Electromagnetic Scattering Analysis Of Complicated Rotational Symmetry Body Target

With the rapid development of computers and the urgent need of national defense, there is a big development in the computational electromagnetic. In civilian or military application, more and more researches for electromagnetic scattering by thin materials are paid attention, especially in the aeronautics and astronautics industries.Firstly, this work presents a technique for evaluating singular integrals in the solution of electromagnetic scattering by the bodies of revolution (BoR) using the method of moments (MoM). In this thesis, the singular part of the kernels is transformed to an elliptic integral, which is calculated by a closed form or replaced by an accuracy approximation based on the arithmetic geometric mean. What is more, the scattering characteristics of dielectric antenna radome of revolution are discussed.Secondly, the electromagnetic scattering by conductor-backed thin materials is analyzed. The polarization current and charge are expressed in terms of the surface induced current on the conductor surfaces, so there is only one unknown in the integral. Compared to the surface integral equation approach and traditional BOR, there are less unknowns in this method which saves time and memory consumption. A series of numerical examples are presented to demonstrate this approach accuracy and efficiency, and it can be seen that this method is better than traditional methods.At last, the adaptive crossover approximation (ACA) algorithm is combined with the PMCHW. The sub-matrixes can be compressed utilizing the low rank of the coupling matrix blocks in the ACA algorithm. Due to the low rank character, the sub-matrixes in the far field can be decomposed by picking out rows and columns with the same number as the rank. As a result, the memory and the time can be saved greatly.