Rotation Of Crystal Axis (e.g., Cut Angle) Patents (Class 310/360)
  • Patent number: 6924588
    Abstract: In a gallium phosphate crystal, a crystallographic Y-axis and a Z-axis that have been rotated about an X-axis counterclockwise through an angle ? is referred to as a Y?-axis and a Z?-axis, respectively, where the angle ? is in a range from 10° to 20°. A piezoelectric crystal material made of gallium phosphate is provided as a plate-shaped member which is elongate in an X-axis direction and cut from the gallium phosphate crystal parallel to an X-Z? crystal plane of the gallium phosphate, and the plate-shaped member has sides parallel to an axis that is obtained by rotating the Y?-axis counterclockwise about the X-axis in an angular range from 1° to 3°.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: August 2, 2005
    Assignee: Nihon Dempa Kogyo Co., Ltd.
    Inventors: Masanobu Okazaki, Morio Onoue, Hitoshi Sekimoto
  • Patent number: 6865945
    Abstract: An angular velocity sensor, which is able to reduce the variations of driving resonance frequency of the vibrator and to improve the reliability of the sensitivity of detection signal with respect to the angular velocity applied, is provided. The angular velocity sensor comprises a vibrator, and a tuning-fork as the vibrator is formed of a silicone substrate with crystal orientation (100) as its main face, and a side face nearly perpendicular to the driving direction (X direction) of the arm of the tuning-fork corresponds to a crystal orientation where the elastic modulus is less dependent on azimuth angle.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: March 15, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Michihiko Hayashi, Hirofumi Tajika, Masaya Nakatani
  • Publication number: 20040189153
    Abstract: A piezoelectric resonator element of crystallographic point group 32, which can be operated as a thickness shear resonator contacting a carrier medium includes a singly rorated Y-cut (S1,S2) that is essentially rotated through an angle &PHgr; about the crystallographic x-axis, which differs from crystal cuts that are temperature-compensated in air or vacuum, wherein the cut has a negative temperature coefficient of the resonance frequency f(T) in a predetermined temperature range, preferably between 10° C. and 40° C., when there is no contact with the carrier medium, while the value of the linear temperature coefficient a of the resonance frequency in the same temperature range is less than 1 ppm/° C., preferably less than 0.5 ppm/° C. when the resonator is in contact with the carrier medium. The resonator element (1) can additionally be provided with at least one layer sensitive to the parameter to be measured.
    Type: Application
    Filed: March 5, 2004
    Publication date: September 30, 2004
    Inventors: Herbert Thanner, Peter Krempl
  • Patent number: 6784595
    Abstract: The invention provides a method for adjusting the temperature-dependent property of a surface acoustic wave device is provided,, The method is appropriate for a temperature-dependent property that is expressed by a cubic function of a surface acoustic wave device using an in-plane rotated ST cut quartz crystal plate. The invention therefore provides a method for adjusting the temperature-dependent property of a surface acoustic wave device using an in-plane rotated ST cut quartz crystal plate having Euler angles of (0°, 113-135°, ±(40-49°)). The range of Euler angles is defined so that the temperature-dependent property of the surface acoustic wave device, using an in-plane rotated ST cut quartz crystal plate having the temperature-dependent property expressed by a cubic function, has an extreme value within the temperature range of −40 to +85° C.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: August 31, 2004
    Assignee: Seiko Epson Corporation
    Inventors: Keigo Iizawa, Takashi Yamazaki, Shigeo Kanna
  • Publication number: 20040163226
    Abstract: A micro-actuator having a stage capable of a see-saw motion and a method for its manufacture are disclosed. In the micro-actuator according to the present invention, a plurality of parallel driving comb-type electrodes are formed on the bottom of the stage, and a plurality of parallel fixed comb-type electrodes are formed on a base plate. At both sides of the stage is a torsion bar that enables the see-saw motion. The torsion bar is supported by a frame comprised of a first frame layer and a second frame layer. The torsion bar and the first frame layer form one body. The first and second frame layers are bonded by a metal eutectic bonding layer between metal layers.
