Orientation Of Piezoelectric Material Patents (Class 310/313A)
  • Patent number: 6163099
    Abstract: A surface acoustic wave device includes a piezoelectric substrate made of a Langasite single crystal and at least one interdigital transducer including a pair of comb-shaped electrodes which are interdigitated with each other and are in contact with the piezoelectric substrate. The piezoelectric substrate has a Euler angle of approximately (0.degree., 130.degree. to 170.degree., 23.degree. to 30.degree.), whereby the surface acoustic wave device has an excellent TCD and also has a large K.sup.2 value.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: December 19, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Michio Kadota, Makoto Kumatoriya
  • Patent number: 6154105
    Abstract: A surface acoustic wave device includes a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) that satisfies 122.degree..ltoreq..theta..ltoreq.131.degree.. An interdigital transducer made of an electrode material including at least one of Ta and W is disposed on the quartz substrate.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: November 28, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Koji Fujimoto, Michio Kadota, Toshimaro Yoneda, Takeshi Nakao
  • 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: 6140738
    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: September 13, 1999
    Date of Patent: October 31, 2000
    Assignee: TDK Corporation
    Inventors: Kenji Inoue, Katsuo Sato
  • 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: 6127768
    Abstract: The SAW device comprises a diamond or quartz substrate as a wave propagation layer, a piezoelectric layer on the wave propagation layer and at least one interdigitated electrode on the piezoelectric layer.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: October 3, 2000
    Assignee: Kobe Steel USA, Inc.
    Inventors: Brian R. Stoner, Robert B. Henard, David L. Dreifus, Bradley A. Fox
  • 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: 6097131
    Abstract: A lanthanum gallium tantalate single crystal substrate, referred to as langatate, 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 langatate piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langatate 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: March 17, 1999
    Date of Patent: August 1, 2000
    Assignee: Sawtek Inc.
    Inventors: Natalya F. Naumenko, Leland P. Solie
  • Patent number: 6084333
    Abstract: On a substrate made of a single crystal of La.sub.3 Ga.sub.5.5 Nb.sub.0.5 O.sub.14, an excitation electrode 2 for generating a surface acoustic wave is provided to produce a surface acoustic wave device S. The cutting angles of the substrate and the direction of propagation of the surface acoustic wave are defined in Eulerian angle indication (.phi., .theta., .psi.) by .phi.=50.degree.+60.degree..times.m1, .theta.=125.degree.+180.degree..times.m2 and .psi.=40.degree.+180.degree..times.m3 (where m1, m2 and m3 are integers). Eulerian angles may be .phi.=10.degree.+60.degree..times.n1, .theta.=125.degree.+180.degree..times.n2, and .psi.=70.degree.+180.degree..times.n3 (where n1, n2 and n3 are integers) or .phi.=a1+60.degree..times.b1, .theta.=a2+180.degree..times.b2 and .psi.=a3+180.degree..times.b3 (where 0.degree..ltoreq.a1.ltoreq.60.degree., 125.degree..ltoreq.a2.ltoreq.165.de gree., 110.degree..ltoreq.a3.ltoreq.165.degree., and b1, b2 and b3 are integers).
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: July 4, 2000
    Assignee: Kyocera Corporation
    Inventors: Shinji Inoue, Akihiko Kataoka, Shin Murakami, Takayuki Shimizu, Tetsuo Niwa
  • Patent number: 6072264
    Abstract: A lanthanum gallium silicate single crystal substrate, referred to as langasite, 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 langasite piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langasite crystal cut and wave propagation directions are defined which reduce insertion loss due to SAW transduction, diffraction, and beam steering. As a result, temperature stability for the SAW device is improved. A low power flow angle and reduced level of diffraction is also achieved.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: June 6, 2000
    Assignee: Sawtek Inc.
