Phaseless computational imaging with a radiating metasurface

TL;DR

This paper introduces a new 3D microwave imaging system that uses intensity-only measurements and phase retrieval techniques, reducing complexity while maintaining high image fidelity.

Contribution

It presents a novel phaseless computational imaging method using a radiating metasurface, validated through experimental microwave range demonstrations.

Findings

Successful experimental demonstration of phaseless imaging in microwave range

Comparable image quality between complex-valued and intensity-only measurements

Reduction in measurement complexity without sacrificing image fidelity

Abstract

Computational imaging modalities support a simplification of the active architectures required in an imaging system and these approaches have been validated across the electromagnetic spectrum. Recent implementations have utilized pseudo-orthogonal radiation patterns to illuminate an object of interest---notably, frequency-diverse metasurfaces have been exploited as fast and low-cost alternative to conventional coherent imaging systems. However, accurately measuring the complex-valued signals in the frequency domain can be burdensome, particularly for sub-centimeter wavelengths. Here, computational imaging is studied under the relaxed constraint of intensity-only measurements. A novel 3D imaging system is conceived based on 'phaseless' and compressed measurements, with benefits from recent advances in the field of phase retrieval. In this paper, the methodology associated with this novel principle is described, studied, and experimentally demonstrated in the microwave range. A comparison of the estimated images from both complex valued and phaseless measurements are presented, verifying the fidelity of phaseless computational imaging.