Self-Dual Integral Equation Based DDM for Scattering From Compound BoR-and-Non-BoR IBC Object

A domain decomposition method (DDM) based on self-dual integral equation (SDIE) has been developed to analyze the scattering from a combinational structure with impedance boundary condition (IBC). From geometrical point of view, the combinational object is partially body of revolution (BoR) and is decomposed into BoR and non-BoR parts in the DDM framework. For the surface of all subdomains, which are modeled by IBC, the efficient SDIEs are used to construct the IE-based DDM. However, special care must be taken for the touching interfaces between subdomains. After choosing appropriate surface impedance for touching interfaces, the SDIEs of these surfaces are replaced by adapted self-dual Robin-type transmission conditions, which are derived by imposing field continuities in the SDIEs. Then, for transforming the IEs to a matrix system, the method of moments (MoM) is applied in an efficient manner to obtain an effectively reduced number of unknowns. Specifically, while the Rao-Wilton-Glisson (RWG) basis functions are used in non-BoR subdomains, the efficient BoR basis functions are utilized for expanding the currents of BoR subdomains. Memory requirements are considerably reduced in the proposed method, first by using the DDM, and second by utilizing the BoR basis in the BoR subdomain. Numerical results confirm the accuracy and efficiency of this approach.