• 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.

• 전기의세계
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• v.19 no.5
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• pp.8-16
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• 1970

The characteristics of dielectric absorption and dispersion in polymerized materials produced in Korea was investigated in MHz band and at several sets of temperature. For this study the theoretical basis stood on the Cole-Cole's empirical formula and it has been extended to the form convenient to investigate the observation. As the result, it has been confirmed that in most cases, two or much more sorts of dipole participate in dielectric propertics of these polymers and the materials containing aromatic molecular structure have, in general, greater loss angle than those constructed chain type molecular structure.

• Macromolecular Research
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• v.8 no.2
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• pp.53-58
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• 2000

Stabilities and structures of resorcinol formaldehyde resins (RF resins) and their dependence on solvent were studied by molecular mechanics and molecular dynamics. Dimers to decamers of the RF resins in the conditions of dielectric constant = 1.00, 21.01, 36.64, and 80.10 were calculated. The average distance between oxygen atoms in 1-hydroxyl groups of adjacent resorcinols of the resins became longer with increased dielectric constant of the environment. The number of intramolecular hydrogen bonds of the resins decreased by increasing the dielectric constant of the environment. The RF resin structure on the surface of fabric or steel cord was explained based on the present calculation.

• Transactions on Electrical and Electronic Materials
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• v.7 no.2
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• pp.67-71
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• 2006

In this paper, we have investigated the structure and dielectric properties of the $(Ba_{0.6}Sr_{0.4})TiO_3$ (BST) thin films fabricated on MgO(100)/Si substrate by an alkoxide-based sol-gel method. Both the structure and morphology of those films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). For the MgO(100)/Si substrate, the BST thin films exhibited highly (100) orientation. The highly (100)-oriented BST thin films showed high dielectric constant, tunability, and figure of merit (FOM). The dielectric constant, dielectric loss and tunability of the BST thin films annealed at $700^{\circ}C$ deposited on the MgO(100)/Si substrate measured at 10 kHz were 515.9, 0.0082, and 54.3%, respectively.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.129-135
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• 2007

In this paper, we present a set of numerical schemes to solve the Muller integral equation for the analysis of electromagnetic scattering from arbitrarily shaped three-dimensional (3-D) dielectric bodies by applying the method of moments (MoM). The piecewise homogeneous dielectric structure is approximated by planar triangular patches. A set of the RWG (Rao, Wilton, Glisson) functions is used for expansion of the equivalent electric and magnetic current densities and a combination of the RWG function and its orthogonal component is used for testing. The objective of this paper is to illustrate that only some testing procedures for the Muller integral equation yield a valid solution even at a frequency corresponding to an internal resonance of the structure. Numerical results for a dielectric sphere are presented and compared with solutions obtained using other formulations.

• Electrical & Electronic Materials
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• v.10 no.7
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• pp.651-658
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• 1997

In this paper, effect of interpenetrating polymer network(IPN) introduction on the dielectric properties, heat proof properties, internal structure and defects of the Epoxy/SiO$_2$composite materials, were investigated. we reported a relation between network structures and electrical properties, especially dielectric characteristics with variation of network structures for epoxy composite materials. According to experimental results, the specimens which have single network structures have lower dielectric constant than interpenetrating polymer network(IPN) specimens, but have relatively larger dependency to variation of temperature and frequency. It was confirmed that change of structures is attained by introducing of IPN to insulating materials. Therefore it is counted that introduction of multiple structure including IPN is necessary to improve heat proof and electrical properties.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.167-170
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• 2021

Integrated passive device (IPD) technology has emerged with the need for 5G. In order to integrate and miniaturize capacitors inside IPD, various studies are actively performed using high-k materials and trench structures. In this paper, an EM(Electromagnetic) simulation study was performed by applying an oxide dielectric to the capacitors having a various trench type structures. Commercially available materials HfO₂, Al₂O₃, and Ta₂O₅ are applied to non, circle, trefoil, and quatrefoil type trench structures to confirm changes in each material or structure. As a result, the bigger the capacitor area and the higher dielectric constant of the oxide dielectric, the insertion loss tended to decrease.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.237-238
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• 2006

The electrical properties such as dielectric constants and dielectric losses in the spinel samples of $LiGaTiO_4$, Li(Ga,Eu)$TiO_4$, $Li(Ga.Yb)TiO_4$ have been characterized by varying measuring temperature and frequency. The long range order structures are analyzed by rietveld refinement method. and local atomic disorder structures are analyzed by MEM (maximum entropy method). The relation between the crystal structure and dielectric properties are discussed. $LiGaTiO_4$ spinel has the IMMA with lattice constant, a = 5.86333, b=17.5872. c = 8.28375 ${\AA}$, Li-sites are partially substituted by Ga or Ti. Two crystallographic oxygen sites are partially occupied(40~50%). The dielectric constants of $LiGaTiO_4$, $LiYbTiO_4$, and $LiGa_{2/6}Eu_{1/6}Ti_{1.5}O_4$ ceramics were 127, 75 and 272, respectively at 100 kHz. The dielectric relaxation were observed in the $LiGaTiO_3$ ceramics and the temperature where dielectric loss shows maximum was $390^{\circ}C$ at 1 kHz and increased with increasing the measuring frequency.

• Journal of the Korean Ceramic Society
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• v.44 no.10
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• pp.537-541
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• 2007

Microwave dielectric properties of $0.95 Ca_{0.85}Nd_{0.1}TiO_3-0.05LnAlO_3$ (Ln=Sm, DH, Er) were investigated as a function of sintering temperature and lanthanide ion type. A single perovskite phase with an orthorhombic structure was obtained throughout the entire range of composition. The dielectric constant (K) was dependent upon the dielectric polarizabilities and the B-site bond valence in the $ABO_3$ perovskite structure. The quality factor (Qf) of the specimens with $ErAlO_3$ was smaller than those with $SmAlO_3\;and/or\;DyAlO_3$ due to the smaller grain size. The temperature coefficient of resonant frequency (TCF) could be controlled from $107.28ppm/^{\circ}C$ at Ln=Sm to $87.23ppm/^{\circ}C$ at Ln=Er due to the changes of B-site bond valence in the $ABO_3$ perovskite structure.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.165-168
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• 2005