Single-source equivalence principle algorithm for the analysis of complex structures

In this letter, a novel single-source equivalence principle algorithm is presented. In the traditional equivalence principle algorithm (EPA), double sources, which are equivalence electric and magnetic currents, are constructed on the equivalence surface to replace the currents of the enclosed scatterers. According to the extinction theorem, electric current is related to magnetic current. Therefore, only electric or magnetic current, called single-source, is the final unknown on the equivalence surface. The accuracy of two kinds of single-source EPA is investigated. Multilevel Fast Multipole Algorithm (MLFMA) is used to accelerate the couplings between equivalence surfaces. Numerical results demonstrate the accuracy and efficiency of the proposed method.