• Title/Summary/Keyword: crystal resonator

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Growth of $LiNbO_3$ single crystals and evaluation of the dependence of its piezoelectric properties on temperature ($LiNbO_3$단결정 성장 및 온도에 따른 압전 특성 평가)

  • 정화구;김병국;강길영;윤종규
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.2
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    • pp.155-165
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    • 1996
  • Growth of $LiNbO_3$ single crystal by Czochralski method was carried out to study the piezoelectric effects. Piezoelectric coefficients and elastic compliances of the $LiNbO_3$ single crystal were determined by the resonance method of length-extentional mode of bar resonator from the room temperature up to $100^{\circ}C$. Two dielectric constants of $LiNbO_3$ were also determined by measuring the capacitance of the plate specimen. Measured constants were piezoelectric coefficients $d_{15},d_{22},d_{31},d_{33}$ elastic compliances $s^E_{11},s^E_{33},2s^E_{13}+2s^E_{44},s^E_{14}$ and dielectric constants $K^T_{11},K^T_{33}$. As temperature increased, elastic compliances changed very slowly while piezoelectric coeffiecients and dielectric constant $K^T_{33}$ changed very rapidly. Electromechanical coupling constant of zyw ($45^{\circ}C$)-bar was as high as 0.51 in room temperature and nearly constant up to $1000^{\circ}C$. The increase of piezoelectric coefficients was mainly due to the increase of dielectric permittivity.

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Monolithic film Bulk Acoustic Wave Resonator using SOI Wafer (SOI 웨이퍼를 이용한 압전박막공진기 제작)

  • 김인태;김남수;박윤권;이시형;이전국;주병권;이윤희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.12
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    • pp.1039-1044
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    • 2002
  • Film Bulk Acoustic Resonator (FBAR) using thin piezoelectric films can be made as monolithic integrated devices with compatibility to semiconductor process, leading to small size, low cost and high Q RF circuit elements with wide applications in communications area. This paper presents an MMIC compatible suspended FBAR using SOI micromachining. It is possible to make a single crystal silicon membrane using a SOI wafer In fabricating active devices, SOI wafer offers advantage which removes the substrate loss. FBAR was made on the 12㎛ silicon membrane. Electrode and Piezoelectric materials were deposited by RF magnetron sputter. The maximum resonance frequency of FBAR was shown at 2.5GHz range. The reflection loss, K$^2$$\_$eff/, Q$\_$serise/ and Q$\_$parallel/ in that frequency were 1.5dB, 2.29%, 220 and 160, respectively.

Characterization of the mechanical and micro-fracture properties of material for ME the resonance frequency (공진주파수 분석을 통한 MEMS용 Si 소재의 기계적 물성 및 미세파손 분석 기법)

  • Kim, Jae-Sug;Lee, Se-Ho;Kwon, Dong-Il
    • Proceedings of the KIEE Conference
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    • 2000.11c
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    • pp.575-577
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    • 2000
  • (100) single crystal Si은 좋은 anisotropy etching 성질과 기계적 강도를 가지고 있어 MEMS 구조용 소재로 사용되고 있다. (100) Si의 신뢰성 평가를 위하여 필요한 탄성계수를 측정하고 반복동작에 의한 응력에 의한 파손특성을 평가하기 위하여 micromachining을 통해 resonator를 제작하였다. Resonator의 공진주파수를 분석함으로써 탄성계수를 추하고자 하였으며 반복응력에 대한 파괴특성을 평가하기 위하여 공진 상태에서 파괴가 일어날 때까지의 사이를 수를 측정함으로써 반복음력에 대한 Si의 피로특성을 평가하고자 하였다. 실험 결과 (100) Si의 <110> 방향으로의 탄성 개수를 측정할 수 있었으며 Si의 미세파손의 응력에 대한 의존성을 평가할 수 있었다. 평가결과 Si의 미세파손 메커니즘은 억제된 균열의 진전에 의한 subcritical crack에 의한 피로파괴 현상보다는 과도한 스트레스에 의한 순간적인 균열전파에 의해 지배됨을 관찰할 수 있었다.

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Crystal chemistry and growth of$La_3Ga_5SiO_{14}$ for the applications of filter and resonator (필터와 레죠네이터 응용을 위한 $La_3Ga_5SiO_{14}$ 의 결정화학 및 성장)

  • Jung, Il-Hyoung;Joo, Kyung;Shim, Kwang-Bo;Auh, Keun-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.1
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    • pp.74-79
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    • 1999
  • Langasite($La_3Ga_5SiO_14$) is a new piezoelectric material which is similar to quartz, LN($LiNbO_3$) and LT($LiTaO_3$) in its acoustic behavior. In this study, pure Langasite and Lagnasite family groups were synthesized by the solid state reactions in air. The diffusion species for synthesis were investigated and the sintered body was studied on dielectric property to comparison of characteristics. Also, Langasite single crystals were grown by self-designed Czochralski system and characterized.

