Far-field Imaging beyond the Diffraction Limit Using a Single Radar

TL;DR

This paper introduces a novel single radar imaging method that surpasses the diffraction limit by using a resonant aperture antenna to convert evanescent waves into propagating waves, enabling real-time super-resolution imaging.

Contribution

The paper proposes a new single radar imaging technique utilizing a resonant aperture antenna to achieve super-resolution beyond the diffraction limit without arrays or scanning.

Findings

Resonant aperture converts evanescent waves into propagating waves.

The method enables real-time, super-resolution imaging.

It relaxes the need for near-field scanning or antenna arrays.

Abstract

Far-field imaging beyond the diffraction limit is a long sought-after goal in various imaging applications, which requires usually an array of antennas or mechanical scanning. Here, we present an alternative and novel concept for this challenging problem: a single radar system consisting of a spatial-temporal resonant aperture antenna (referred to as the slavery antenna) and a broadband horn antenna (termed the master antenna). We theoretically demonstrate that such resonant aperture antenna is responsible for converting parts of the evanescent waves into propagating waves, and delivering them to the far-field. We also demonstrate that there are three basic requirements on the proposed subwavelength imaging strategy: the strong spatial-temporal dispersive aperture, the near-field coupling, and the temporal (or broadband) illumination. Such imaging concept of a single radar provides unique ability to produce real-time data when an object is illuminated by broadband electromagnetic waves, which lifts up the harsh requirements such as near-field scanning, mechanical scanning or antenna arrays remarkably. We expect that this imaging methodology will make breakthroughs in super-resolution imaging in the microwave, terahertz, optical, and ultrasound regimes.