• Journal of IKEEE
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• v.25 no.2
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• pp.309-314
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• 2021

The proposed preamplifier for the static random access memory reduces the time required for the sense amplifier enable during the read operation by 55%, which leads to a significant speed up the total spped. This is attirbuted to the novel circuit techqniue that cancels out the transistor mismatch which is induced by the process variation. In addition, a selective enable circuit for preamplifier circuit is proposed, so the proposed preamplifier is enabled only when it is required. Accordingly the energy overhead is limited below 4.45%.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.315-319
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• 2012

The aim of this study was to develop a signal process circuit for a position sensitive avalanche photodiode detector. The circuit parts consisted of amplification, differential and peak/hold circuit. This research was the baseline to develop highly compact radiation detector. The signal was amplified by an amplification chip and its shape was changed in a differential circuit to minimize the pulse tailing. The peak/hold circuit detect the peak of the signal from the differential circuit and hold the amplitude of the peak for data acquisition. In order to test the intrinsic function of the circuit, the input signal was transmitted from a commercial pulse generator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.6
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• pp.854-862
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• 1993

All of the CMOS analog and analog-digital systems have composed with several basic circuits, and among them, a important block, the amplifier part can affect the system's performance, Therefore, according to the uses in the system, the amplifier circuit have designed as various architectures (high-gain, low-noise, high-speed circuit, etc...). In this paper, we have proposed a new CMOS differential amplifier circuit. This circuit is differential to single ended input stage comprised of CMOS complementary gain circuits having internally biasing configurations. These architectures can be achieved the high gain and reduced the transistors for biasing. As a results of SPICE simulation with the standard $1.5{\mu}m$ processing parameter, the gain of the proposed circuit have a doubly value of the typical circuit's while maintaining other characteristics(phase margin, offset, etc...). And the proposed circuit is applicated in a simple CMOS comparator which has the settling time in 7nsec(CL=1pF) and the igh output swing $({\pm}4.5V)$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1079-1086
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• 2012

In this paper, X-band 60 W Solid-State Power Amplifier with sequential control circuit and pulse width variation circuit for improve bias of SSPA module was designed. The sequential control circuit operate in regular sequence drain bias switching of GaAs FET. The distortion and efficiency of output signals due to SSPA nonlinear degradation is increased by making operate in regular sequence the drain bias wider than that of RF input signals pulse width if only input signal using pulsed width variation. The GaAs FETs are used for the 60 W SSPA module which is consists of 3-stage modules, pre-amplifier stage, driver-amplifier stage and main-power amplifier stage. The main power amplifier stage is implemented with the power combiner, as a balanced amplifier structure, to obtain the power greater than 60 W. The designed SSPA modules has 50 dB gain, pulse period 1 msec, pulse width 100 us, 10 % duty cycle and 60 watts output power in the frequency range of 9.2~9.6 GHz and it can be applied to solid-state pulse compression radar using pulse SSPA.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.138-144
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• 2017

In this paper, we propose a high frequency boosting circuits compensating for age-related hearing loss. The frequency response of this hearing loss is quite similar to that of a low-pass filter of which the critical frequency get lower with age. Therefore the voltage gain of this compensation circuits increase proportionally to the frequency of signals when the frequency is higher than the critical frequency and the voltage is constant irrespective of the frequency of signals when the frequency is lower than the critical frequency. The proposed circuits consist of a differential circuit and a unity gain amplifier. Because the critical frequency of the proposed circuits is controlled simply in the shape of a volume control lever, the aged people can adjust the high frequency boosting level easily according to one's hearing loss level. The critical frequency is continuously controllable in the whole audible frequency band and the gain of this high frequency boosting circuits is above 80dB at 10kHz.

• Journal of the Korean Institute of Telematics and Electronics
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• v.9 no.4
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• pp.33-37
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• 1972

Amplifier circuits with differential characteristics, that is, amplifier circuits the voltage gain of which are proportional to the complex frequency are described. It is shown that the characteristics of the circuit predicted on the basis of the nullator-norator model of the transistor coincides with the result of the exact analysis of the circuit, and experimental result coincides with the theory.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.12
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• pp.40-48
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• 1998

An offset compensation scheme for rail-to-rail CMOS op-amps with complementary input stages is presented. Two auxiliary amplifiers are used to compensate for the offsets of NMOS and PMOS differential input stages, and ping-pong control is employed for continuous-time operation. A 3V offset-compensated rail-to-rail CMOS op-amp has been designed and fabricated using a 0.8$\mu\textrm{m}$ single-poly, double-metal CMOS process. Measurement results show that offsets are reduced about 20 times by this scheme.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.98-99
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• 2000

코어 가까이 측면 연마한 광섬유를 이용하여 광 여파기, 편광기, 감쇠기등의 광통신 소자로 응용하고자 하는 연구가 많이 진행되고 있다.$^{[1]}$ 이 소자는 광섬유를 절단하지 않은 상태에서 코어 가까이 측면 연마하여 광학적 기능을 가진 소자를 제작함으로서 공정이 간단하고 삽입손실이 작은 특성을 가지며 기계적 신뢰성이 우수하다. 측면 연마된 광섬유를 이용한 광 증폭의 경우 광섬유의 소산장(evanescent field)과 펌핑광에 의해서 여기되는 활성 물질과의 상호작용에 의해서 광 이득을 얻는다. 소산장 결합에 의한 평면도파로에서의 광 증폭$^{[2]}$ 과 다중 모드 광섬유에서의 펄스 레이저 증폭, 단일 모드 광섬유에서 632.8nm He-Ne 레이저의 연속광원 증폭$^{[3]}$ 은 이미 보고되었다. 본 논문에서는 측면 연마된 다중 모드 광섬유의 연마된 부위에 색소가 첨가된 용액을 떨어뜨림으로서 발생하는 소산장 결합에 의해서 광섬유내를 진행하는 연속적인 He-Ne 레이저 광을 증폭시키는 방법을 제안하고자 한다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.9-12
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• 1990

본 연구는 KrF 엑사이머 레이저 증폭을 하기 위하여 먼저 능동매질을 N도 사용하여 발전기와 증폭기의 시간적인 동기회에 주 목적을 두었고 안정한 증폭기의 출력을 얻기 위해 방전관 에너지의 5%를 예비전리로 최적화 시켰으며 방전에 사용되는 Spark Gap Switch의 내부 인덕턴스를 고찰하였다.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.74-79
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• 1991

측뢰 4 광파 혼합법으로 여러 가지 용매와 색소를 매질로 이용하여 위상공파를 발생시키고 발생한 위상공액파를 증폭하였다. 광원은 Q-switching된 루비레이저이다. 위상 공액파의 반사율, R을 증가시키기 위해 여러 가지의 색소와 용매를 이용하여 위상공액파를 방생시키고 이들 중 반사율이 좋은 조합으로 루비봉을 이용한 증폭기를 통과시켜 증폭실험을 수행하였다. 증폭기를 거친 최종적인 반사율은 Renh로 정의하였을 때 실험 결과는 DMSO와 Cryptocyanine의 조합에서 최대 Renh/R = 6.3 $\pm$ 0.38를 얻을 수 있었다.