Electromagnetic Scattering Of Electrically Large Dielectric-Coated Cavities With Complex Terminations

Cavities are specific electromagnetic structures. Along with the increasingly demands for military affairs and the development of information technology, studying on the scattering of electrically large complex cavities is meaningful. The method of moment (MoM) is a classical numerical method for the analysis of electromagnetic characteristics of complex objects. However it is difficult in solving the scattering of electrically large complex cavities due to the low efficiency. 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. For the shortages of analyses efficiency of the two methods, this thesis is mainly discussed about the use of MFIE-IPO to raise the analyses efficiency of electrically large complex cavities.A MFIE based MoM solution was used to solve the scattering problems of cylindrical cavities with or without dielectric covers. A theory model was set up for calculating the RCS of a PEC cylindrical cavity and then the Surface Impedance Condition was introduced to connect the current with the magnetic current in order to solve the same RCS problem of the cavity with dielectric covers. The data results show that this MFIE solution is quite accurate.In the last chapter, a MFIE-IPO method was used to solve electrically large cavities with complex terminals, e.g. with four blades or six blades. By taking advantage of the periodicity properties of BOR (Body of Revolution), the substantial computational efficiency can be achieved. The MFIE-IPO data is in good agreement with reference data based on the mode-matching method.