• 전기학회논문지
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• 제59권7호
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• pp.1237-1241
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the characteristics of charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle. An analysis performed in this paper indicates that supercapacitor storage system may be cost effective for high cycle applications.

• 전기학회논문지
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• 제56권11호
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• pp.2017-2022
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• 2007

In a memory, most power is dissipated in line of high capacitance such as decoder lines, word lines, and bit * lines. The decoder size as well as the parastic capacitances of the bit-line are going to reduce, if ROM core size reduces. This paper proposes to reduce a mathod of power dissipation for reducing ROM core size. Design result of ROM used in FFT[2], proposed method lead to up to 40.6%, 42.12%, 37.82% reduction in area, power consumption and number of Tr. respectively compared with previous method.

• 한국전기전자재료학회논문지
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• 제17권4호
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• pp.373-377
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• 2004

We have investigated the electrical characterization of metal-oxide-semiconductor (MOS) capacitors formed on the inductively coupled plasma (ICP) etch-damaged both n- and p-type 4H-SiC. We found that there was an effect of a sacrificial oxidation treatment on the etch-damaged surfaces. Current-voltage and capacitance-voltage measurements of these MOS capacitors were used and referenced to those of prepared control samples without etch damage. It has been found that a sacrificial oxidation treatment can improve the electrical characteristics of MOS capacitors on etch-damaged 4H-SiC since the effective interface density and fixed oxide charges of etch-damaged samples have been found to increase while the breakdown field strength of the oxide decreased and the barrier height at the SiC-SiO$_2$ interface decreased for MOS capacitors on etch-damaged surfaces.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2213-2215
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• 2000

In this paper we implemented a novel re-entrant mode microstrip directional coupler for realizing the high directivity characteristic using finite element (FE) analysis. In microstrip configuration, the high directivity can be reached by matching the even- and odd-mode effective phase velocities. Through the values of capacitance obtained from 2-dimensional finite element(FE) analysis, the phase velocities for each mode and the design parameter were extracted for the proposed coupled-line configuration. Based on the extracted design parameter with phase matching condition we designed and fabricated 30dB directional coupler at 850MHz. Experimental results show good performance with excellent isolation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.612-614
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• 1998

As chip feature size decrease, interconnect delay gains more importance. A accurate timing analysis required to estimate interconnect delay as well as cell delay. In this paper, we present a timing-level delay calculation tool of which the accuracy is bounded within 10% of SPICE results. This delay calculation tool generates delay values in SDF(Standard Delay Format) for parasitic data extracted in SPEF(Standard Parasitic Exchange Format). The efficiency of the tool is easily seen because it uses AWE(Asymptotic Waveform Evaluation) algorithm for interconnect delay calculation, and precharacterized library and effective capacitance model for cell delay calculation.

• ETRI Journal
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• 제11권2호
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• pp.109-119
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• 1989

Based on the 2-dimensional charge-control simulation[4], a purely analytical model for MODFET's is proposed. In this model, proper treatment of the diffusion effect in the 2-DEG transport due to the gradual channel opening along the 2-DEG channel was made to explain the enhanced mobility and increased thershold voltage. The channel thickness and gate capacitance are experssed as functions of gate vlotage including subthreshold characteristics of the MODFET's analytically. By introducing the finite channel opening and an effective channel-length modulation, the slope of the saturation region of the I-V curves was modeled. The smooth transition of the I-V curves from linear-to-saturation region of the I-V curves was possible using the continuous Troffimenkoff-type of field-dependent mobility. Furthermore, a correction factor f was introduced to account for the finite transtition section forming between the GCA and the saturated section. This factor removes the large discrepanicies in the saturation region fo the I-V curves presicted by existing 1-dimensional models. The fitting parameters chosen in our model were found to be predictable and vary over relatively small range of values.

• 대한전자공학회논문지
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• 제22권6호
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• pp.46-52
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• 1985

본 논문은 구형 마이크로스트립 안테나의 H-plane 상호결합에 관한 연구이다. 두 안테나의 상호결합을 계산하기 위해서 단일 마이크로스트립 패치의 교사저항을 구하였으며 결합된 전송선로를 even mode와 add mode로 분발하여 각 mode의 특성저항와 실효 유전률을 계산하였다. 이로부터 자계적으로 결합된 안테나를 S-band 주파수에서 S-parameter를 구한 결과 이론치와 실험치가 거의 일치함을 확인할 수 있었다.

• 대한전자공학회논문지SD
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• 제41권3호
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• pp.109-114
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• 2004

본 논문에서는 반도체 방식의 직접 터치식 용량 형 지문인식센서의 신호처리를 위한 회로를 제안하였다. 센서로부터의 용량의 변화를 전압의 신호로 전환하기 위해서 전하분할 방식의 회로를 적용하였다. 지문센서 감도저하의 가장 큰 원인인 센서 플레이트에 존재하는 기생용량을 제거하고 융선과 계곡 사이의 전압차를 향상시키기 위하여 기존과는 다른 아날로그 버퍼회로를 설계 적용하였다. 센서 하부회로와의 isolation 대책을 통하여 ESD 및 노이즈방지를 위한 설계를 실시하였다. 제안된 신호 처리회로는 0.35마이크론 표준 CMOS 공정에 의해 레이아웃 되었다.

• Corrosion Science and Technology
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• 제5권5호
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• pp.177-180
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• 2006

The anticorrosive performance of epoxy coating was examined by using the hygrothermal cyclic test and the degradation mechanism of the coating was investigated by using the AC impedance method. The relationship between the results obtained from different tests was studied. It was revealed that the hygrothermal cyclic test can be used as an effective acceleration test for the degradation of organic coating. It was also found in hygrothermal cyclic test that the epoxy coatings have the resistance to stresses at some extent. The degradation of organic coating seems to be caused by the decrease of resistance of coating and the increase of both capacitance and free volume in the organic coating.

• Journal of Magnetics
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• 제21권2호
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• pp.187-191
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• 2016

Retrieving the equivalent electromagnetic parameters (permittivity and permeability) plays an important role in the research and application of metamaterials. Frequency dispersion of magnetic permeability has been theoretically predicted in a metamaterial composed of cut wire pairs (CWP) separated by dielectric substrate on the basis of circuit theory. Magnetic resonance resulting from antiparallel currents between the CWP is observed at the frequency of minimum reflection loss (corresponding to absorption peak) and effective resonator size can be determined. Having calculated the circuit parameters (inductance L, capacitance C) and resonance frequency from CWP dimension, the frequency dispersion of permeability of Lorentz like magnetic response can be predicted. The simulated resonance frequency and permeability spectra can be explained well on the basis of the circuit theory of an RLC resonator.