Application of Multiregion Model to EM Scattering From a Dielectric Rough Surface With or Without a Target Above It

An efficient multiregion model is extended by the single integral equation (SIE) method for the first time to calculate electromagnetic (EM) scattering from a dielectric rough surface with or without a perfectly electric conducting target above it. In the multiregion model, the rough surface is divided into multiple regions depending on their positions along the rough surface and the energy distribution of the incident wave. Two intermediate regions are chosen as the dominant regions in which the method of moment is adopted. If a target is located above the surface, the target is also included in the dominant region. Hence, the new model can markedly reduce the number of unknowns compared with full SIE analysis. Mutual couplings between different regions are approximately considered based on magnetic and electric field integral equations from which closed-form approximations for currents in other regions are derived.