    Inventors: Natalya F. Naumenko, Victor S. Orlov
  • 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: 6049155
    Abstract: In accordance with the invention, the piezoelectric layer of a SAW device is mechanically coupled to a substrate of temperature-sensitive material having a large coefficient of thermal expansion or contraction. In a preferred embodiment, the temperature-sensitive material is a nickel/titanium alloy having high negative coefficient of thermal expansion of about -200.times.10.sup.-6. The frequency of the device can be tuned by changing the temperature of operation.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: April 11, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: John Edwin Graebner, Sungho Jin, Hareesh Mavoori, Wei Zhu
  • 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: 6037699
    Abstract: The invention provides a surface acoustic wave device which has a thin film formed on a surface of a substrate adapted to excite longitudinal wave-type surface acoustic waves, longitudinal wave-type quasi surface acoustic waves or longitudinal wave-type surface skimming bulk waves to thereby give an increased electromechanical coupling coefficient and at the same time minimize the temperature coefficient of delay time. For example, in a surface acoustic wave device having an aluminum thin film formed on a surface of a lithium tantalate substrate, the direction of propagation of longitudinal wave-type quasi surface acoustic waves is (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles and within a range equivalent thereto, and the product of wave number of longitudinal wave-type quasi surface acoustic waves and the thickness of the thin film is at least 1.0, preferably in the range of 1.3 to 2.0. The device provided exhibits higher performance than in the paior art.
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: March 14, 2000
    Assignees: Sanyo Electric Co., Ltd., Yasutaka Shimizu
    Inventors: Yasumi Kobayashi, Kuniyuki Matsui, Yasuhiro Hirao, Kosuke Takeuchi, Kenichi Shibata, Yusuke Takahashi, Tateo Kondo, Yasutaka Shimizu
  • Patent number: 6031315
    Abstract: A quartz single crystal substrate (12), includes a prescribed range of Euler angles for substrate and crystal orientation which improves signal processing for surface acoustic wave (SAW) devices (10). When a voltage is applied to an input inter digital transducer (IDT) (16) of the SAW device (10), a surface acoustic wave is generated in the quartz substrate (12). The surface acoustic wave propagates in a direction generally perpendicular to electrodes (20) of the IDT (16). The quartz crystal cut and wave propagation directions are defined to reduce the adverse effects of diffraction on SAW devices (10). As a result, frequency response distortions and insertion loss increases due to diffraction are reduced while maintaining good temperature stability and a low power flow angle.
    Type: Grant
    Filed: July 15, 1998
    Date of Patent: February 29, 2000
    Assignee: Sawtek Inc.
    Inventor: Benjamin P. Abbott
  • Patent number: 6025636
    Abstract: A surface acoustic wave device includes at least diamond, a single crystal LiNbO.sub.3 layer formed on the diamond, and an interdigital transducer formed in contact with the LiNbO.sub.3 layer and uses a surface acoustic wave (wavelength: .lambda..sub.n .mu.m) in an nth-order mode (n=1 or 2). When the thickness of the LiNbO.sub.3 layer is t.sub.1 (.mu.m), kh.sub.1 =2.pi.(t.sub.1 /.lambda..sub.n) and the cut orientation (.theta., .PHI., and .psi. represented by an Eulerian angle representation) with respect to the crystallographic fundamental coordinate system of the LiNbO.sub.3 layer are selected from values within specific ranges. Consequently, a surface acoustic wave device which increases the propagation velocity (V) of a surface acoustic wave and improves the electromechanical coupling coefficient (K.sup.2) is realized.
    Type: Grant
    Filed: October 16, 1997
    Date of Patent: February 15, 2000
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Hideaki Nakahata, Masashi Narita, Kenjiro Higaki, Satoshi Fujii, Hiroyuki Kitabayashi, Shin-ichi Shikata
  • 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: 5959389
    Abstract: A first surface acoustic wave device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention is a SAW device of "type A" device shown in FIG. 6A, wherein a parameter kh3=2.pi.(t.sub.A /.lambda.) is: 0.033.ltoreq.kh3.ltoreq.0.099, and wherein a parameter kh1=2.pi.(t.sub.Z /.lambda.) and a parameter kh2=2.pi.(t.sub.S /.lambda.) are given within a region ABCDEFGHIJKLA in a two-dimensional Cartesin coordinate graph of FIG. 1.
    Type: Grant
    Filed: November 4, 1997
    Date of Patent: September 28, 1999
    Assignee: Sumitomo Electronic Industries, Ltd.
    Inventors: Hideaki Nakahata, Tomoki Uemura, Kenjiro Higaki, Satoshi Fujii, Hiroyuki Kitabayashi, Shin-ichi Shikata
  • Patent number: 5959388
    Abstract: In accordance with the invention, the operating frequency of a SAW device is magnetically tuned. In a first embodiment, the SAW device comprises a piezoelectric layer mechanically coupled to a substrate or body of magnetostrictive material. Strains magnetically induced in the magnetostrictive substrate is coupled to the piezoelectric layer, altering the velocity at which it can transmit acoustic waves. In an alternative embodiment, surface waves are directly generated in a magnetostrictive material and the velocity is directly altered by an applied magnetic field.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: September 28, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: John Edwin Graebner, Sungho Jin, Wei Zhu
  • 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: 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: 5920143
    Abstract: A surface acoustic wave device is disclosed which includes a piezoelectric substrate upon which a surface wave propagation film, which is comprised of a diamond-like carbon or aluminum nitride film, is provided.