    Type: Application
    Filed: March 4, 2004
    Publication date: August 26, 2004
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Jin-ho Lee, Young-chul Ko, Do-hyun Kong
  • Patent number: 6781290
    Abstract: A piezoelectric actuator includes a single-crystal piezoelectric thin film having a crystal orientation aligned with the crystal orientation of a single-crystal Si substrate, and first and second electrode films formed on first and second sides of the single-crystal piezoelectric thin film, respectively.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: August 24, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazuaki Kurihara, Motoyuki Nishizawa, Masaki Kurasawa, Keishiro Okamoto
  • Patent number: 6744182
    Abstract: A piezoelectric quartz plate having reduced frequency deviation as a function of temperature, wherein the quartz plate is cut at an angle described by: T f = 3.9 + 6.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: June 1, 2004
    Inventor: Mark Branham
  • Patent number: 6700300
    Abstract: A compact and wide band surface acoustic wave device for intermediate-frequency is disclosed. A piezoelectric substrate for use in a surface acoustic wave device having high electromechanical coupling factor and low SAW velocity is also disclosed. The surface acoustic wave device is constituted of a piezoelectric substrate 1 and inter-digital electrodes 2, 2 formed on the piezoelectric substrate 1. The piezoelectric substrate 1 has a crystal structure of Ca3Ga2Ge4O14 and is represented by the chemical formula, Ca3TaGa3Si2O14. A cut angle of the piezoelectric substrate 1 cut out of the single crystal and a direction of propagation of surface acoustic waves on the piezoelectric substrate represented in terms of Euler's angles (&phgr;, &thgr;, &psgr;) are found in an area represented by −2.5°≦&phgr;≦2.5°, 30°≦&thgr;≦90°, and −65°≦&psgr;≦65°.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: March 2, 2004
    Assignee: TDK Corporation
    Inventors: Kenji Inoue, Katsuo Sato, Hiroki Morikoshi, Katsumi Kawasaki, Jun Sato
  • Patent number: 6621194
    Abstract: A piezoelectric element includes a piezoelectric substrate formed of a piezoelectric material and a pair of electrodes formed on a first principal plane and a second principal plane of the piezoelectric substrate, wherein thickness shear vibration occurs, and the vibration direction of the thickness shear vibration is nonparallel to the side walls of the piezoelectric substrate.
    Type: Grant
    Filed: November 10, 2000
    Date of Patent: September 16, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masato Sugimoto, Tetsuro Otsuchi, Katsunori Moritoki
  • Publication number: 20030164657
    Abstract: A compact and wide band surface acoustic wave device for intermediate-frequency is disclosed. A piezoelectric substrate for use in a surface acoustic wave device having high electromechanical coupling factor and low SAW velocity is also disclosed.
    Type: Application
    Filed: October 2, 2001
    Publication date: September 4, 2003
    Inventors: Kenji Inoue, Katsuo Sato, Hiroki Morikoshi, Katsumi Kawasaki, Jun Sato
  • Patent number: 6580196
    Abstract: There is disclosed a piezoelectric single crystal wafer wherein an etching pit density on the front surface of the wafer on which an electrode for transmit-receive of surface acoustic wave or leaky surface acoustic wave is formed is 7.8×104/mm2 or less, and a piezoelectric single crystal wafer wherein surface roughness Ra on the peripheral surface other than the front surface and the reverse surface of the wafer is 2.3 &mgr;m or less. There can be provided a piezoelectric single crystal wafer wherein a deviation of surface acoustic wave velocity or leaky surface acoustic wave velocity is small, namely the uniformity of the velocity is excellent, and fine contaminations adhered on the surface where electrode is formed and breakage of the wafer can be significantly reduced, and therefore a device such as a filter having excellent property can be produced in high yield.
    Type: Grant
    Filed: August 14, 2000
    Date of Patent: June 17, 2003
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Yoshiyuki Shiono, Yoshinori Kuwabara, Toshihiko Ryuo
  • Patent number: 6518778
    Abstract: Methods are included for determining deviations from &phgr;=0° in test resonators based on the quasi-pure modes' displacement ratio variations with &phgr; angle. A direct relationship between deviation from &phgr;=0° and the c-mode displacement ratio has been observed, so that the larger the deviation from &phgr;=0°, then the larger is the change in the normalized frequency of the c-mode upon immersion in, or contact with, a fluid. The method includes measuring &thgr; and &phgr; angles in reference resonators with different small &phgr; angles and quasi-pure mode frequencies of reference resonators in both air and a test fluid at ambient temperatures, calculating the normalized frequency changes between the air and fluid measurements as a reference point, measuring the test resonator in air then in the fluid and comparing the results.
    Type: Grant
    Filed: January 23, 2001
    Date of Patent: February 11, 2003
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: John R. Vig, Arthur Ballato
  • Publication number: 20020153809
    Abstract: This invention is directed to a transducer comprising a lead-based single crystal wherein the crystal is diagonally oriented and has an effective coupling constant of at least 0.70. In one embodiment, the lead-based crystal has the formula Pb(B′B″)O3—PbTiO3 wherein B′ is Mg2+, Zn2+, Ni2+ or Sc3+ and B″ is Nb5+, Ta5+ or W6+. Preferably, the lead-based crystal is of the formula Pb(B′B″)O3—PbTiO3 where B′ is Mg2+, Zn2+, Sc3+ and B″ is Nb5+ or more specifically Pb(Mg⅓Nb⅔)O3—PbTiO3 (“PMN-PT”), Pb(Zn⅓Nb⅔)O3—PbTiO3 (“PZN-PT”), and Pb(Sc⅓Nb⅔)O3—PbTiO3 (“PSN-PT”).
