• Title, Summary, Keyword: dielectric

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The Simulation of Electric Field Distribution for Globular Dielectric in the Atmosphere (대기중에서 구(球)형 유전체의 전계 분포 시뮬레이션)

  • 이동훈;박재윤;박홍재;고희석
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.7
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    • pp.305-309
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    • 2003
  • This paper was shown the simulation of electric field distribution of globular dielectric for design of ideal packed-bed plasma reactor. When discharge gap between the electrodes and input voltage are each 20[mm]. 10000[V] in the atmosphere, the results of simulation to the electric field was measured stronger at globular dielectric of $\phi$5[mm] than 1$\phi$[mm] and 3.33$\phi$[mm]. And the maximum electric field or globular dielectric with $\phi$10[mm] was increased about 5[%] to maximum electric field of globular dielectric with $\phi$5[mm] in the atmosphere. when dielectric constant of globular dielectric is 100, it was simulated about 90[%] of maximum electric field of globular dielectric over 1000 dielectric constant. Ana the highest electric field appeared as globular electric was parallel structure with the other globular dielectric side by side of the globular dielectric and connected to electrodes.

Design of a Cylindrical Dielectric Resonator Antenna with a Dielectric Clad (유전체 클래드를 갖는 원통형 유전체 공진 안테나 설계)

  • 이권익;김흥수
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.4
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    • pp.54-59
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    • 2003
  • In this paper, a cylindrical dielectric antenna with dielectric clad is designed and analyzed. Design parameters of a cylindrical dielectric resonator antenna are calculated from the wave equation of cylindrical dielectric. The variations of characteristics of the antenna are analyzed as varying the thickness and the relative permittivity of its clad. From the results, when the ratio of the outside radius of the dielectric clad to the radius of the cylindrical dielectric is 1.3 and the relative permittivity of the dielectric clad is one-third of the cylindrical dielectric resonator antenna, the relative bandwidth of the antenna is 49%, which is improved by 2.3 times than the cylindrical dielectric resonator antennas. However, the thickness and the relative permittivity of the dielectric clad have not effect on the radiation pattern, beamwidth and gain of the antenna.

High-Performance Amorphous Indium-Gallium Zinc Oxide Thin-Film Transistors with Inorganic/Organic Double Layer Gate Dielectric

  • Lee, Tae-Ho;Kim, Jin-U;No, Yong-Han
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.465-465
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    • 2013
  • Inorganic 물질인 SiO2 dielectric 위에 organic dielectric PVP (4-vinyphenol)를 spin coating으로 올려, inorganic/organic dielectric 형태의 double layer구조로 High-performance amorphous indiumgallium zinc oxide thin-film transistors (IGZO TFT)를 제작하여 보았다. SiO2 dielectric을 buffer layer로 80 nm, PVP는 10Wt% 400 nm로 구성하였으며, 200 nm single SiO2 dielectric과 동일한 수준의 leakage current 특성을 MIM Capacitor 구조를 통해서 확인할 수 있었다. 이 소자의 장점은 용액공정의 도입으로 공정 시간의 단축 및 원가 절감을 이룰 수 있으며, dielectric과 channel 사이의 균일한 interface의 형성으로 interface trap 개선 및 Yield 향상의 장점을 갖는다. 우리는 실험을 통해서 SiO2 buffer layer가 수직 electric field에 의한 leakage current을 제어하고, PVP dielectric은 interface를 개선하는 것을 확인하였다. Vth의 negative shift 및 slope의 향상으로 구동전압이 줄어들고, 균일한 I-V Curve 형성을 통해서 Process Yield의 향상을 확인하였다.

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A Study on the Dielectric Strength of Composite Materials(I) (복합재료의 전기적 절연특성과 개발에 관한 연구(I))

  • 정은식;강창남;박정후
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.34 no.8
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    • pp.323-330
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    • 1985
  • Dielectric loss tangent and ac dielectric strength of GFRP (Glass Fiber Reinforced Plastics, G-10)was investigated as parameters of mechanical and thermal stresses, in order to study the basic dielectrical characteristics of composite insulating materials. The dielectric loss tangent was increased and the ac dielectric strength was decreased with increase in the mechanical stresses beyond the mechanical yield point on account of fiber-matrix debonding, but the dielectric constant was not varied sigificantly. the dielectric strength of G-10 was about 2 MV/cm and the dielectric constant was about 4.8.

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A Dielectric Measurement Technique of Thin Samples at Microwave Frequencies (마이크로파에서 얇은 유전체의 유전상수 및 유전손실의 측정방법에 대한 연구)

  • Kim, Jin-Hun
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.12
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    • pp.1582-1585
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    • 1988
  • A cavity perturbation technique is employed to determine the dielectric property of thin samples. Substrates in microwave integrated circuits are fabricated in sheet form and are expected to have a dielectric constant less than 10 and a dielectric loss better than 10**-3. This research aimed to determine both dielectric constant and dielectric loss with good accuracy. The tecynique makes use of thin circular disk samples placed in a right circular cylindrical cavity. The accuracy of measurements is within \ulcorner% for dielectric constnat and 3x10**-4 for dielectric loss.

