Single-source EPA for electromagnetic scattering by array structures

In traditional equivalence principle algorithm (EPA), the unknown currents of the scatterers are replaced by equivalent electric and magnetic currents on the virtual equivalence surface. In this paper, a single electric/magnetic current on the equivalence surface is used to generate the scattered field. According to the extinction theorem, a relation between the equivalence electric current and magnetic current can be established, which is similar to generalized impedance boundary condition (GIBC). Therefore, only the electric/magnetic current is the unknown in the final EPA formulation. Numerical results for the array structures are obtained to demonstrate the accuracy and efficiency of the proposed method.