| The accurate calculations of electromagnetic fields play a crucial role in aircraft design and antenna design. The methods proposed in the literature for the EM fields calculation of scattering from large cavities are not be fast, accurate and easily implemented enough.;In this dissertation, the calculations of EM fields for 2D large open cavities are considered first. By defining two extension operators, the exact solution and the mode matching solution maybe formulated under the same framework, which makes it possible to analyze the difference. Using an asymptotic technique, we present a new (improved) mode matching method. In particular, the explicit solution and the error estimate are given. Numerical examples, including EM fields calculations and RCS calculations, are presented. The second part of the dissertation is about the calculations of EM fields for 3D cavities. Following the similar idea, mode matching method and improved mode matching method are presented. Numerical examples are showed to demonstrate the efficiency of the method. |
