• Title/Summary/Keyword: Parasitic characteristics

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A Case of Eucoleus aerophilus Infection in Jeju Weasel (Mustela sibirica quelpartis)

  • Han, Jeong-Hee;Yoon, Young-Min;Yang, Hyoung-Seok;Kim, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.34 no.5
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    • pp.384-387
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    • 2017
  • A dead male Jeju weasel with clinical signs of severe dehydration and moribund was submitted for the necropsy. Grossly, purple-red ecchymoses were scattered in the surface of the entire lungs. Milky-white mucoid materials occupied in the left bronchial lumens. Histopathologically, an adult worm with thick cuticle layer surrounded by chronic inflammatory cells was embedded in the left caudal lung lobe. Numerous oval or barrel-shaped parasitic eggs with muco-purulent exudates were observed in the dilated bronchus of another section of left caudal lobe. Operculate parasitic eggs showed typical morphologic characteristics such as barrel shape with asymmetry bipolar plugs and thick bi-layered wall. Based on the histopathologic findings and morphological characteristics of parasitic eggs in the pulmonary tissue section, this case was diagnosed as verminous pneumonia associated Eucoleus aerophilus infection in Jeju weasel.

Active Damping Characteristics on Virtual Series Resistances of LCL Filter for Three-phase Grid-connected Inverter (인덕터 내부저항을 고려한 LCL 필터의 능동댐핑 특성)

  • Kim, Yong-Jung;Kim, Hyosung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.1
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    • pp.88-93
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    • 2016
  • LCL filters are widely used in high-order harmonics attenuation of output currents in grid-connected inverters. However, output currents of grid-connected inverters with LCL filters can become unstable because of the resonance of the filters. Given that the characteristics of output currents in inverters mostly depend on filter performance, the exact analysis of filters by considering parasitic components is necessary for both harmonics attenuation and current control. LCL filters have three or four parasitic components: the series and/or parallel resistance of the filter capacitor and the series resistance of the two filter inductors. Most studies on LCL filters have focused on the parasitic components of the filter capacitor. Although several studies have addressed the parasitic components of the filter inductor at the inverter side, no study has yet investigated the concurrent effects of series resistance in both filter inductors in detail. This paper analyzes LCL filters by considering series resistance in both filter inductors; it proposes an active damping method based on the virtual series resistance of LCL filters. The performance of the proposed active damping is then verified through both simulation and experiment using Hardware-in-the-Loop Simulator(HILS).

Small ESPAR Antenna with 180 Degree Azimuth Beam Coverage (180도 방위 빔 커버리지 특성을 갖는 UNII대역 소형 전자 빔 조향 기생 배열 안테나)

  • Choi, Ik-Guen;Ju, Sang-Ho
    • Journal of Korea Society of Industrial Information Systems
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    • v.15 no.2
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    • pp.11-16
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    • 2010
  • In this papar, we have proposed a small electronically steerable parasitic array radiator with 180 degree azimuth beam coverage and high gain characteristics. The proposed antenna is composed of a uniplanar Yagi dipole as a feeding element and two dipoles as parasitic elements. The fabricated antenna is tested by electronically changing the reactance loaded on the parasitic dipoles and the results show that it has 5.2dB~6.7dB gain in $-90^{\circ}{\sim}90^{\circ}$wide azimuth range and -10dB return loss characteristics within 5.725GHz~5.825GHz UNII band.

Wideband modulation analysis of a packaged semiconductor laser in consideration of the bonding wire effect (실장된 반도체 레이저의 본딩와이어를 고려한 광대역 변조 특성 해석)

  • 윤상기;한영수;김상배;이해영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.2
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    • pp.148-162
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    • 1996
  • Bonding wires for high frequency device packaging have dominant parasitic inductances which limit the performance of semiconductor lasers. In this paper, the inductance sof bonding wires are claculated by the method of moments with incorporation of ohmic loss, and the wideband modulation characteristics are analyzed for ddifferent wire lengths and structures. We observed the modulation bandwidth for 1mm-length bonding wire lengths and structures. We observed the modulation bandwidth for 1mm-length bonding wire is 7 GHz wider than that for 2mm-length bonding wire. We also observed th estatic inductance calculation results in dispersive deviation of the parasitic inductance and the modulation characteristics from the wideband moment methods calculations. The angled bonding wire has much less parasitic inductance and improves the modulation bandwidth more than 6 GHz. This calculation resutls an be widely used for designing and packaging of high-speed semiconductor device.

