MICROWAVE DETECTION OPTIMIZATION OF DISBOND IN LAYERED DIELECTRICS WITH VARYING THICKNESS

The detection sensitivity optimization of air disbond in layered diele ctric composites, using an open-ended rectangular waveguide, is studie d both theoretically and experimentally. The sensitivity of the disbon d detection is strongly influenced by the proper choice of parameters such as the operating frequency and the layered composite geometry (co nductor backed or terminated by an infinite half-space of air). The ca pability of optimizing the measurement system parameters to detect and estimate the thickness of a disbonded layer independent of some chang es in the thickness of the dielectric coating is also demonstrated. Th e impact of the parameters influencing detection optimization is theor etically investigated and then experimentally verified.