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Download or read book Electromagnetic Scattering from Inhomogeneous Objects of Arbitrary Shape Embedded in a Layered Medium written by Ergun Şimşek and published by . This book was released on 2006 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, novel surface and hybrid integral equation solvers have been developed for the electromagnetic scattering from inhomogeneous objects in a layered medium. To evaluate the layered medium Green's functions (LMGFs) efficiently, a new extraction procedure is developed which is valid for any kind of source-field point combination. The extraction procedure is implemented appropriately for each individual term of the integrand and the contribution of the each term is calculated analytically. To calculate the scattered electric and magnetic fields from homogeneous objects of arbitrary shape embedded in a layered medium, the surface integral equation is solved by using the Method of Moments (MoM). Then, its exterior part is utilized as a radiation boundary condition for the finite-element method (FEM) which allows the objects inside the surface to be arbitrarily inhomogeneous. For the sake of computational efficiency, the sparse and symmetric FEM matrix is stored by using a row-indexed scheme to reach its the non-zero elements quickly. The coupled FEM/MoM matrix solved by using the biconjugate-gradient (BCG) method which requires O(KN2) CPU time and O( N2) memory, where N is the number of unknowns and K is the number of iterations. The CPU time for the evaluation of LMGFs is reduced by a simple interpolation technique. The overall accuracy and efficiency of the developed method are supported with several examples including two and three-dimensional inhomogeneous and composite structures. For the 2D case, it is shown that a spectral accuracy in the integral can be achieved by using the fast Fourier transform (FFT) algorithm and the subtraction of singularities in Green's functions. The number of points on the radiation boundary is only around 5 points per wavelength, that gives substantial saving in memory and CPU time requirements.