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Circuit Performance Prediction of Scaled FinFET Following ITRS Roadmap based on Accurate Parasitic Compact Model (정확한 기생 성분을 고려한 ITRS roadmap 기반 FinFET 공정 노드별 회로 성능 예측)

  • Choe, KyeungKeun;Kwon, Kee-Won;Kim, SoYoung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.10
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    • pp.33-46
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    • 2015
  • In this paper, we predicts the analog and digital circuit performance of FinFETs that are scaled down following the ITRS(International technology roadmap for semiconductors). For accurate prediction of the circuit performance of scaled down devices, accurate parasitic resistance and capacitance analytical models are developed and their accuracies are within 2 % compared to 3D TCAD simulation results. The parasitic capacitance models are developed using conformal mapping, and the parasitic resistance models are enhanced to include the fin extension length($L_{ext}$) with respect to the default parasitic resistance model of BSIM-CMG. A new algorithm is developed to fit the DC characteristics of BSIM-CMG to the reference DC data. The proposed capacitance and resistance models are implemented inside BSIM-CMG to replace the default parasitic model, and SPICE simulations are performed to predict circuit performances such as $f_T$, $f_{MAX}$, ring oscillators and common source amplifier. Using the proposed parasitic capacitance and resistance model, the device and circuit performances are quantitatively predicted down to 5 nm FinFET transistors. As the FinFET technology scales, due to the improvement in both DC characteristics and the parasitic elements, the circuit performance will improve.

Optimum Return Loss of Right-Angle Triangular Slot Antenna

  • Tangkaphiphop, K.;Anantrasirichai, N.;Wakabayashi, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.466-469
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    • 2004
  • In this paper, we improve the matching impedance of antennas by inserting parasitic slots on the ground plane of right-angle triangular slot antennas. The designed antennas characteristics are analyzed by using Finite Different Time Domain (FDTD) method, the specific design frequency is 10 GHz and match impedance is 50 ohms. Simulation results show that the efficient of return loss and radiation patterns are improved and enhance. In this case, the right-angle triangular slot antennas with parasitic slots have matching impedance better than antennas without parasitic slots.

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Novel Design of A Wideband Folded Monopole Antenna with Parasitic Element for DVB-H Application

  • Jeon, Seung-Gil;Ryu, Kwang-Woo;Choi, Jae-Hoon
    • Journal of electromagnetic engineering and science
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    • v.7 no.3
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    • pp.116-121
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    • 2007
  • Novel design of a wideband monopole antenna for DVB-H service is presented. The proposed antenna is designed based on a monopole antenna. It consists of folded monopole and parallel parasitic element. The folded segment of the folded monopole makes the antenna shorter. The length of the parasitic element obtains additional resonance frequencies. The gap distance between the folded monopole and the parasitic element is a key parameter to control impedance matching for wideband operation. The antenna has wide band performance, good impedance and radiation characteristics from 470 MHz to 870 MHz. The measured return loss for operating frequencies over DVB-H band is better than 10 dB. Good radiation patterns are also obtained. The measured results are compared with calculated results using Ansoft HFSS(High Frequency Structure Simulator).

A Triple-Band Printed Dipole Antenna using Parasitic Elements for Multiple Wireless Services

  • Chang, Ki-Hun;Kim, Hyung-Rak;Hwang, Kwang-Sun;Yoon, Ick-Jae;Yoon, Young-Joong
    • Journal of electromagnetic engineering and science
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    • v.4 no.1
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    • pp.8-12
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    • 2004
  • In this paper, a triple-band printed dipole antenna using parasitic elements is proposed for the multiple wireless services. The proposed antenna is designed and experimentally analyzed at the bands of PCS, IMT-2000, and ISM services. To achieve triple frequency operation, the proposed antenna contains two parasitic elements, which act as additional resonators by coupling from the driving dipole antenna. From the measured results, the resonant frequencies of this antenna are 1.79 ㎓, 2.03 ㎓, and 2.41 ㎓ and the measured impedance bandwidths are 90 MHz(1760∼1850 MHz), 210 MHz(1,930∼2,130 MHz), and 30 MHz(2,400∼2,430 MHz) for VSWR<2. The measured antenna gains are 2.14 ㏈i, 0.9 ㏈i, and 0.5 ㏈i, respectively. Antenna parameters for trifle-band operation are investigated and several antenna characteristics are discussed.

Design of the Multi-band Monopole Antenna using a Parasitic branch (기생 가지를 이용한 다중대역 모노폴 안테나 설계)

  • Choi, Jong-Kyun;Kim, Che-Young;Park, Jeung-Keun;Choi, Won-Jun
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.155-156
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    • 2007
  • A wideband monopole antenna using a parasitic branch is proposed for allowing operations at multiple frequency bands specified in GSM($824{\sim}894MHz$), PCS($1750{\sim}1870MHz$), WiBro($2.3{\sim}2.4GHz$), WLAN/ISM ($2.4{\sim}2.48GHz$) and SDMB($2.605{\sim}2.655GHz$). We have used two branch monopoles and the one parasitic branch. Prototype of the multiband antenna have been successfully implemented and good radiation characteristics the operating frequency bands have been obtained. The effect of a parasitic branch was also studied.

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MOSFET Characteristics with Channel Variation fabricated by $0.35-{\mu}m$ Process ($0.35{\mu}m$공정을 이용하여 제작된 MOSFET의 채널 변화에 따른 특성연구)

  • Kang, Jung-Han;Ahn, Min-Su;Yun, Il-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.47-48
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    • 2006
  • In this paper, intrinsic n channel MOSFETs with external parasitic components are modeled. Using sensitivity analysis, effective parasitic components are tested and the optimized model is extracted. The extracted model is fitted to the measured S-parameters with different channel width. Based on this methodology, this method, external parasitic components that affect MOSFET operations can be analyzed and modeled.

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