• Title, Summary, Keyword: Dielectric material

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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 Study on Dielectric layer Design and Manufactor for Luminance Improvement of Red Organic Light Emitting Device (적색 유기발광소자의 휘도향상을 위한 Dielectric layer 설계 및 제작에 관한 연구)

  • Ki, Hyun-Chul;Kim, Seon-Hoon;Kim, Doo-Gun;Kim, Sang-Gi;Jeong, Haeng-Yun;Choi, Young-Sung;Hong, Kyung-Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.5
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    • pp.918-921
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    • 2010
  • We have proposed an dielectric layer to improve the luminance of red organic light emitting device. Here, we have calculated refractive index of dielectric layer material that was revised refractive index of organic material, ITO and glass. Refractive index of dielectric layer material was 1.711. The structure of dielectric layer was designed in organic material/ITO/dielectric layer/glass. Dielectric material changed thickness that deposited by ion-assisted deposition system. Transmittances of ITO were 95.66-98.85 [%]. Red OLED was fabricated with the structure of TPD($400[{\AA}]$)/DCMII($20[{\AA}]$), Rubrene($20[{\AA}]$)/Alq3($500[{\AA}]$)/LiF($15[{\AA}]$)/Al($1,000[{\AA}]$). Turn-on voltage and Luminance of Red OLED were 10 [V] and 5,857 cd/m2.

A Small Composite Right/Left-Handed Transmission Line Metamaterial Antenna Using a Magneto-Dielectric Material (Magneto-Dielectric Material을 이용한 소형 Composite Right/Left-Handed Transmission Line Metamaterial 안테나)

  • Jang, Kyung-Duk;Kim, Jae-Hee;Kim, Gi-Ho;Seong, Won-Mo;Park, Wee-Sang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.2
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    • pp.223-230
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    • 2008
  • A CRLH-TL based compact metamaterial antenna on a magneto-dielectric material is proposed. The proposed antenna is composed of two patches and vias, which is loaded by a magneto-dielectric material constructed by SRRs. The characteristic of SRRs is studied, and the size reduction of the antenna by using the magneto-dielectric material is confirmed. The simulated resonant frequency of the antenna has showed a decrease of 7.13 % at - 1st-order resonant mode, and 23.9 % at zeroth-order resonant mode. A zeroth-order resonant antenna is fabricated and measured, which has a resonant frequency of 1.888 GHz, a bandwidth of 0.48 %, a gain of 0.534 dBi, and an efficiency of 51.7 %.

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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Ultransonic Effect on the Break-Down Characteristics of Liquid Dielectrics (액체유도체의 절연특성에 미치는 초음파의 영향)

  • Choon Saing Jhoun;Hong Keun Kim;Bong Sik Hong
    • 전기의세계
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    • v.26 no.4
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    • pp.61-67
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    • 1977
  • This paper treats the Ultrasonic effects on the break down characteristics of Liquid Dielectric Material 1) Relative Dielectric constant, Es of Liquid Dielectric Material at a constant temperature decreases in proportion to the irradiated time of Ultrasonic radiation and its intensity, and reaches to a certain saturated value. The saturated value varies with the intensity of Ultrasonic radiation. 2) Power factor of Liquid Dielectric Material at a constant temperature increases in proportion tothe irradiated time of Ultrasonic radiation and its intensity, and reaches to a certain saturated value. The saturated value varies with the intensity of Ultrasonic radiation. 3) Relative resistance of Liquid Dielectric Material at a constant temperature decrease with the irradiated time of Ultrasonic radiation, but the effect of its intensity is very irregular. 4) Break-down strength of Liquid Dielectric Material, at a constant temperature decreases with the irradiated time of Ultrasonic radiation and its intensity, and then reaches to a saturated value.

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The structural and dielectric polarization characteristics of composite oxide material in $(Ba Ca)TiO_3$-Zn (복합산화물 $(Ba Ca)TiO_3$-ZnO의 구조적 및 유전분극 특성)

