Pyramid horn-a near field sensor for NDT

Due to its sensitive, speedy, and no contact to the material surface, the microwave method is suitable for in-situ nondestructive test (NDT) of disbond defects in multilayered composite materials. The traditional microwave method treats the disbond in a composite material as a non-uniformity in a transmission line. In our new method, the disbond is in fact a perturbation inside a resonator, which operates in a high order electromagnetic mode. Hence it is more sensitive than the convential ones. The working principle of our NDT method is described and the preliminary experimental results are given