• 한국미생물·생명공학회지
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• 제19권3호
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• pp.228-234
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• 1991

DNA 자동합성기를 이용하여 오릴고뉴클레오타이드들을 합성하였으며 이로부터 인간 인터루킨-2를 코드하는 유전자를 제조하였다. 합성 유전자의 염기서열은 대장균에서 사용빈도가 높은 코돈을 고려하여 결정하였으며, 이때 인터루킨-2의 아미노산 서열은 변화시키지 않았다. 합성된 유전자는 람다 피엘 프로모터를 사용하여 대장균에서 발현시켰다. 인터루킨-2는 대장균에서 불용성의 침전물로 생성되었다. 생성된 인터루킨-2는 인터루킨-2 요구 배양세포주의 성장을 촉진하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권4호
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• pp.329-335
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• 2011

In this paper, a dual-band integer-N frequency divider is proposed for 2.4/5.2 GHz multi-standard wireless local area networks. It consists of a multi-modulus imbalance phase switching prescaler and two all-stage programmable counters. It is able to provide dual-band operation with high resolution while maintaining a low power consumption. This frequency divider is integrated with a 5 GHz VCO for multi-standard applications. Measurement results show that the VCO with frequency divider can work at 5.2 GHz with a total power consumption of 22 mW.

• 한국전자파학회논문지
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• 제23권11호
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• pp.1280-1287
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• 2012

3.2~6.5 GHz 광대역 특성을 갖는 YTO(YIG Tuned Oscillator) 모듈을 설계 및 제작하였다. 위상 잡음 특성을 개선하기 위해 샘플링 믹서를 이용한 offset PLL(Phase Locked Loop) 구조로 설계하였다. 이 방식은 샘플링 믹서, 위상 비교기, 루프 필터, 전류 드라이버 회로, YTO로 구성된다. 측정 결과, 4.5 GHz에서 위상 잡음은 수식으로 도출한 값과 유사한 10 kHz offset 주파수에서 -100 dBc/Hz를 얻었다. 제작된 YTO 모듈의 위상 잡음은 동작 주파수 대역에서 기존 PLL 구조에 비해 10 dB 이상 우수함을 확인하였다.

• 조명전기설비학회논문지
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• 제20권3호
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• pp.84-89
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• 2006

고조파에 의한 누전차단기 동작이 계속적으로 보고되어 왔으나 누전차단기 동작을 설명할 수 있는 자료가 없는 실정이다. 본 논문에서는 누전차단기에 대한 고조파 영향을 규명하기 위해 누전차단기 오동작 현황에 대한 조사 및 누전차단기 원인불명 동작이 자주 발생하는 건물에서 고조파를 측정 및 분석하였다. 또한 왜곡된 파형을 발생시킬 수 있는 고조파 합성장치를 이용하여 누전차단기 동작 특성을 시험하였다. 시험결과 3차 고조파가 기본파에 합성되었을 때 가장 작은 값의 누설전류에 누전 차단기가 동작되었고 기본파에 더해진 고조파 차수가 증가할 수 록 누전차단기 동작전류는 증가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.475-476
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• 2007

Electroglottography (EGG) is a technique used to register laryngeal behavior indirectly by a measuring the change in electrical impedance across the throat during speaking. However, EGG waveform is affected by laryngeal muscles which fluctuate the vocal cords, and which result in baseline wander. It is required to reduce baseline wander in EGG waveform, because EGG waveform is used for input signal of nonlinear speech synthesizer in next chapter. In vocal cords, the abduction-adduction of glottis is mainly controlled by the posterior cricoarytenoid (abductor) and interarytenoid (adductor) muscles respectively. Empirical Mode Decomposition method was adopted in cancellation of EGG waveform baseline wandering, and showd better performance than that of high pass filter with 500 order.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.195-196
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• 2007

Since the digital TV signal band is very wide ($54{\sim}806MHz$), the VCO used in the frequency synthesizer must also have a wide frequency tuning range. Multiple LC VCOs have been used to cover such wide frequency band. However, the chip area increases due to the increased number of integrated inductors. In this paper, a scheme is proposed to cover the full band using only one VCO. The RF VCO block designed using a 0.18um CMOS process consists of a wideband LC VCO, five divide-by-2 circuits and several buffers. The simulation results show that the designed circuit has a phase noise at 10kHz better than -87dBc/Hz throughout the signal band and consumes 10mA from a 1.8V supply.

