Applications of Adaptive Integral Method in Electromagnetic Scattering by Large-Scale Composite Media and Finite Arrays.

Abstract

The aim of the thesis is to develop Adaptive Integral Method (AIM) solvers for the analysis of the electromagnetic scattering by large-scale composite media objects and large finite periodic arrays. For the solution of composite media scattering problem, we first developed AIM based on Surface Integral Equation (SIE) to solve the scattering problem by large-scale homogeneous chiral objects and then developed AIM based on Volume Integral Equation (VIE) for solving the scattering problem by large-scale bi-anisotropic objects due to the lack of closed form Green's function for the bi-anisotropic media. Numerical results have tested the accuracy as well as the efficiency of the solvers. Conventional AIM solvers have been known to be inadequate when applied to solve large periodic array problems. It is due to the ignorance of the structure's periodicity and hence the problem can become intractable. However, recently developed macro basis functions can greatly reduce the unknowns for a unit cell thus relief the burden of conventional AIM in solving these problems. Therefore, new AIM solvers called accurate-sub-entire-domain AIM (ASED-AIM) and characteristic basis function method AIM (CBFM/AIM) are developed. ASED-AIM is accurate enough to calculate the far field RCS, but it is not accurate in calculating the near fields. However, CBFM/AIM is accurate in calculating both the near fields and far fields. Numerical results demonstrate that they are much more efficient than the conventional AIM.