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Numerical Method for Computing the Resonant Frequencies and Q-factor in Microwave Dielectric Resonator

  • Kim, Nam-young;Yoo, Hojoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.245-248
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    • 1997
  • The dielectric resonators(DRs) with dielectric properties are widely used in microwave integrated circuit(MICs) and monolithic microwave integrated circuits(MMICS). The variational method as numerical simulation scheme would be applied to calculate the resonant frequencies(fr) and Q-factors of microwave dielectric resonators. The dielectric resonator with a cylindrical “puck” structure of high dielectric material is modeled in this simulation. The parameters, such as the diameter, the height, and the dielectric constant of dielectric resonator, would determine the resonant frequency and the Q-factor. The relationship between these parameters would effect each other to evaluate the approximate resonant frequency. This simulation method by the variational formula is very effective to calculate fr, and Q-factor. in high frequency microwave dielectric resonator The error rate of the simulation results and the measured results would be considered to design the microwave dielectric resonators.

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The Thickness Change of the Phosphor Ink Layer and the Dielectric Ink Layer of a Inorganic Powder EL Lamp That was produced by Screen Printing Technique (스크린 인쇄 기법에 의해 제작된 분산형 무기 EL 램프의 형광층 및 유전층의 두께 변화)

  • Moon, Kil-Hwan;Kang, Young-Reep
    • Journal of the Korean Printing Society
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    • v.29 no.2
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    • pp.83-92
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    • 2011
  • A inorganic powder EL lamp was made by screen printing technique with phosphor ink and dielectric ink. The thickness change of a phosphor ink layer and a dielectric ink layer were not influenced on dielectric content, but rely on phosphor size and vehicle. Once finishing screen printing technique with phosphor ink and dielectric ink, and its surface has been printed again before not drying of phosphor ink and dielectric ink. Then phosphor ink and dielectric ink were not transferred. The electric capacity of inorganic powder EL lamp was more influenced on dielectric content than the thickness of dielectric ink layer, and it was more dependent on the thickness of phosphor ink layer than the thickness of dielectric ink layer.

Study on electro-optical characteristic of FFS mode using LC with a positive dielectric anisotropy according to the magnitude of dielectric anisotropy (양의 액정을 사용하는 FFS mode에서 액정의 유전율 이방성에 따른 전기 광학 특성 연구)

  • An, Young-Joo;Park, Ji-Woong;Jung, Jun-Ho;Lee, Hee-Kyu;Lee, Seung-Eun;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.399-400
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    • 2008
  • The light efficiency of fringe-field switching (FFS) mode when using a liquid crystal (LC) with positive dielectric anisotropy was found to be dependent on the magnitude of dielectric anisotropy, such that the lower dielectric anisotropy, the higher. We studied out not only light efficiency but also response time according to dependence on the magnitude of dielectric anisotropy. Rising and decay time became fast and slow respectively according to decreasing the magnitude of dielectric anisotropy. This paper investigates electro-optical characteristic of FFS mode using LC with a positive dielectric anisotropy dependent on the magnitude of dielectric anisotropy of the LC.

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Dependence of Ozone Generation in a Micro Dielectric Barrier Discharge on Dielectric Material and Micro Gap Length

  • Sakoda, Tatsuya;Sung, Youl-Moon
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.5
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    • pp.201-206
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    • 2004
  • In order to investigate the optimum conditions for the effective ozone formation in a dielectric barrier discharge, measurements of ozone concentration were carried out for various conditions such as the gap length, the dielectric material and the operating gas. It was found that the optimum discharge conditions differed exceedingly in the types of operating gases and dielectric materials. In dry air, dielectric material with low dielectric constant and thermal conductivity, which might contribute to the restriction of the gas temperature rise in the discharge region, proved effective in obtaining both high ozone yield and concentration. The optimum gap length was considered to be in the range of 600-800 mm. In oxygen, using a quartz glass disk as a dielectric material, the required condition to obtain the high ozone yield and concentration was expanded.

The Simulation of Electric Field Distribution of Dielectric Tube with Single Layer and Globular Dielectric in Water (수중에서 구형 유전체와 단층 절연 방전관의 전계 분포 시뮬레이션)

  • Lee, Dong-Hoon;Park, Jae-Youn;Lee, Jae-Dong;Park, Hong-Jae;Koh, Hee-Seog
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.1119-1122
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    • 2003
  • In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric in water was simulated. The reactor was made up of the spherical dielectric that is diameter 2.5[mm], ${\epsilon}_r$ : 5, 100, 1000, 5000 respectively and one glass plate being 2[mm] thickness, ${\epsilon}_r$ : 5 as electrode. The discharge gap was 7[mm]. As a result of the simulation, in case of being about the same value between the dielectric constant of spherical dielectric and water, when the reactor was applied to high voltage dielectric polarization characteristic was trending toward disappearance. To get more strong electric field, the dielectric constant should be higher comparatively, Increasing the spherical dielectric constant, the location of equippotential line was shifting from the interior to the exterior.

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