Solving electromagnetic scattering from complex composite objects with domain decomposition method based on hybrid surface integral equations

A new domain decomposition method (DDM) is proposed to solve the electromagnetic scattering from microstrip antennas and arrays conformally mounted on a perfect electrically conducting (PEC) platform. Based on the local geometrical structures and material properties, the complex composite structures is first decomposed into independent sub-domains, following the philosophy of divide and conquer. The combined field integral equation (CFIE), the electric field integral equation (EFIE), and the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) formulation are then combined seamlessly in the framework of DDM. These equations are applied for different sub-domains: CFIE is used for the platform (closed PEC) sub-domains and EFIE-PMCHWT is employed for the microstrip (composite structure with dielectric substrate and open PEC sheet) sub-domains. To ensure the continuities of fields, the transmission conditions (TCs) are applied on the touching-faces. Compared with the traditional method, the newly developed DDM not only releases the burden of geometry preparation, but also results in a better conditioned matrix.