• Title/Summary/Keyword: channel junction

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The Change of Flow depending upon the Discharge and Approaching Angle at Channel Junctions (합류부의 유량 및 접근각도에 따른 흐름변화)

  • Choi, Gye-Woon;Park, Young-Suop;Han, Man-Shin
    • Journal of Korea Water Resources Association
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    • v.37 no.8
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    • pp.623-630
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    • 2004
  • In this paper, the hydraulic model tests are conducted for the hydraulic characteristics at channel junctions. The experiments are examined through the variation of approaching angle, discharge in the upstream main channel and the discharge ratio between the main channel and the tributary. The experiments are conducted in the channel model having the length of 450cm, the widths of 40cm and 32cm. Four water tanks and pumps are installed in the experimental channel. The length of stagnation zone is increased by Increasing of approaching angle and the discharge in the upstream channel. The length of stagnation increase with the discharge ratio between the main channel and the tributary. However, the variation of the stagnation zone near the channel junctions is little at the same approaching angles and the discharge ratioes between the main channel and tributary. However, the variation of the stagnation zone near the channel junctions is little at the same approaching angles and the discharge ratioes between the main channel and tributary. Accelerating zone of the velocity is occurred in the middle of the channel in the small approaching angle. However, the influence zone of the accelerating velocity is increased by increasing the approaching angle.

Improvement in Image Rejection of Multi-Port Junction-based Direct Receivers (다중 접합 기반 수신기의 영상 제거비 평가 및 향상 방법)

  • Park, Hyung Chul
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.43-48
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    • 2012
  • This paper presents an iterative single-frequency continuous-wave signal-based I/Q regeneration method for improving image-rejection performance of multi-port junction-based direct receivers (MPDRs). This paper analyzes I/Q regeneration in MPDRs as I/Q mismatch compensation for direct conversion receivers. Based on the analysis, this paper evaluates the accuracy of I/Q regeneration in terms of the image-rejection ratio (IRR). The proposed method improves the IRR performance more than 20 dB compared to existing I/Q regeneration methods. Simulation results show that MPDRs using the proposed method can achieve an IRR of more than 70 dB, and that the bit error rate performances are almost the same as those of conventional coherent demodulators, even in fading channels.

Partially-insulated MOSFET (PiFET) and Its Application to DRAM Cell Transistor

  • Oh, Chang-Woo;Kim, Sung-Hwan;Yeo, Kyoung-Hwan;Kim, Sung-Min;Kim, Min-Sang;Choe, Jeong-Dong;Kim, Dong-Won;Park, Dong-Gun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.6 no.1
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    • pp.30-37
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    • 2006
  • In this article, we evaluated the structural merits and the validity of a partially insulated MOSFET (PiFET) through the fabrication of prototype transistors and an 80 nm 512M DDR DRAM with partially-insulated cell array transistors (PiCATs). The PiFETs showed the outstanding short channel effect immunity and off-current characteristics over the conventional MOSFET, resulting from self-induced halo region, self-limiting SID shallow junction, and reduced junction area due to PiOX layer formation. The DRAM with PiCATs also showed excellent data retention time. Thus, the PiFET can be a promising alternative for ultimate scaling of planar MOSFET.

An Amorphous Silicon Local Interconnection (ASLI) CMOS with Self-Aligned Source/Drain and Its Electrical Characteristics

  • Yoon, Yong-Sun;Baek, Kyu-Ha;Park, Jong-Moon;Nam, Kee-Soo
    • ETRI Journal
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    • v.19 no.4
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    • pp.402-413
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    • 1997
  • A CMOS device which has an extended heavily-doped amorphous silicon source/drain layer on the field oxide and an amorphous silicon local interconnection (ASLI) layer in the self-aligned source/drain region has been studied. The ASLI layer has some important roles of the local interconnections from the extended source/drain to the bulk source/drain and the path of the dopant diffusion sources to the bulk. The junction depth and the area of the source/drain can be controlled easily by the ASLI layer thickness. The device in this paper not only has very small area of source/drain junctions, but has very shallow junction depths than those of the conventional CMOS device. An operating speed, however, is enhanced significantly compared with the conventional ones, because the junction capacitance of the source/drain is reduced remarkably due to the very small area of source/drain junctions. For a 71-stage unloaded CMOS ring oscillator, 128 ps/gate has been obtained at power supply voltage of 3.3V. Utilizing this proposed structure, a buried channel PMOS device for the deep submicron regime, known to be difficult to implement, can be fabricated easily.

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Characteristic Analysis of 4-Types of Junctionless Nanowire Field-Effect Transistor (4가지 무접합 나노선 터널 트랜지스터의 기판 변화에 따른 특성 분석)

  • Oh, Jong Hyuck;Lee, Ju Chan;Yu, Yun Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.381-382
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    • 2018
  • Subthreshold swings (SSs) and on-currents of four types of junctionless nanowire tunnel field-effect transistor(JLNW-TFET) are observed. Ge-Si structure for the source-channel junction has the highest drive current among Si-Si, Si-Ge, and Ge-Ge junction, and the drive current increases up to 1000 times compared to others. Minimum SS of Si-Si junction is reduced by up to 5 times more than others.

