Research On The Fast Algorithm Of Surface Integral Equation Method In Electromagnetic Scattering Problem

Nowadays, the research of the accurate and efficient analysis of electromagnetic scattering by three-dimensional objects with electrically large size and complex structures has been a hot topic in electromagnetic field. This dissertation presents an efficient method for the generation of MoM matrix—the equivalent dipole-moment method. Based on the RWG basis function and SIE, the surface of the dielectric object is discretized into several triangular patches. Each RWG common edge element containing two triangular patches is regarded as a pair. The impedance matrix elements are calculated by conventional MoM when the pair of triangular patches of source point is not so far away from the field point, otherwise the electric and magnetic surface currents on the pair of triangular patches of source point can be equivalence as electric and magnetic dipole-moment, respectively. Then the matrix elements can be thought as the reaction of the fields produced by the equivalent dipoles with the current basis function of the filed point. The whole dissertation is based on this method and includes three aspects in principle.The first portion systemically introduces some basic principles, including the establishment of the surface integral equation of PEC Objects—Electric Field Integral Equation (EFIE), Magnetic Field Integral Equation (MFIE), Combined Field Integral Equation (CFIE), the principle of MoM, the choice of basis functions and test functions, the method of removing singularity and the principle of equivalent dipole model. Then the equivalent dipole-moment method for PEC objects is deduced based on the above theories.In the second portion, the PMCHW equations for homogeneous dielectric objects are reviewed, and the equivalent dipole-moment method for homogeneous dielectric objects is deduced in detail.The last portion first provides a brief introduction to the EFIE-PMCHW equations for mixed homogeneous dielectric and PEC objects, and then the equivalent dipole-moment method for mixed homogeneous dielectric and PEC objects is proposed. Numerical results demonstrate the accuracy and efficiency of the equivalent dipole-moment method.