• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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• pp.109-122
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• 2002

The standard capacitor must have not only precise value of the capacitance but also the basic properties of low dielectric loss tangent. In the reforming process of capacitors, the dielectric loss tangent must be also reformed. In this paper, the development of standard capacitors of 10 and 100pF for the dielectric loss tangent standard using $Al_{2}O_{3}$ Crystal and the measurement of dielectric loss tangent are discussed. The dielectric loss tangent depends upon the surface between electrode and dielectric in capacitor. With using the Electric Field Simulator, precise design values of electrode are simulated. For the purpose of measuring capacitance effect just in the dielectric, 3-Terminal and 4-Terminal Pair configuration are applied respectively at the electrode and the connector for the measuring equipment. As stated above method, the standard capacitors of 10 and l00pF for the establishment of the dielectric loss tangent standard using the $Al_{2}O_{3}$ Crystal are made with low dielectric loss tangent less than 10-4.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1466-1468
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• 1996

The standards of the capacitance arc measured and analyzed by the dry nitrogen or mica film as a dielectric. In this paper, respectively the standard capacitors of 10 pF and 100 pF for the establishment of the dielectric loss tangent are made by $Al_{2}O_{3}$ crystal disc with the low dielectric loss tangent, and then measured the dielectric loss tangent with precision. To regard for the existence of capacitances just in the dielectric, 3-terminal configuration electrode is used. With using the 2D electric field simulator, precise design values are derived in addition to stray capacitance. As stated above method, respectively the standards of the capacitances with 10 pF and 100 pF arc made with the low dielectric loss tangent less than $10^{-4}$.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.847-851
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• 2014

The characteristics of dielectric constant and $tan{\delta}$ of low viscosity silicone oils with changing degree of polymerization were investigated. The result shows dipole loss mechanism at low temperature range. The dielectric loss in the range of low frequencies are predominantly of ionic nature with temperature increase. The peak of dielectric loss is the detrapping of the electrons which is were trapped in the localized level of the silicone oils at the frequency of 30 kHz. The increase of ionic conduction is attributed to the presence of ionizable oxidation products and their increased dissociation feature. The activation energy ${\Delta}H$ and dipole moment ${\mu}_d$ were increased whit increasing degree of polymerization.

• 한국전기전자재료학회논문지
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• 제11권11호
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• pp.1007-1013
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• 1998

In this paper, the dielectric properties of fabricated Polyvinylidene fluoride(PVDF, $PVF_2$) thin film with substrate temperature from 30 to at vapor deposition. The dielectric properties of PVDF thin film had been studied in the frequency range from 10Hz to 4MHz at measuring temperature between 20 and $100^{/circ}C$. The anomalous increasing in dielectric constant and dielectric loss at low frequencies and high temperature was described for PVDF thin film containing ion impurities. In particularly, ion mobility of fabricated PVDF thin film at substrate temperature at $30^{/circ}C$ decrease from $2\times10^{-5}\;to\;3.07$\times10^{-7}cm^2/V.s$ On the other hand, ion density increase abruptly from 1.49\times$$10^{13}$ to $1.5\times$10^{16}$cm^{-3}$ In spite of decreasing of ion mobility, dielectric constants and dielectric loss for PVDF thin film increase rapidly with decreasing frequency and high temperature. It was concluded that the dielectric constants and dielectric loss was related to ion density than to ion mobility at low frequency and high temperatures.

• International Journal of Computer Science & Network Security
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• 제24권7호
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• pp.118-122
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• 2024

The dielectric material is a basic element which impacts considerably on a microstrip structure performances. This project demonstrates how filter performances such as gain, bandwidth, return loss and insertion loss change proportionally with substrate material variation. The RT/Duroid 5880 and the FR-4 are two dielectric materials proposed as substrates of a low pass microstrip filter. The design and simulation are done on ADS software. The transmission and reflection characteristics show that the RT/ Duroid 5880 as a dielectric substrate permits to obtain better performance as compared to the FR-4 substrate.

• 한국조명전기설비학회지:조명전기설비
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• 제6권5호
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• pp.27-37
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• 1992

We studied the dielectric and dynamic mechanical losses according to the quenching condition in low density polyethylene being used to power cables. According to severe quenching condition, characteristics of the temperature in internal friction los peak have decreased the magnitude of loss peak as amorphous region lengthen. From now on, the frequency dependent characteristics of dielectric loss have investigated at room temperature, and the dielectric loss peak due to interface polarization, between crystal and amorphous region, occurs about 30[Hz], and that, the peak due to orientation polarization in correspondence to the loss peak in internal friction has observed at about 3 [MHz]. As quenching velocity increased, the effect on quenching condition about the dielectric loss has decreased the magnitude of the loss peak. Thus, estimation has been carried out on the activation energies nd the degree of crystallinity by means of X-ray diffraction are obtained as follows: room quenching : 26.4 [kal/mole] and 54.73 [%], ice quenching : 25.6 [kcal/mole] and 48.47 [%], liquid nitrogen quenching specimens : 22.56 [kcal/mole] and 40.95 [%].

• Journal of electromagnetic engineering and science
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• 제6권1호
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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$(tan\;{\delta}{\sim}10^{-4})$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.813-816
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• 2001

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 frequency range of 30[Hz]∼1[MHz] about temperature 20[$^{\circ}C$],100[$^{\circ}C$] and 140[$^{\circ}C$] respectively from a series of experiments. When the filler is added, between epoxy and silica is formed interface. Therefore, observed higher values of dielectric permittivity and loss in filled epoxy are attributed to MWS polarization effect. Also, glass transition temperature was shifted to higher temperature and value of dielectric permittivity and loss were decreased due to 2nd curing. Deformation of interfacial state is improved and value of dielectric permittivity and loss were decreased at low frequency region by the surface treatment of fillers with silane coupling agents.

• 대한전자공학회논문지
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• 제27권10호
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• pp.10-15
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• 1990

Dielectric rod resonator 방법을 이용하여 고주파 대역에서 낮은 유전 손실을 갖는 유전체의 유전 특성을 측정하는 이론과 실험결과를 보였다. 유전체 시편과 금속 도체판 사이에 존재하는 공기층 효과를 최소화하기 위해 $TE_{011}$ mode 공진 주파수를 이용하였다. 컴퓨터를 사용하여 공진 주파수와 시편 크기, 2-dB 대여폭으로부터 유전 특징을 계산하였다. 측정의 오차 범위는 유전 상수인 경우 ${\pm}3{\%}$ 유전 손실인 경우 ${\pm}12{\%}$ 이내였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권11호
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• pp.603-608
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• 2000

$(Ba, Sr)TiO_{3}$[BST] thin films were fabricated on the Pt/TiO$_2$/SiO$_2$/Si substrate by the RF sputtering. The structure and dielectric properties of the BST thin films with the substrate temperature were investigated. Increasing the substrate temperature, The BST phase increased and barium multi titanate phases decreased. Increasing the frequency, the dielectric constant decreased and the dielectric loss increased. The dielectric constant and dielectric loss of the BST thin films deposited at 50$0^{\circ}C$ were 300 and 0.018, respectively at 1 kHz. The leakage current density of the BST thin films deposited at 50$0^{\circ}C$ was $10^{-9}$ A/$\textrm{cm}^2$ with applied voltage of 3V. Because of the high dielectric constant(300), low dielectric loss(0.018) and low leakage current($10^{-9}$ A/$\textrm{cm}^2$), BST thin films deposited at 50$0^{\circ}C$ is expecting for the application of DRAM.