    Type: Application
    Filed: March 8, 2000
    Publication date: October 24, 2002
    Inventors: Jie Chen, Rajesh Kumar Panda, Turuvekere R. Gururaja, Heather Beck
  • Patent number: 6465937
    Abstract: This invention is directed to a transducer comprising a lead-based single crystal wherein the crystal is diagonally oriented and has an effective coupling constant of at least 0.70. In one embodiment, the lead-based crystal has the formula Pb(B′B″)O3—PbTiO3 wherein B′ is Mg2+, Zn2+, Ni2+ or Sc3+ and B″ is Nb5+, Ta5+ or W6+. Preferably, the lead-based crystal has of the formula Pb(B′B″)O3—PbTiO3 where B′ is Mg2+, Zn2+, Sc3+ and B″ is Nb5+ or more specifically Pb(Mg1/3Nb2/3)O3—PbTiO3 (“PMN—PT”), Pb(Zn1/3Nb2/3)O3—PbTiO3 (“PZN—PT”), and Pb(Sc1/3Nb2/3)O3—PbTiO3 (“PSN—PT”). The invention also includes a transducer comprising a plurality of lead-based single crystal transducers.
    Type: Grant
    Filed: March 8, 2000
    Date of Patent: October 15, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jie Chen, Rajesh Kumar Panda, Turuvekere R Gururaja, Heather Beck
  • Patent number: 6369667
    Abstract: A surface acoustic wave device includes a quartz substrate having Euler angles (0°, &thgr;, 90°±5°) in which &thgr; is in a range of 119°≦&thgr;≦140°, and an IDT for exciting an SH wave is formed on the quartz substrate by use of an electrode material containing as a major component at least one of Ag, Mo, Cu, Ni, Cr, and Zn and having a density of at least about 7 g/cm3. The film thickness of the IDT is such that the attenuation constant is approximately zero.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: April 9, 2002
    Assignee: Murata Manufacturing Co., LTD
    Inventors: Michio Kadota, Toshimaro Yoneda, Koji Fujimoto
  • Publication number: 20020030723
    Abstract: Providing a mechanism which can eliminate an influence of residual strain in a piezoelectric thin film, having excellent piezoelectric strain characteristics.
    Type: Application
    Filed: June 1, 2001
    Publication date: March 14, 2002
    Inventors: Kouji Sumi, Qiu Hong
  • Patent number: 6356167
    Abstract: A surface acoustic wave resonator includes a piezoelectric substrate made of a langasite single crystal and an interdigital transducer made of Al provided on the surface of the piezoelectric substrate. A Euler angle (&phgr;, &thgr;, &phgr;) of the piezoelectric substrate is approximately (0°, 140° to 150°, 24° ±1°), and the film thickness H of the interdigital transducer is within the range of about 0.005 to 0.15 with respect to the wavelength &lgr; of a surface acoustic wave generated on the piezoelectric substrate.
    Type: Grant
    Filed: August 12, 1999
    Date of Patent: March 12, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Michio Kadota, Jun Nakanishi, Makoto Kumatoriya
  • Publication number: 20020017828
    Abstract: Substrate lamina made of langasite or langatate with a crystal cut (X1, X2, X3) for langasite in a range around the Euler angle combination (100°, 1400°, 166°) or the Euler angle combinations equivalent thereto, or respectively with special angle combinations of langatate.
    Type: Application
    Filed: August 7, 2001
    Publication date: February 14, 2002
    Applicant: SIEMENS AG.
    Inventor: Ulrike Roesler
  • Patent number: 6316861
    Abstract: A low-loss surface acoustic wave filter on a quartz substrate with optimized cutting. A range of cutting angles and directions of propagation of the waves on the quartz substrate are defined, making it possible to obtain high coefficients of reflection of the electrodes used in the filter. The range of cutting angles and directions of propagation of the waves are decisive factors for the making of the filter.
    Type: Grant
    Filed: October 19, 1999
    Date of Patent: November 13, 2001
    Assignee: Thomson-CSF
    Inventors: Sylvain Ballandras, Marc Solal, Emmanuelle Briot
  • Patent number: 6317014
    Abstract: A surface acoustic wave resonator includes a piezoelectric substrate including a langasite single crystal material and at least one interdigital transducer having at least one pair of comb-shaped electrodes arranged so as to contact the piezoelectric substrate. The surface acoustic wave resonator operates using a surface acoustic wave including an SH wave as the main component.
