Application Of Meshless Method In Electromagnetic Scattering

With the rapid development of national defense technology, the fast computation of Radar Cross Section (RCS) plays an important role for radar target recognition. Therefore, the research of Radar Cross Section (RCS) characteristics has been the focus of many scholars.In the traditional numerical methods, the currents are described by a set of basis functions, which are defined on a simplicial tessellation and can ensure the continuity of the current between the meshes. Since these basis functions depend on the meshes, it will reduce the computational accuracy and efficiency when the meshes don’t meet the conditions of function. The Meshless Method is introduced in this article, which can eliminate the relationship between the basis functions. The Meshless Method based on the integral equation is applied to solve the scattering problems from the three-dimensional targets.First of all, the Meshless Method is used to solve the electromagnetic scattering problems from metal targets. There are four parts during the process, the construction for shape function, discretization for integral equations, calculation for impedance elements and analysis for iteration process. The treatment for singularity is introduced in detail during the computation process of impedance matrix elements. Then, the Meshless Method is used for the analysis of scattering from the dielectric material, and the steps for the derivation of formula are detailedly described.Finally, in order to calculate the scattering from electrical large objects, the Multilevel Fast Multipole Algorithm (MLFMA) is applied to accelerate the computation of matrix-vector product (MVP), which can greatly reduce the computation of the interaction between two well-part groups and the requriment of CPU time and memory. Some numerical examples are presented to validate the correctness and efficiency of the proposed scheme in this article.