• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.292-293
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• 2006

$ZnNb_2O_6$ ceramics were sintered under the presence of zinc-borosilicate(ZBS) glass and resultant microwave dielectric properties were investigated with a view to applying the composition to LTCC technology. The addition of 10~30 wt% ZBS glass ensured successful sintering below $900^{\circ}C$. In general, increased addition of ZBS glass increased sinterability but it decreased the dielectric properties significantly due to the formation of an excessive liquid and second phases. The sintered $ZnNb_2O_6$ ceramics at $900^{\circ}C$ with 25 wt% ZBS glass demonstrated 15.8 in dielectric constant(${\varepsilon}_r$), 5,400 in quality factor($Q{\times}f_0$), and $-98\;ppm/^{\circ}C$ in temperature coefficient of resonant frequency(${\tau}_f$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.326-326
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• 2007

Influence of $Nd_2O_3$ addition to $ZnO-B_2O_3$-based glass on the water leaching resistance of the glass was first investigated. The optimized $Nd_2O_3-ZnO-B_2O_3$ (NZB) glass was ball milled for varying time, mixing with followed by $Al_2O_3$ crystalline phase to form $Al_2O_3$-NZB glass composites at $875^{\circ}C$ for 1h. Microwave dielectric properties of the composites were investigated as a function of the ball milling time of the NZB glass. Dielectric constant and quality factor were 5.70 and 9497 GHz, respectively, when the NZB glass was ball milled for 6h prior to mixing with $Al_2O_3$.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.470-474
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• 1996

The dielectric properties, dielectric constant (${\varepsilon}‘$) and loss factor (${\varepsilon}’$), of skin and pulp of fresh ginseng were measured from $25^{\circ}C$ to $67^{\circ}C$ using an open-ended coaxial probe technique for 915 MHz and 2450 MHz. Pulp and skin had dielectric constant of $30{\sim}64$ and loss factor between 10 and 20, each variable having a respective frequency dependence typical of materials with high water content. Although the loss factor was nearly constant, the dielectric constant increased as moisture content increased. The dielectric constant of ginseng pulp increased as temperature increased (temperature ${\leq}56^{\circ}C$), but any significant differences were not found in skin dielectric properties. Penetration depth for fresh ginseng were about 2 cm at 91.5 MHz and 1cm at 2450 MHz.

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.339-343
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• 2016

Background: Evaluation of deoxyribonucleic acid (DNA)-strand break is important to elucidate the biological effect of ionizing radiations. The conventional methods for DNA-strand break evaluation have been achieved by Agarose gel electrophoresis and others using an electrical property of DNAs. Such kinds of DNA-strand break evaluation systems can estimate DNA-strand break, according to a molecular weight of DNAs. However, the conventional method needs pretreatment of the sample and a relatively long period for analysis. They do not have enough sensitivity to detect the strand break products in the low-dose region. Materials and Methods: The sample is water, methanol and plasmid DNA solution. The plasmid DNA pUC118 was multiplied by using Escherichia coli JM109 competent cells. The resonance frequency and Q-value were measured by means of microwave dielectric absorption spectroscopy. When a sample is located at a center of the electric field, resonance curve of the frequency that existed as a standing wave is disturbed. As a result, the perturbation effect to perform a resonance with different frequency is adopted. Results and Discussion: The resonance frequency shifted to higher frequency with an increase in a concentration of methanol as the model of the biological material, and the Q-value decreased. The absorption peak in microwave power spectrum of the double-strand break plasmid DNA shifted from the non-damaged plasmid DNA. Moreover, the sharpness of absorption peak changed resulting in change in Q-value. We confirmed that a resonance frequency shifted to higher frequency with an increase in concentration of the plasmid DNA. Conclusion: We developed a new technique for an evaluation of DNA damage. In this paper, we report the evaluation method of DNA damage using microwave dielectric absorption spectroscopy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.926-931
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• 2000

The microwave dielectric properties and the microstructures as a mole fraction of (1-x)ZnNb$_2$O$_{6}$-xPb$_{5}$Nb$_4$O$_{15}$ ceramics with CuV$_2$O$_{6}$, Sb$_2$O$_3$ and glass(ZNPN ceramics) was investigated. 0.98ZN-0.02PN ceramics containing 1.5 wt% CuV$_2$O$_{6}$ 1.0 wt% Sb$_2$O$_3$ and 1.0 wt% glass had a dielectric constant($\varepsilon$$_{r}$) of 23, Qxf$_{o}$ value of 15000 and TCF(Temperature Coefficient of resonance Frequency) of -25 ppm/$^{\circ}C$ and it is possible to be co-fired with Ag electrode at 90$0^{\circ}C$. As sintered temperature increases over 90$0^{\circ}C$ the grain size of ZNPN ceramics was increasing for growth and it has poor co-fired properties with Ag electrode.e.ctrode.e.e.

