High Resolution Near Field Microwave Imaging using Loaded Circular Aperture Probe

TL;DR

This paper introduces a loaded circular aperture probe with a resonant iris for enhanced resolution and sensitivity in high-frequency near-field microwave imaging, validated through simulations and experiments.

Contribution

It proposes a novel loaded circular aperture probe with a resonant iris that improves imaging resolution and sensitivity in the X-band frequency range.

Findings

Enhanced imaging resolution compared to conventional probes

Higher sensitivity demonstrated in experimental imaging

Superior performance in practical dielectric and metallic sample imaging

Abstract

Circular aperture probes have been successfully used for high-resolution near-field microwave imaging. It has been established that circular aperture probes could conceivably provide higher image fidelity compared to rectangular aperture probes used conventionally for near-field imaging. In this paper, it is proposed to further enhance the near-field imaging resolution and sensitivity by loading the circular aperture with a resonant iris. The proposed probe herein operates in the X-band frequency range and exhibits very localized near-field distribution at the opening of the iris. Consequently, its imaging resolution and sensitivity are enhanced compared to the conventional aperture probes operating over the same frequency band. The imaging capability of the proposed probe is analyzed using 3D electromagnetic simulation, and its performance is validated experimentally. The efficacy of the proposed probe for high-resolution imaging is demonstrated by practical imaging dielectric and metallic samples. Furthermore, the obtained images using the proposed probe are compared to those acquired using conventional circular and rectangular aperture probes. It will be demonstrated that the proposed probe provides higher sensitivity and resolution compared to the conventional aperture probes.