• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.3
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• pp.26-31
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• 1991

The scattering property of TMz illuminated a elliptic dielectric cylinders with arbitrary cross section are analyzed by the boundary element techniques. The boundary element equations are for- mulated via Maxwell's equations, weighted residual of Green's theorem, and the boundary conditions. The unknown surface fields on the boundaries are then calculated by the boundary element integral equations. Once the surface fields are found, the scattered fields in far-zone and scattering widths (SW) are readily determined. To show the validity and usefulness of this formulation, computations are compared with those obtained using analytical method and one layer circular cylinder. As exten- sion to arbitrary cross-sectioned cylinders, plane wave scattering from a elliptic dielectric cylinders are numerically analyzed. A general computer program has been developed using the quadratic ele- ments(Higher order borndary elements) and the Gaussian quadrature.

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.183-188
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• 2013

In this paper, the TE (Transverse Electric) scattering problems by a perfectly conducting strip grating over a grounded two dielectric layers with edge boundary condition are analyzed by applying the FGMM (Fourier Galerkin Moment Method). For the TE scattering problem, the induced surface current density is expected to the zero value at both edges of the strip, then the induced surface current density on the strip is expanded in a series of the multiplication of the Chebyshev polynomials of the second kind and the functions of appropriate edge boundary condition. The numerical results shown the fast convergent solution and good agreement compared to those of the existing papers.

• Journal of Advanced Navigation Technology
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• v.11 no.2
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• pp.196-202
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• 2007

In this paper, The TE(transverse electric) scattering problems by a resistive strip grating over a grounded dielectric plane with edge boundary condition are analyzed by applying the FGMM(Fourier-Galerkin Moment Method) known as a numerical procedure. For a TE scattering problem, the induced surface current density is expected to the zero value at both edges of the resistive strip, then the induced surface current density on the resistive strip is expanded in a series of the multiplication of Gegenbauer(Ultraspherical) polynomials with the first order and functions of appropriate edge boundary condition. To verify the validity of the proposed method, the numerical results of normalized reflected power for the uniform resistivity R = 100 ohms/square and R = 0 as a conductive strip case show in good agreement with those in the existing papers.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.6
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• pp.650-655
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• 2011

Analysis of two-dimensional Rayleigh wave scattering pattern by a surface defect is studied through modified boundary element method. BEM proposed in this paper has special treatment at each end of boundary which should have the Rayleigh wave go away without any generation of virtual reflections. It is shown that treatment for truncated boundary which is used to model two-dimensional Rayleigh waves' behavior in an elastic half-space is successfully implemented. To check numerical results' accuracy, time domain IFFT signal of the displacements is presented. Improvement on getting rid of unwanted influence of truncated boundary induced by 2-D Rayleigh waves on a flat surface of an elastic half-infinite medium is shown. As a final goal, the numerical results of Rayleigh wave scattering trend are plotted and they are compared with theoretical curves to prove its accuracy.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.18-21
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• 1987

The problem of electromagnetic scattering from arbitrarily shaped lossy dielectric bodies of revolution is studied. Two coupled vector integral equations are formulated from the potential formulas, the equivalence principle and boundary condition. The unknown surface currents (both electric and magnetic) can be found by the moment method, Galerkins's procedure. After the surface currents are determined, the scattering pattern can be evaluated.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.3
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• pp.38-44
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• 1995

The scattered electric field from a multilayered circular dielectric cylinder is caculated. Approximate boundary condition used in on-surface radiation boundary condition(OSRC) method has been applied to all the boundary surface of N-layered dielectric cylinder. It was assumed that scattered electric field at inner boundary surface in one region transmitted to the adjacent region at outer boundary surface. In the whole region, the unknown coefficients of electric field are acquired by the given incident electric field with ease. Electric field distribution at each boundary surface and the scattered electric field in free space are taken with the calculated unknown coefficients. the results obtainted were compared with those results that were used by regular surface boundary condition.

• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.16-21
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• 2013

This study presents the angular effects of virtual vertices inserted for effective treatment of the boundary edge laid on an infinite conducting surface in a half-space scattering problem. We investigated the angular effects of virtual vertices by first computing the radar cross section (RCS) of a specific scatterer; i.e., a tilted conducting plate in contact with the ground surface, by inserting the virtual vertex in half-space. Here, the electric field integral equation is used to solve this problem with various virtual vertex angles (${\theta}_{\nu}$) and conducting plate inclination angles (${\theta}_r$) ranging from $0^{\circ}$ to $180^{\circ}$. The effects of the angles ${\theta}_{\nu}$ and ${\theta}_r$ on the RCS computation are clearly shown with numerical results with and without the virtual vertices in free- and half-spaces.

• Journal of Advanced Navigation Technology
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• v.17 no.4
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• pp.429-434
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• 2013

In this paper, the TM (Transverse Magnetic) scattering problems by a perfectly conducting strip grating over a grounded two dielectric layers with edge boundary condition are analyzed by applying the FGMM (Fourier Galerkin Moment Method). For the TM scattering problem, the induced surface current density is expected to the very high value at both edges of the strip, then the induced surface current density on the conductive strip is expanded in a series of the multiplication of the Chebyshev polynomials of the first kind and the functions of appropriate edge boundary condition. Generally, when the value of the relative permittivity of dielectric layers over the ground plane increased, the strip width according to the sharp variation points of the reflected power is shifted to a higher value. The numerical results shown the fast convergent solution and good agreement compared to those of the existing papers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.2
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• pp.181-186
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• 1992

The scattering property of TMz illuminated perfectly conducting and dielectric cylinders of arbitrary cross section are analyzed by the boundary element techniques. The boundary element equations are formulated via Maxwell’s equations, weighted residual or Green’s theorem, and the boundary conditions. The unknown surface fields on the boundaries are then calculated by the boundary element integral equations. Once the surface fields are found, the scattered fields in from a perfectly conducting circular and elliptic cylinders, a dielectric circular and elliptic cylinders are numerically analyzed. A general computer program has been developed using the quadratic elements(higher order boundary elements) and the Gaussian quadrature.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.1087-1094
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• 2014

An numerical technique of impedance boundary condition to improve an efficiency in the process of moment method with CFIE(Combined Field Integral Equation), which is widely used to analyze the scattering property of dielectric scatterers, and results of its cross-validations are presented in this study. Application of the impedance boundary allows to represent the equivalent surface currents of dielectric scatterer depicted by both kinds of electric/magnetic surface currents(Js, Ms) to the single surface current by Js or Ms only. Accuracy of this technique is validated by the existing CFIE and theoretical values such as Mie-series solution and small perturbation scattering model. The computational difference of less than 1 dB was verified within an imaginary part of dielectric constant more than 12, as well.