• ETRI Journal
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• v.28 no.1
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• pp.9-16
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• 2006

In this paper, we analyzed and measured the electrical crosstalk characteristics of a 1.25 Gbps triplexer module for Ethernet passive optical networks to realize fiber-tothe-home services. Electrical crosstalk characteristic of the 1.25 Gbps optical triplexer module on a resistive silicon substrate should be more serious than on a dielectric substrate. Consequently, using the finite element method, we analyze the electrical crosstalk phenomena and propose a silicon substrate structure with a dummy ground line that is the simplest low-crosstalk layout configuration in the 1.25 Gbps optical triplexer module. The triplexer module consists of a laser diode as a transmitter, a digital photodetector as a digital data receiver, and an analog photodetector as a cable television signal receiver. According to IEEE 802.3ah and ITU-T G.983.3, the digital receiver and analog receiver sensitivities have to meet -24 dBm at $BER=10^{-12}$ and -7.7 dBm at 44 dB SNR. The electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysis and measurement results, the proposed silicon substrate structure that contains the dummy line with $100\;{\mu}m$ space from the signal lines and 4 mm separations among the devices satisfies the electrical crosstalk level compared to a simple structure. This proposed structure can be easily implemented with design convenience and greatly reduce the silicon substrate size by about 50 %.

• Electrical & Electronic Materials
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• v.8 no.2
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• pp.151-157
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• 1995

Frequency-dependent electrical properties of $C_{22}$-Quinolinium(TCNQ) LB films were investigated in a frequency range of 10[Hz]-13[MHz] along a perpendicular direction. The films were heat-treated to understand an electrodynamic response in a temperature range of 20-240[.deg. C]. Frequencydependent dielectric constants show that there are two characteristic dispersions; one is a dispersion occuring near 1[MHz] coming from the orientational polarization of the molecules and the other one is an interfacial polarization effect below 1[kHz] or so when the annealing temperature is above 80 [.deg. C]. The overall frequency-dependent dielectric constant is higher near 80[.deg. C]. It may be due to a softness of the alkyl chains. Several other methods were employed to identify the internal structure change of the films. DSC(differential scanning calorimetry) data of the $C_{22}$-Quinolinium(TCNQ) molecules shows that there is an endothermic process near 110[.deg. C] and a weak exothermic process near 180[.deg. C]. While the endothermic process is related to a disordering of the alkyl chains, the exothermic process seems to be due to a chemical structure change of the TCNQ molecules. Thickness measurement by ellipsometry shows that there is a thickness drop near 100[.deg. C], and the thickness above 120[.deg. C] becomes around 20[%] of the room-temperature value.lue.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.686-694
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• 2014

A power semiconductor device, usually used as a switch or rectifier, is very significant in the modern power industry. The power semiconductor, in terms of its physical properties, requires a high breakdown voltage to turn off, a low on-state resistance to reduce static loss, and a fast switching speed to reduce dynamic loss. Among those parameters, the breakdown voltage and on-state resistance rely on the doping concentration of the drift region in the power semiconductor, this effect can be more important for a higher voltage device. Although the low doping concentration in the drift region increases the breakdown voltage, the on-state resistance that is increased along with it makes the static loss characteristic deteriorate. On the other hand, although the high doping concentration in the drift region reduces on-state resistance, the breakdown voltage is decreased, which limits the scope of its applications. This addresses the fact that breakdown voltage and on-state resistance are in a trade-off relationship with a parameter of the doping concentration in the drift region. Such a trade-off relationship is a hindrance to the development of power semiconductor devices that have idealistic characteristics. In this study, a novel structure is proposed for the Insulated Gate Bipolar Transistor (IGBT) device that uses conductivity modulation, which makes it possible to increase the breakdown voltage without changing the on-state resistance through use of a P-floating layer. More specifically in the proposed IGBT structure, a P-floating layer was inserted into the drift region, which results in an alleviation of the trade-off relationship between the on-state resistance and the breakdown voltage. The increase of breakdown voltage in the proposed IGBT structure has been analyzed both theoretically and through simulations, and it is verified through measurement of actual samples.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.3
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• pp.246-251
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• 2023

