to the design of RIS aided wireless systems.