• Title, Summary, Keyword: Dielectric material

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Measurement of High Temperature Dielectric Property at Microwave Frequency Using Cavity Perturbation Method (Cavity Perturbation Method를 이용한 마이크로파 주파수대의 고온 유전특성 측정 연구)

  • Kim, Dong-Eun;Jung, Jin-Ho;Lee, Sung-Min;Kim, Hyung-Tae
    • Journal of Korean Powder Metallurgy Institute
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    • v.13 no.6
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    • pp.455-461
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    • 2006
  • High temperature dielectric constants of the various ceramic materials have been measured using cavity perturbation method. The measurements were applied to refractory, traditional and fine ceramic powder compacts from room temperature to $1200^{\circ}C$. Calibration constant in the equation suggested by Hutcheon et al., was determined from the dielectric constants of reference specimen (teflon and alumina) at room temperature. From these results, informations on the refectory materials were obtained for the microwave kiln design and understanding of the microwave heating effects of ceramics have been improved.

Effect of Sintering and Tunable Dielectric Properties of BST Thick Films with MgO addition (MgO를 첨가한 $Ba_xSr_{1-x}TiO_3$ 후막의 소결거동과 가변 유전특성)

  • Jeon, So-Hyun;Kim, In-Sung;Song, Jae-Sung;Yoon, Jon-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.205-206
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    • 2006
  • (BaSr)$TiO_3$ thick films were prepared by tape casting method, using $BaTiO_3$ and $SrTiO_3$ powder slurry in order to investigate dielectric properties. With MgO additives, the sintering density was 5.8 $g/cm^3$ and the BST sample exhibited the maximum dielectric constant, tunability at temperatures near phase transition point. Dielectric loss be on the decrease because the interface is not a pore. BST sample be applicable on tunable device.

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Dielectric Properties of BSCT Ceramics for Phase Array Antenna (위상차 배열 안테나용 BSCT 세라믹스의 유전특성)

  • 조현무;이성갑;임성수;박인길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.989-992
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    • 2001
  • (Ba$\sub$0.6-x/Sr$\sub$0.4/Ca$\sub$x/)TiO$_3$(x=0.10, 0.15, 0.20) specimens were fabricated by the solid state reaction method and then the structural and dielectric properties as a function of the composition ratio and sintering temperature were studied. The BSCT(50/40/10) specimen sintered at 1500$^{\circ}C$ showed the highest average grain size(18.25 ${\mu}$m). The Curie temperature and dielectric constant at room temperature decreased with increasing Ca content. The dielectric constant and dielectric loss of the BSCT(50/40/10) specimen, sintered at 1450$^{\circ}C$, were about 4324 and 0.972% at 1KHz, respectively. Dielectric constant at room temperature decreased with increasing an applied field, tunability of the BSCT(50/40/10) sintered at 1300$^{\circ}C$ was 18%.

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Dielectric Properties Analysis in Paraelectric $ZrTiO_4$Thin Films (상유전 $ZrTiO_4$박막의 유전특성 분석에 관한 연구)

  • 허진희;김경해;이준신
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.547-549
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    • 2001
  • The dielectric constants and dielectric losses of ZrTiO$_4$thin films deposited by DC magnetron reactive sputtering were investigated. The paraelectric properties were measured in the 100kHz range. As the deposition temperature increased (up to 67$0^{\circ}C$), the dielectric losses (tan$\delta$) decreased (down to 0.017$\pm$0.007), while the dielectric constants ($\varepsilon$) were in the range of 35$\pm$7. Post annealing at 80$0^{\circ}C$ in oxygen for 2h reduced tan$\delta$ down to 0.005$\pm$0.001, higher than those of well-sintered bulk ZrTiO$_4$.

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The Microwave Measurement of the Dielectric Properties of Low-Loss Materials by the Dielectric Rod Resonator Method (마이크로파에서 Dielectric rod resonator method에 의한 저유전 손실 물질의 유전 특성 측정에 관한 연구)

  • 심화섭;이한영;김근영;김진헌
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.21-25
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    • 1989
  • Theory and experimental results are presented to show the possibility of using a dielectric rod resonator method for characterizing dielectric materials at microwave frequency. The measuring structure is a resonator made up of a cylindrical dielectric rod placed between two parallel conducting plates. In this system, the TE$\_$011/ mode frequency was adapted to minimize the effect of the air-gap between the rod and the conducting plates. The dielectric properties are computed from the resonance frequencies, structure dimensions and 3-dB bandwidth.

