Fast Algorithms For Electromagnetic Scattering Of Electrically Large Cavities

Cavities are specific electromagnetic structures, and their scatterings are different from convex objects. Along with the increasingly demands for military affairs and the development of information technology, studying on the fast algorithm for the scattering of electrically large complex cavities is meaningful. The method of moment (MOM) is an exact numerical method for the analyses of electromagnetic characteristics of complex objects, but the efficiency is lower, so it is difficult in solving the scattering of electrically large complex cavities. Iterative physical optics (IPO) technique is a more efficient method in analyzing the electromagnetic characteristics of mid electrically large cavities, but it can't be used in complex objects. Also, when the electrical size is getting larger, the analyses efficiency is getting lower. For the shortages of analyses efficiency of the two methods, this dissertation is mainly discussed about the use of fast algorithm in MOM, IPO and IPO-MOM to raise the analyses efficiency of electrically large complex cavities.When using FMM in MOM, we also have optimized the calculation and storage of the matrix, by doing this, the analyses efficiency of electrically large complex cavities improved a lot. The analyses efficiency of electrically large cavities have notable raised when applied FAFFA in IPO. Aggregation- process in FAFFA has been improved by taking the phase affection between triangles and the group center into account. This made the results more accurate.At last, using the accelerated IPO and MOM based on FMM into the complex- method, By using this method, the analyses efficiency of the electrically large cavities have been efficiently improved.