TM Electromagnetic scattering from 2D multilayered dielectric bodies-numerical solution (original) (raw)
Related papers
TM Electromagnetic Scattering from Multilayered Dielectric Bodies -- Numerical Solution
An integral equation approach is derived for an electromagnetic scattering from an M multilayered dielectric domain. The integral equation is valid for 2D and 3D Helmholtz equation. Here we show the numerical solution for the 2D case by using the Nyström method. For validating the method we develop a mode matching method for the case when the domains are multilayered circular cylinders and give numerical results for illustrating the algorithm.
Physical-density integral equation methods for scattering from multi-dielectric cylinders
Journal of Computational Physics
An integral equation-based numerical method for scattering from multi-dielectric cylinders is presented. Electromagnetic fields are represented via layer potentials in terms of surface densities with physical interpretations. The existence of null-field representations then adds superior flexibility to the modeling. Local representations are used for fast field evaluation at points away from their sources. Partially global representations, constructed as to reduce the strength of kernel singularities, are used for near-evaluations. A mix of local-and partially global representations is also used to derive the system of integral equations from which the physical densities are solved. Unique solvability is proven for the special case of scattering from a homogeneous cylinder under rather general conditions. High achievable accuracy is demonstrated for several examples found in the literature.
In this paper, we derive a new integral equation method for direct electromagnetic scattering in homogeneous media and present a numerical confirmation of the new method via a computer simulation. The new integral equation method is based on a paper written by DeSanto [1], originally for scattering from an infinite rough surface separating homogeneous dielectric half-spaces. Here, it is applied to a bounded scatterer, which can be an ohmic conductor or a dielectric, with some simplification of the continuity conditions for the fields. The new integral equation method is developed by choosing the electric field and its normal derivative as boundary unknowns, which are not the usual boundary unknowns. The new integral equation method may provide significant computational advantages over the standard Stratton–Chu method [2] because it leads to a 50% sparse, rather than 100% dense, impedance (collocation) matrix. Our theoretical development of the new integral equation method is exact.
A Fast-Converging Scheme for the Electromagnetic Scattering from a Thin Dielectric Disk
Electronics
In this paper, the analysis of the electromagnetic scattering from a thin dielectric disk is formulated as two sets of one-dimensional integral equations in the vector Hankel transform domain by taking advantage of the revolution symmetry of the problem and by imposing the generalized boundary conditions on the disk surface. The problem is further simplified by means of Helmholtz decomposition, which allows to introduce new scalar unknows in the spectral domain. Galerkin method with complete sets of orthogonal eigenfunctions of the static parts of the integral operators, reconstructing the physical behavior of the fields, as expansion bases, is applied to discretize the integral equations. The obtained matrix equations are Fredholm second-kind equations whose coefficients are efficiently numerically evaluated by means of a suitable analytical technique. Numerical results and comparisons with the commercial software CST Microwave Studio are provided showing the accuracy and efficienc...
Journal of scientific computing, 2000
The problem of electromagnetic scattering by a homogeneous dielectric object is usually formulated as a pair of coupled integral equations involving two unknown currents on the surface S of the object. In this paper, however, the problem is formulated as a single integral equation involving one unknown current on S. Unique solution at resonance is obtained by using a combined field integral equation. The single integral equation is solved by the method of moments using a Galerkin test procedure. Numerical results for a dielectric sphere are in good agreement with the exact results. Furthermore, the single integral equation method is shown to have superior convergence speed of iterative solution compared with the coupled integral equations method.
The efficient solution of electromagnetic scattering for inhomogeneous media
Journal of Computational and Applied Mathematics, 2007
We consider an electromagnetic scattering problem for inhomogeneous media. In particular, we focus on the numerical computation of the electromagnetic scattered wave generated by the interaction of an electromagnetic plane wave and an inhomogeneity in the corresponding propagation medium. This problem is studied in the VV polarization case, where some special symmetry requirements for the incident wave and for the inhomogeneity are assumed. This problem is reformulated as a Fredholm integral equation of second kind, which is discretized by a linear system having a special form. This allows to compute efficiently an approximate solution of the scattering problem by using iterative techniques for linear systems. Some numerical examples are reported.
Comparison of three integral formulations for the 2-D TE scattering problem
IEEE Transactions on Microwave Theory and Techniques, 1990
Electromagnetic modeling for biomedical applications requires effective numerical methods. At present, one of the most efficient methods used to solve diffraction problems with dissipative dielectric objects is the FFT-CGM (fast-Fourier-transform conjugate gradient method) ll]-[3]. However, in contrast to TM polarization, substantial errors are found 141 when we use it for computing the internal field distribution in the TE polarization case for 2-D objects. We here analyze the source of these errors and show that the modified method, empirically introduced in 141, is not required if correct terms in the integral equation are accounted for. With this aim in mind, we propose another integral formulation using generalized functions and compare it to several formulations available in the literature. Numerical comparisons are carried out for inhomogeneous dissipative cylinders whose electromagnetic parameters are close to those of biological tissues. The solution associated with this integral formulation appears to behave better than the others, in comparison with the exact analytical solutions.
IEEE Transactions on Antennas and Propagation, 2011
The integral equation (IE) method is commonly utilized to model time-harmonic electromagnetic (EM) problems. One of the greatest challenges in its applications arises in the solution of the resulting ill-conditioned matrix equation. We introduce a new domain decomposition method (DDM) for the IE solution of EM wave scattering from non-penetrable objects. The proposed method is a non-overlapping/non-conformal DDM and it provides a computationally efficient and effective preconditioner for the IE matrix equations. Moreover, the proposed approach is very suitable for dealing with multi-scale electromagnetic problems since each sub-domain has its own characteristics length and will be meshed independently. Furthermore, for each sub-domain, we are free to choose the most effective IE sub-domain solver based on its local geometrical features and electromagnetic characteristics. Additionally, the multilevel fast multi-pole algorithm (MLFMA) is utilized to accelerate the computations of couplings between sub-domains. Numerical results demonstrate that the proposed method yields rapid convergence in the outer Krylov iterative solution process. Finally, simulations of several large-scale examples testify to the effectiveness and robustness of the proposed IE based DDM. Index Terms-Domain decomposition, integral equation (IE) method, method of moments, multilevel fast multipole algorithm (MLFMA), scattering. Zhen Peng (M'09) received the B.S. in electrical engineering and information science from the University of Science and Technology of China, in 2003 and the Ph.D. degree from the Chinese Academy of Science, in 2008. From 2008 to 2009, he was a Postdoctoral Fellow at the ElectroScience Laboratory, Ohio State University. He has been working as a Senior Research Associate at the ElectroScience Laboratory, Ohio State University since 2009. His research interests are in scientific computing, specifically in the area of fullwave numerical methods in computational electromagnetic. Recently research directions include the domain decomposition methods for both finite element method and boundary integral method, the hybrid finite element-boundary integral method, and the multilevel fast multipole method. Applications of his research include: novel antennas for wireless communication systems, electromagnetic compatibility and interference analysis of multiple antenna systems on military and commercial aircrafts, signal integrity and package analyses for modern ultra-large integrated circuits, and the design tolls for energy efficient LCD back-light unit. Xiaochuan Wang (S'09) was born in Shandong Province, China. He received the B.Eng. and M.Sc. degrees in electrical engineering from Tsinghua University, Beijing, China, in 2005 and 2007, respectively. He is currently a Graduate Research Associate at The Ohio State University, where he is working towards the Ph.D. degree. His research interests include domain decomposition method in computational electromagnetics.