• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.165-170
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• 1995

This paper describes the fabrication and characteristics of a Si Hall sensor fabricated on a SOI (Si-on-insulator) structure. The SOI structure was formed by SDB(Si-wafer direct bonding) technology and the insulator of the SOI structure was used as the dielectrical isolation layer of a Hall sensor. The Hall voltage and sensitivity of the implemented SDB SOI Hall sensors showed good linearity with respect to the applied magnetic flux density and supplied current. The product sensitivity of the SDB SOI Hall sensor was average 600V/A.T and its value has been increased up to 3 times compared to that of bulk Si with buried layer of 10.mu.m. Moreover, this sensor can be used at high-temperature, high-radiation and in corrosive environments.

• 대한전자공학회논문지
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• 제8권5호
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• pp.1-9
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• 1971

양산화를 전제로한 계수형계측기로서 4자리표시, 정도 ±0.1% 진치 ±1 digit 이내, 입력 impedance 1000MΩ 이상(1.500V 범위), 측정범위 1mV∼1,000V 4단절환, 자동영점교정으로 저항 및 직류전류 측정기능도 갖춘 Digital Voltmeter를 목표로 이에 적합한 A/D 변환기를 추구하였다. 이 결과 A/D 변환기에서 일어나는 적분 slope의 직선성에 미치는 요인을 해석하여 매우 간단한 회로구성으로도 효과적인 성능을 보장 할 수 있음을 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.221-224
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• 2004

This paper proposed an ultra low-power CMOS exponential voltage-mode circuit using the Pseudo-exponential function for realizing the exponential characteristics. The proposed circuit provides high dB-linear output voltage range at low-voltage applications. In a $0.25\;\mu m$ CMOS process, the simulations show more than 35 dB output voltage range and 26 dB with the linearity error less than $\pm0.5\;dB.$ The average current consumption is less than 80 uA. The proposed circuit can be used for the design of an extremely low-power variable gain amplifier (VGA) and automatic gain control (AGC).

• Archives of Pharmacal Research
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• 제22권6호
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• pp.614-618
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• 1999

A reversed-phase high-performace liquid chromatographic method was developed to determine the optical purity of metoprolol enantiomers. The enantiomers were converted to diastereomeric derivatives using (-)-menthyl chloroformate reagent. Separation of the enantiomers as diastereomers was achieved by reversed-phase HPLC within 30 min using Inertsil C8 column. This method allowed determination of 0.05% of either enantiomer in the presence of its stereoisomer and method validation showed adequate linearity over the required range. Owing to the reaction condition during the derivatization with (-)-menthyl chloroformate, the possibility of racemization had to be established. Different ratios of (S)-(-)-metoprolol and (R)-(+)-metoprolol were prepared. Enantiomeric separation of these mixtures took place on a chiralcel OD column or, after derivatization with (-)-menthyl chloroformate, on a C8 column. The results form the these two independent separation systems were compared with trace racemization and were in very good agreement. No racemization was found during the experiment.

• 한국통신학회논문지
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• 제31권3A호
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• pp.356-359
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• 2006

A monolithic SiGe HBT variable gain driver amplifier(VGDA) with high dB-linear gain control and high linearity has been developed as a driver amplifier with ground-shielded microstrip lines for 5-GHz transmitters. The VGDA consists of three blocks such as the cascode gain-control stage, fixed-gain output stage, and voltage control block. The circuit elements were optimized by using the Agilent Technologies' ADSs. The VGDA was implemented in STMicroelectronics' 0.35${\mu}m$ Si-BiCMOS process. The VGDA exhibits a dynamic gain control range of 34 dB with the control voltage range from 0 to 2.3 V in 5.15-5.35 GHz band. At 5.15 GHz, maximum gain and attenuation are 10.5 dB and -23.6 dB, respectively. The amplifier also produces a 1-dB gain-compression output power of -3 dBm and output third-order intercept point of 7.5 dBm. Input/output voltage standing wave ratios of the VGDA keep low and constant despite change in the gain-control voltage.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권6호
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• pp.359-367
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• 2004

The switched reluctance motor(SRM) has considerable potential for industrial applications because of its high result lily as a result of the absence of rotor windings. In some applications with SRM, paralleling strategy is often used for cost saving, increasing of current capacity and system reliability. A SRM inverter has very low ,switching frequency. This results in reducing the burden for a high-speed of the gate-amp interface circuit. and the linearity of optocoupler is used to protect the instantaneous peak current for the stable operation. In this paper, series resistor is used to equal the current sharing of each switching device and a linear gate-amp is proposed to protect the instantaneous peak current which occurs in transient state. The proposed paralleling strategy is verified by experimental results.

• Carbon letters
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• 제27권
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• pp.50-63
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• 2018

An imprinted potentiometric sensor was developed for direct and selective determination of gabapentin. Sensor is based on carbon paste electrode adapted by graphene oxide that is decorated with silver nanoparticles and mixed with molecularly imprinted polymers nanoparticles using gabapentin as a template molecule. The synthesized nanoparticles were characterized by Fourier transmission infrared spectroscopy, transmission electron microscopy and X-ray diffraction. Under optimal experimental conditions, the studied sensor exhibited high selectivity and sensitivity with LOD of $4.8{\times}10^{-11}mol\;L^{-1}$. It provided a wide linearity range from $1{\times}10^{-10}$ to $1{\times}10^{-3}mol\;L^{-1}$ and high stability for more than 3 mo. The sensor was effectively used for the determination of gabapentin in pharmaceutical tablets and spiked plasma samples.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권3호
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• pp.188-196
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• 2004

Amplifier linearity plays a major role in the quality of mordern communication systems. The Power amplifier should be operated near saturation region to achieve high efficiency But at this region amplitude and phase distortions of the amplifier remarkably increase with the input power increase and cause a significant adjacent channel interference. In this paper, an independently controllable AM/AM and AM/PM predistortion linearizers consisted of two bias feed resistance linearizers is proposed. This linearizer allows independent adjustment of the AM/AM and AM/PM curves by using two adjustable voltages to compensate tile power amplifier non-linearities. The predistortion linearizer can improve the ACPR by 5.3dB with cdma2000 multi carrier signals. And by applying this linearizer to two-tone(880MHz) power amplifier, third order IMD products are improved up to 8(dB).

• 센서학회지
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• 제22권5호
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• pp.321-326
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• 2013

In this paper, the usability of a compact silicon strain gauge load cell in a weighting disdrometer for measuring the impact load of a falling raindrop is introduced for application in a multi-meteorological sensor. The silicon strain gauge load cell is based on the piezoresistive effect, which has a high linearity output from the momentum of the raindrop and the simplicity of signal processing. The weighting disdrometer shows a high sensitivity of 7.8 mV/g in static load measurement when the diaphragm thickness of the load cell is $250{\mu}m$.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.403-408
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• 2008

In this paper, the high efficiency and linearity Doherty power amplifier using DGS and adaptive bias technique has been designed and realized for 2.3GHz WiBro applications. The Doherty amplifier has been implemented us-ing silicon MRF 281 LDMOS FET. The RF performances of the Doherty power amplifier (a combination of a class AB carrier amplifier and a bias-tuned class C peaking amplifier) have been compared with those of a class AB amplifier alone, and conventional Doherty amplifier. The Maximum PAE of designed Doherty power amplifier with DGS and adaptive bias technique has been 36.6% at 34.01dBm output power. The proposed Doherty power amplifier showed an improvement 1dB at output power and 7.6% PAE than a class AB amplifier alone.