• Title, Summary, Keyword: Temperature coefficient of resonant frequency

Search Result 184, Processing Time 0.033 seconds

Temperature Stability of Length-Extensional Vibration Modes in PZT Ceramics (PZT세라믹스에 있어서 길이진동모드의 온도안정성)

  • 이개명;현덕수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.9
    • /
    • pp.726-730
    • /
    • 2001
  • Temperature stabilities of dielectric constraints and resonant frequencies of the substrates are very important in piezoelectric ceramics oscillators and filters. In this study, it was investigated temperature stability of the length-extensional vibration mode of Pb(Zr$\_$y/Ti$\_$1-y/)O$_3$+x[wt%]Cr$_2$O$_3$ ceramics. The mode can be utilized in fabricating ultra-small 455 kHz IF devices. Addition of Cr$_2$O$_3$ in morphotrophic phase PZT decreased the variations of dielectric constant, electro-mechanical coupling factor k$\_$31/ and resonant frequency by thermal shock. As additive weight of Cr$_2$O$_3$increased, the temperature coefficient of resonant frequency changed from positive number to negative one. And the composition tith temperature coefficient of resonant frequency was shifted to the one with increased Cr$_2$O$_3$ additive weigh by thermal aging.

  • PDF

A Study on the Elastic Wave Delay Line (II) (탄성파지연선에 관한 연구(II))

  • 김종상
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.13 no.2
    • /
    • pp.1-4
    • /
    • 1976
  • In this paper, temperature dependence of the resonant frequency of thickness shear mode in X cut plate of $LiN_bO_3$ is theoretically analyzed. An a result of this analysis, theoretical value -78.43${\times}10^{-5}/^{\circ}C$ of the temperature coefficient of resonant frequency is obtained.

  • PDF

Microwave Dielectric Properties of $(Pb_{1-x}Ca_x)ZrO_3$ and $(Pb_{0.63},Ca_{0.37-x}M_x)ZrO_3$ (M = Mg, Sr) Ceramics ($(Pb_{1-x}Ca_x)ZrO_3$$(Pb_{0.63},Ca_{0.37-x}M_x)ZrO_3$ 세라믹스의 고주파 유전 특성)

  • 윤중락;이헌용
    • Electrical & Electronic Materials
    • /
    • v.10 no.6
    • /
    • pp.533-540
    • /
    • 1997
  • The microwave dielectric properties of ((P $b_{1-x}$ C $a_{x}$)Zr $O_3$ and (P $b_{0.63}$,C $a_{0.37-x}$ $M_{x}$)Zr $O_3$(M=Mg,Sr) ceramics were investigated. In (P $b_{1-x}$ C $a_{x}$)Zr $O_3$ (X=0.33~0.40) ceramics, high quality factor and small temperature coefficient of resonant frequency were obtain in (P $b_{0.63}$C $a_{0.37}$)Zr $O_3$with perovskite structure. In the case of (P $b_{0.63}$C $a_{0.37-x}$M $g_{x}$)Zr $O_3$ dielectric constant temperature coefficient of resonant frequency increased and quality factor decreased due to increase of polarization of A-O bonding. When replacing Ca ion with Sr ion with large ion radius, polarization decreased with increased of bonding length and thus dielectric constant and temperature coefficient of resonant frequency decreased.decreased.creased.

  • PDF

Dielectric, Piezoelectric Properties and Temperature Stability of Resonant Frequency in PSN-PMN-PZT Ceramics (PSN-PMN-PZT 세라믹스의 유전 및 압전 특성과 공진 주파수의 온도안정성)

