• 전자공학회논문지A
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• 제32A권3호
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• pp.124-133
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• 1995

A theoretical self-consistent thermoelectric model has been developed for optimal thermal design in the self-signal processing infraed detectors. The model is achived by employing the coupled thermoelectric equation which allows which allows the simultaneous investigation of the termal and electrical aspects of device behavior. The thermal limitation of detectivity and responsivity are determined by the enegy gap, carrier concentration, lifetime, and mobility as a function of the temperature. The calculated results indicate that the detectivity is decreased at bias fields above about 50 V/cm, because the performence is limiting by temperature when the bias voltage reached the level associated with Joule heating. It has been also found that the improvement in the mid-band modulation transfer function(MTF) may be restricted by increasing the bias fields. Further, the important paramerers in the thermal optimization of SPIR detector, such as temperature in the device, ambipolar velocity, element thickness and length, are also considered. The analytical study provides a mathematical basis for optimal design of such a photoconductive IR detector and the agreement between the experimental and theoretical results are seen to be good.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.635-636
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• 2006

A self-biased CMOS current reference is described which provides supply and temperature independent bias current. The supply independency is obtained by subtracting two bias currents which have the same supply dependency. Unlike the conventional self-bias CMOS current reference, excellent supply independency can be obtained even with the minimum channel length devices and thus smaller area implementation becomes possible. The supply independent bias current is then applied to a temperature compensating circuit and as a result supply and temperature independent bias current is obtained. The current reference has been implemented in a $0.25{\mu}m$ standard CMOS technology. The active silicon area is only $45{\mu}m{\times}45{\mu}m$. The simulated temperature coefficient is 64ppm/$^{\circ}C$ in temperature range between $0^{\circ}C$ and $120^{\circ}C$. Supply voltage can be as low as 1.3V and the supply dependency of the current reference is measured to be smaller than 4500ppm/V. While providing $10.25{\mu}A$ output current, the current reference consumes $160{\mu}W$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.35-37
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• 2001

The Al etching was studied employing negative ions generated in the downstream $Cl_2$ plasma. In order to etch the Al film practically on an insulator covered electrode coupled with RF power, reduction of the negative self bias voltage (Vdc) was examined using a magnetic filter which trapped electrons. Addition of $SF_6$ and $H_2$ to a $Cl_2/BCl_3$ mixture reduced significantly Vdc.

• Journal of electromagnetic engineering and science
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• 제17권2호
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• pp.105-107
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• 2017

The self-biasing circuit through a feedback resistor is applied to a gallium nitride (GaN) distributed power amplifier (PA) monolithic microwave circuit (MMIC). The self-biasing circuit is a useful scheme for biasing depletion-mode compound semiconductor devices with a negative gate bias voltage, and is widely used for common source amplifiers. However, the self-biasing circuit is rarely used for PAs, because the large DC power dissipation of the feedback resistor results in the degradation of output power and power efficiency. In this study, the feasibility of applying a self-biasing circuit through a feedback resistor to a GaN PA MMIC is examined by using the high operation voltage of GaN high-electron mobility transistors. The measured results of the proposed GaN PA are the average output power of 41.1 dBm and the average power added efficiency of 12.2% over the 6-16 GHz band.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.206-208
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• 1996

Thin films of magnesium oxide(MgO) were deposited on glass substrates by RF magnetron sputtering method. The characteristics of MgO thin films were analyzed as a function of various deposition conditions such as substrate temperature, substrate self-bias, input power and pressure. As the substrate temperature and bias voltage were increased, the grain size of MgO thin film increased. XRD peaks of (111) and (222) direction became dominant, as the substrate bias voltage increases and temperature decreases.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.108-111
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• 2003

Currently, molecular devices are reported utilizing active self-assembled monolayers containing the nitro group as the active component, which has active redox centers[1]. We confirm the electrical properties of 4,4-di(ethynylphenyl)-2'-nitro-1-benzenethiolate. To deposit the SAM layer onto gold electrode, we transfer the prefabricated Au(111) substrates into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured current-voltage curve using ultra high vacuum scanning tunneling microscopy (UHV STM), I-V curve also clearly shows several current peaks between the negative bias region (-0.3958V) and the positive bias region (0.4658V), respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1301-1304
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• 2007

We have investigated degradation of short channel n-type poly-Si TFTs with LDD under high gate and drain voltage stress due to self-heating. We have found that the threshold voltage of short channel TFT is shifted to negative direction on the selfheating stress, whereas the threshold voltage of long channel is moved to positive direction.

