• Title/Summary/Keyword: Qualify Factor(Q)

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Enhancement of Q Factor in Parallel-Branch Spiral Inductors (병렬분기 방법을 이용한 박막 나선 인덕터의 Q 인자 향상)

  • 서동우;민봉기;강진영;백문철
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.1
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    • pp.83-87
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    • 2003
  • In the present paper we suggested a parallel branch structure of aluminum spiral inductor for the use of RF integrated circuit at 1∼3 GHz. The inductor was implemented on p-type silicon wafer (5∼15Ω-cm) under the standard CMOS process and it showed a enhanced qualify(Q) factor by more than 10 % with no degradation of inductance. The effect of the structure modification on the Q factor and the inductance was scrutinized comparing with conventional spital inductors

K-band Coplanar Stripline Resonator for Microwave Tunable Devices (마이크로파 가변 소자용 K-band Coplanar Stripline 공진기 설계)

  • Kang, Chong-Yun;Yoon, Seok-Jin;Kim, Hyun-Jai
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.6
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    • pp.532-537
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    • 2005
  • In order to develop a tunable resonator which can be easily operated by DC bias and applied for microwave tunable filters and devices using ferroelectric thin or thick films, the non conductor backed-and conductor backed- coplanar stripline resonators have been designed and analyzed. They have been designed to be operated at 25 GHz which involve coplanar stripline input and output ports. The resonators have been simulated and analyzed using Ansoft HFSS. The research has been focused on the Quality factor of the coplanar stripline resonator. The conductor Q, box Q, and radiation Q of the resonators have been analyzed and calculated according to the substrate thickness & conductor width of the resonators. From these parameters, the loss factors of the coplanar stripline resonator have been investigated. The conducting Q of the coplanar stripline resonator has no relation with the thickness of dielectric substrate and increases as the conductor width increases. The box Q has no much relation with the thickness of substrate and the conductor width, which is above 2000. The radiation loss increases as the thickness of substrate and the conductor width increase. To decrease the radiation loss of the coplanar stripline resonator, a conductor backed coplanar stripline resonator has been proposed which has the unloaded Q of 170.

Microwave Dielectric Properties of Low Temperature Co-fired Ceramics with Glass Frit and TiO2 Additives (Glass Frit 및 TiO2 첨가에 따른 LTCC용 마이크로파 유전체의 유전 특성)

  • 윤중락;이석원;이헌용
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.9
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    • pp.942-946
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    • 2004
  • The crystalline and dielectric properties on Al$_2$O$_3$ filled glass frit (CaO-Al$_2$O$_3$-SiO$_2$-MgO-B$_2$O$_3$) with admixtures of TiO$_2$ have been investigated. The dielectric constant value of 7.5 ∼ 7.8, qualify factor value of 700 were obtained for glass frit : Al$_2$O$_3$(50 : 50 wt%) ceramics. Addition of TiO$_2$ less than 5 wt% slightly increased the dielectric constant from 7.8 to 8.8 due to higher dielectric constant of TiO$_2$. With increasing the amount of TiO$_2$ up to 5 wt%, the temperature coefficient of dielectric properties was improved. When the TiO$_2$ 5 wt% were added, dielectric properties were dielectric constant 8.8, quality factor 840 and the temperature coefficient of dielectric 45 ppm/$^{\circ}C$ at a sintering temperature 920$^{\circ}C$.

Microwave Dielectric Properties of (1-x)ZnWO4-xTiO2 Ceramics ((1-x)ZnWO4-xTiO2 세라믹스의 마이크로파 유전특성)

  • 윤상옥;김대민;심상흥;강기성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.5
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    • pp.397-403
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    • 2003
  • Microwave dielectric properties of (1-x)ZnW $O_4$-xTi $O_2$ ceramic systems were investigated with calcination temperatures and Ti $O_2$ contents. The ZnW $O_4$ ceramic could be suitably sintered at 1075$^{\circ}C$ and showed the dielectric constant of 13.6, quality factor(Q$\times$ $f_{O}$value) of 22,000 and temperature coefficient of resonant frequency($\tau$$_{f}$) of -65$\pm$2ppm/$^{\circ}C$. Increasing the amount of Ti $O_2$ in the range of 0.25 to 0.45 mol, the dielectric constant and $\tau$$_{f}$ increased due to the role of Ti $O_2$ but the quality factor decreased due to the increase of phase boundaries. The 0.7ZnW $O_4$-0.3Ti $O_2$ ceramic showed the dielectric constant of 19.8, qualify factor(Q$\times$ $f_{0}$) of 20,000 and $\tau$$_{f}$ of -3$\pm$1ppm/$^{\circ}C$.>.EX>.>.>.

