Generalized Transition Matrix Method with Physical Optics Approximation for Large Open-Ended Cavities

This paper introduces a novel hybrid method for the generalized transition matrix (GTM) method with the physical optics (PO) approximation. The entire structure of an open-ended cavity is divided into the interior and exterior regions by the reference surface on the aperture of the cavity. The PO approximation is applied to the exterior surface, while the interaction of the interior region can be modeled onto the reference surface using the GTM model. The computational complexity and memory usage are reduced by the proposed method. Numerical results are presented and discussed in this paper.