• 한국정보통신학회논문지
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• 제3권3호
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• pp.569-577
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• 1999

본 논문에서는 이동위성통신용 광대역 수신단을 저잡음증폭기와 고이득증폭단으로 나누어서 구현 및 성능 평가를 하였다. 저잡음증폭기의 설계ㆍ제작에는 저잡음 GaAs FET인 ATF-10136파 내부정합된 MMIC인 VNA-25를 이용하였으며, 저잡음증폭기의 입력단 정합회로는 저항 결합회로, 전원회로는 자기 바이어스 회로를 사용하였다. INA-03184를 이용한 고이득증폭단은 양단 정합된 단일 증폭기 형태로 제작하였으며, 바이어스 안정화 저항을 사용하여 회로의 전압강하 및 전력손실을 가능한 줄이고 온도 안정성을 고려하여 능동 바이어스 회로를 사용하였으며, 스퓨리어스를 감쇠시키기 위해서 저잡음증폭기와 고이득증폭단 사이에 감쇠 특성이 우수한 대역통과 필터를 사용하였다. 측정 결과, 사용 주파수 대역내에서 55dB 이상의 이득, 50.83dBc의 스퓨리어스 특성 및 1.8. 1 이하의 입ㆍ출력 정재파비를 나타내었으며, 특히 1537.5 MHz에서 1 KHz 떨어진 점에서의 C/N비가 43.15 dB/Hz를 나타냄으로써 설계시 목표로 했던 사양을 모두 만족시켰다.

• 한국진공학회지
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• 제9권4호
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• pp.382-388
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• 2000

ECR-PECVD 방법을 이용하여 ECR power, $CH_4/H2$ 가스 혼합비와 유량, 증착시간, negative DC self bias 전압 등을 변화 시켜가면서 수소가 함유된 비정질 탄소 박막을 제조하고, 증착조건에 따른 박막의 결합구조 변화를 FTIR로 분석하였다. a-C:H 박막에 대한 FTIR 스팩트럼의 흡수 peak들은 2800~3000 $\textrm{cm}^{-1}$ 영역에서 관측되었으며, 대부분 $sp^3$ 결합을 하고있고 일부 $sp^2$ 결합구조가 존재함을 알 수 있었다. $CH_4/H_2$ 가스 혼합비와 유량의 미소 변화는 a-C:H 박막의 탄소와 수소의 결합구조에 큰 영향을 미치지 않았으며, 증착 시간이 증가할수록 탄소와 수소 원자들의 결합구조가 $CH_3$ 구조로부터 $CH_2$ 나 CH 구조로 변하고 있음을 확인하였다. 또한, bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 현상도 확인할 수 있었으며, 증착조건에 따른 a-C:H 박막의 결합구조 분석을 토대로 산업에 응용할 수 있는 높은 경도와 밀착성을 갖는 박막을 ECR-PECVD 방법으로 제조할 수 있음을 확인하였다.

• ETRI Journal
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• 제31권6호
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• pp.755-764
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• 2009

This paper presents a switched self-biasing and a tail current-shaping technique to suppress the 1/f noise from a tail current source in differential cross-coupled inductance-capacitance (LC) voltage-controlled oscillators (VCOs). The proposed LC VCO has an amplitude control characteristic due to the creation of negative feedback for the oscillation waveform amplitude. It is fabricated using a 0.13 ${\mu}m$ CMOS process. The measured phase noise is -117 dBc/Hz at a 1 MHz offset from a 4.85 GHz carrier frequency, while it draws 6.5 mA from a 0.6 V supply voltage. For frequency tuning, process variation, and temperature change, the amplitude change rate of the oscillation waveform in the proposed VCO is 2.1 to 3.2 times smaller than that of an existing VCO with a fixed bias. The measured amplitude change rate of the oscillation waveform for frequency tuning from 4.55 GHz to 5.04 GHz is 131 pV/Hz.