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Characterization of Channel Electric Field in LDD MOSFET (LDD MOSFET 채널 전계의 특성해석)

  • Park, Min-Hyoung;Han, Min-Koo
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.363-367
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    • 1988
  • A simple analytical model for the lateral channel electric field in gate - offset structured Lightly Doped Drain MOSFET has been developed. The model's results agree well with two dimensional device simulations. Due to its simplicity, our model gives a better understanding of the mechanisms involved in reducing the electric field in the LDD MOSFET. The model shows clearly the dependencies of the lateral channel electric field as function of drain and gate bias conditions and process, design parameters. Advantages of analytical model over costly 2-D device simulations is to identify the effects of various parameters, such as oxide thickness, junction depth, gate / drain bias, the length and doping concentration of the lightly doped region, on the peak electric field that causes hot - electron phenomena, individually. We are able to find the optimum doping concentration of LDD minimizing the peak electric field and hot - electron effects.

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Implementation of Waveguide Manifold Multiplexer for Ku-band Satellite Transponder (Ku-대역 위성중계기용 도파관 Manifold 멀티플렉서 설계)

  • 정근욱;이재현
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.6
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    • pp.787-798
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    • 1995
  • We implement the E-plane T-juncition manifold mutiplexer having low insertion loss for output multiplexer of Ku-band satellite transponder. Manifold multiplexer implemented here is composed of 2 channel filters, T-junctions, half-wave waveguide connecting channel filters and manifold, and manifold itself.[1-4] Considering the mass and volume of the satellite transponder, the channel filters are designed to dual-mode.[5-13] And Elliptic filter function is used, which has good characteristics of suppressing the interference between 2 channels. Since the performance of manifold multiplexer depends on the manifold waveguide transmission line length, it's necessary proper analysis. In this paper, we do optimization process of T-junction and other elements by using CAD and implement the manifold multiplexer. An experiment shows that characteristic response of multiplexer matches wel its modeling result.

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Development of electroosmotic flow control technique in micro fluidic devices (전기 삼투를 이용한 미세 유체 소자에서의 유량 제어 기술 개발)

  • Choi, Eun-Soo;Jeong, Dae-Joong;Sim, Won-Chul;Yang, Sang-Sik
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1991-1993
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    • 2002
  • This paper presents the PDMS surface characteristic change after the plasma process and the electroosmotic flow control technique for the two-dimensional focusing in the micro channels made of PDMS and glass. The channels are fabricated by plastic molding and micromachining technique. To observe the surface characteristic change as time elapses, we measure the contact angle of water on the surface and the velocity of the electroosmotic flow in a channel. The electric field adequate for focusing of a core flow in a confluence channel is obtained by the experiment. The computer simulation is performed to obtain the width and the depth of the core flow for several junction angles of the confluence channel.

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Improvement of the On-Current for the Symmetric Dual-Gate TFT Structure by Floating N+ Channel

  • LEE, Dae-Yeon;Hwang, Sang-Jun;Park, Sang-Won;Sung, Man-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.342-344
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    • 2005
  • We have simulated a symmetric dual-gate TFT which has triple floating n+ channel to improve the on-current of the dual-gate TFT. We achieved a low hole concentration at the source and channel junction causes the improvement the potential barrier so that we observed the reduction of the kink-effect. In this paper, we observed the reduction of the kink-effect compared with the conventional single-gate TFT and the improvement of the on-current compared with the conventional dual-gate TFT.

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A Design of the Diplexer for Satellite Transponder using Waveguide E-plane Discontinuities (도파관 전계면 불연속 구조를 이용한 위성 중계기용 다이플렉서의 설계)

  • 최상윤;강우정;이상웅;최성진;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.4
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    • pp.1-10
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    • 1993
  • This paper presents the designing/manufacturing scheme of the diplexer for satellite transponder which is composed of 2-channel bandpass filters, coupled with E-plane T-junction, having symmetrical waveguide E-plane step discontinuity structures. The 2-channel bandpass filters of the diplexer are designed by the scheme of connecting ${\lambda}_{g}$/2 shunt stub to the waveguide E-plane, playing the role of heat sinks without attaching a special heat sinks and to give the profitable productivity and allow the low-cost manufacturing at mass production, tuning screws are eliminated which have been used to compensate the operating characteristics of manufactured filters. The 2 channel bandpass filters of manufactured 14/12 GHz diplexer for domestic Ku-band satellite transponder have the return loss of 25 dB, insertion loss of 0.3 dB in passband, and below-50 dB of stopband characteristics (T$_{x}$ : f$_{o}{\pm}$250 MHz, R$_{x}$ : f$_{o}{\pm}$220 MHz) at room temperature.

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