  • 윤광희;류주현;민석규;이명수;서성재
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.391-395
    • /
    • 2000
  • In this study, the temperature coefficient of resonant frequency(TC $F_{r}$), dielectric and piezoelectric properties of Pb[(S $b_{1}$2/N $b_{1}$2/)$_{0.0035}$-(M $n_{1}$3/N $b_{2}$3/)$_{0.0065}$-(Z $r_{x}$ $Ti_{1-x}$ )$_{0.90}$] $O_3$ceramics is investigated with Zr/Ti ratio. The dielectric constant and electromechanical coupling factor( $k_{p}$) showed the highest values of 1257, 0.562 respectively when the Zr/Ti ratio is 49.5/50.5. The mechanical quality factor( $Q_{m}$) is the lowest value of 713 when the Zr/Ti ratio is 49.5/50.5, and increased with the decrease of the Zr/Ti ratio. The temperature coefficient of resonant frequency(TC $F_{r}$) change abruptly at the morphotropic phase boundary(MPB), which is between the rhombohedral phase with highly negative TC $F_{r}$ of -106ppm/$^{\circ}C$ and the tetragonal phase with highly positive TC $F_{r}$ of +64pp $m^{\circ}C$ as Zr/Ti ratio changes from 50/50 to 49.5/50.5.50.5..5.50.5.5.

  • PDF

Microwave dielectric properties of the 0.15(B $a_0.95$S $r_ 0.05$)O-0.15S $m_2$ $O_3$-0.7TiO $_2$ ceramics (0.15(B $a_0.95$S $r_ 0.05$)O-0.15S $m_2$ $O_3$-0.7TiO $_2$ 세라믹스의 마이크로파 유전특성)

  • 박인길;정장호;배선기;이영희
    • Electrical & Electronic Materials
    • /
    • v.8 no.2
    • /
    • pp.224-228
    • /
    • 1995
  • 0.15(B $a_{0.95}$ S $r_{0.05}$)O-0.15S $m_{2}$ $O_{3}$-0.7Ti $O_{2}$ ceramics were fabricated by the mixed-oxide method. Microwave dielectric properties were investigated with sintering conditions. Increasing the sintering temperature from 1300 to 1375[.deg. C], the sintered density was increased from 5.44 to 5.63[g/c $m^{3$]. Increasing the sintering temperature, dielectric constant and quality factor were increased and temperature coefficient of resonant frequency was independent of sintering temperature. In the specimen sintered at 1375[.deg. C], dielectric constant, quality factor and temperature coefficient of resonant frequency were 80.79, 2784(at 3[GHz]), +11.07[ppm/.deg. C], respectively..

  • PDF

Structural and Microwave Dielectric Properties of the Mg$_{1-x}Sr_xTiO-3$ Ceramics with Sintering Temperature and Sr Mole Ratio (소결온도와 Sr몰비에 따른 Mg$_{1-x}Sr_xTiO-3$ 세라믹스의 구조 및 마이크로파 유전특성)

  • Choi, Eui-Sun;Chung, Jang-Ho;Ryu, Ki-Won;Lee, Young-Hie
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.50 no.5
    • /
    • pp.226-231
    • /
    • 2001
  • The $Mg_{1-x}Sr_xTiO_3\;(x=0.02{\sim}0.08)$ ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were $1250^{\circ}C{\sim}1350^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite $SrTiO_3$ and ilmenite $MgTiO_3$ structures were coexisted in the $Mg_{1-x}Sr_xTiO_3\;(x=0.02{\sim}0.08)$ ceramics. The dielectric constant( ${\epsilon}_r$) was increased with addition of $SrTiO_3$. The temperature coefficient of resonant frequency( ${\tau}_f$) was gradually varied from negative value to the positive value with increasing the $SrTiO_3$. The temperature coefficient of resonant frequency of the $Mg_{1-x}Sr_xTiO_3(x=0.036)$ ceramics was near zero, where the dielectric constant, quality factor, and ${\tau}_f$ were 20.65, 95120 and +1.3ppm/$^{\circ}C$, respectively.

  • PDF

Microwave Dielectric Properties of the MgTiO$_3$-SrTiO$_3$Ceramics (MgTiO$_3$-SrTiO$_3$세라믹스의 마이크로파 유전특성)

  • 최의선;이문기;정장호;김강;이영희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.843-846
    • /
    • 2000
  • The (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.02∼0.08) ceramics were fabricated by conventional mixed oxide method. The sintering temperature and time were 1250$^{\circ}C$∼1400$^{\circ}C$, 2hr., respectively. The structural and microwave dielectric properties were investigated by varying sintering temperature and composition ratio. In the (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.02) ceramics, the cubic SrTiO$_3$and hexagonal MgTiO$_3$phases were coexisted. The dielectric constant was increased and the temperature coefficient of resonant frequency( $\tau_f$) was decreased with addition of SrTiO$_3$. The temperature coefficient of resonant frequency($\tau_f$) was gradually varied from negative value to positive value with increasing the SrTiO$_3$.