Dielectric and Piezoelectric Properties of 0.57Pb(Sc1/2Nb1/2)O3-0.43PbTiO3 Ceramics with Dopant Additions (도펀트 첨가에 따른 0.57Pb(Sc1/2Nb1/2)O3-0.43PbTiO3 세라믹스의 유전 및 압전특성)

  • Ji, Seung-Han;Kwon, Sang-Jik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.2
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    • pp.124-129
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    • 2007
  • Dielectric and piezoelectric properties of $0.57Pb(Sc_{1/2}Nb_{1/2})O_{3}-0.43PbTiO_{3}$, which is the morphotropic phase boundary composition for the PSN-PT system, were investigated as a function of $Fe_{2}O_{3},\;Nb_{2}O_{5}\;and\;MnO_{2}$ addition 0 wt% to 0.9 wt%. The maximum dielectric constant of ${\varepsilon}_{33}/{\varepsilon}_{o}=2054$ and the minimum dielectric loss of $tan{\delta}=0.37\;%$ at room temperature were obtained at 0.1 wt% of $Fe_{2}O_{3}$ and 0.5 wt% of $MnO_{2}$ addition, respectively. With addition of 0.5 wt% $Nb_{2}O_{5}$ and $0.5\;wt%\;MnO_{2}$, the electromechanical coupling factor $k_{p}$ and mecanical quality factor $Q_{m}$ were significantly increased, respectively. The maximum electromechanical coupling factor $k_{p}=61.5\;%$ was obtained by addition of $Nb_{2}O_{5}$ and high mechanical quality factor $Q_{m}=919$ was obtained by addition of $MnO_{2}$. The $Q_{m}(=919)$ value is 3.3 times larger than that of non-doped 0.57PSN-0.43PT ceramics.

Electrical Properties of Multilayer Piezoelectric Transformer using PMN-PZN-PZT Ceramics (PMN-PZN-PZT 세라믹스를 이용한 적층형 압전변압기의 전기적 특성)

  • Lee, Chang-Bae;Yoo, Ju-Hyun;Paik, Dong-Soo;Kang, Jin-Kyu;Cho, Hong-Hee;Lee, Sung-Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.7
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    • pp.655-661
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    • 2006
  • Dielectric and piezoelectric properties of PMN-PZT ceramics with a high mechanical quality factor$(Q_m)$ and a low temperature sintering temperature were investigated as a function of PZN substitution in order to develop multilayer piezoelectric transformer for AC-DC converter. Multilayer piezoelectric transformers were subsequently manufactured using the PMN-PZN-PZT ceramic offering the optimal behavior and then the electrical performance were invetigated. At the sintering temperature of $940^{\circ}C$, density, electromechanical coupling factor$(k_p)$, mechanical qualify factor$(Q_m)$ and dielectric constant$(\varepsilon_r)$ of 8 mol% PZN substituted specimen were $7.73g/cm^3$, 0.524, 1573 and 1455, respectively. The PZN substitution caused a increase in the dielectric constant and the electromechnical coupling factor. The voltage step-up ratio of multilayer piezoelectric transformer showed the maximum value at near the resonant frequency of 76.55 kHz and increased according to the increase of load resistance. The multilayer piezoelectric transformer with the output impedance coincided with the load resistance showed the temperature increase of less than $20^{\circ}C$ at the output power of 10 W. Based on the results, the manufactured multilayer transformer using the low temperature sintered PMN-PZN-PZT ceramics can be stably driven for both step-up and down transformers.

Development of High-Performance Ultra-small Size RF Chip Inductors (고성능의 초소형 RF 칩 인덕터 개발)

  • 윤의중;천채일
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.3
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    • pp.340-347
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    • 2004
  • Ultra-small size, high-performance, solenoid-type RF chip inductors utilizing low-loss A1$_2$O$_3$ core materials were investigated. The dimensions of the RF chip inductors fabricated were 1.0mm${\times}$0.5mm${\times}$0.5mm and copper coils were used. The materials (96% A1$_2$O$_3$) and shape (I-type) of the core, the diameters (40${\mu}{\textrm}{m}$) and position (middle) of the coil, and the lengths (0.35mm) of solenoid were determined by a high-frequency structure simulator (HFSS) to maximize the performance of the inductors. The high-frequency characteristics of the inductance (L) and quality-factor (Q) of the developed inductors were measured using a RF impedance/material analyzer (E4991A with E16197A test fixture). The developed inductors exhibit an inductance of 11 to 11.3nH and a qualify factor of 22.3 to 65.7 over the frequency ranges of 250 MHz to 1.7 GHz, and show results comparable to those measured for the inductors prepared by Coilcraft$^{TM}$. The simulated data described the high-frequency data of the L and Q of the fabricated inductors well.