• 대한전자공학회논문지
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• 제27권11호
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• pp.83-91
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• 1990

전압제어 발진기(VCO:coltage controlled oscillator)는 FM 신호 변조, 주파수 안정기와 디지탈 클럭 재생과 같은 부분의 적용에 필수적인 기본회로이다. 본 논문에서는 BiCMOS 회로를 이용한 차동 증폭기를 사용하여 OTA(operational transconductance amplifier)회로와 OP amp를 설계하고 이를 토대로 하여 VCO 회로를 설계하였다. 그리고 이 VCO는 OTA와 전압 제어 적분기, 그리고 슈미트 트리거 회로로 구성이 되어 있다. 종래에는 CMOS를 사용하여 VCO를 설계하였지만 여기서는 구동능력이 좋은 BiCMOS를 사용하여 VCO를 설계하였다. 이 회로를 SPICE로 시뮬레이션 한 결과 출력 주파수는 105KHz에서 141KHz이며 변화 감도는 15KHz였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권3호
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• pp.342-348
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• 2015

This paper presents a 1.9-GHz digital ${{\Delta}{\Sigma}}$ fractional-N PLL with a finite impulse response (FIR) filter embedded for noise suppression. The proposed digital implementation of FIR provides a simple method of increasing the number of taps without complicated calculation for gain matching. This work demonstrates 32 tap FIR filtering for the first time and successfully filtered the in-band phase noise generated from delta-sigma modulator (DSM). Design considerations are also addressed to find the optimum number of taps when the resolution of time-to-digital converter (TDC) is given. The PLL, fabricated in $0.11-{\mu}m$ CMOS, achieves a well-regulated in-band phase noise of less than -100 dBc/Hz for the entire range inside the bandwidth of 3 MHz. Compared with the conventional dual-modulus division, the proposed PLL shows an overall noise suppression of about 15dB both at in-band and out-of-band region.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권3호
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• pp.381-389
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• 2015

A fully integrated multistandard multiband CMOS mobile TV tuner with small silicon area and low power consumption is proposed for receiving multiple mobile digital TV signals and FM signal. In order to reduce the silicon area of the multistandard multiband receiver, other RF front-end circuits except LNAs are shared and a local oscillator (LO) signal generation architecture with a single VCO for a frequency synthesizer is proposed. To reduce the low frequency noise and the power consumption, a vertical NPN BJT is used in an analog baseband circuits. The RF tuner IC is implemented in a $0.18-{\mu}m$ CMOS technology. The RF tuner IC satisfies all specifications for DVB-H/T, T-DMB, and ISDB-T with a sufficient margin and a successful demonstration has been carried out for DVB-H/T, T-DMB, and ISDB-T with a digital demodulator.

• 천문학회보
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• 제37권2호
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• pp.228.1-228.1
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• 2012

Digital waveform generation technology for SAR payload can be divided into DDS(Direct Digital Synthesizer) method and Memory Mapped(M/M) method. DDS is the single chip which consists of the Sine Table, NCO(Numerically Controlled Oscillator), DAC, and so on. DDS method is a very simple method because the circuit configuration is not complex but has a disadvantage that can not control phase and amplitude easily by using NCO. M/M method has the complexity of the circuit configuration because it requires the memories which stores the waveforms, the control circuits, and DAC. And this method should apply the high interface technology for being compatible with the wide bandwidth of the digital signal and has the difficulty for PCB design because the number of the signal lines should be increased according to the number of the data bits for DAC. Although it has several disadvantages, this method has the capability of pre-distortion function which can compensate the phase and amplitude characteristics of the system and also has an excellent advantage to make any arbitrary waveform, so this method is considered as an important technology with DDS method. This research describes the technological trends of the waveform generator for the SAR payload and analyzes the characteristics of the technology.