• Composites Research
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• v.30 no.5
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• pp.273-279
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• 2017

This paper describes the fabrication techniques and analysis of hybrid composite plates with an active frequency selective surface (FSS). For fabricating hybrid composite plate with active FSS, an active FSS with a resonance frequency located in the C band can obtained using varactor diodes. The hybrid composite plate was first designed and simulated to determine its electromagnetic properties using the commercial software HFSS. After simulation, active FSSs and hybrid composite plates were fabricated by mounting with varactor diodes. After fabrication, free space measurement was used to determine the electromagnetic properties of active FSS and the hybrid composite plates. The simulation and experimental results were in good agreement.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.44-50
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• 1985

This paper describes the design and fabrication of an integrated circuit which controls the phase of VTR servo systems. The integrated circuit was designed using 6#m design rule and its chip size is 3.6$\times$3.55mm$^2$. On the other hand it was fabricated using SBC, analog-compatible 12 L and double layer metal fabrication process technology. As a result, we succeeded in fabrication of If which satisfied D. C. characteristics and phase control function.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.4
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• pp.269-274
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• 2004

Current delivery system, in which the analog current produced by a unique DAC circuit is stored into a current-memory circuit and delivered in a time-divided sequence, shows variation of output current as low as 4% in a current source data-driver IC for AM-OLED driven by a current-programmed method without any fuse repairing after fabrication. This driver IC has 54 outputs and can sink constant current as low as 3 ${\mu}A$ with 6-bit analog levels. Such a low current level without variation can hardly be obtained by an ordinary MOS transistor because the current level is in the sub-threshold region and changes exponentially with threshold voltage variation. Thus we adopted a current mirror circuit composed of bipolar transistors to supply well-controlled current within a nano-ampere range.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.861-863
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• 2003

In this work, the preparations and characteristics of capacitors and inductors for RF IC as a integrated devices are investigated. These kinds of capacitors and inductors can be applicable to the passive components utilized in voltage controlled oscillator(VCO), low noise amplifier(LAN), mixer and synthesizer for mobile telecommunication of radio frequency band(900 MHz to 2.2GHz), and in a library of monolithic microwave integrated circuit(MMIC). The results show that these inductors and capacitors array for RF IC may be applicable to the RF IC passive components for mobile telecommunication.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.95-99
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• 1992

본 논문은 삼차원 거리영상화 장비중 고속으로 거리영상을 잡을 수 있는 거리영상화 소자를 IC로 시험 제작하여 그 결과를 보였다. 제작된 IC에 대한 실험은 각 부분의 성능과 센서 자체의 정밀도 측정에 중점을 두었다. 각 부분의 성능에 대해서는 빛 감지부분의 신호의 크기, 소자들의 동작성, 정보 저장부분의 입력 전압에 대한 출력 전압의 변형등을 다룬다. 센서 자체의 정밀도는 각 부분에서 발생하는 오차를 측정하였다. 제작된 센서는 아나로그방식으로 정밀도에 제한을 받는 단점이 있어 구조를 달리하여 디지탈 방식으로 접근한 센서를 제안한다. 아나로그 방식에 비해 셀 면적을 줄일 수 있을 뿐 아니라, 정밀도도 높고, 속도도 떨어지지 않아 아나로그 방식 IC 센서의 단점을 극복한다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.105-108
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• 2003

Long length of Bi-2223 superconducting wires were fabricated by stacking, drawing process with different precursor owders and different heat-treatment histories. The precursor powders were 2 kinds of Pb content. And a part of the tapes were experienced pre-annealing process which caused tetragonal structure of Bi-2212 phase to orthorhombic structure of it was during drawing process. We confirmed the transformation of Bi-2212 phase from tetragonal structure to orthorhombic structure and reduction of second phases. We designed and made a continuous Ic measurement system for Bi-2223/Ag HTS tape. We could achieve best Ic of 65 A at the Bi-2223/Ag tape using low Pb content of precursor powder and experienced pre-annealing process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.13-17
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• 2013