• Journal of the Korean Ceramic Society
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• v.38 no.7
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• pp.597-601
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• 2001

The effect of CuO, $B_2$ $O_3$, $V_2$ $O_{5}$ and CuO-B $i_2$ $O_3$additives on microwave dielectric properties of (P $b_{0.45}$C $a_{0.55}$) [(F $e_{0.5}$N $b_{0.5}$)$_{0.9}$S $n_{0.1}$] $O_3$(PCFNS) were investigated. The PCFNS ceramics were sintered at 11$65^{\circ}C$. To decrease the sintering temperature for using as a low-temperature co-firing ceramics (LTCC), CuO, $B_2$ $O_3$, $V_2$ $O_{5}$ and CuO-B $i_2$ $O_3$were added to the PCFNS. As the content of CuO increased, the sintered density and dielectric constant increased and the temperature coefficient of resonance frequency ($\tau$$_{f}$) shifted to the positive value. When the CuO-B $i_2$ $O_3$were added, dielectric properties were $\varepsilon$$_{r}$ of 83, Q. $f_{0}$ of 6085 GHz, and $\tau$$_{f}$ of 8ppm/$^{\circ}C$ at a sintering temperature of 100$0^{\circ}C$. The relationship between the microstructure and properties of ceramics was studied by X-ray diffraction and scanning electron microscopy.icroscopy.y.icroscopy.y.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.171-176
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• 1997

A hair-pin shaped microstrip-line resonator and dielectric resonator for injection-locked oscillators have been designed and fabricated for the comparative studying of their performances. In general, a commonly used dielectric resonator shows lower phase noise value than hair-pin resonator in the free-running mode. In the injection-locked mode, however, a hair-pin resonator is superior to the dielectric resonator, the wider tuning range, the 22% improved locking bandwidth, the lower noise effect, the short term stability, and the higher power level. The planar structure of a hair-pin shaped microstrip-line resonator will be easily applied to monolithic microwave integrated circuits.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.783-787
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• 2004

Microwave dielectric properties and the microstructure of $Ba_5Nb_4O_{15}$ ceramics with $PbO-B_2O_3-SiO_2$ glass frit were investigated to reduce the sintering temperature of $Ba_5Nb_4O_{15}$ ceramics as a function of the amount of glass frit from $0.5wt\%$ to $10wt\%$ and the sintering condition. The sintered density and the microwave dielectric properties of $Ba_5Nb_4O_{15}$ ceramics were remarkably changed with the amount of glass fit which existed as a liquid phase and assisted the densification. $Ba_5Nb_4O_{15}$ with $3wt\%$ $PbO-B_2O_3-SiO_2$ glass frit sintered at $900^{\circ}C$ for 2 h showed dielectric constant (K) of 41.4, a quality factor (Q $\times$f) of 13,485 GHz, and a Temperature Coefficient of resonant Frequency (TCF) of 9 ppm/$^{\circ}C$. Due to no trace of physical and chemical reaction between this composition and Ag electrode cofired at $900^{\circ}C$ for 2 h, this ceramics can be a good candidate for the multilayer dielectric filter.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1299-1300
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• 2007

In this study, low temperature sintering property of (1-x)$TiTe_{3}O_{8}-xMgTiO_{3}$ ceramics were investigated for LTCC application which enable to cofiring with Ag electrode. $TiTe_{3}O_{8}$ mixed with $MgTiO_3$ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of $TiTe_{3}O_{8}$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. The bulk densities and dielectric constants were decreased with increasing of $MgTiO_3$. However, the quality factors were increased with $MgTiO_3$ addition. Also, TCRF was shifted to negative(-) direction. Microwave dielectric properties of (1-x)$TiTe_{3}O_{8}-xMgTiO_{3}$ ceramics had similar tendency with calculated value by the mixing rule. The dielectric constant, quality factor and TCRF of $05TiTe_{3}O_{8}-0.5MgTiO_{3}$ ceramics sintered at $830^{\circ}C$ for 3h. were 26.19, 43,290GHz and $-3.9ppm/^{\circ}C$, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.208-209
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• 2006

Sinterability and microwave dielectric properties of the $Zr1-x(Zn_{1/3}Nb_{2/3})xTiO_4$(x=4, 6) system ceramics have been investigated as functions of zinc-borosilicate(ZBS) glass contents and amount of $Zn_{1/3}Nb_{2/3}O_2$ substitution with a view to applying the composition to LTCC technology. The addition of 25 wt% ZBS glass ensured successful sintering below $925^{\circ}C$. With increasing ZBS glass and $Zn_{1/3}Nb_{2/3}O_2$ contents increased dielectric constant and sinterability but addition ZBS glass decreased the quality factor significantly due to the formation of an excessive liquid and second phases. The sintered $Zr4(Zn_{1/3}Nb_{2/3})6TiO_4$ system ceramics at $925^{\circ}C$ with 25 wt% ZBS glass demonstrated 27.7 in dielectric constant (${\varepsilon}_r$), 3,850 m quality factor($Q{\times}f_0$), and +6 ppm/$^{\circ}C$ in temperature coefficient of resonant frequency($\tau_f$).