    Type: Grant
    Filed: August 12, 1999
    Date of Patent: November 13, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Michio Kadota
  • Patent number: 6281619
    Abstract: A four-beam tuning fork is provided in which the base part thereof is stationary regardless of the vibration of the resonator, the same vibration mode being used for both excitation and detection, and the outputs from a plurality of beams are used to cancel the noise output caused by externally applied vibration
    Type: Grant
    Filed: May 8, 1998
    Date of Patent: August 28, 2001
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Tohru Yanagisawa, Izumi Yamamoto
  • Publication number: 20010009341
    Abstract: A method for manufacturing a langasite single crystal substrate comprises the steps of polishing at least one of the main surfaces of a raw material substrate; and wet-etching said polished main surface of the substrate with a solution including H3PO4, HNO3 and CH3COOH.
    Type: Application
    Filed: January 11, 2001
    Publication date: July 26, 2001
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Makoto Kumatoriya, Jun Nakanishi, Masashi Omura
  • Patent number: 6243933
    Abstract: A wafer with a reversed domain is prepared for two piezoelectric single crystal plates and of about the same thickness by using direct bonding without any adhesive. Driving electrodes are formed on two principal planes of the wafer with a reversed domain to provide a piezoelectric resonator. A piezoelectric resonator having the structure with a reversed polarization and using odd-order vibration modes vibrating with a fundamental wave has a wavelength of a thickness thereof and suppresses scattering of the thickness of the domains with a reversed polarization. In the direct bonding, the axes of the spontaneous polarization of the two piezoelectric single crystal plates are reverse to each other and crystalline axes other than the axes of polarization are shifted intentionally by an angle other than zero. Thus, spurious modes are suppressed in a simple way.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: June 12, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masato Sugimoto, Katsu Takeda, Yoshihiro Tomita, Osamu Kawasaki
  • Patent number: 6153961
    Abstract: A surface acoustic wave element having a cut-out angle from a langasite single crystal and a direction of propagating a surface acoustic wave of (180.degree.+.alpha., 40.degree.+.beta., 20.degree.+.gamma.) in Eulerian angles where .alpha.=-2.degree. to +6.degree., .beta.=-4.degree. to +9.degree., and .gamma.=-1.degree. to +9.degree.; of (0.degree.+.alpha., 140.degree.+.beta., 24.degree.+.gamma.) where .alpha.=-6.degree. to +6.degree., .beta.=-5.degree. to +5.degree., and .gamma.=-5.degree. to +5.degree.; or of (9.degree.+.alpha., 150.degree.+.beta., 37.degree.+.gamma.) where .alpha.=-5.degree. to +5.degree., .beta.=-5.degree. to +5.degree., and .gamma.=-5.degree. to +5.degree.. The element may be used in a filter that selects the frequency used in a communication device or a resonator that is used in a highly stabilized oscillator.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: November 28, 2000
    Assignee: Mitsubishi Materials Corporation
    Inventors: Chunyun Jian, Sinichro Inui
  • Patent number: 6137207
    Abstract: The present invention provides a small yet wide-passband surface acoustic wave device that is excellent in selectivity, i.e., temperature characteristics. The surface acoustic wave device contains an interdigital electrode on the surface of a substrate made up of a langasite single crystal having the formula, La.sub.3 Ga.sub.5 SiO.sub.14, and belonging to a point group 32. When the cut angle of the substrate cut out of the langasite single crystal and the direction of propagation of a surface acoustic wave on the substrate are represented in terms of Euler's angles (.phi., .theta., and .psi.), .phi., 74 and .psi. are found within areas represented by .phi.=-5 to 5 , .theta.=136 to 146-, and .psi.=21 to 30, respectively. The relationship between the normalized thickness h/.lambda. (%) where the thickness, h, of the interdigital electrode is normalized with the wavelength .lambda. of a surface acoustic wave and the above .psi.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: October 24, 2000
    Assignee: TDK Corporation
    Inventors: Kenji Inoue, Katsuo Sato
  • Patent number: 6121713
    Abstract: A surface including interdigital electrode on the surface thereof, which is reduced in size and improved in selectivity, and has a broad band. To achieve this, a langasite single crystal belonging to a point group 32 is first used for the substrate. Secondly, I. a piezoelectric film is provided for covering the surface of the substrate and the surface of the interdigital electrode, II. a piezoelectric film is provided on the surface of the substrate and the interdigital electrode is provided on the surface of the piezoelectric film, III. a piezoelectric film is provided for covering the surface of the substrate and the surface of the interdigital electrode and an opposite electrode film is provided on the surface of the piezoelectric film, or IV. an opposite electrode film is provided on the surface of the substrate, a piezoelectric film is provided on the opposite electrode film and the interdigital electrode is provided on the surface of the piezoelectric film.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: September 19, 2000
    Assignee: TDK Corporation
    Inventors: Kenji Inoue, Katsuo Sato
  • Patent number: 6088462
    Abstract: A surface acoustic wave device includes a quartz rotated Y-cut plate and at least one interdigital transducer disposed on the quartz rotated Y-cut plate. The quartz rotated Y-cut plate has a Euler angle represented by (0, .theta., .phi.). The angle .theta. is within a range of about 125.degree.<.theta.<130.degree. or equivalents thereto, and the angle .phi. is approximately 90 degrees. The interdigital transducer is made of tungsten.