RADAR(Radio Detection and Ranging) is an important system for surveillance and reconnaissance by detecting a reflected signal which obtains the range from the radar to the target, and the velocity of the target. The magnitude of the reflected signal varies due to the radar cross section of the target, characteristic of the transmission and reception antenna, distance between the radar and the target, and power and wavelength of the transmitted signal. Thus, the RCS is the important characteristic of the target to determine if the target can be observed by the RADAR system. It is based on the material and shape of the target. We have measured the reflection signal of a simple square-shaped (20 × 20 cm) target made of a new material, a gallium-based liquid metal alloy and compared that of well-known metals including copper, aluminum. The magnitude of reflected signal of the aluminum target was the largest and it was 2.4 times larger than that of the liquid metal target. We also investigated the effect of the shape by measuring reflectance of the F-22 3D model(~1/95 ratio) target covered with/without copper, aluminium, and liquid metal. The largest magnitude of the reflected signal measured from side-view with the copper-covered F-22 model was 2.6 times greater than that of liquid metal. The reflectance study of the liquid metal would be helpful for liquid metal-based frequency selective surface or metamaterials.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.263-269
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• 2012

In order to present that the electromagnetic compatibility standards following the frequency goes up which is based automotive electronics, in this paper, a hybrid/electric vehicle battery which reflects the frequency of the equivalent circuit model is introduced. By using this circuit modeling, the impedance characteristics can be analysed and an analyze of battery one cell is finished. Using this model, each different from the discharging situation, the discharge characteristic curve could be led. Basic theoretical approaches and measuring results through MATLAB and experimental validation of the EIS measurement equipment was used.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.565-569
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• 2003

In this paper, a robust filter is proposed to effectively estimate the system states in the case where system model uncertainties as well as disturbances are present. The proposed robust filter is constructed based on the linear approximation methods for a general nonlinear uncertain system with an integral quadratic constraint. We also derive the important characteristic of the proposed filter, a modified $H_{\infty}$ performance index. Analysis results show that the proposed filter has robustness against disturbances, such as process and measurement noises, and against parameter uncertainties. Simulation results show that the proposed filter effectively improves the performance.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.579-582
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• 2005

In this study, the electrical characteristic of asymmetric high voltage MOSFET (AHVMOSFET) for display IC was investigated. Measurement data are taken over range of temperature (300K-400K) and various extended drain length, and gate oxide thickness ($175{\AA}$, $350{\AA}$). In high temperature condition, drain current decreased over 30% and max transconductance deceased over 40%, and specific on-resistance increased over 30% in comparison with room temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.35-38
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• 2002

In this paper, for digital x-ray conversion receptor development studied by hybrid technology of based on CdZnTe. For this study, First searched fabricate method of CdZnTe x-ray receptor. Second, search the phosphor material & fabricate method for scintillator layer. Fabricated sample is analyzed with physical & electric measurement. This result is showed good SNR ratio hybrid thechnology with direct method & indirect method. In this paper offer the method can reduce the dark-current in the hybrid X-ray detector.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.29-32
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• 2003

Recently, the development of diagnosis technique with high confidence is important on power equipment, for this reason is to use for measurement and analysis of PD with prior appearance of insulation breakdown In this paper, we presents the analysis of trouble signal to use both method of general analysis of $\Phi$-Q-N in PD and statistical parameter by this interpretation Equipment of simulation has made independently DS for 170kV GIS of one phase with same on field. The detected signal through the sensor of Induction and Acoustic Emission is classified which used to characteristic neural network algorithm and then it is analysis.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.426-430
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• 2005

The fiber-optic interferometer which is a powerful application for nondestructive measurement techniques has many advantages such as capability of making portable system, easy optical arrangement, low optical loss. In spite of these advantages, this system has an environmental sensitivity of thermal drifts and vibrations. Against environmental perturbations and nonlinear characteristic of phase modulator, the accurate and fast ${\pi}/2$ phase stepping has been achieved by using zero-crossing detection. CCD camera trigger signal is generated at the 4 zero-crossing points. Our System has achieved up to 100 Hz of image capture speed and 0.6 mrad of accuracy of phase stepping, accuracy.