Resonant Characteristics of SMD Type - Modified PbTiO3 Ceramic Resonator with the Variations of Electrode Weight (전극질량 변화에 따른 SMD형 변성 PbTiO3세라믹 공진자의 공진특성)

  • 오동언;류주현;박창엽;류성림;김종선;정영호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.202-206
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    • 2003
  • In this study, modified PbTi $O_3$ ceramics was manufactured to apply for 30MHz SMD type ceramic resonator with the variations of electrode weight. To investigate the effects of electrode weight on resonant characteristics of ceramic resonator using 3$^{rd}$ overtone thickness vibration mode, ceramic wafers for resonator were fabricated by evaporating electrode weights of 0.66, 1.765, 2.32, 3.87$\times$ 10$^{-4}$ g/c $m^2$ with silver, respectively. And then, SMD type ceramic resonators were fabricated with the size of 3.7$\times$3.1mm and electrode radius size of 0.77mm. With increasing electrode weight, resonant resistance was gradually decreased. At the electrode weight of 2.32$\times$10$_{-4}$ g/c $m^2$, mechanical quality factor( $Q_{mt3}$) and dynamic range(D.R) showed the maximum value of 2,152 and 49dB, respectively.

Dielectric and Piezoelectric Properties of Low Temperature Sintering PCW-PMN-PZT Ceramics according to MnO2 Addition (MnO2 첨가에 따른 저온소결 PCW-PMN-PZT세라믹스의 유전 및 압전특성)

  • Chung, Kwang-Hyun;Lee, Duck-Chool;Lee, Chang-Bae;Lee, Sang-Ho;Yoo, Ju-Hyun;Lee, Hyeung-Gyu;Kang, Hyung-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.2
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    • pp.136-141
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    • 2005
  • In this study, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, PCW-PMN-PZT ceramics using Li$_2$CO$_3$, Bi$_2$O$_3$, and CuO as sintering aids were manufactured according to the amount of MnO$_2$ addition. Their microstructural, dielectric and piezoelectric properties were investigated. When the sintering aids were added, specimens could be sintered below 95$0^{\circ}C$, but mechanical qualify factor decreased. Therefore, MnO$_2$ was added excessively to the PCW-PMN-PZT ceramics to increase mechanical quality factor. At the sintering temperature of 95$0^{\circ}C$, the density, dielectric constant($\varepsilon$$_{r}$), electromechanical coupling factor(k$_{p}$), mechanical quality factor(Q$_{m}$) and Curie temperature(T$_{c}$) of 0.1 wt% MnO$_2$ added specimen showed the optimal values of 7.75 g/㎤, 1503, 0.57, 1502, and 337, respectively, for multilayer piezoelectric transformer application.ation.n.

Design and Fabrication of a X-band Voltage Control Dielectric Resonator Oscillator with The Low Phase Noise (낮은 위상잡음을 갖는 X-band 전압제어 유전체 공진형 발진기의 설계 및 제작)

  • 박창현;최병하
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.5
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    • pp.69-76
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    • 2004
  • In this paper, a VCDRO (Voltage Control Dielectric Resonator Oscillator) with low phase noise for X-band application has been designed and fabricated. A low noise and low flicker noise MESFET and a high Q dielectric resonator were selected to obtain good phase noise Performance. Also, a varactor diode having high Q, qualify factor was used to reduce the loading effects and a big Gamma of diode was chosen for linearity of frequency over voltage tuning range. The fabricated circuits was simulated with circuit design tools, ADS to provide the optimum performances. As the measured results of fabricated oscillator, the output power was 5.8 ㏈m at center frequency 12.05㎓ and harmonic suppression -30㏈c, phase noise -114 ㏈c at 100 KHz offset frequency, respectively, and the frequency tuning range as the function of valtage applied to varactor diode was 15.2 MHz and its power variation with frequency was 0.2 ㏈. This oscillator could be available to a local oscillator in X-band.