• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1094-1099
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• 2012

This paper presents the reduction characteristics of electromagnetic penetration through a slot in conducting screen by loaded plate. The FDTD method is used in theoretical analysis. And the characteristics of penetrated electric fields are calculated in terms of length, width, position, and height of the loaded plate to find out how the geometry of plate influences the reduction characteristics of the electromagnetic penetration. The results show that the characteristics of penetrated electric field depend on the geometry of loaded plate. In particular, the optimal geometry of loaded plate which minimize penetrated electric field are verified.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.1
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• pp.25-32
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• 2005

In this paper, it is attempted to provide a unified explanation for typical short channel GaAs MESFET’s and SOI-structured Si JFET's behaviors such as: i) drain voltage-induced threshold voltage roll-off, ii) finite output ac resistance beyond the saturation, and iii) weak dependence of the drain saturation current on the channel length. Replacing the conventional GCA with a new assumption that is suggested in order to include the longitudinal field variation, and taking into account the channel current continuity and the field-dependent mobility, we can derive the two-dimensional potential in both depletion region and undepleted conducting channel. Obtained expressions for the threshold voltage and the drain current will be considerably accurate over the entire operating region. Moreover, in comparison with the conventional channel length shortening models, our model seems to be more reasonable in explaining the Early effect.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.1
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• pp.46-53
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• 2008

In general, the cassegrain dual offset reflector is used for the satellite communication antenna, but is analyzed as the reflector system for the CPTR(Compact Payload Test Range) facility in here. The near-field at the test zone of the CPTR is obtained by using the physical optics approximation. The CPTR has to provide a uniform plane wave with the minimum amplitude and phase ripple and the low cross polarization. Therefore, in this paper, the near-field pattern are calculated, and the ripple and taper of the field and the cross polarization are investigated with the variation of the reflector geometry and the position of the test region. Especially, the cross polarization of the antenna axis direction which is not found in the satellite reflector antennas is investigated.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.703-705
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• 1987

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.558-560
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• 1995

Tunneling current from filed emission display tips is calculated by numerical analysis using a finite element method software. For simple tip structures it is shown that the image charge method could provide an efficient way to estimate the tunneling current.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.257-260
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• 2006

This paper presents electromagnetic finite element analysis of power cables for wind turbine application. Eddy current losses are calculated due to high currents along metallic part, and dielectric strength on power cables is investigated for case study, which suggests the optimal cabling configuration for wind turbine construction.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.5
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• pp.376-383
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• 1996

In general, the electromagnetic field analysis of a vertical dipole mainly deals with the space. wave. But when only the space wave is considered, as a receiving point is close to the surface of medium, the receiving electric field strength is rapidly decreased. In this paper, to solve this problem, we considered both the surface wave and the space wave contribution. When the vector potential is used with the angular spectrum transformation method, the space wave and the surface wave are included in the final electric field expression. By using this final electric field expression, the effect of the surface wave is analyzed through simulations and the factors having effect on a propagation phenomenon of sea surface are studied in detail. Also, the justification of the theoretical formula was proved by comparing theoretical values with measuring ones at 880. 2MHz which is the frequency of mobile communication.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.89-91
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• 1999

The performance of circuit interruption of $SF_6$ puffer cylinder type gas circuit breaker(GCB) has been evaluated from the results of electrical insulation strength which is depend on material property, such as $SF_6$ gas density in circuit breaker tank. In order to determine circuit breaker dimension in the safety criteria. electrical field analysis has been done by finite element method. Gas density of concerned area in the circuit breaker has been calculated. In order to predict small current break performance, Electrical field analysis result must be calculated based the results of density from cold flow dynamics. The proposed method has been carried out and evaluated for 362kV class high voltage GIS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.451-454
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• 2000

The impact ionization(I.I.) is necessary to analyze carrier transport properties under the influence of high electric field. The full band I-k relation and Fermi's golden rule are used for the calculation of impact ionization rate. We have investigated the temperature- and field-dependent impact ionization coefficient for silicon using full band Monte Carlo simulation. The impact ionization coefficients calculated by our impact ionization model are agreed with experimental data at look. We know that impact ionization coefficients and electron energies are decreasing along increasing temperature due to increase of phonon scattering, especially by emission. The logarithm of impact ionization coefficients are fitted to linear function for temperature and field. The residuals of linear function are within the error bound of 5%. We know logarithmic impact ionization coefficients are linearly dependent on temperature and field.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1664-1666
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• 2004

This paper describes the use of Armaid papers and varnishes in electric motors. We compare with boundary element method(BEM) and finite element method(FEM) by calculated electric field strength. Several computer software package to perform such calculations based on electrostatic field and applicable DC are available.