A 2D-programmable and Scalable Reconfigurable Intelligent Surface Remotely Controlled via Digital Infrared Code

TL;DR

This paper presents a scalable, remotely controllable 2D programmable RIS for Wi-Fi that uses infrared signals for digital control, enabling flexible aperture scaling and phase manipulation.

Contribution

It introduces a novel infrared-controlled, modular RIS design with distributed light-sensitive controllers allowing easy scalability and full 2D phase encoding.

Findings

Demonstrated a 1-bit RIS for 5-GHz Wi-Fi with scalable architecture.

Achieved full 2D phase encoding capability.

Enabled remote infrared control for dynamic reconfiguration.

Abstract

Reconfigurable Intelligent Surfaces (RISs) are promising and relatively low-cost tools for improving signal propagation in wireless communications. An RIS assists a base station in optimizing the channel and maximizing its capacity by dynamically manipulating with reflected field. Typically, RISs are based on dynamically reconfigurable reflectarrays, i.e. two-dimensional arrays of passive patch antennas, individually switchable between two or more reflection phases. Different communication scenarios and environments require RISs to provide a different spatial resolution of reflected field patterns, which depends on the aperture dimensions and the number of patches. Here we demonstrate a 1-bit RIS for 5-GHz Wi-Fi band made by assembling together multiple independently operating building blocks all powered by the same DC source. Each block contains four separately phase-switchable patch antennas with varactor diodes and a common microcontroller extracting digital control commands from modulated infrared light illuminating the entire RIS. Such distributed light-sensitive controllers grant the possibility of scaling the aperture by adding or removing blocks without re-designing any control circuitry. Moreover, in the proposed RIS a full 2D phase encoding capability is achieved along with a robust remote infrared control.