• JSTS:Journal of Semiconductor Technology and Science
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• 제15권6호
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• pp.653-657
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• 2015

A new paired gate-source voltage RF capacitance-voltage (C-V) method of extracting the effective channel length and parasitic capacitance using the intersection between two closely spaced linear regression lines of the gate capacitance versus gate length measured from S-parameters is proposed to remove errors from conventional C-V methods. Physically verified results are obtained at the gate-source voltage range where the slope of the gate capacitance versus gate-source voltage is maximized in the inversion region. The accuracy of this method is demonstrated by finding extracted value corresponding to the metallurgical channel length.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.256-258
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• 2010

MPM(Microwave Power Module)은 진공 전력증폭기인 진행파관(TWT,Traveling Wave Tube)과 반도체 전력증폭기(SSA, Solid State Amplifier)를 결합한 구조로서, 미세한 RF신호를 입력 받아 고출력의 RF 신호로 증폭하는 장치이다. 본 논문은 MPM을 구동하기 위해, 필요한 수 kV이상의 높은 전압을 TWT에 공급해주는 고전압 전원공급기(HVPS, High Voltage Power Supply)에 관한 것이다. Main Topology는 Resonant Phase Shift Full Bridge Converter이며, 승압의 효과를 높이기 위해 2차 측에는 Voltage Multiplier를 사용하였다. MPM을 구동하는데 필요한 전압인Cathode(-4kV), FE_Bias(-5.25kV), Collector(-2kV)를 생성하며, FE_ON, OFF신호에 따라 고전압 스위칭 동작을 하여, RF 증폭을 제어 할 수 있다. 최종적으로 Prototype을 제작하고, 고찰된 실험결과를 제시하여 개발된 HVPS의 우수성을 검증한다.

• Journal of Semiconductor Engineering
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• 제3권1호
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• pp.154-160
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• 2022

In this paper, we design a DC-DC boost converter with RF noise immunity to supply a stable positive output voltage for OLED displays. For RF noise immunity, an input voltage variation reduction circuit (IVVRC) is adopted to ensure display quality by reducing the undershoot and overshoot of output voltage. The boost converter for a positive voltage Vpos operates in the SPWM-PWM dual mode and has a dead-time controller using a dead-time detector, resulting in increased power efficiency. A chip was fabricated using a 0.18 um BCDMOS process. Measurement results show that power efficiency is 30% ~ 76% for load current range from 1 mA to 100 mA. The boost converter with the IVVRC has an overshoot of 6 mV and undershoot of 4 mV compared to a boost converter without that circuit with 18 mV and 20 mV, respectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 추계학술발표강연 및 논문개요집
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• pp.53-53
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• 2002

• 전자공학회논문지
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• 제50권7호
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• pp.115-121
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• 2013

본 연구에서는 TiInZnO(TiIZO)를 채널층으로 하는 thin film transistors(TFTs)를 제작하였다. TiIZO 층은 InZnO(IZO)와 Ti target을 이용하여 RF-magnetron co-sputtering system 방식으로 상온에서 증착하였으며, 어떠한 열처리도 하지 않았다. Ti의 첨가가 어떠한 영항을 주는지 연구하기 위해 X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) 분석을 시행하였으며, 전기적인 특성을 측정하였다. Ti의 첨가는 Ti target의 rf power 변화에 따라 달리하였다. Ti의 첨가가 전류점멸비에 큰 영향을 주는 것을 확인하였고, 이것은 Ti의 산화력이 In과 Zn보다 뛰어나 산소결함자리의 형성을 억제하기 때문이다. Ti의 rf power가 40W일 때 가장 좋은 특성을 나타냈으며, 전류점멸비, 전자이동도, 문턱전압, subthreshold swing이 각각 $10^5$, 2.09 [$cm^2/V{\cdot}s$]. 2.2 [V], 0.492 [V/dec.]로 측정되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.323-326
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• 2003

본 논문은 무선 음성/영상 송수신용 RF모듈 설계 및 제작하였다. RF 주파수는 정보통신부에서 고시한 영상전송용 2410, 2430, 3450, 2470MHz 사용하였으며 IF 주파수는 479.5MHz를 사용하였다. 설계 및 제작된 RF 모듈은 FR-4 재질인 유전체 4.6, 두게 0.8mm, 양면구조의 기판을 사용하여 50mm x 40mm 크기로 제작되었다. 설계된 송신기 모듈은 ＋5V 단일전원으로 9±1dBm의 출력과 주파수허용편차 50×10/sup -6/이하, 스퓨리어스 발사강도 기본주파수의 평균전력보다 40dB이하의 성능을 만족하였다. 수신기 모듈은 +5V 단일 전원으로 -80dBm이하의 수신감도로 만족할만한 성능을 보였다.

