Finite-element domain decomposition using an iterative approach: computation of mutual coupling

An iterative finite element-boundary integral (FE-BI) approach in conjunction with domain decomposition is proposed in order to compute effectively coupling among multiple cavity-backed slot (CBS) antennas placed arbitrarily with respect to each other on a flat infinite conducting surface. Each cavity is treated as an isolated FE-BI domain whereas interaction among these radiating elements is taken into account through an iteration algorithm. This iterative algorithm becomes extremely useful when the two CBS antennas are identical, since the memory requirements and CPU time can be reduced significantly. It also provides a mechanism to achieve full hybridization of the FEM method with other techniques such as the GTD and PO. The formulation of this iterative FE-BI method is presented and applied to the problem of computing the coupling parameters of two identical CBS antennas flush-mounted on an infinite conducting ground plane. The results obtained using the proposed iterative algorithm are compared with results obtained using the direct FE-BI approach and measurements.