Single-Antenna Non-Line-of-Sight Matrix Imaging via Reconfigurable Intelligent Surfaces

TL;DR

This paper demonstrates that a reconfigurable intelligent surface combined with a single antenna can reconstruct the full reflection matrix for high-fidelity imaging and wave control in complex environments, reducing hardware complexity.

Contribution

It introduces a novel method to use RIS as a programmable synthetic antenna array for matrix imaging with only one physical antenna, enabling advanced sensing capabilities.

Findings

Reconstructs reflection matrix using a single antenna and RIS.

Enables high-fidelity imaging and real-time target tracking.

Reduces hardware complexity for matrix-based imaging.

Abstract

Modern imaging and sensing in complex environments, ranging from biomedical diagnostics to wireless communication, relies on accurately measuring and then controlling the wave propagation. Conventional approaches demand large arrays of antennas or transducers to reconstruct the full reflection or transmission matrix, enabling advanced protocols such as selective focusing or adaptive wave control. Yet, these arrays are expensive, bulky, and difficult to implement at microwave frequencies. Here, we show that a single transmitting-receiving antenna, when combined with a reconfigurable intelligent surface (RIS), can fully reconstruct the reflection matrix from far-field measurements, effectively transforming the RIS into a programmable synthetic antenna array. This approach allows high-fidelity imaging of complex scenes, selective focusing through clutter, and real-time tracking of moving targets. Our results establish RIS as a versatile, low-cost platform for matrix-based imaging, with broad implications for adaptive wave control, real-time sensing, and imaging in environments previously considered inaccessible.