    Type: Grant
    Filed: July 15, 1997
    Date of Patent: July 6, 1999
    Assignee: Sanyo Electric Co. Ltd.
    Inventors: Hisaki Tarui, Keiichi Kuramoto, Hitoshi Hirano, Yoichi Domoto
  • Patent number: 5917265
    Abstract: A lanthanum gallium silicate single crystal substrate, referred to as langasite, 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 langasite piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langasite crystal cut and wave propagation directions are defined which reduce insertion loss due to SAW transduction, diffraction, and beam steering. As a result, temperature stability for the SAW device is improved. A low power flow angle and reduced level of diffraction is also achieved.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: June 29, 1999
    Assignee: Sawtek Inc.
    Inventors: Natalya F. Naumenko, Victor S. Orlov
  • Patent number: 5914645
    Abstract: In a surface acoustic wave device comprising a substrate of lithium tantalate or lithium niobate, and interdigital electrodes formed on the substrate and made of a thin film consisting primarily of aluminum, the interdigital electrodes are optimized in the ratio of the thickness of the film to the period of a plurality of electrode digits connected to a common terminal with propagation loss taken as an objective function. The ratio is set in the range of 0.03 to 0.10 to ensure a lower propagation loss than in the prior art.
    Type: Grant
    Filed: June 4, 1997
    Date of Patent: June 22, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasumi Kobayashi, Kuniyuki Matsui, Naoki Tanaka, Hiroshi Okano, Tatsuro Usuki, Kenichi Shibata
  • Patent number: 5905325
    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: January 6, 1998
    Date of Patent: May 18, 1999
    Assignee: Sawtek Inc.
    Inventors: Natalya F. Naumenko, Leland P. Solie
  • Patent number: 5896636
    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 22, 1997
    Date of Patent: April 27, 1999
    Assignee: Motorola Inc.
    Inventor: David Penunuri
  • Patent number: 5895996
    Abstract: A SAW device utilizing elastic surface waves, in which the Q value indicating resonance sharpness is high, and which presents excellent frequency temperature characteristics and short-term frequency stability. In a SAW device according to the present invention, an IDT and two reflectors are in parallel in the propagation direction of the phase of the elastic surface waves. The IDT and reflectors are disposed to cover the power flow direction, which is the propagation direction of energy of the elastic surface waves, whereby the energy of the elastic surface waves is efficiently confined. Moreover, it becomes possible to manufacture the SAW device utilizing a piezoelectric crystal in which angle .theta. and angle .psi. indicating excellent frequency temperature characteristics are 25 to 45 degrees and 40 to 47 degrees, respectively. It is also possible to manufacture the SAW device utilizing a piezoelectric crystal where angle .psi. is related to angle .theta. such that .theta.=2.775.times.(.psi.-32.5)+6.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: April 20, 1999
    Assignee: Seiko Epson Corporation
    Inventors: Michiaki Takagi, Eishi Momosaki, Yoshinori Ikusaka
  • Patent number: 5891557
    Abstract: A diamond base material for surface acoustic wave device, which includes: a low-resistivity base material, and a high-resistivity diamond layer having a thickness of 5-50 .mu.m disposed on the low-resistivity base material.
    Type: Grant
    Filed: April 15, 1997
    Date of Patent: April 6, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shin-ichi Shikata, Hideaki Nakahata, Kenjiro Higaki, Satoshi Fujii, Akihiro Hachigo
  • Patent number: 5888646
    Abstract: A surface acoustic wave device comprises a diamond layer (12) or a substrate (11) with a diamond layer (12) formed thereon, an Al electrode (13) formed on the diamond layer (12), and a ZnO piezoelectric thin film layer (14) formed on the diamond layer (12) with the Al electrode (13) covered by the ZnO piezoelectric thin film layer (14). The ZnO piezoelectric thin film layer (14) has a thickness h1 within a range defined by 0.65.ltoreq.kh1.ltoreq.0.75 while the Al electrode (13) has a thickness h2 within a range defined by 0.03.ltoreq.kh2.ltoreq.0.04, where k is given by k=2 .pi./.lambda. and .lambda. represents an electrode period.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: March 30, 1999
    Assignees: NEC Corporation, Sumitomo Electric Industries, Ltd.
