Microwave Sensor System for Nondestructive Characterization of Multi-Layered Non-Conductive Composites and Coatings

Open-ended waveguide probes have been developed and successfully tested for nondestructive characterization of multi-layered non-conductive composite structures as well as coatings on conductive substrates. These probes have been used to inspect radomes, fiberglass composites, coating thickness, corrosion under paint and composites, specialty coatings such as radar absorbing materials and resistive coatings to name a few. Over two decades of development resulted in a complete and accurate theoretical model for this probe as well as a patented design for the probe aperture that provides measurements matching the theoretical model, which is essential for accurately calculating geometrical and materials properties. These developments combined with commercial off-the-shelf (COTS) vector reflectometers that are small, handheld, and USB powered, resulted in a minimum viable product (MVP) that has been successfully tested for many applications including several DoD-supported projects. Furthermore, the theoretical model has been coded into an efficient software package that seamlessly integrates with the measuring hardware. During the Phase I work, we worked with the sponsor and explored the benefits of this product and matching it to the requirements of potential Air Force (AF) and other DoD and commercial end-users. In Phase II, we will work with AF end-users to further develop this MVP into an actual solution for AF, other DoD and commercial customers.