Efficient Analysis Of Body Of Revolution And Its Application

With the development of computer science and electromagnetics, accurate and fast computational electromagnetics is an important topic in many areas, such as recognizing the target, stealth and anti-stealth technology, micro-wave imaging. The field of some spectial geometry like body of revolution (BOR) can be expressed in a Fourier series because of the axial symmetry of the geometry. The computational complesity is reduced because of the orthogonality of each mode. The 3-D domain is reduced to 2.5-D which will depress the scale of electromagnetic computation. The thesis mainly concentrates on the fast and efficient algorithm based on body of revolution. And it contains five parts as follows.The method of moments (MoM) for scattering problem of body of revolution is reviewed in the first part. Triangular basis and pluse basis are used to expand the equivalent electric and magnetic currents. Electric field integral equation (EFIE), magnetic field integral equation (MFIE) and combined field integral equation (CFIE) are used for solving perfect electric conductor (PEC) BOR's radar cross section (RCS). Poggio-Miller-Chang-Harrington-Wu(PMCHW)equation is implemented to analyze homogeneous BOR's problems. Composite BOR is then simulated with EFIE in PEC region and PMCHW equation in dielectic region.Fast inhomogeneous plane wave algorithm (FIPWA) is introduced for BOR's scattering prolem in the second part. The Green's function is expanded in inhomogeneous plane waves by using Weyl identity. Traditional MoM is used for near field part. FIPWA is used for far field interaction. Using the integral expression of Bessel function, the aggregation and disaggregation factors can be expressed in analytical form. The memory requirment and CPU time are saved by using FIPWA for scattering problems of large scale BOR.A finite element method (FEM) with hybrid nodal and edge basis functions for solving nonaxisymmetric modes in axisymmetric resonators filled with inhomogeneous media is presented. The material is inhomogeneous on the cross section of the cavity. Non-zero eigenvalues can be reduced by choosing proper basis functions. Higher-order basis functions are used to improve the accuracy with the same number of unknowns.FEM and boundary integration (BI) method are combined for solving the scattering problem of imhomogeneous BOR in the forth part. FEM is used for solving the inhomogeneous interior region with nodal and edge basis functions. BI is used for solving the exterior region part. This hybrid algorithm takes the advantages of FEM and BI. It can handle inhomogeneous problem efficiently and guarantee the accuracy at the same time.Muiti-region iteration (MRI) is used for solving multi-BOR problems in the last part. Each BOR is set as one region and solved independently. The coupling is considered during the iteration. Large scale 3-D PEC objects or multi-objects with arbitrary shape are also simulated by proposed MRI. The memory requirement is saved and the accuracy is guaranteed at the same time.Integral equation (IE), FEM, higher-order FEM and FEM-BI are studied for BOR problem in the thesis. The efficienncy and accuracy are improved by using these different methods. The studies of this thesis demonstrate that fast and efficient algorithm for BOR can be used to improve the efficiency and accuracy and will be extended in future research and engineering application.