• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.84-87
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• 2020

The properties of ultra-thin two-dimensional (2D) organic ferroelectric Langmuir-Blodgett (LB) films of the poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] were investigated to find possible applicability in flexible and wearable electronics applications. In the C-V characteristics of the MFM capacitor of 2-monolayer of 5 nm films, a butterfly hysteresis curve due to the ferroelectricity of P(VDF-TrFE) was confirmed. Typical residual polarization value was measured at 2μC/㎠. When the MFM capacitor with ultra-thin ferroelectric film was measured by applying a 10 Hz bipolar pulse, it was shown that 65% of the initial polarization value in 105 cycles deteriorated the polarization. The leakage current density of the 2-monolayer film was maintained at about 5 × 10-8 A/㎠ for the case at a 5MV/cm electric field. The resistivity of the 2-monolayer film in the case at an electric field at 5 MV/cm was more than 2.35 × 1013 Ω·cm.

• 한국전기전자재료학회논문지
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• 제11권12호
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• pp.1115-1121
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• 1998

MLS capacitor with lipid ultra thin films were deposited by Langmuir-Blodgett (LB) method on the silicon wafer. The current versus voltage and capacitance versus voltage relationships are depend on the applied voltage, electrode area and electrode materials. LB films deposited were made of L-$\alhpa$-DLPC, the 1 layer’s thickness of 35${\AA}$ was measured by ellipsometer. And MLS capacitor with different electrode materials, the work function of these materials was investigated to increase the leakage current. The result indicated the lower leakage current and very high saturation value of capacitance was reached within 700-800 pF when the two electrode was Ag. And $\varepsilon$1, $\varepsilon$2 versus photon energy showed good film formation.

• 전기학회논문지
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• 제56권8호
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• pp.1471-1475
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• 2007

In this paper, a novel embedded ultra wideband (UWB) band-pass filter is presented on a FR-4 package substrate including high Dk resin coated copper (${\varepsilon}_r=30$) film. The proposed UWB filter is comprised of a parallel resonator with meander-type uniform impedance resonator (UIR) and two series resonators with high Q circular stacked spiral inductor and metal-insulator-metal (MIM) capacitor. In order to obtain excellent attenuation characteristics by generating attenuation poles in lower and upper stop bands, a single MIM capacitor is added to each resonator. The fabricated FR-4 embedded UWB filter has insertion loss of -1.0dB and return loss of -11dB, respectively. It has also extremely wide bandwidth (over 50%) and small size ($3.7{\times}4{\times}0.77\;mm^3$) which is compatible with LTCC devices.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.299-302
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• 2008

본 논문에서는 결함 기저면 구조(DGS)를 이용하여 WLAN 차단 필터 포함하는 소형의 초광대역 대역통과 필터를 제안하였다. H-모형의 슬롯은 IDC(Inter-Digital Capacitor)의 커플링을 이용하여 대역통과 필터의 성능을 향상시키기 위하여 채택하였고, 끝이 점점 작아지는 결함 접지 구조 3쌍은 대역 신호를 제외한 전송이 0이 되기 위하여 형성된 것이다. 또한 구부러진 슬롯은 원하지 않는 WLAN 무선 신호들을 걸러내도록 개발하였다. 이러한 세 구조들의 조합으로 소형의 UWB 대역통과 필터를 얻을 수 있었다.

• 한국정보통신학회논문지
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• 제12권11호
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• pp.1909-1913
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• 2008

본 논문에서는 결함 기저면 구조(DGS)를 이용하여 WLAN 차단 필터 포함하는 소형의 초광대역 대역통과 필터를 제안 하였다. H-모형의 슬롯은 IDC(Inter-Digital Capacitor)의 커플링을 이용하여 대역통과 필터의 성능을 향상시키기 위하여 채택 하였고, 끝이 점점 작아지는 결함 접지 구조 3쌍은 대역신호를 제외한 전송이 0이 되기 위하여 형성된 것이다. 또한 구부러진 슬롯은 원하지 않는 WLAN 무선 신호들을 걸러내도록 개발하였다. 이러한 세 구조들의 조합으로 소형의 UWB 대역통과 필터를 얻을 수 있었다.

