Abstract
Composite materials are being used in a plethora of applications these days due to advantageous features like low weight, high strength and stiffness. However, they are vulnerable to various anomalies, which require periodic inspection to prevent major catastrophes. Microwave near field imaging has demonstrated remarkable capability in detecting subsurface defects in composites. In this paper, a novel circular aperture probe loaded with a resonant iris, operating in X-band frequency range is proposed for near field imaging. To illustrate the effectiveness of the probe, its imaging performance for multilayer composites is compared to a rectangular waveguide. It is elucidated that the proposed probe produces images of high quality with relatively higher dynamic range.