    Inventors: Yoshihiro Takahashi, Yasushi Yamamoto, Natsuhiko Sakairi, Shin-Ichi Shikata, Hideaki Nakahata, Kenjiro Higaki, Satoshi Fujii, Hiroyuki Kitabayashi
  • Patent number: 5874869
    Abstract: A surface acoustic wave device includes a piezoelectric substrate of a LiTaO.sub.3 single crystal, the crystal having X, Y and Z axes and a cut plane. The X axis of the crystal is oriented in a direction of propagation of surface acoustic waves. The cut plane of the crystal is rotated around the X axis at a rotated angle from the Y axis to the Z axis, the rotated angle being in a range between 40.degree. and 42.degree.. A pair of reflectors are formed on the substrate and aligned in a row in the direction of propagation. Interdigital transducers are formed on the substrate and aligned in the row in the direction of propagation, the interdigital transducers interposed between the reflectors, each interdigital transducer having pairs of mutually opposed primary electrode fingers and secondary electrode fingers, the interdigital transducers including at least a front transducer, a middle transducer and a rear transducer aligned in the row in the direction of propagation.
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: February 23, 1999
    Assignee: Fujitsu Limited
    Inventors: Masanori Ueda, Osamu Kawachi, Gou Endoh, Yoshiro Fujiwara
  • Patent number: 5867074
    Abstract: A surface acoustic wave resonator unit using surface acoustic wave, in which a surface acoustic wave resonator formed by disposing an IDT and reflectors on a piezoelectric member thereof is mounted by a cantilever method so that a surface acoustic wave resonator unit exhibiting very stable resonance frequency, a low resonance resistance and a large Q-value is realized. By accommodating the surface acoustic wave resonator in a housing in a vacuum state, the Q-value can be enlarged. By anodic-oxidizing the electrodes forming the IDT, a thick oxide film can be formed, the oxide film enabling the electrodes to be protected from problems, such as short circuit taking due to foreign matters, such as dust, with the characteristics maintained. If the high performance surface acoustic wave resonator unit is molded together with a lead frame by resin, a surface acoustic wave device, that can be mounted on the surface, and that exhibits excellent reliability and high quality, can be provided.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: February 2, 1999
    Assignee: Seiko Epson Corporation
    Inventors: Hiroyuki Ogiso, Shuuichi Iguchi, Fumitaka Kitamura
  • 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: 5838089
    Abstract: Embedded IDT electrodes are provided in a multilayer structure consisting of a diamond layer on a substrate with IDT electrodes formed on the diamond and a very thin interlayer covering the interdigitated transducer structure and the diamond, thus embedding the IDT electrodes between the diamond layer and the interlayer, with a piezoelectric layer on the interlayer so that an acoustic surface wave propagates in the diamond layer. The very thin interlayer between the diamond and the piezoelectric layer greatly increases the uniformity of the piezoelectric layer but does not interfere with the acoustic properties of a SAW device.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: November 17, 1998
    Assignee: Kobe Steel USA Inc.
    Inventors: David L. Dreifus, Joseph S. Holmes
  • Patent number: 5838090
    Abstract: An object of the present invention is to improve an SAW propagation velocity V, an electromechanical coupling coefficient (K.sup.2), and a delay time temperature coefficient (TCD) to achieve a high-frequency SAW device and power saving and size reduction of the device. An SAW device according to the present invention includes at least diamond as a substrate material, a c-axis oriented polycrystalline LiNbO.sub.3 layer, arranged on the diamond, an SiO.sub.2 layer arranged on the LiNbO.sub.3 layer, and an interdigital transducer and uses an SAW in an nth mode (n=0, 1, 2: wavelength: .lambda. .mu.m). When the thickness of the LiNbO.sub.3 layer is t.sub.1 (.mu.m), and the thickness of the SiO.sub.2 layer is t.sub.2 (.mu.m), kh.sub.1 =2.pi.(t.sub.1 /.lambda.) and kh.sub.2 =2.pi.(t.sub.2 /.lambda.) fall within predetermined ranges. In addition, the mode of the SAW is selected. With this arrangement, an SAW device having a propagation velocity (V) of 7,000 m/s or more, an electromechanical coupling coefficient (K.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: November 17, 1998
    Assignee: Sumitomo Electric Industries, ltd.
