Bistatic Dimensional Electromagnetic Scattering Wide-angle Parabolic Equation Analysis Of RCS

Great developments are made in the computational electromagnetic method with the development of both the computers and the electronic communication. And it has wide range of applications in both the industry and the military. A large number of unknowns are needed for the numerical methods with high accuracy to analyze three dimension electromagnetic scattering from electrically large objects such as the finite element method (FEM), the finite differential method (FDFD) and the method of moment (MOM). On the other hand, the high-frequency method brings large errors with lower computational requirement. The parabolic equation (PE) is an approximation of the wave equation. The calculation is taken to march from plane to plane along the paraxial direction and in this way the3D problem can be converted into a series of2D problems to be solved. Both the memory requirement and the CPU time can be saved by the PE method.The thesis focuses on the analysis of three-dimensional parabolic equation method for wider angle scattering. This thesis is constructed as follows:Firstly, the theories of the three dimensional scalar parabolic equation method, the three dimensional vector parabolic equation method and the three dimensional parabolic equation method for wider angle scattering are introduced.Moreover, the three dimensional scalar parabolic equation method for wider angle scattering is discussed in detail. The FD scheme is used to the directions x, y and z. Then the three-dimensional wider-angle parabolic equations can be gotten and used to efficiently analyze the PEC scatterings.At last, the FD scheme is used along the x-direction and the radial point interpolation meshless (RPIM) method is applied to the transverse (y-z) plane for the three-dimensional wider-angle parabolic equation method. Compared with the traditional finite difference method, the RPIM method can be used as an efficient tool for modeling scatterers with complex shape.The axial direction of parabolic equation is the scattering direction. The finite difference (FD) scheme is used along the axial direction while either the FD scheme or the meshless method is applied to the transverse (y-z) plane in this thesis. Numerical results demonstrate the efficiency of the proposed method for electrically large scattering problems.