• Progress in Superconductivity
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• 제13권2호
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• pp.105-110
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• 2011

SQUID sensor-based ultra low-field magnetic resonance apparatus with ${\mu}T$-level measurement field requires a strong prepolarization magnetic field ($B_p$) to magnetize its sample and obtain magnetic resonance signal with a high signal-to-noise ratio. This $B_p$ needs to be ramped down very quickly so that it does not interfere with signal acquisition which must take place before the sample magnetization relaxes off. A MOSFET switch-based $B_p$ coil driver has current ramp-down time ($t_{rd}$) that increases with $B_p$ current, which makes it unsuitable for driving high-field $B_p$ coil made of superconducting material. An energy cycling-type current driver has been developed for such a coil. This driver contains a storage capacitor inside a switch in IGBT-diode bridge configuration, which can manipulate how the capacitor is connected between the $B_p$ coil and its current source. The implemented circuit with 1.2 kV-tolerant devices was capable of driving 32 A current into a thick copper-wire solenoid $B_p$ coil with a 182 mm inner diameter, 0.23 H inductance, and 5.4 mT/A magnetic field-to-current ratio. The measured trd was 7.6 ms with a 160 ${\mu}F$ storage capacitor. trd was dependent only on the inductance of the coil and the capacitance of the driver capacitor. This driver is scalable to significantly higher current of superconducting $B_p$ coils without the $t_{rd}$ becoming unacceptably long with higher $B_p$ current.

• 한국정보전자통신기술학회논문지
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• 제14권6호
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• pp.479-486
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• 2021

본 논문에서는 신호감지회로(Signal Sensing Circuit : SSC)를 추가하여 2개의 루프로 구성된 단일 커패시터 루프필터를 가진 극소형 위상고정루프(Phase Locked Loop : PLL)를 제안하였다. 위상고정루프 크기를 극단적으로 줄이기 위하여 가장 많은 면적을 차지하는 수동소자 루프필터를 극소형 단일 커패시터(2pF)로 설계하였다. 신호감지회로가 포함된 내부 부궤환 루프 출력이 외부 부궤환 루프의 단일 커패시터 루프필터 출력에 부궤환 역할을 하여 제안한 극소형 위상고정루프가 안정적으로 동작하도록 설계하였다. 위상고정루프 출력 신호 변화를 감지하는 신호 감지 회로는 루프필터의 커패시턴스 전하량을 조절하여 위상고정루프 출력 주파수의 초과 위상변이를 줄였다. 제안된 구조는 기존 구조에 비해 1/78 정도의 작은 커패시터를 가짐에도 불구하고 지터 크기는 10% 정도 차이가 난다. 본 논문의 위상고정루프는 1.8V 180nm 공정을 사용하였고, Spice를 통해 안정하게 동작하는 시뮬레이션 결과를 보여주었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.262-262
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• 2013

In surface chemistry area, many scientists studied the electrochemical reaction by changing work-function of metal; however, these methods had the weakness that it did not create the electric field. Unlike earlier studies, our capacitor-method makes a strong electric field in ice film. This electric field was induced by soft landing $Cs^+$ ions on ice film, and the strength was measured by the vibrational Stark shift of acetonitrile. In our system, the electric field strength is $10^9$ V/m and it is almost same in the electrochemical cell. This capacitor model provides new method to investigate the electrochemical reaction in vacuum system.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권2호
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• pp.100-106
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• 2010

The impact of surface quantization on device parameters of a Si metal oxide semiconductor (MOS) capacitor has been analyzed in the present work. Variation of conduction band bending, position of discrete energy states, variation of surface potential, and the variation of inversion carrier concentration at charge centroid have been analyzed for different gate voltages, substrate doping concentrations and oxide thicknesses. Oxide thickness calculated from the experimental C-V data of a MOS capacitor is different from the actual oxide thickness, since such data include the effect of surface quantization. A correction factor has been developed considering the effect of charge centroid in presence of surface quantization at strong inversion and it has been observed that the correction due to surface quantization is crucial for highly doped substrate with thinner gate oxide.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.365-368
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• 2010

순수 전기에너지로 움직이는 전기자동차는 저장에너지 시공간의 한계로 인하여 회생제동은 필수적이다. 본 연구에서는 전기자동차의 시스템 설계의 중요한 부분인 축전지 용량 크기와 수명에 영향을 미칠수 있는 회생 제동에 의한 에너지 효율 및 회생제동 순간 에너지 저장을 위한 울트라 캐패시터의 사이징에 대한 상관관계를 분석하여 효율적인 전기 자동차의 시스템 설계에 활용하고자 한다. 미국의 도심주행 코스를 대상으로 시뮬레이션을 수행하여 축전지 사이징과 회생제동의 효율, 울트라 캐패시터의 사이징에 대한 효율 관계를 제시하였다.