In this paper, we designed a charge pump circuit using level shifter for LED driver IC. The designed circuit makes the 15 V output voltage from the 5 V input in condition of 50 kHz switching frequency. The prototype chip which include the proposed charge pump circuit and its several internal sub-blocks such as oscillator, level shifter was fabricated using a 0.35 um 20 V BCD process technology. The size of the fabricated prototype chip is 2,350 um ${\times}$ 2,350 um. We examined performances of the fabricated chip and compared its measured results with SPICE simulation data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.1059-1067
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• 1996

A 128/129 dual-modulus prescalar IC is designed for application to frequency synthesizers in high frequency communication systems. The FET logic used in this design is SCFL(Source Coupled FET Logic), employing depletion-mode 1.mu.m gate length GaAs MESFETs with the threshold voltage of -1.5V. This circuit consists of 8 flip-flops, 3 OR gates, 2 NOR gates, a modulus control buffer and I/O buffers, which are integrated with about 440 GaAs MESFETs on dimensions of 1.8mm. For $V_{DD}$ and $V_{SS}$ power supply voltages 5V and -3.3V Commonly used in TTL and ECL circuits are determined, respectively. The simulation results taking into account the threshold voltage variation of .+-.0.2V and the power supply variation of .+-.1V demonstrate that the designed prescalar can operate up to 2GHz. This prescalar is fabricated using the ETRI MMIC foundary process and the measured maximum operating frquency is 621MHz.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.241-247
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• 2000

77 K와 self-field에서 22 A 의 Ic 를 갖는 길이 120 m, 19-심 Bi-2223상 선재를 제조하여, 두 개의 double pancake 코일로 구성된 proto-type 고온초전도 자석을 설계, 제작하여 이 자석에서의 4.2 K와 77 K에서의 I-V 특성과 운전 특성을 평가한 결과, 이 자석은 77 K 등온조건에서는 9.5 A 의 Ic를, 77 K 헬륨가스 속에서는 8.3 A 의 Ic를 나타내었고, 4.2 K 등온조건에서는 93.7 A 의 Ic와 102 A 의 Iq를, 4.2K헬륨가스 속에서는 88.4A의 Ic 와 92.0 A 의 Iq를 나타내어, 이 자석은 4.2 K 와 77 K 의 등온조건에서 각각 0.58 T 와 0.06 T 의 자장을 발생하였는데, 이는 해석적 방법으로 계산한 결과와 잘 일치하였다. 그리고 이 자석이 전도냉각되어 4.2 K 에서 운전될 때의 안정성 특성평가로서, Ic 보다 약간 큰 전류인 89 A 를 인가한 결과, 전류인가 후 82.6초 후에 quench가 발생하였는데, 이 quench는 네 번째 pancake의 전류도입선부 연결부에서와 약간 늦지만 첫 번째 pancake의 전류도입선부 연결부에서 거의 동시에 개시되어 전체로 파급된 것으로 사료되었는데, Ic 가 낮은 첫번째 pancake에서 더 높은 전압 강하가 나타났다. 또한 장착된 heater를 통하여 77 K 에서 8.9 A 의 전류로 운전되고 있는 코일에 146 joule 의 열을 가했을 때 quench 가 일어났는데, 이때 quench 는 방위각 방향의 Bi-2223/Ag 선재를 따라서 보다 Kapton 절연층을 관통하는 선재의 반경방향으로 훨씬 빨리 전파하였다.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.4
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• pp.195-200
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• 2006

The conventional discrete circuit for ABS/TCS system was examined and the problems of the system were analyzed by computer simulation. In order to improve the performance of ABS/TCS system, interface IC which has error compensation, comparator and under voltage lock-out circuit was designed and their electrical characteristics were investigated. The voltage regulator was included to compensate the temperature variation in the temperature range from $-20^{\circ}C$ to $120^{\circ}C$ for automobile environment. ABS and brake signal were separated using the duty factor of same frequency or different frequencies. UVLO(Under Voltage Lock-Out) circuit and constant current circuit were applied for the elimination of noise, and protection circuit was applied to cut the excess current off. Layout for IC fabrication was designed to enhance the electrical performance of ABS/TCS system. Layout was consisted of 11 masks, arrayed effectively 8 pads to reduce the current loss. We can see that the result of layout simulation was better than the result of bread board.