Research On Methods For Open-Ended Cavity EM Scattering

The paper mainly introduces and discusses the mechanism of cavity scattering and the different methods for calculating cavity RCS, with their advantages and shortages analyzed. And it puts emphasis on the analysis of the CRE (Complex Ray Expansion) and IPO (Iterative Physical Optics).With the CRE method, complex ray expansion of plane waves is derived successfully. The RCS of the target is got through an application of the paraxial approximation in finding the far field after calculating the electromagnetic field in the axis direction by ray tracing. In the calculation of RCS of simple cavities with IPO, the method of predigest integral in FEM is introduced successfully, which results in predigestion of the program and reduction of calculating time. Based on the analysis of CRE and IPO, the RCS computational results of some simple cavity models are presented in the paper, which show that the CRE and IPO are efficient methods in cavity scattering.The dissertation puts forward some ideas of improving CRE and IPO according to the problem of complex cavity. The limitation of time and energy does not allow a careful discussion of those ideas, which remain to be a topic requiring further research in the future.