• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.541-550
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• 2012

An improved method of moments using a hybrid Galerkin-interpolation technique for numerical analysis of electromagnetic wave scattering in the 3-dimensional space is presented in this paper. Basically, the EFIE(electric field integral equation) and RWG(Rao-Wilton-Glisson) basis function are used to compute a property of electromagnetic wave scattering. We propose a hybrid technique combining the existing Galerkin's method with the interpolation method to improve the efficiency of the numerical computation. Then, an index of relative distance of each cells was defined to distinguish the relatively far elements, which interpolation method can be applied. To verify the performance of the proposed technique, the analytical Mie-series solution was used to compute the theoretical RCS of a conducting sphere for the purpose of comparison. We also applied this hybrid technique to various scatterers such as trihedral/omni-directional corner-reflectors to analyze the radar backscattering properties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.640-645
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• 2020

To produce an input device stably using the transparent electromagnetic pattern of an electromagnetic induction method, pattern inspection is required in advance in the production process. Various methods of inspecting the capacitive pattern for hand-touch have been proposed, but it is difficult to find the related technical data for the pattern inspection method of the transparent electromagnetic induction method. In this study, to develop an inspection system for a fused electromagnetic resonance pen sensor with a copper-etched metal mesh pattern, an inspection algorithm and method for measuring the antenna impedance inside the sensor was proposed by measuring only the exposed FPCB connector. The proposed method was configured as a control board consisting of a microprocessor that forms a loop between specific channels according to the command of a computer, a computer-controlled by the Windows program, an LCR meter measuring the impedance between specific channels, and transmitting the measurement results back to the computer. An evaluation of the proposed system and measurements of nine specimens showed that it could detect the defects of the sensor used in the actual product.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.9
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• pp.701-706
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• 2018

The characteristic basis function method, or CFBM, is one of the representative electromagnetic methods widely used today. In this paper, we propose an accelerating algorithm for the far field interaction calculation of CBFM, to efficiently analyze the electromagnetic characteristics of arbitrarily large structures. To effectively analyze the electromagnetic characteristics of a large structure, it is essential to shorten the computation time. In the CBFM analysis method, the complexity can be greatly reduced by using approximations created via the multipole expansion method. The new algorithm proposed in this paper is applied to the computation of radar cross sections of conductor spheres and fighter aircraft, and it is confirmed that calculation time is reduced by 34 % and 74 %, respectively, without loss of accuracy compared with existing CBFM.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.7
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• pp.1204-1210
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• 2000

An analysis method for obtaining transient response of electromagnetic pulse(EMP) coupled via a slot aperture into a parallel-plate waveguide, is considered. The mixed-potential integral equation(MPIE), in which the vector and scalar potential Green's functions for the unknown equivalent magnetic surface current of the aperture in parallel-plate region are expressed in closed forms derived by use of the improved complex image method, is formulated. When the method of moments(MoM) is used to solve the MPIE, the matrix-fill time is significantly reduced because of closed-form Green's functions. In order to check the validity of the present method, the numerical results obtained by the present method are compared with those obtained by the previous method. Fairly good agreements between them are observed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.259-267
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• 2000

This paper presents the method for an estimation of discharge current waveshapes in short gap discharge by radiated electromagnetic fields. The method of current waveform estimation described is using the one antenna method(single field method) and two antennal method(complex field method) with a measured electric or magnetic fields at given field point by a time domain antenna. In order to verify the availability of the estimation theory, the discharge current waveshape estimation was performed by one and two antenna methods using the measured electric fields of Wilson & Ma and compared with experiments.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.4 s.107
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• pp.393-399
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• 2006

In this paper we applied a ray tracing method to estimate the scattering characteristics from large scale random rough surfaces. For the electromagnetic field evaluation, we have used the diffracted coefficient of the knife edge diffraction for the diffracted rays and Fresnel's reflection coefficients in connection with reflected rays. In addition, we examine to search for the traced rays using the imaging method which can be obtained all rays to arrived at receivers accurately and the diffracted field from rough surfaces is considered. Numerical examples have been carried out for the scattering characteristics of an ocean wave-like rough surface and delay spread characteristics of a building-like surface. In the present work we have demonstrated that the ray tracing method is effective to numerical analysis of a rough surface scattering.

• International Journal of Contents
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• v.7 no.4
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• pp.44-49
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• 2011

The scattering solutions for multiple rectangular metallic gratings in a perfectly conducting plane excited by the TE and TM delta sources are presented using an overlapping T-block method. A reflectarray composed of rectangular metallic gratings shows fanbeam radiation patterns that are useful for an electromagnetic fence. The scattering characteristics of multiple rectangular gratings were computed in terms of total radiated power and antenna directivity. The design method of a fan-beam reflectarray to obtain high directivity was also compared with superdirective radiation and parabolic reflector phase.

• Journal of KSNVE
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• v.7 no.4
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• pp.663-668
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• 1997

In general, the noise of alternator is generated by structure of attachment and structural characteristics of alternator itself. In this paper, general phenomena and causes of alternator noise have been considered. Especially, electromagnetic noise source of alternator has been discussed by consideration about the vibration of stator teeth. Also experimental method and simulation method have been used for the proof.

• Journal of the Korean Institute of Navigation
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• v.19 no.4
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• pp.93-102
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• 1995

A design method of an electromagnetic wave absorber with ferrite fins in the second layer, which has very wide band frequency characteristics, is proposed and discussed. A theoretical model using the equivalent material constants method is adopted, assessed for its accuracy by comparision with the Hashin-Shtrikman formulas and compared with the conventional absorbers. Based on the model, a wide band electromagnetic wave absorber with excellent reflectivity frequency characteristics in frequency range of 30MHZ to 3530MHZ has been designed.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.4
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• pp.8-16
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• 1997

A wide band design method of an electromagnetic wave absorber with using exponentially tapered ferritic is proposed and discussed. A theoretical model using the equivalent material constants method is also proposed to analyze the regions varying sptially in the shape of ferrite. Based on the developed model, wide band electromagnetic wave absorbers with excellent reflectivity frequency charaateristics in the freqency rang eof 30MHz to 2,150MHz or 2,430MHz were designed.