    Type: Grant
    Filed: July 6, 1999
    Date of Patent: July 11, 2000
    Assignee: Murata Manufacturing, Co., Ltd.
    Inventors: Koji Fujimoto, Michio Kadota, Toshimaro Yoneda
  • Patent number: 6054794
    Abstract: A lanthanum gallium niobate single crystal substrate, referred to as langanite, has a prescribed range of Euler angles for substrate and crystal orientation for improving signal processing for a surface acoustic wave (SAW) device. When a voltage is applied to an input interdigital transducer (IDT) of the SAW device, a surface acoustic wave is generated in the langanite piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langanite crystal cut and wave propagation directions are defined which reduce insertion loss and frequency response distortion due to SAW transduction, diffraction, and beam steering, while achieving improved temperature stability SAW device as compared to other commonly used crystal substrates. A low power flow angle and reduced level of diffraction is also achieved.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: April 25, 2000
    Assignee: Sawtek Inc.
    Inventors: Natalya F. Naumenko, Leland P. Solie
  • Patent number: 6037847
    Abstract: A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO.sub.3 and an electrode pattern provided on the piezoelectric substrate. The electrode pattern contains Al as a primary component and has a thickness in a range of 0.03-0.15 times a wavelength of a surface acoustic wave excited on the piezoelectric substrate. The piezoelectric substrate has an orientation rotated about an X-axis thereof from a Y-axis thereof toward a Z-axis thereof, with a rotational angle of 39-46.degree..
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: March 14, 2000
    Assignee: Fujitsu Limited
    Inventors: Masanori Ueda, Osamu Kawachi, Gou Endoh, Osamu Ikata, Ken-ya Hashimoto, Masatsune Yamaguchi
  • Patent number: 6031317
    Abstract: A shock sensor sensitive to linear shocks along two axes and to rotational shocks in a given plane and comprised of two piezoelectric sensors and an integrated circuit is disclosed. The first piezoelectric sensor is polarized in a direction that is angularly offset from a plane in which the shock sensor lies and produces a first response to shocks having components along a first and a second orthogonal axis that define a plane perpendicular to the plane in which the shock sensor lies. The second piezoelectric sensor is polarized in a direction that is angularly offset from the plane in which the sensor lies and that is angularly offset 180.degree. from the first direction. The second piezoelectric sensor produces a second response to shocks having components along the first and second orthogonal axis. The integrated circuit is responsive to the first and second responses and produces a signal indicating a linear shock and a signal indicating a rotational shock by combining the first and second responses.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: February 29, 2000
    Assignee: Aeptec Microsystems, Inc.
    Inventor: Steven Chien-Young Chen
  • Patent number: 6005325
    Abstract: In a surface acoustic wave device comprising an inter-digital electrode on a surface of a substrate wherein said substrate is a langasite single crystal belonging to a point group 32, a combination of a cut angle of the substrate out of the single crystal and-a propagation direction of surface acoustic waves is optimized. This makes it possible to achieve a surface acoustic wave device comprising a substrate having a temperature coefficient of SAW velocity, TCV, the absolute value of which is small, a large electromechanical coupling factor k.sup.2, and low SAW velocity. It is thus possible to achieve a filter device which is improved in terms of temperature stability, has a wide passband, and is reduced in size, especially an intermediate-frequency surface acoustic wave filter having improved characteristics best-fitted for mobile communication terminal equipment.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: December 21, 1999
    Assignee: TDK Corporation
    Inventors: Kenji Inoue, Katsuo Sato
  • Patent number: 6005331
    Abstract: The present invention relates to radioelectronics and can find application in developing signal frequency discriminators. According to the invention, the filter comprises a piezoelectric-crystal plate 1 made of La--Ga silicate, two pairs of overlap exciting electrodes 2, 3 and 4, 5, and leads 6. There were selected experimentally in the proposed filter such a ratio between the length of the electrodes along the axis of acoustical coupling, the area of the electrodes, and the wafer thickness that makes it possible to extend the filter frequency range towards higher frequencies. The proposed filter construction provides for a higher temperature stability of the filter average frequency in a wide range of above-zero temperatures, and a reduced level of side passbands.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: December 21, 1999
    Assignee: Rafida Development Incorporated
    Inventors: Sergei Alexandrovich Sakharov, Andrei Valerievich Medvedev, Jury Vladimirovich Pisarevsky, Valentin Petrovich Litvinov
  • Patent number: 5994821
    Abstract: Rectangular piezoelectric substrates each of which has main surfaces opposed to each other, measures 50 .mu.m thick by 1 mm wide by 8 mm long, and is made of lithium niobate (LiNbO.sub.3), are directly bonded on the main surfaces so that their axes of polarization are set in directions reverse to each other, thereby composing a piezoelectric element. Electrodes which are 0.2 .mu.m thick and made of chromium-nickel are formed on the two main surfaces of the piezoelectric element opposed to each other, thereby resulting in a precision displacement control actuator of a bimorph type mechanical-electrical converter element. This configuration makes it possible to provide a compact precision displacement control actuator which has a large displacement and extremely small variations of characteristics such as displacement and resonance frequency.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: November 30, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsumi Imada, Tetsuro Otsuchi, Masato Sugimoto, Yoshihiro Tomita, Osamu Kawasaki
  • Patent number: 5955825
    Abstract: A crystal oscillator and method for manufacturing same including excitation electrode portions formed upon a crystal substrate and thus forming an excitation portion of the area defined between the electrode portions. Axis inversion portions possess an electrical axis (-X) opposite to the electrical axis (X) of the excitation portion, these axis inversion portions being formed within the crystal substrate at a position other than that of the excitation portion. A stable resonance frequency and filter frequency can be obtained even under conditions of ambient temperature fluctuation, by means of a relatively simple temperature compensation circuit, wherein handling is easy and no complicated adjustment is necessary, and low costs can be realized.