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Studies on the Microstrip Bandpass Filter Using Stepped Impedance Resonator and the Wideband Microstrip Bandpass Filter (스텝 임피던스 공진기를 이용한 마이크로스트립 대역통과 필터와 광대역 마이크로스트립 대역통과 필터에 관한 연구)

  • 박봉근;박동철
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.4
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    • pp.10-16
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    • 1991
  • A microstrip bandpass filter using stepped impedance resonators and tapped input / output is realized with Teflon substrate, whose center frequency is 3.5 GHz and fractional bandwidth is 20%. In order to realize a wider bandwidth of 30%, the Crystal's design method and the input / output tapping scheme are used. Another microstrip filter designed as mentioned above is realized with Epsilam-10 substrate. This case shows good agreement between the theoretical responses and the measured ones.

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Development of high-speed near-field scanning optical microscopy by using a high-frequency quartz-crystal resonator (고주파 수정진동자를 이용한 고속 근접장 광학 현미경 제작)

  • 서용호;제원호
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.120-121
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    • 2001
  • 고분해능을 장점으로 하는 근접장 광학 현미경(NSOM)은 최근 높은 관심을 모으고 있으나, 그 촬영 속도가 너무 느린 이유로 실제적인 활용이 미비한 상황이다. scanning 속도를 높이고자 하는 노력들이 많이 진행되고 있으나[1-2] 아직도 실시간 촬영과는 거리가 멀다. 기존의 근접장 광학 현미경(NSOM)은 tuning fork를 사용하여 탐침을 진동시키고 그 진동의 진폭 또는 위상의 변화를 측정함으로써 탐침과 시료의 거리를 측정하는 방식을 사용한다. (중략)

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Intracavity frequency doubling of a slab Nd:YAG laser pumped by high power diode laser array

  • Lee, Jong-Min;Moon, Hee-Jong;Yi, Jong-Hoon
    • Journal of the Optical Society of Korea
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    • v.2 no.1
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    • pp.5-8
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    • 1998
  • A high power diode-array-pumped slab Nd:YAG laser is described. The resonator consists of three mirrors in folded geometry. The laser is operated in acousto-optic Q-switching mode and intracavity frequency doubling is tried. We demonstrate that the laser exhibits frequency doubling efficiency of ∼60% with a type I LBO crystal.

A CMOS Temperature Control Circuit for Direct Mounting of Quartz Crystal on a PLL Chip (온 칩 수정발진기를 위한 CMOS 온도 제어회로)

  • Park, Cheol-Young
    • Journal of Korea Society of Industrial Information Systems
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    • v.12 no.2
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    • pp.79-84
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    • 2007
  • This papar reports design and fabrication of CMOS temperature control circuit using MOSIS 0.25um-3.3V CMOS technology. The proposed circuit has a temperature coefficient of $13mV/^{\circ}C$ for a wide operating temperature range with a good linearity. Furthermore, the temperature coefficient of output voltage can be controlled by adjusting external bias voltage. This circuit my be applicable to the design of one-chip IC where quartz crystal resonator is mounted on CMOS oscillator chips.

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A Study on Temperature Stability of PZT Piezoelectric Ceramic Resonators using Length Extensional Vibration (길이진동을 이용하는 PZT계 세라믹 공진자의 온도안정성에 관한 연구)

  • Han, Seong-Hun;Lim, Dae-Kwan;Lee, Gae-Myoung
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.885-887
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    • 1999
  • The piezoelectric ceramic resonator using length extensional vibration rather than contour extensional vibration in terms of the size is suitable for personal portable communication. In this paper, $Pb(Zr_{x}Ti_{l-x})O_{3}$ + r[wt%]$Cr_{2}O_{3}$ ceramics, x=0.56, 0.53, 0.50 (ie, Zr/Ti ratios = 56 /44, 53/47, 50/50) r=0, 0.3[wt %], were fabricated. Temperature stability of length extensional vibration mode of those specimens was investigated. Both crystal structure with rhombohedral phase in the case of no addition of $Cr_{2}O_{3}$ and crystal structure with morphotrophic phase boundary in case of additions of 0.3[wt %]$Cr_{2}O_{3}$ had the vest temperature stability and improved temperature stability through thermal aging.

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GROWTH AND CHARACTERIZATIONS OF $La_3Ga_5SiO_{14}$ SINGLE CRYSTALS AND SINTERED BODY FOR THE APPLICATIONS OF FILER AND RESONATOR

  • Jung, Il-Hyoung;Kyung Joo;Shim, Kwang-Bo;Auh, Keun-Ho
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.09a
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    • pp.73-77
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    • 1998
  • Langasite(La3Ga5SiO14) is a new piezoelectric material which is similar to quartz, LN(LiNbO3) and LT(LiTaO3) in its acoustic behavior. In this study, pure Langasite and Langasite family groups were synthesized by the solid state reactions in air. For the synthesis process, diffusion species were investigated and sintered body of synthesized powders were studied on dielectric property according to surface microstructures.

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