    Inventors: Hideaki Nakahata, Kenjiro Higaki, Satoshi Fujii, Hiroyuki Kitabayashi, Shin-ichi Shikata
  • Patent number: 5837332
    Abstract: A method and apparatus for preparing thin films, a device, an electronic and magnetic apparatus, an information recording and reproducing apparatus, an information processing apparatus and a crystal preparing method from the molten state. A thin film is prepared as the substrate or the surface of the substrate is being excited and characterized by a device having at least a substrate and a thin film with at least one layer prepared thereon and an electronic and magnetic apparatus having integration of the devices, wherein at least one layer of the thin film is prepared as the surface of the substrate is being excited. The recording and reproducing apparatus for recording and reproducing information is composed of an information memory medium device having a recording layer of the thin film prepared as the surface of the substrate is being excited and a recording head whose core is prepared as the surface of the substrate is being excited.
    Type: Grant
    Filed: July 31, 1996
    Date of Patent: November 17, 1998
    Assignees: Nihon Victor Kabushiki-kaisha, Kabushiki-kaisha Hitachi Seisakusho
    Inventors: Migaku Takahashi, Katsuya Yokoyama, Jun Yamada, Takashi Shiba
  • 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: 5814918
    Abstract: The present invention directed to a SAW device comprising a diamond layer a ZnO layer and an SiO.sub.2 layer, which can be operated at the frequency of 2 GHz or higher, with superior durability and less energy loss. The SAW device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention comprises: (i) a diamond layer, (ii) a ZnO layer formed on the diamond layer, the ZnO layer having a thickness t.sub.z, (iii) an interdigital transducer (IDT) formed over the ZnO layer, and (iv) a SiO.sub.2 layer formed over the interdigital transducer onto the ZnO layer, the SiO.sub.2 layer having a thickness of t.sub.s ; wherein parameters kh.sub.z =(2.pi./.lambda.)t.sub.z and kh.sub.s =(2.pi./.lambda.)t.sub.s are given within a region A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-A in a two-dimensional Cartesian coordinate graph having abscissa axis of kh.sub.z and ordinate axis of kh.sub.
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: September 29, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideaki Nakahata, Kenjiro Higaki, Satoshi Fujii, Hiroyuki Kitabayashi, Shinichi Shikata
  • Patent number: 5783896
    Abstract: A first surface acoustic wave device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention is a SAW device of "type A" device shown in FIG. 6A, wherein a parameter kh3=2.pi.(t.sub.A /.lambda.) is: 0.033.ltoreq.kh3.ltoreq.0.099, and wherein a parameter kh1=2.pi.(t.sub.z /.lambda.) and a parameter kh2=2.pi.(t.sub.s /.lambda.) are given within a region ABCDEFGHIJKLA in a two-dimensional Cartesin coordinate graph of FIG. 1.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: July 21, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideaki Nakahata, Kenjiro Higaki, Satoshi Fujii, Hiroyuki Kitabayashi, Shin-ichi Shikata
  • Patent number: 5777422
    Abstract: The present invention directed to a SAW device comprising a diamond layer thinner ZnO layer, which can be operated at higher frequency, with superior characteristics including less energy loss. The first SAW device according to the present invention comprises a layer constitution shown in FIG. 23, wherein, for 0th mode surface acoustic wave having a wavelength .lambda., a parameter kh3 =(2.pi./.lambda.)t3 satisfies: 0.0470.ltoreq.kh3.ltoreq.0.0625, and wherein a parameter kh1 =(2.pi./.lambda.)t1 and a parameter kh2=(2.pi./.lambda.)t2 are given within a region A-B-C-D-E-F-A in a two-dimensional Cartesian coordinate graph having ordinate axis of the kh1 and abscissa axis of kh2, the outer edge of the region A-B-C-D-E-F-A being given by a closed chain in the Cartesian coordinate, consisting of points A, B, C, D, E, and F, and lines A-B, B-C, C-D, D-E, E-F and F-A, as shown in a two-dimensional Cartesian coordinate graph of FIG. 3.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: July 7, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroyuki Kitabayashi, Hideaki Nakahata, Kenjiro Higaki, Satoshi Fujii, Shin-ichi Shikata
  • 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: 5773911
    Abstract: A surface acoustic wave device including a piezoelectric substrate having NSPUDT behavior and a directionality reversed electrode structure including positive electrode, negative electrode and floating electrode. Positive and negative electrode fingers each having a width of .lambda./8 are arranged interdigitally at a pitch of .lambda. and floating electrode fingers having a width of 3 .lambda./8 are arranged between successive positive and negative fingers with an edge distance of .lambda./8. A directivity due to NSPUDT behavior of the substrate can be reversed. Positive and negative electrode fingers are arranged interdigitally at a pitch of .lambda. and between successive positive and negative electrode fingers are arranged floating electrode fingers having a reflecting coefficient different from that of the positive and negative electrodes.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: June 30, 1998
    Assignee: NGK Insulators, Ltd.
