Analysis of the Electromagnetic Scattering by Perfectly Conducting Convex Polygonal Cylinders (original) (raw)
Through-wall electromagnetic scattering by N conducting cylinders
Journal of the Optical Society of America A, 2013
A spectral-domain analysis is presented for the scattering by perfectly conducting cylindrical objects behind a dielectric wall. The solution is developed with an analytical-numerical technique, based on the cylindrical wave approach. Suitable cylindrical functions and their spectral representations are introduced as basis functions for the scattered fields, to deal with their interaction with the planar interfaces bounding the wall. The numerical solution is given in TE and TM polarizations states, and in both near-and far-field zones. The model yields an accurate computation of direct scattering that can be useful for through-wall-imaging applications. A stack of three different dielectric media is considered in the theoretical model. In the numerical results, the upper medium, where the incident field is generated, is assumed to be filled by air, the central layer represents the wall, and the lower medium, which contains the scatterers, is air filled, too. Also general problems of scattering by buried objects can be simulated, being the cylinders buried in a medium of arbitrary permittivity, placed below a dielectric layer.
Progress In Electromagnetics Research B, 2017
The analysis of the electromagnetic scattering from perfectly electrically conducting (PEC) objects with edges and corners performed by means of surface integral equation formulations has drawbacks due to the interior resonances and divergence of the fields on geometrical singularities. The aim of this paper is to show a fast converging method for the analysis of the scattering from PEC polygonal cross-section closed cylinders immune from the interior resonance problems. The problem, formulated as combined field integral equation (CFIE) in the spectral domain, is discretized by means of Galerkin method with expansion functions reconstructing the behaviour of the fields on the wedges with a closed-form spectral domain counterpart. Hence, the elements of the coefficients' matrix are reduced to single improper integrals of oscillating functions efficiently evaluated by means of an analytical asymptotic acceleration technique.
Journal of Physics D, 1994
In this paper, a finite element method (FEM) is implemented to compute the radar cross section of a two-dimensional (2-D) cavity embedded in an infinite ground plane. The method is based on the variational formulation which uses the Fourier transform to couple the fields outside the cavity and those inside the cavity; hence, the scattering problem can be reduced to a bounded domain. The convergence of the discrete finite element problem is analyzed. Numerical results are presented and compared with those obtained by the standard finite element-Green function method and by the 2-D integral equation method.
Light Scattering from Microstructures
An analytical-numerical technique for the solution of the two-dimensional scattering of an electromagnetic wave by a set of circular cylinders in the presence of a plane discontinuity for the electromagnetic constants is discussed. Since the interface is only characterized by its reflection coefficient, a wide class of reflecting surfaces can be treated with the same formalism. The solution is obtainable for both the near and the far region, regardless the polarization state of the incident wave. The method exploits the possibility of representing any two-dimensional field in terms of a suitable superposition of cylindrical waves. The expansion coefficients represent the unknowns in a typical scattering problem and can be determined by imposing the boundary conditions. The presence of the interface leads to the necessity of evaluating the reflected cylindrical waves, and this is achieved starting from the Fourier spectrum of the cylindrical functions on a plane.
On some numerical aspects of the scattering problem by buried cylinders
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, 2013
Purpose-The purpose of this paper is to investigate the numerical aspects of the electromagnetic scattering of a plane wave by a set of buried cylinders. Design/methodology/approach-The cylindrical wave approach is employed. The analytical model is implemented in a Fortran code. The numerical aspects of the technique are presented, with particular emphasis on the numerical evaluation of the integrals involved in the procedure. Findings-The tool obtained allows a fast computation of the electromagnetic field scattered by an arbitrary disposition of circular cylinders below an interface. Comparisons with the finite element method are proposed, showing the very good agreement between the results obtained with the two different approaches. Originality/value-The advantages of the proposed technique in terms of computational weight are explained. The method can be useful in a wide class of application, e.g. in the ground penetrating radar applications, microscopy, biomedical applications, etc.
Scattering from an impedance cylinder embedded in a nonconcentric dielectric cylinder
2002
The electromagnetic scattering from an impedance cylinder embedded in a nonconcentric dielectric cylinder is derived rigorously by using a boundary value approach. The two cylinders are assumed to be infinite in length and of circular cross-section. The incident electromagnetic field is in terms of an electric or a magnetic field component parallel to both cylinder axes. The problem is two dimensional and the solution to either types of polarisation (TM or TE) can be found independently. Plane wave and line source excitations are considered in this analysis. The effects of various geometrical and electrical parameters (such as the cylinder's radii, permittivity, surface impedance and eccentricity) on the near field distribution and the far scattered field pattern are examined. Bistatic and monostatic scattering cross-sections of the composite cylinder which minimise or maximise the radar crosssection are also investigated.
Electromagnetic scattering analysis of arbitrarily shaped material cylinder by FEM-BEM method
1996
A hybrid method that combines the finite element method (FEM) and the boundary element method (BEM) is developed to analyze electromagnetic scattering from arbitrarily shaped material cylinders. By this method, the material cylinder is first enclosed by a fictitious boundary. Maxwell's equations are then solved by FEM inside and by BEM outside the boundary. Electromagnetic scattering from several arbitrarily shaped material cylinders is computed and compared with results obtained by other numerical techniques.
Journal of The Optical Society of America A-optics Image Science and Vision, 1996
A general approach is presented for treating the two-dimensional scattering of a plane wave by an arbitrary configuration of perfectly conducting circular cylinders in front of a plane surface with general reflection properties. The method exploits the angular spectrum representation of cylindrical waves and turns out to be fairly efficient, as demonstrated by a number of examples. Our approach seems promising for several applications both in optics and in microwaves. native approaches are used. Our method allows us to deal with reflecting surfaces of general behavior, such as lossy, anisotropic, and multilayered interfaces. It seems particularly efficient in terms of computation time, stability, and reliability of the results.
Line Source Scattering by Buried Perfectly Conducting Circular Cylinders
International Journal of Antennas and Propagation, 2012
A two-dimensional scattering problem of a line source by a set of perfectly conducting circular cylinders buried in a semi-infinite medium is solved, in both TE and TM polarization. A cylindrical-wave approach is used and applied to both the field emitted by the source and the field scattered by the buried objects. Reflection and transmission of such fields through the planar interface are evaluated making use of the plane-wave spectrum of a cylindrical wave. Numerical results are presented, with checks confirming the validity of the method.