  • PDF

Microwave Dielectric Properties of the $MgTiO_3-SrTiO_3$ Ceramics ($MgTiO_3-SrTiO_3$ 세라믹스의 마이크로파 유전특성)

  • 배경인;이상철;최의선;배선기;이영희
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.50 no.8
    • /
    • pp.376-381
    • /
    • 2001
  • The(1-x) MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics were fabricated by the conventional mixed oxide method. The structural and microwave dielectric properties were investigated by XRD, SEM, EDS and network analyzer. The sintering temperature and time were 1275$^{\circ}C$~135$0^{\circ}C$ and 2hours, respectively. In the XRD results of 0.96MgTiO$_3$-0.04SrTiO$_3$ceramics, the perovskite structure of SrTiO$_3$and ilmenite structure of MgTiO$_3$phase were coexisted. The dielectric constant($\varepsilon$(sub)${\gamma}$) and temperature coefficient of resonant frequency($\tau$(sub)f) were increased with addition of SrTiO$_3$. In thie case of 0.96MgTiO$_3$-0.04SrTiO$_3$ ceramics sintered at 13$25^{\circ}C$, the dielectric constant, quality factor(Q) and temperature coefficient of resonant frequency($\tau$(sub)f) were 20.13, 7956(at 7.27GHz), and +1.76ppm/$^{\circ}C$, respectively.

  • PDF

Microwave Dielectric Properties of the MST Ceramics with addition of Ce (Ce첨가에 따른 MST 세라믹스의 마이크로파 유전특성)

  • Choi, Eui-Sun;Park, In-Gil;Bae, Seon-Gi;Lee, Young-Hie
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.430-433
    • /
    • 2001
  • The $0.96MgTiO_{3}-0.04SrTiO_{3}+xCe(x=0{\sim}1.6wt%)$ ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were $1300^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite $SrTiO_{3}$ and ilmenite $MgTiO_{3}$ structures were coexisted in the $0.96MgTiO_{3}-0.04SrTiO_{3}+xCe(x=0{\sim}1.6wt%)$ ceramics. The dielectric constant$(\varepsilon_{r})$ was increased with addition of Ce. The temperature coefficient of resonant frequency$(\Gamma_{f})$ was gradually varied from positive value to the negative value with increasing the Ce. The temperature coefficient of resonant frequency of the $0.96MgTiO_{3}-0.04SrTiO_{3}+0.2Ce$ ceramics was near zero, where the dielectric constant, quality factor, and $\Gamma_{f}$ were 20.68, 50,272 and ${-0.5ppm/^{\circ}C}$, respectively.

  • PDF

Microwave Dielectric Properties of the MST Ceramics with Addition of Ce (Ce첨가에 따른 MST 세라믹스의 마이크로파 유전특성)

  • 최의선;박인길;배선기;이영희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.430-433
    • /
    • 2001
  • The 0.96MgTiO$_3$-0.04SrTiO$_3$+xCe(x=0∼1.6 wt%) ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were 1300$^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite SrTiO$_3$ and ilmenite MgTiO$_3$ structures were coexisted in the 0.96MgTiO$_3$-0.04SrTiO$_3$+xCe(x=0∼1.6 wt%) ceramics. The dielectric constant($\varepsilon$$\sub$r/) was increased with addition of Ce. The temperature coefficient of resonant frequency($\tau$$\sub$f/) was gradually varied from positive value to the negative value with increasing the Ce. The temperature coefficient of resonant frequency of the 0.96MgTiO$_3$-0.04SrTiO$_3$+0.2Ce ceramics was near zero, where the dielectric constant, quality factor, and $\tau$$\sub$f/ were 20.68, 50, 272 and -0.5pm/$^{\circ}C$, respectively.

  • PDF