특성 저하를 최소화하는 광대역 안정화 기법에 관한 연구

정명래,이상원,김학선,홍신남,이윤현 한국항행학회 1999 韓國航行學會論文誌 Vol.3 No.2

본 연구는 소자의 S-파라미터로부터 소스측과 부하측에 최소 직렬 안정화 저항 값 및 최소 병렬 안정화 컨덕턴스를 계산하는 수식을 유도하여, 안정도를 유지하면서 최대 가용 이득의 손실을 최소화하기 위한 설계 방법을 제시하였다. 1.9GHz 대역에서 사용되는 KGF1254B 트랜지스터에 일반적으로 사용되고 있는 단순한 안정화 회로를 적용하였을 때는 최대 가용 이득이 5.2㏈ 감소되나 본 논문의 방법을 적용함으로써 1㏈ 감소만으로도 회로를 안정화시킬 수 있었다. In this paper, the equations which can be used to calculate the minimum series stabilizing resistance and /or the minimum parallel stabilizing conductance using the S parameters of an active device has been derived. The equation derived can be used to design a stabilizing circuit of minimum loss of a maximum available gain of a device when the circuit is adopted. For the case of KGF1254B which can be used at 1.9GHz, the circuit proposed in this paper reduce the maximum available gain by 1㏈, while conventional simple resistor circuit reduce it by 5.2㏈.

合意管轄

鄭明來 청주대학교 법학회 1973 法學論考 Vol.9 No.-

갈륨비소 MESFET를 利用한 차동증폭기의 設計 및 시뮬레이션에 關한 硏究

鄭明來 木浦海洋大學校 1994 論文集 Vol.2 No.1

Gallium-Arsenide(GaAs) Integrated dircuit technology has become a popular vehicle for realizing high-speed electronic circuits, principally because of its high electron mobility and early saturation velocity in comparison with Silicon(Si). And then, application of this technology to GaAs MESFET has recently been developed like switched capacitor filter, A/D and D/A converter, etc. But it is difficult to obtain the high gain which is esswntial to the operational amplifier due to its drain resistance decreased by phenomenon such as frequency dispersion and process variation arised in proportion to the higher frequency. In this paper, in order to improve voltage gain and compare various types of existing circuits the newly designed GaAs MESFET single amplifier circuit is presented. PSPICE simulation results show that the differential gain, the cut-off freqency and CMRR of the newly designed GaAs MESFET differential amplifier are 57.66[㏈], 2.46[㎓] and 67.2[㏈] respectively.

Rat 전지 상완의 근섬유형 구성에 대한 연구

정명래,김홍선,신태균 충남대학교 의과대학 지역사회의학연구소 1987 충남의대잡지 Vol.14 No.2

This study was to determine the fiber-type populations and calculate the cross-sectional areas in each fiber-type in the muscle of the brachium of the rat. For 20 rats, the flexors (brachialis and biceps brachii) and extensors (triceps brachii) of the elbow taken from dissection. The fibers were classfied histochemically as fast-twitch oxidative glycolytic fiber(FOG), fast-twitch glycolytic fiber (FG), or slow-twitch oxidative fiber(SO), and their populations were determined. The cross-sectional areas of each type muscle fibers were calculated with microcomputer image analyzer. The results were as follows ; I. The variations in fiber-type population of various muscles with which their positions were observed as well as those reported in ot4er studies. 2. In both extensor and flexor groups, the deep region of the muscles was consisted of higher populaions of SO fibers, while more superficial regions of the same muscles were more FG fibers. 3. The percentage of SO fibers were larger in the extensors than that of flexors. 4. Except the SO fibers, the cross-sectional areas of FOG and FG fibers in the extensors were larger than that of flexors.

광대역 RF 시스템의 발진 방지에 관한 연구

정명래 木浦海洋大學校 1998 論文集 Vol.6 No.1

본 연구는 광대역 RF회로를 설계 및 제작할 경우 불안정 상태를 고찰하고, 뜻하지 않게 발생하는 발진의 원인을 분석하여, 그 해결 방법을 제시한다. 또한, 소스측과 부하측의 안정도 원을 이용하여 최적의 안정도를 유지하며 최대 가용 이득의 손실을 최소화 하기 위한 설계 방법을 제시한다. In this paper, design method for the broadband RF or microwave circuit Stabilization is presented. Basically RF or microwave device has conditional stable state depending on the frequency. Reported techniques adapted constant resistance for series or constant admittance for parallel connection that must sacrifice maximum available gain. So presented RLC parallel circuit that varies real impedance depending on the frequency. this method has an unconditional stable state and minimum loss of maximum available gain, so will be increased in the linearity in RF system.

LNA 잡음원의 분석

정명래 木浦海洋大學校 1997 論文集 Vol.5 No.2

본 논문은 전자회로의 잡음에 관한 일반적인 연구로서 저잡음증폭기 설계를 위하여 전기적 또는 기계적인 원인에 의한 기초 이론과 잡음의 양적인 표현법 및 증폭회로에서의 잡음의 영향을 기술한다. (다음에는, 시뮬레이션으로 증폭기의 최소잡음특성을 확인하고 저잡음증폭기 회로설계의 구현을 위한 자료로 응용하는데 있다.)

