A Generalized Transition Matrix Model for Open-Ended Cavity With Complex Internal Structures

In this paper, a novel generalized transition matrix (GTM) algorithm is proposed to analyze the electromagnetic problems of open-ended cavity structures. An artificial reference surface is applied to seal the slots and/or apertures to reshape the target cavity into an interior domain (containing inner metallic surface and internal structures) and an exterior domain (containing the outer surface of the cavity). Special junctions at the transitional connection of the two domains are applied to guarantee the current continuity on the metallic surface. Based on the Huygens principle, an associated GTM is constructed on the reference surface and the special junctions to extract the characteristics of the interior region of the cavity. The GTM is independent of the outer shape of the cavity and the exterior electromagnetic environment. The computational complexity can be effectively reduced, especially when the interior region is with fine structures and internal sources. To investigate the feasibility and effectiveness of the proposed approach, several numerical examples are presented.