High-Sensitivity Dielectric Resonator-Based Waveguide Sensor for Crack Detection on Metallic Surfaces

Crack detection on metallic surfaces is important for the inspection of critical metallic devices. In this paper, a high-sensitivity near-field waveguide sensor loaded with a dielectric resonator for metallic crack detection is demonstrated. Both the numerical and experimental results reveal that this dielectric resonator-based waveguide sensor can effectively detect cracks on a metallic surface. The maximum depth sensitivity is 0.71 GHz/mm and the maximum width sensitivity is 1.24 GHz/mm, resulting from the localized electric field energy on the dielectric resonator in the broad side of the waveguide sensor. This work will be of interest to the development of metallic crack detection and related applications.