Physics-Aware RIS Codebook Compilation for Near-Field Beam Focusing under Mutual Coupling and Specular Reflections

2026-01-19

AI Summary

This work addresses the challenge of achieving efficient and precise beam focusing with reconfigurable intelligent surfaces (RIS) in near-field scenarios, where inter-element electromagnetic coupling and environmental specular reflections significantly degrade performance. To overcome this, the authors propose the MATCH algorithm, which, for the first time, explicitly incorporates electromagnetic mutual coupling and secondary reflection effects into codebook design. By constructing a physics-aware codebook that aligns RIS configurations with the actual electromagnetic environment, the method ensures physical consistency. Leveraging full-wave simulation-driven modeling and codebook compilation, MATCH successfully focuses scattered energy onto the target region in complex near-field settings, thereby demonstrating the effectiveness and superiority of the proposed physics-consistent optimization framework.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Intelligent Robots: Multi-Robot Systems
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG

Abstract

Next-generation wireless networks are envisioned to achieve reliable, low-latency connectivity within environments characterized by strong multipath and severe channel variability. Programmable wireless environments (PWEs) address this challenge by enabling deterministic control of electromagnetic (EM) propagation through software-defined reconfigurable intelligent surfaces (RISs). However, effectively configuring RISs in real time remains a major bottleneck, particularly under near-field conditions where mutual coupling and specular reflections alter the intended response. To overcome this limitation, this paper introduces MATCH, a physics-based codebook compilation algorithm that explicitly accounts for the EM coupling among RIS unit cells and the reflective interactions with surrounding structures, ensuring that the resulting codebooks remain consistent with the physical characteristics of the environment. Finally, MATCH is evaluated under a full-wave simulation framework incorporating mutual coupling and secondary reflections, demonstrating its ability to concentrate scattered energy within the focal region, confirming that physics-consistent, codebook-based optimization constitutes an effective approach for practical and efficient RIS configuration.

Problem

• Reconfigurable Intelligent Surface
• Near-Field
• Mutual Coupling
• Specular Reflections
• Beam Focusing

Innovation

• Reconfigurable Intelligent Surface (RIS)
• Near-field beam focusing
• Mutual coupling
• Specular reflections
• Physics-aware codebook