• 한국정보통신학회논문지
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• 제14권12호
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• pp.2609-2614
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• 2010

본 논문에서는 온도센서를 이용한 온도보상회로를 구현하였으며, 이를 이용하여 전력증폭기의 동작 온도범위인 $-30^{\circ}C{\sim}60^{\circ}C$에서 전력증폭기의 혼변조 규격을 만족할 수 있도록 하였다. 온도보상회로의 출력이 온도에 따라 170mV정도 변화하도록 하여 출력이 3W인 증폭기의 TR 게이트에 인가한 결과, $-30^{\circ}C{\sim}60^{\circ}C$에서 우측 3차 혼변조 성분이 -18.5~-26dBm, 좌측 3차 혼변조 성분이 -18.5~-35dBm으로 변화하였으며, 5차 혼변조 성분은 좌 우측 모두 -24~-26dBm으로 규격인 -17dBm이하라는 전력증폭기의 혼변조 성분 규격을 만족하는 것을 확인할 수 있었다.

• 대한기계학회논문집B
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• 제20권11호
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• pp.3666-3675
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• 1996

A new hardware temperature compensation method for hot-wire anemometer is investigated and an analog compensating circuit is proposed in this article. A photoconductive cell is introduced here as a variable resistor in the anemometer bridge and the linearized output of a thermistor is used to monitor the input of the photoconductive cell. In contrast with the conventional method, any type of temperature sensor can be used for compensation if once the output of thermometer varies linearly with temperature. So the present technique can diversify the compensating means from a conventional passive compensating resistance to currently available thermometers. Because the resistance of a photoconductive cell can be set precisely by adopting a stabilizing circuit whose operation is based on the integration function of the operational amplifier, the accuracy of compensation can be enhanced. As an example of linearized thermometer, thermistor sensor whose output is linearized by a series resistor was used to monitor the fluid temperature variation. Validation experiment is conducted in the temperature ranged from 30 deg. C to 60 deg. C and the velocity up to 40 m/s. It is found that the present technique can be adopted as a compensating circuit for anemometer and hot-wire type airflow meter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.655-657
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• 1996

The objective of this paper is to compare the series and shunt approaches of controlled reactive power compensation to improve power system transient stabilities. Including main circuit considerations of series and shunt compensators, application aspects are thought to have major impacts on efficiency and economy of the installation of the compensators. The concept is studied by means of EMTP simulations on one machine-Infinite Bus Test System which consists of a 612MVA steam turbin generator and transformer and double circuit 345KV transmission line. Idealized dynamic models of Thyristor Controlled Series Compensation and Shunt Compensation are used for the comparative study of the series and shunt compensation approach to damp power system oscillations.

• 대한전자공학회논문지SD
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• 제46권4호
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• pp.45-52
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• 2009

본 연구를 통해서 대 면적, 고 휘도 AMOLED 응용에 적합한 화소 회로와 이에 대한 구동 방식을 제안하였다. 균일도는 다소 떨어지지만 안정성이 뛰어난 저온 다결정 실리론(LTPS) 박막 트랜지스터(TFT)를 기반으로 설계했다. 영상 화소의 균일도를 향상시키기 위해, 화소 TFT의 $V_{TH}$와 이동도 편차를 함께 보상할 수 있도록 했다. 기존의 이동도 보상 회로가 갖는 문제점을 극복하여 대 면적 패널에 적합하도록 했고, 동영상 특성을 개선하기 위해 black data insertion 방식을 도입하였다. 이동도 보상 시 휘도가 떨어지는 문제를 개선하기 위해, 패널이 두 가지 보상 모드에서 동작할 수 있도록 하였다. 화소 회로를 제어하기 위한 스캔 구동 회로를 최적화하여, 이를 통해서 보정 모드를 쉽게 제어할 수 있었다. 최종 구동 타이밍은 여유 있는 마진으로 안정적인 동작이 가능하다. 14.1" WXGA top emission AMOLED 패널에 대해 설계했으며, 이동도 보상 시간을 1us로 했을 때 패널의 불균일도는 5% 이하로 예측되었다.