    Type: Grant
    Filed: January 23, 1997
    Date of Patent: September 21, 1999
    Assignee: Mitsubishi Materials Corporation
    Inventor: Takehiko Uno
  • Patent number: 5953433
    Abstract: A surface acoustic wave device includes a quartz rotated Y-cut plate and at least one interdigital transducer disposed on the quartz rotated Y-cut plate. The quartz rotated Y-cut plate has a Euler angle represented by (0, .theta., .o slashed.). The angle .theta. is within a range of about 125.degree.<.theta.<130.degree. or equivalents thereto, and the angle .o slashed. is approximately 90 degrees. The interdigital transducer is made of tungsten.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: September 14, 1999
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Koji Fujimoto, Michio Kadota, Toshimaro Yoneda
  • Patent number: 5939956
    Abstract: In a multiple-stage-connected multiple-mode piezoelectric filter unit having a single container 1 in which there are connected, in cascade, two multiple-mode piezoelectric filter elements comprising at least one piezoelectric substrate and two electrode groups each comprising a pair of input/output electrodes and a grounding electrode, the electrode pairs being formed on one side of the piezoelectric substrate with a predetermined gap provided and the grounding electrodes being formed on the other side of the piezoelectric substrate at positions respectively opposite to the electrode pairs, it is an object of the present invention to enhance the ability of preventing the two filter elements from being coupled with each other, thus facilitating the final adjustment thereof. Formed in a single container 1 are two piezoelectric substrates 2, 3 on each of which formed are a pair of input/output electrodes and a grounding electrode.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: August 17, 1999
    Assignee: Daishinku Corporation
    Inventors: Hiroyuki Arimura, Kimonori Kawano
  • Patent number: 5936329
    Abstract: A sapphire single crystal wafer 11 having a diameter not less than two inches and having an off-angled surface which is obtained by rotating an R (1-102) surface about a ?11-20! axis by a given off-angle is introduced in a CVD apparatus, and a double-layer structure of first and second aluminum single crystal layers 12 and 13 is deposited on the off-angled surface of the sapphire single crystal wafer by MOCVD. The thus deposited aluminum single crystal layer 13 has (1-210) surface. The first aluminum nitride single crystal layer 12 serves as a buffer layer and has a thickness of 5-50 nm, and the second aluminum nitride single crystal layer 13 has a thickness not less than 1 .mu.m. The off-angle is preferably set to a value not less than .+-.1.degree., much preferably a value .+-.2.degree., more preferably a value not less than -3.degree., and particularly preferable to a value within a range from -2.degree.-+10.degree..
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: August 10, 1999
    Assignee: NGK Insulators, Ltd.
    Inventors: Tomohiko Shibata, Yukinori Nakamura
  • Patent number: 5929555
    Abstract: A wafer with a reversed domain is prepared for two piezoelectric single crystal plates 11 and 12 having about the same thickness as each other by using direct bonding without any adhesive. Then, driving electrodes 13 are formed on two principal planes of the wafer with a reversed domain to provide a piezoelectric resonator. A piezoelectric resonator having the structure with a reverses polarization and using odd-order vibration modes vibrating with a fundamental wave has a wavelength of a thickness thereof suppresses scattering of the thickness of the domains with a reversed polarization. In the direct bonding, the axes of the spontaneous polarization of the two piezoelectric single crystal plates are reverse to each other and crystalline axes other than the axes of polarization are shifted intentionally by an angle other than zero. Thus, spurious modes are suppressed in a simple way.