• 한국세라믹학회지
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• 제35권5호
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• pp.472-478
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• 1998

Ferroelectric SrBi2Ta2O9(SBT) films were deposited on Pt/Ti/SiO2/Si substrates at 50$0^{\circ}C$ using a sintered SBT target Bi and Ta targets by modified rf magnetron sputtering and then were annealed at 80$0^{\circ}C$ for 10min in oxygen ambinet(760 torr) The composition of the SBT films could be easily controlled using the mul-ti-targets. The film composition of {{{{ {Sr }_{0.8 } {Bi }_{2.9 } {Ta}_{2.0 } {O }_{9 } }} was obtained with SBTd sputtering power of 100 W Bi of 25W and Ta of 10 W. A 250nm thick SBT films exhibited a dense and uniform microstructure and showed the remanent polarization(Pr) of 14.4 $\mu$C/cm2 and the coercive field({{{{ {E }_{c } }})of 60 kV/cm at applied voltage of 5 V. The SBT films show practically no polarization fatigue up to {{{{ {10 }_{10 } }} cycles under 5V bipolar pulse. The retention characteristics of the SBT films looked very promising and the leakage current density of the SBT films was about 1.23$\times${{{{ {10 }^{-7 } }}A/c{{{{ {m }^{2 } }} at 120kV/cm.

• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.977-982
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• 2005

Al/AlN/n-type 6H-SiC (0001) MIS structures were prepared by AlN layers on vicinal 6H-SiC(0001) substrates with reactive RF magnetron sputtering method. The AlN films were annealed at $900^{\circ}C$, $N_2$ atmosphere lot 1 minutes showed the best result. With XRD analysis, AlN(0002) peak was clearly found. The typical dielectric constant value of the AlN film in the MIS capacitors was obtained as 8.4 from photo C-V. Also, the gate leakage current density of the MlS capacitor was $10^{-10}\;A/cm^2$ order within the electric field of 1.8 MV/cm. Finally, the amount of interface trap densities, $D_{it}$, was evaluated as $5.3\times10^{10}\;eV^{-1}cm^{-2}$ at (Ec-0.85) eV.

• Nuclear Engineering and Technology
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• 제46권2호
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• pp.247-254
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• 2014

A study on the superconducting RF linac is underway in order to increase the beam energy up to 1 GeV by extending the Proton Engineering Frontier Project (PEFP) 100-MeV linac. The operating frequency of the PEFP superconducting linac (SCL) is 700 MHz, which is determined by the fact that the frequency of the existing normal conducting linac is 350 MHz. A preliminary study on the beam dynamics showed that two types of cavities with geometrical betas of 0.50 and 0.74 could cover the entire energy range from 100 MeV to 1 GeV. An inductive output tube (IOT) based RF system is under consideration as a high-power RF source for the SCL due to its low operating voltage and high efficiency. As a prototyping activity for a reduced beta cavity, a five-cell cavity with a geometrical beta of 0.42 was designed and fabricated. A vertical test of the prototype cavity at low temperatures was performed to check the performance of the cavity. The design study and the prototyping activity for the PEFP SCL will be presented in this paper.

• 한국가구학회지
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• 제17권1호
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• pp.33-46
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• 2006

This study was carried out to investigate a radio-frequency/vacuum (RF/V) drying ability and physical properties of the green boards and the pre-kiln dried boards with 40 mm thickness, and the 70 mm-thick green board of Iroko (Milicia excelsa). The major results were summarized as follows; The drying time from initial moisture content (MC) of 110% to approximate 6% MC for a 40mm-thick green board was 192 hours, and about 200 hours for the 70 mm-thick green board, respectively and so the RF/V drying times were dramatically shortened compared to conventional kiln drying time. The case hardenings at the RF/V drying completion stage test were very negligible, thus represented almost no existence of the residual stress. The checks were very slightly formed on all of the boards during the RF/V drying test, but crook appeared quite severely. During the accelerating test, the water-resistant treated specimens had not experienced any signs of checking occurred, whereas the control boards had encountered very frequent occurrences of end checking and slight surface checking. There were no observations of warping and discoloring regardless of the treatment.