• 한국인터넷방송통신학회논문지
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• 제20권4호
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• pp.129-133
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• 2020

본 논문에서는 W-대역 저잡음증폭기의 온도에 따른 이득 변동을 경감시킬 수 있는 온도보상회로를 기술하였다. 제안된 캐스코드 온도보상 바이어스회로는 공통-소스 저잡음증폭기의 게이트 바이어스를 자동으로 조절하여 소신호 이득의 변화를 억제한다. 설계된 회로는 100-nm GaAs pHEMT 공정 디자인킷으로 구현되었다. 제안된 바이어스 회로를 적용한 W-대역 저잡음증폭기의 시뮬레이션 이득값은 -35~71℃ 범위에서 20 dB 이상, ±0.8 dB 내의 변동값을 보였다. 본 논문에서 제시한 회로는 레이더용 밀리미터파 수신기에 적용되어 안정적인 성능을 낼 수 있을 것으로 기대된다.

• 전자공학회논문지B
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• 제32B권11호
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• pp.1374-1382
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• 1995

In TFT-LCDs, as the display size area becomes larger, and the resolution higher, we have to consider the image degradation effects due to the incorporation of the TFT-LCD parameters such as the data-line resistance, the common electrode resistance, the data-line to common parasitic capacitance, and the output characteristics of driver ICs. One of the degradation effects is crosstalk resulting from the coupling between the source bus-line and common electrode. Since a source signal which represents a large number of display data is supposed to vary frequently, the common signal level is affected through the coupling effect, resulting in the degradation of nearby pixel drive signals. Therefore, we proposed a method to compensate for this source-common electrode coupling effect, we also designed and experimented the feasibility of our crosstalk compensation circuit in the actual TFT-LCD. We saw that the newly designed compensation circuit greatly reduced the crosstalk in display pattern image.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.293-296
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• 2009

2002부터 미국에서 전기화재 보호를 위하여 AFCI(Arc Fault Circuit Interrupter)사용이 의무화되었으며 중성선의 선로저항을 이용하여 아크를 검출하는 방식의 AFCI의 경우 중성선 선로저항의 저항온도계수에 대한 온도보상이 필요하다. 이러한 온도보상회로를 주문형반도체(ASIC)에서 구현하는 방안을 제시하고 ARC 신호에 대하여 시뮬레이션하여 전기적 특성 및 온도특성을 검증하였다.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.141-145
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• 2021

The brightness of the Organic Light Emitting Diode (OLED) display is controlled by thin-film transistors (TFTs). Regardless of the materials and the structures of TFTs, an OLED suffers from the instable threshold voltage (V_th) of a TFT during operation. When designing an OLED pixel with circuit simulation tool such as SPICE, a designer needs to take V_th shift into account to improve the reliability of the circuit and various compensation methods have been proposed. In this paper, the effect of the compensation circuits from two typical OLED pixel circuits proposed in the literature are studied by the transient simulation with a SPICE tool in which the stretched-exponential time dependent V_th shift function is implemented. The simulation results show that the compensation circuits improve the reliability at the beginning of each frame, but V_th shifts from all TFTs in a pixel need to be considered to improve long-time reliability.

• Journal of information and communication convergence engineering
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• 제14권3호
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• pp.147-152
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• 2016

In radio-over-fiber (RoF) systems, nonlinear compensation is essential to improve performance. Among the several existing nonlinear compensation techniques, we investigate a predistortion technique for a directly modulated laser in an RoF system. First, we obtain the input-to-output response of a directly modulated laser at 160, 820, and 1,540 MHz. The results show that the laser response is dependent on the frequency band. Second, we design an optimal predistortion circuit to compensate for the nonlinear responses of three frequency bands. We design the predistortion circuit with two options: each predistortion circuit for each frequency band and one single predistortion circuit for all the three frequency bands. Finally, we present the simulation results of the predistortion system obtained using a commercial simulator. These results show that the third intermodulation distortion (IMD3) is improved by 0.6-9 dB for the three frequency bands with only a single predistortion circuit.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권1호
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• pp.11-19
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• 2007

This paper presents two novel compensation circuits for leakage current and power supply noise (PSN) in phase locked loop (PLL) using a nanometer CMOS technology. The leakage compensation circuit reduces the leakage current of the charge pump circuit which becomes more serious problem due to the thin gate oxide and small threshold voltage in nanometer CMOS technology and the PSN compensation circuit decreases the effect of power supply variation on the output frequency of VCO. The PLL design is based on a 32nm predictive CMOS technology and uses a 0.9V power supply voltage. The simulation results show that the proposed PLL achieves a 88% jitter reduction at 440MHz output frequency compared to the PLL without leakage compensator and its output frequency drift is little to 20% power supply voltage variations. The PLL has an output frequency range of $40M{\sim}725MHz$ with a multiplication range of 11023, and the RMS and peak-to-peak jitter are 5ps and 42.7ps, respectively.