    Type: Grant
    Filed: April 15, 1997
    Date of Patent: July 27, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masato Sugimoto, Katsu Takeda, Yoshihiro Tomita, Osamu Kawasaki
  • Patent number: 5925968
    Abstract: A piezoelectric vibrator includes a piezoelectric element having an electromechanical coupling coefficient of a thickness-extensional vibration mode greater than that of a thickness-share vibration mode, and a pair of electrodes arranged on surfaces of the piezoelectric element so that harmonic energy of the thickness-extensional vibration of the piezoelectric element is trapped.
    Type: Grant
    Filed: March 1, 1996
    Date of Patent: July 20, 1999
    Assignee: Fujitsu Limited
    Inventors: Masanori Yachi, Masaaki Ono
  • Patent number: 5923231
    Abstract: In a surface acoustic wave device for processing signals of relatively high frequencies, as of above 1 GHz, by the use of surface acoustic waves which propagate on the surface of a piezoelectric substrate, radiating bulk waves in the direction of depth of the piezoelectric substrate, an IDT structure is provided, which does not increase propagation loss and has sufficiently low electric resistance. The device comprises a piezoelectric substrate 10, and an electrode of a conducting film 12 for exciting, receiving, reflecting and/or propagating surface acoustic waves, and the surface acoustic waves propagate on the surface of the piezoelectric substrate, radiating at least one transverse component of bulk waves in the direction of depth of the piezoelectric substrate 10.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: July 13, 1999
    Assignee: Kinseki Limited
    Inventors: Yukio Ohkubo, Takahiro Sato
  • Patent number: 5854527
    Abstract: The surface acoustic wave device of the invention comprises a piezoelectric substrate of lithium niobate or lithium tantalate and electrodes formed on the substrate for propagating surface acoustic waves. The substrate has a cut plane and a surface acoustic wave propagation direction which are (.phi., .theta., .psi.) as expressed in Eulerian angles and within ranges substantially equivalent thereto. When the substrate is made of lithium niobate, .phi., .theta. and .psi. are 0.degree.-86.degree. or 95.degree.-180.degree., 73.degree.-118.degree. and 0.degree.-44.degree., respectively. When the substrate is made of lithium tantalate, .phi., .theta. and .psi. are 0.degree.-87.degree. or 91.degree.-180.degree., 80.degree.-120.degree. and 0.degree.-44.degree., respectively. This enables the device to exhibit high performance.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: December 29, 1998
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasutaka Shimizu, Atsuhiro Nishikata, Shigetaka Tonami
  • Patent number: 5847486
    Abstract: An inexpensive Love-wave device having a wide frequency difference between its resonant and antiresonant frequencies includes a Y-cut substrate made from LiNbO.sub.3 for X propagation. An interdigital transducer including a thin film of Ta or W is located on the substrate for exciting a Love wave.
    Type: Grant
    Filed: November 13, 1996
    Date of Patent: December 8, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Michio Kadota, Toshimaro Yoneda, Naoki Mizoguchi
  • Patent number: 5821673
    Abstract: A surface acoustic wave device capable of exhibiting high temperature stability and being downsized. The device includes a wafer constructed of a trigonal lanthanum/gallium silicate crystal cut out at predetermined cut angles (.alpha., .beta.). Application of a predetermined voltage signal to the wafer permits a surface acoustic wave to be excited in the wafer and propagate in the wafer. Supposing that the crystal has three crystal axes including an X-axis (electric axis), a Y-axis (mechanical axis) and a Z-axis (optical axis), the wafer is cut out so that a normal line (n) on a surface of the wafer has the cut angle .alpha. defined to be 20.degree..ltoreq..alpha..ltoreq.40.degree. with respect to the Y-axis in a counterclockwise direction from the Y-axis in a Y-Z plane and a propagation direction (S) of the surface acoustic wave has the cut angle .beta. defined to be 35.degree..ltoreq..beta..ltoreq.70.degree.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: October 13, 1998
    Assignees: Santech Company LImited, Bunch Limited
    Inventors: Jury Vladimirovich Pisarevsky, Vladimir Nikolaevich Fedorets, Vladimir Aleksandrovich Pankov
  • Patent number: 5804907
    Abstract: An actuator incorporating the invention includes a body of a ferroelectric material. The material is single crystalline and incorporates solid solutions of lead zinc niobate-lead titanate or lead magnesium niobate-lead titanate, described by the formulae: Pb(Zn.sub.1/3 Nb.sub.2/3).sub.1-x Ti.sub.x O.sub.3 and Pb(Mg.sub.1/3 Nb.sub.2/3).sub.l-y Ti.sub.y O.sub.3 l where x and y are defined as 0.ltoreq.x<0.10, and 0.ltoreq.y<0.40. Electrodes enable application of an electric field across the body in a direction that is generally aligned with a <001> crystallographic axis of the ferroelectric material.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: September 8, 1998
    Assignee: The Penn State Research Foundation
    Inventors: Seung-Eek Park, Thomas R. Shrout
  • Patent number: 5777419
    Abstract: A piezoelectric substrate (120) and a method for preparing same. The method includes steps of (i) providing a boule of piezoelectric material, (ii) orienting the boule to Euler angles chosen to provide a boundary condition matched to a partially-metallized surface and (iii) sawing the boule into at least a first slice (120) having first and second surfaces, at least one of the first and second surfaces comprising a planar surface. The method desirably but not essentially further includes steps of (iv) polishing at least one of the first and second surfaces to provide a substantially planar polished surface, (v) disposing a layer of metal on the at least one of the first and second surfaces and (vi) patterning the layer of metal to provide at least one interdigitated pattern (105, 110) comprising an acoustic wave transducer (105, 110), the acoustic wave transducer (105,110) providing the boundary condition matched to a partially-metallized surface.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: July 7, 1998
    Assignee: Motorola Inc.
