A fast circuit model for interaction of open-ended rectangular waveguide probes with surface long cracks in metals

This paper proposes a modeling technique that predicts the output signal of an open-ended rectangular waveguide probe when scanning a long crack. The technique is based on a circuit approximation model and hence remarkably reduces the computation burden. In this model, the waveguide probe is replaced with a transmission line, the crack is replaced with a shorted transmission line, and the interface between the probe and the crack is replaced with an appropriate impedance. The validity of the proposed model is demonstrated by comparing the simulation results of several case studies with those obtained using a commercial finite integration technique code.