A connection algorithm on the problem of EM scattering from arbitrary cavities

An algorithm to extend the use of the boundary-integral method (BIM) with high efficiency to the case of arbitrary cavities is presented. The cavity is divided into several sections and the BIM is applied to each section. By using the concept of input and load admittance, one can cascade these sections step by step and arrive at the cavity aperture admittance. By the generalized network admittance approach, the aperture field can be found and the far field can be determined in terms of the aperture electric field. The connection algorithm has the following advantages: (1) it reduces the computer memory requirement for long cavities, (2) identical sections such as bends and steps which may be encountered in cavities need not be recomputed, and (3) cavities filled with different materials in the interior regions can be handled easily. As an example, a two-dimensional S-shaped cavity was calculated using the proposed approach.<>