• 제목/요약/키워드: folded

검색결과 674건 처리시간 0.027초

Hot-Carrier 현상에 의한 Folded-Cascode CMOS OP-Amp의 성능 저하 (The performance degradation of a folded-cascode CMOS op-amp due to hot-carrier effects)

  • 김현중;유종근;정운달;박종태
    • 전자공학회논문지D
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    • 제34D권12호
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    • pp.39-45
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    • 1997
  • This study presents the first experimental data for the impact of hot-carrier degradtion on the performance of CMOS folded-cascode op-amps. A folded-cascode op-amp which has an NMOS input pair has been designed and fabricated using a 0.8.mu.m single-poly, double-metal CMOS process. After high voltage stress, the degradtion of perfomrance parameters such as open-metal CMOS process. After high voltage stress, the degradation of performance parameters such as open-loop voltage gain, unity-gain frequency and phase margin has been analized and physically explaniend in terms of hot carrier degradation.

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위성 DMB 대역을 위한 수정된 폴디드 루프 안테나 (Design of Planar Modified Folded Loop Antennas for S-DMB band)

  • 이현진
    • 전기학회논문지P
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    • 제61권1호
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    • pp.1-4
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    • 2012
  • In this paper, the planar type modified folded loop antennas for S-DMB band is proposed. The proposed antenna consisted of opened center of a conventional closed loop and folded terminal of microstrip line to inside loop antenna. The sizes proposed antenna was minimized by folding the terminal of the loop. Also, It was minimized reactance value by increasing capacitances between coupled microstrip line. Therefore the proposed antennas compacted about 20% than a conventional loop antenna and increased efficiency of antenna. The proposed antennas got an omni-directional pattern, the antenna gain was 3.67 [dBi] and the bandwidth was 900 MHz (2.6-3.56 GHz) with VSWR${\leq}$2 from the simulated and the measured results. The frequency utilization coefficient was 29.9 %. These properties could satisfy the S-DMB band.

Q-Switching of a Diode-Pumped Nd:YVO4 Laser with a Closely Folded Resonator

  • Lee Hyuncheol;Lee Yongwoo;Kwak Chonghoon;Kwon Jinhyuk;Yi Jonghoon;Lim Yong-Sik
    • Journal of the Optical Society of Korea
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    • 제9권2호
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    • pp.64-67
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    • 2005
  • A diode-pumped $Nd:YVO_4$ laser is developed. The laser has a closely folded resonator. The laser beam in two arms of the folded resonator passes the same acousto-optic modulator. The laser output power and pulsewidth dependence on a Q-switching frequency were measured. It is found that the newly proposed geometry provides an effective means for reducing the pulsewidth while maintaining almost the same output power compared with the usual folded resonator, where the beam in one arm of the resonator passes the acousto-optic modulator.

연속파 테라헤르츠 포토믹수를 위한 폴디드 공진 안테나 (Resonant Folded Dipole Antennas for Continuous-Wave Terahertz Photomixer)

  • 문경식;박홍규;김정회;정은아;이경인;한해욱
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.181-182
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    • 2006
  • Photoconductive three-wire folded dipole antennas for terahertz photomixers have been developed. The folded antennas are characterized by a free space time-domain measurement technique, and the measured data are in good agreement with the simulation results. The folded dipole antennas have much higher antenna resistance than other resonant dipole antennas, implying that they can be used for higher output power of THz photomixers.

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3개의 폴디드 라인을 갖는 이동통신용 CPW 안테나 (A CPW Antenna with Three Folded Lines for Mobile Communication)

  • 신호섭;최인태
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2013년도 추계학술대회
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    • pp.900-902
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    • 2013
  • 본 논문에서는 소형화를 위하여 3개의 폴디드 형태의 선로를 갖는 CPW 안테나를 제안한다. LTE 사용 주파수의 공진을 위해 중앙을 미앤더 라인으로, 그 외에는 폴디드 라인으로 구성하였다. 대역폭을 넓히기 위하여 라인들의 폭을 점진적으로 변화시킴으로써 설계하였다.

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An assumed-stress hybrid element for static and free vibration analysis of folded plates

  • Darilmaz, Kutlu
    • Structural Engineering and Mechanics
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    • 제25권4호
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    • pp.405-421
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    • 2007
  • A four-node hybrid stress element for analysing orthotropic folded plate structures is presented. The formulation is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. The proposed element has six degree of freedom per node and permits an easy connection to other type of elements. An equilibrated stress field in each element and inter element compatible boundary displacement field are assumed independently. Static and free vibration analyses of folded plates are carried out on numerical examples to show that the validity and efficiency of the present element.

폴디드 하이퍼큐브와 HFH 네트워크 사이의 임베딩 알고리즘 (Embedding Algorithm between Folded Hypercube and HFH Network)

  • 김종석;이형옥;김성원
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제2권4호
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    • pp.151-154
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    • 2013
  • 본 논문에서는 폴디드 하이퍼큐브와 HFH 네트워크 사이의 임베딩을 분석한다. 폴디드 하이퍼큐브 $FQ_{2n}$는 HFH($C_n,C_n$)에 연장율 4, 확장율 $\frac{(C_n)^2}{2^{2n}}$에 임베딩 가능함을 보이고, HFH($C_d,C_d$)를 폴디드 하이퍼큐브 $FQ_{4d-2}$에 임베딩하는 비용은 O(d)임을 보인다.

경계요소법과 축소모형실험을 이용한 주기적 구조를 갖는 굴절형방음벽의 설계에 관한 연구 (A Study on Design of Periodically Folded Barrier by BEM and Scale Model Test)

  • 전재홍;이상권
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.84-87
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    • 2005
  • This study is aimed to compare the insertion losses of periodically folded barriers which have same folded width, depth and period of arrangement but different direction of arrangement. One is vortical to the roadside and another is parallel. The pressure levels and the insertion losses at the receiving points behind finite length barriers are measured in an anechoic room by scale model test. The measured insertion losses are compared with calculated insertion losses by 3D BEM models.

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Design and Experimental Demonstration of Coaxially Folded All-reflective Imaging System

  • Xiong, Yupeng;Dai, Yifan;Chen, Shanyong;Tie, Guipeng
    • Current Optics and Photonics
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    • 제3권3호
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    • pp.227-235
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    • 2019
  • With slimmer, lighter and all-reflective imaging systems in high demand for consumer and military applications, coaxially folded optical image systems are widely considered because they can extend focal length and reduce track length. Most of these systems consist of multiple surfaces, and these surfaces are machined on one element or grouping processing on two elements. In this paper, we report and first experimentally demonstrate an all-aluminum all-reflective optical system which consists of two optical elements, with two high order aspherical surfaces in each element. The coaxially folded system is designed with Seidel aberration theory and advanced optimization with Zemax. The system is made of all-aluminum material processing by single point diamond turning (SPDT). On this basis, we completed the system integration and performed an imaging experiment. The final system has the advantages of short track length and long focal length and broad application prospects in the micro-unmanned aerial vehicle field.