2.45GHz ISM 대역의 송신 전력 제어를 위한 전력 검출 기법 비교 연구

정명래,이상원,김학선,이윤현,이형재 대전산업대학교 반도체기술연구소 1999 半導體技術硏究所報 Vol.1 No.-

본 논문에서는 2.45GHz ISM 대역의 전력 제어시 추정 오차를 줄이기 위하여 콘덴서를 이용한 직접 결함 전력 검출기와 방향성 결합기에 의한 전력 검출기를 설계하여 전압 감도, 대역폭, 기판 크기 등의 특성을 비교. 분석하였다. 측정한 결과, 전압 감도는 입력 전력이 -50dBm 에서 -25dBm까지는 전압 감도가 거의 비슷하지만 -25dBm에서 -10dBm까지는 방향성 결합기에 의한 전력 검출기의 전압 감도가 최대 3.5㎶/㎼ 정도 우수하며, 대역폭은 방향성 결합기에 의한 전력 검출기가 콘덴서를 이용한 직접 결합 전력 검출기보다 63MHz 더 넓었다. 그러므로 전력 제어를 위한 검출기 선정시에 송신기의 출력 레벨이 -20dBm 이하인 경우는 특성이 비슷하므로 기판 크기를 줄이기 위해서는 콘덴서를 이용한 전력 검출기를 선정하는 것이 좋고, -20dBm 이상 또는 광대역의 경우는 전압 감도를 고려하여 방향성 결합기에 의한 전력 검출기를 선정하는 것이 추정 오차를 줄일 수 있다. In this paper, we designed the power detector with the capacitor to decrease the estimation error and directional coupler which are used in 2.45GHz ISM band, also compared and analyzed the characteristics of the power sensitivity to estimate the performance of detector, the bandwidth and the printed circuit board size. As the results, their voltage sensitivity is constant from -50dBm to -25dBm which is the input power, but the detector composed by the directional coupler is superior about 3㎶/㎼ than that by the single diode from -25dBm to -10dBm and its bandwidth is wider about 63MHz than the directional coupling power detector with the capacitor. Therefore when the output level of transmiter is below -20dBm, the power detector with the capacitor had better be selected as the detector for the power control to reduce the area because of the similar characteristics, and above -20dBm or in the wide band system, the estimation error can be eliminated by the selection of directional coupler considered the voltage sensitivity for the power detector.

마이크로파 분포형 증폭기의 이론과 성능에 관한 연구

鄭明來 木浦海洋大學校 1996 論文集 Vol.4 No.1

The performance characteristics of n-link dstributed amplifiers employing GaAs MESFET's are studied. At first, formulas of the symmetrical amplifier using lumped circuit elements are developed for the case of an idealized FET model. The theoretical analysis is then extended to distributed line elements and later to an S-parameter derived transistor model. In efforts to optimize amplifier performance characteristics of two concepts, that of equal characteristic impedances and that of equal line lengths, are proposed and compared. Based on this analysis and practical considerations, several three-link hybrid amplifiers utilizing the equal line lengths approach have been assembled and test results are reported. A gain of G = 5.5± 0.6 ㏈ was measured over the bandwidth of 2-20 ㎓. Across this frequency band a maximum VSWR of 2.2:1 for the input and 2.5:1 for the output terminal have been realized, while a minimum output power at the 1-㏈ compression points of 19.3 ㏈m was achieved from 2-18 ㎓. Agreement between measured and computed small-signal gain as well as reverse isolation is excellent.

근거리 해상 이동통신에서의 정보통신 서비스 개선방안에 관한 연구 ( A Study on the Improvement plan of Info-communication service in the Neighboring Maritime Mobile Telecommunication )

정명래,최병하,박경호 한국통신학회 1996 한국통신학회 학술대회논문집 Vol.- No.-

OP amp의 차동 입력회로 設計에 關한 硏究

鄭明來 木浦海洋大學校 1995 論文集 Vol.3 No.1

A Study on the Design of Differential Input Circuts Using GaAs MESFETS In the high speed analog system, satellite communication system, video signal processing and optical fiber interface circuits, high gain operational amplifier for implementation in GaAs technology is advantageous due to its high electron mobility, peak electron velocity and semi-insulating substrate. But it is difficult to obtain a high gain because of its low transconductance and drawbacks, such as low frequency dispersion and process variation. Therfore in this paper, a circuit design techniques for improving the voltage gain of the GaAs MESFET sigle amplifier is presented. Also, various types of existing current mirror and proposed current mirror of new configuration are compared. To obtain the high differential mode gain and low common mode gain, bootstrap gain enhancement texhnique is used and common mode feedback is employed in differential amplifier. The simulation results show that designed differential amplifier has differential gain of 57.66[dB], unity gain frequency of 2.46[Ghz]. Also differential amplifier using common mode feedback with alternative negative current mirror has CMRR of 67.262[dB], slew rate of 3500v/μm.