    Inventor: David Penunuri
  • Patent number: 5763983
    Abstract: A piezoelectric transformer (10) consisting of a single-crystal elongated plate (12) with electrodes (20, 26). A pair of driving sections (22) are formed on two opposite end regions of the plate (12). A receiving section (24) is formed on a central region of the plate (12). The plate (12) is operated in an even harmonic vibrational mode with the driving sections (22) operating in a transverse extensional mode and the receiving section (24) operating in a length extensional mode. Driving signals (46, 48) applied to the driving sections (22) are at the resonant frequency of the plate (12). The gain of the transformer (10) is adjustable by shifting the relative phase of the driving signals (46, 48) applied to the respective driving sections (22).
    Type: Grant
    Filed: January 12, 1997
    Date of Patent: June 9, 1998
    Assignee: Motorola Inc.
    Inventor: Jin Huang
  • Patent number: 5744902
    Abstract: A chemical/biological sensor is formed from a coated microresonator array. In operation, both mass changes and temperature changes due to the presence of a particular substance or agent will cause an output frequency change which can be attributed to that particular substance or agent. Further, the frequency changes caused by mass loading can be distinguished from those frequency changes caused by temperature changes due to the heat from adsorption or reaction. This is because frequency changes due to mass loading are independent from frequency changes due to temperature changes, and therefore, by measuring the frequency changes of the microresonators coated with a variety of adsorbers, one can independently separate the two types of frequency changes, and, thereby, identify and quantify the adsorbing agents.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: April 28, 1998
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: John R. Vig
  • Patent number: 5739626
    Abstract: An improved piezoelectric sensor for detecting pressure, vibration, acceleration or the like physical quantity is disclosed. The pressure sensor to be attached to a cylinder block of an internal combustion engine includes a main body adapted to be attached to the cylinder and defining an axially extending hole therewithin, a diaphragm attached to one end of the main body for closing the hole; and a piezoelectric element disposed within the hole so that the pressure within the cylinder is transmitted to the piezoelectric element through the diaphragm. The piezoelectric element is a circular or polygonal disc with a thickness of 0.3-1.5 mm and is formed of a single crystal piezoelectric ceramic having a Curie temperature greater than 500.degree. C., such as LiNbO.sub.3.
    Type: Grant
    Filed: April 9, 1992
    Date of Patent: April 14, 1998
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Takao Kojima, Hideki Toyoda, Tetsuma Shimozato
  • Patent number: 5736267
    Abstract: A transparent conductive film of a zinc oxide type containing gallium and silicon, which contains silicon in an amount of from 0.01 to 1.5 mol % in terms of SiO.sub.2.
    Type: Grant
    Filed: August 16, 1995
    Date of Patent: April 7, 1998
    Assignee: Asahi Glass Company Ltd.
    Inventors: Akira Mitsui, Kazuo Sato, Masami Miyazaki, Junichi Ebisawa, Yasuo Hayashi, Masao Higeta, Katsuaki Aikawa, Atsushi Hayashi
  • Patent number: 5675208
    Abstract: A piezoelectric transformer (10) operating in a thickness-shear vibration mode (26). The piezoelectric transformer (10) comprises a lithium niobate substrate (12) having first and second acoustically coupled portions (16,22), and a plurality of substantially opposing pairs of primary and secondary electrodes (14,20) disposed thereon. An input AC voltage applied to the primary electrode pairs (14) exciting a thickness-shear vibration (26) which couples to the secondary electrode pairs (20) producing an output AC voltage therebetween. The primary and secondary electrodes (14,20) being electrically connected in various combinations of parallel and series connections to provide a desired step-up or step-down voltage transfer ratio.
    Type: Grant
    Filed: February 28, 1996
    Date of Patent: October 7, 1997
    Assignee: Motorola, Inc.
    Inventors: Jin Huang, Brian M. Mancini