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A Study on Dielectric Properties of Printed Circuit Board(PCB) Materials with Variation of Frequency and Temperature using Coaxial Air Line Probe (동축선로 프로브를 이용한 프린트 배선 회로용 기판 재료의 주파수 및 온도 변화에 따른 유전특성 연구)

  • 박종성;김종헌
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.187-190
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    • 1998
  • In this paper a probe for the' measurement of dielectric properties of dielectric sheet materials is designed and implemented as a coaxial air line type. Using the broadband impedance method with this measurement probe the dielectric constant and loss tangent of the glass-epoxy and teflon are determined in the frequency range of 0.1 - l.O[GHz] with the temperature variation from $25[^{\circ}C]$ up to $65[^{\circ}C]$. A measured relative dielectric constant of the glass-epoxy is 4.42 and a loss tangents is 0.019 relatively, and the relative dielectric constants of teflon is 2.17 and a loss tangents is 0.002 relatively

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Dielectric Characteristics of Silicone Rubber for Insulators (애자용 실리콘 고무의 유전특성)

  • 이상민;신현택;변두균;신종열;이창형;이충호;홍진웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.451-454
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    • 2002
  • A silicone rubber has been used so many dielectric materials for extremely high voltage(EBW) electric appliances. The reason why it is very stable in the thermal, mechanical and electrical environment. In this paper, we have studied the dependence of dielectric characteristics of silicone rubber on frequency-dependent variation. The dielectric characteristics were measured in the temperature range of 25[$^{\circ}C$] and 150[$^{\circ}C$]. Also we measured in the voltage range of 1[V] and 20[V]. The energy of activation on the dielectric loss obtained 2.44[kcal/mol], 2.1[kcal/mol], 1.63[kcal/mol] and 1.57[kcal/mol] by appling respectively.

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A Study on the Dielectric Properties of Epoxy Composites due to Temperature Variation (온도변화에 따른 에폭시 복합체의 유전특성에 관한 연구)

  • 김상걸;송봉철;정동회;이호식;이원재;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.148-151
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    • 2000
  • In this paper, the dielectric properties of epoxy composites used for transformers are studied. The dielectric permittivity and loss of specimen are measured at the temperature range of 20[$^{\circ}C$]~150[$^{\circ}C$] about frequency 30[Hz], 1[kHZ] and 30[kHz] respectively from a series of experiments. Consequently, observed higher values of dielectric permittivity and loss in filled epoxy are attributed to Maxwell-Wagner Polarization effect. Also, glass transition temperature was shifted to higher temperature and value of dielectric permittivity and loss were decreased due to 2nd curing.

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Piezo-controlled Dielectric Phase Shifter

  • Jeong Moon-Gi;Kim Beom-Jin;Kazmirenko Victor;Poplavko Yuriy;Prokopenko Yuriy;Baik Sung-Gi
    • Journal of electromagnetic engineering and science
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    • v.6 no.1
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    • pp.1-9
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    • 2006
  • A sandwich structure of dielectric material and air gap inside a rectangular waveguide is proposed as a fast electrically tunable low-loss phase shifter. As the dielectric material is shifted up and down by piezoelectric actuator and, thereby, the thickness of air gap is changed, the effective dielectric constant of the sandwich structure is varied. Phase shifters based on the sandwich structure with different dielectric materials showed phase shift of $20{\sim}200^{\circ}/cm$ at X-band as the thickness of air gap varied up to $30{\mu}m$. The idea can be extended toward low-loss millimeter wave phase shifters since modem microwave ceramics have been developed to show very low dielectric loss$(tan\;{\delta}{\sim}10^{-4})$.

The Dielectric Analysis of Insulators for Home Appliances (가전설비용 절연재의 유전열 분석)

  • Jung, Jin-Soo;Jung, Jong-Wook;Yi, Gun-Ho;Bae, Seok-Myung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.206-207
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    • 2006
  • This paper describes the dielectric analysis of several insulators for home appliances. The dielectric characteristics of ABS(acrylonitrile butadiene styrene) were tested in relative permittivity, dielectric loss($tan{\delta}$) and specific resistance and compared with those of the other 4 insulators of PE(polyethylene) series. As a result, the relative permittivity of only the ABS slightly decreased with temperature. In the case of the tan6, the ABS showed higher dielectric loss than the other insulators but more excellent thermal performance. In addition, its changing pattern in specific resistance was very similar to that in $tan{\delta}$.

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