The Research Of MOM From The 3D Simple Target And The 2D PEC Rough Surface

In this thesis, the application of the Method of Moment (MOM) and its parallelization in the electromagnetic (EM) scattering from the rough surface and the three-dimensional (3D) target are systematically introduced. The EM scattering by the 3D simple perfect electric conducting (PEC) targets is calculated by the MOM. At the same time, the EM scattering by the two-dimensional (2D) PEC rough surface without target is also calculated and analyzed with the parallel MOM approach based on different basis function. The main works are as follows:1. The basic principle of the MOM and the essential knowledge for the parallel computation are firstly introduced. The related theory of the conjugate gradient method (CGM) for solving MOM matrix equation is then given. The concrete procedures of the parallel CGM based on the message passing interface (MPI) of the PC Clusters are shown in detail.2. Using parallel MOM based on the pulse basis function, the EM-scattering characteristics by 3D simple target is studied, and the result is compared with that gained from the parallel MOM based on the RWG triangle basis function, and the advantage and validity are presented. A new method called the MOM based on the Asymptotic Waveform Evaluation (AWE) technique is introduced, and it can solve EM-scattering problem of 3-D simple target. The numerical result calculated by the AWE technique is compared with what is done by the previous methods, and the accuracy and validity of AWE technique have been verified.3. The EM-scattering by 2-D Gaussian PEC rough surface is studied by the parallel MOM on PC Clusters. And the Gaussian Beam is introduced as the incident wave to research the EM-scattering by 2-D Gaussian PEC rough surface, and the result is analysed.4. The EM-scattering problem of simple 3-D target is examined by MOM based on modeling target by Non_Uniform Rational B_Spline (NURBS) surface, and the numerical result is given by the commercial software and the MOM based on the RWG triangle basis function. The three kinds of results are compared and analysed. Then using the MOM based on modeling by NURBS surface, the EM-scattering by 2-D Gaussian PEC rough surface is investigated, and the EM-scattering by 2-D Gaussian PEC rough surface is researched by parallel MOM based on the RWG triangle basis function, and the comparison and analysis are gived, the MOM-NURBS shows its priority to MOM-RWG in needing less memory, operating at faster speed, and the accuracy of this method can be guaranteed.