Nondestructive detection of defects in materials using microwaves

The most commonly used nondestructive techniques for materials evaluation are ultrasonics, X and (gamma) -rays, infrared and eddy currents methods. In recent years, considerable efforts have been made in applying microwave techniques to test dielectric materials and metals. Therefore, for a few applications microwave methods can be considered alterative approaches to those conventional means. In this paper we consider the microwave near-field determination of the reflection coefficient of dielectric materials and metals, with varying size of flaws, for nondestructive testing purposes. These measurements and simulations are conducted at 35 GHz. We try to demonstrate that microwaves have their place as one tool in the toolbox of the practitioners.