  • 홍경진;임장섭;정우성;민용기;김용주;김태성
    • Electrical & Electronic Materials
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    • v.10 no.3
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    • pp.239-246
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    • 1997
  • The ZnO is stabilize dielectric constant over a broad temperature range because its addition makes the relaxation time short. In this study, the composite oxide material (B $a_{0.85}$ $Ca_{0.15}$)Ti $O_{3}$ was mixed by ZnO additive material and the dielectric polarization characteristics was studied. The relative density was over 90[%] at all specimen in the structural characteristics. Among of the specimen, the relative density of (B $a_{0.85}$ $Ca_{0.15}$)Ti $O_{3}$ with ZnO (0.4mol) has a 95[%]. The grain size of composite oxide material with an increasing ZnO increased and it was 1.0[.mu.m]-1.22[.mu.m]. In the electrical characteristics, the charge and discharge current was increased by ZnO addition. The dielectric relaxation time was increased by space charge polarization at above 110[.deg. C] and the dielectric relaxation time was fixed by space charge polarization of para-dielectric layer at below 110[.deg. C]. The dielectric relaxation time was maximum when the grain size was small. The dielectric relaxation time is decreased with an additive material ZnO and interface polarization, existing void at the grain and grain boundary. The remnant polarization is increased and the coercive electric field is decreased by ZnO.

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Dielectric Polymers for OTFT Application

  • Choi, Sung-Lan;Kim, Yeon-Ok;Kim, Hong-Doo
    • Journal of Information Display
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    • v.11 no.3
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    • pp.95-99
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    • 2010
  • A series of new dielectric polymers with phenyl, epoxy, and carboxylicacid functional groups was prepared via free-radical polymerization. The effect of such dielectric polymers with various functional groups on the performance of OTFT was investigated. The nonpolar groups of terpolymer made the surface of the dielectric layer more hydrophobic and improved the crystal growth of pentacene on the gate insulator, resulting in higher mobility. By controlling the functional group, the electric characteristics of OTFT performance was varied, with $0.00017-0.15\;cm^2/V{\cdot}s$ mobility.

Low Dielectric Constant Polymeric Materials for Microelectronics Applications (마이크로전자 응용에서의 저유전율 고분자 재료)

  • 이호영
    • Journal of the Microelectronics and Packaging Society
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    • v.9 no.3
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    • pp.57-67
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    • 2002
  • Increased signal speed can be obtained in three ways: changing the layout and/or the ratio of the width to thickness of the metal lines, decreasing the specific resistance of the interconnect metal, and decreasing the dielectric constant of the insulating material (intermetal dielectric). Further advancement cannot be expected from changing layout or decreasing specific resistance. The only alternative is to use an insulating material with a lower dielectric constant than other ones used presently. A large variety of polymers has been proposed for use as materials with low dielectric constants for applications in microelectronics. In this review, the properties of selected polymers as well as various fabrication methods for polymer thin films are discussed. Based on the properties described so far, and the requirements for applications as intermetal dielectric material, the possibilities for further developments also are discussed.

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A Study on the Dielectric Dispersion and Absorption of ITO/$Alq_3$/Al Thin Film (ITO/$Alq_3$/Al 구조 박막의 유전분산과 흡수에 관한 연구)

  • Oh, Y.C.;Kim, S.J.;Sung, N.J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.490-491
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    • 2007
  • We have investigated dielectric dispersion and absorption in organic light-emitting diodes using 8-hydroxyquinoline aluminum($Alq_3$) as an electron transport and emissive material. We analyzed the dielectric dispersion and absorption of organic light emitting diodes using impedance characteristics measurement by the auto-balancing bridge technique of ITO/$Alq_3$/Al. Impedance characteristics was measured complex impedance Z and phase e in the frequency range of 40Hz to $10^8Hz$. We obtained dielectric constant and loss tangent (tan $\delta$) of the device. From these analyses, we are able to interpret a dielectric dispersion and dielectric absorption contributed by an interfacial and orientational polarization.

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Dielectric Characteristics of Polytetrafluoroethylene-based Composites for Microwave Substrates with Formation Pressure (고주파 기판용 PTFE 복합체 형성 압력에 따른 유전 특성)

  • Choi, Hong Je;Chun, Myung Pyo;Cho, Yong Soo;Cho, Hak Rae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.6
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    • pp.429-433
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    • 2013
  • PTFE composites for use of microwave substrate were fabricated by impregnation and heat treatment fabrication with glass fabric. This study shows dielectric properties such as dielectric constant and loss can be controlled by thickness of PTFE composite with change of pressure condition in heating press process. The dielectric constant of the PTFE composites has decreasing tendency as given higher pressure condition. The dielectric loss has similar result too. Especially, the case of the dielectric loss was affected by the condition of pressure at heating press and had the best performance under 3 MPa. In order to see the reason why thickness conditions make different, their microstructures were also observed.