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

D. Xiang
X-wave Innovations, Inc., Maryland, United States

Poster stand number: W145

Keywords: Microwave sensor, nondestructive characterization, RF property, multi-layered composite, coating

Microwave sensors with an open-ended waveguide probe have been developed and successfully tested for nondestructive characterization of multi-layered non-conductive composite structures as well as coatings on conductive substrates. These microwave sensors have been used to inspect radomes, fiberglass composites, coating thickness, corrosion under paint and composites, special 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 microwave sensors combine the specially-designed probe and a software package running developed theoretic models and algorithms, with commercially off-the-shelf (COTS) vector reflectometers to form a compact-size, handheld, and USB powered nondestructive testing and evaluation (NDT&E) tool, which has been successfully used to inspect defects/damage and characterize material RF properties in multi-layered, non-conductive composite materials, including several DoD aircraft platform (e.g., radome and airframe structures of E-3, P-8).