    Inventors: Mitsuhiro Tanaka, Masao Takeuchi, Kazuhiko Yamanouchi, Hiroyuki Odagawa
  • Patent number: 5773917
    Abstract: This invention relates to a surface acoustic wave device and a production process thereof. An electrode is formed by alternately laminating a film of an aluminum alloy containing at least copper added thereto and a copper film on a piezoelectric substrate. While the particle size of the multi-layered electrode materials is kept small, the occurrence of voids in the film is prevented and life time of the surface acoustic wave device is elongated.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: June 30, 1998
    Assignee: Fujitsu Limited
    Inventors: Yoshio Satoh, Osamu Ikata, Hidema Uchishiba, Takashi Matsuda, Tokihiro Nishihara, Mitsuo Takanatsu, Hajime Taniguchi
  • Patent number: 5760524
    Abstract: A surface acoustic wave (SAW) device (300) is formed from a leaky wave mode piezoelectric substrate (310) to have substantially reduced surface wave attenuation when operating at a particular frequency. The SAW device (300) includes a SAW pattern (322, 324), disposed on a surface (321) of the piezoelectric substrate, having a free surface portion (324) and a shorted surface portion (322). The SAW pattern (322, 324) is overlaid with a material (330), preferably glass, which has a thickness selected to reduce surface wave attenuation.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: June 2, 1998
    Assignee: Motorola, Inc.
    Inventors: Robert J. Higgins, Jr., Fred S. Hickernell
  • Patent number: 5760523
    Abstract: A surface acoustic wave transducing device comprising a piezoelectric substrate, a nonpiezoelectric plate and an interdigital transducer formed on an upper end surface of the piezoelectric substrate. One end surface of the nonpiezoelectric plate is mounted on the upper end surface of the piezoelectric substrate through the interdigital transducer. When using the surface acoustic wave transducing device as an input device, an electric signal is applied to the interdigital transducer. In this time, a surface acoustic wave is excited on an area, in contact with the interdigital transducer, of the upper end surface of the piezoelectric substrate, and then, the surface acoustic wave is transmitted to the nonpiezoelectric plate.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: June 2, 1998
    Inventor: Kohji Toda
  • Patent number: 5760522
    Abstract: The invention provides a surface acoustic wave device which has a thin film formed on a surface of a substrate adapted to excite longitudinal wave-type surface acoustic waves, longitudinal wave-type quasi surface acoustic waves or longitudinal wave-type surface skimming bulk waves to thereby give an increased electromechanical coupling coefficient and at the same time minimize the temperature coefficient of delay time. For example, in a surface acoustic wave device having an aluminum thin film formed on a surface of a lithium tantalate substrate, the direction of propagation of longitudinal wave-type quasi surface acoustic waves is (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles and within a range equivalent thereto, and the product of wave number of longitudinal wave-type quasi surface acoustic waves and the thickness of the thin film is at least 1.0, preferably in the range of 1.3 to 2.0. The device provided exhibits higher performance than in the paior art.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: June 2, 1998
    Assignees: Sanyo Electric Co., Ltd., Yasutaka Shimizu
    Inventors: Yasumi Kobayashi, Kuniyuki Matsui, Yasuhiro Hirao, Kosuke Takeuchi, Kenichi Shibata, Yusuke Takahashi, Tateo Kondo, Yasutaka Shimizu
  • Patent number: 5757250
    Abstract: A surface acoustic module is stable, and its operation frequencies can be varied with high precision. A method of manufacturing the surface acoustic module prevents the module's electrodes from being broken during separation of a sheet of modules into individual components. The surface acoustic module includes electrodes for transmitting and receiving a surface acoustic wave, a surface acoustic wave transmitting substrate, a high resistance thin film, and a thin film for differentiating the transmission velocity of a surface acoustic wave at the high resistance thin film from that at the substrate. The method includes the steps of forming a metallic film on a sheet of the surface acoustic wave transmitting substrate, of forming the electrodes on the metallic film, and of irradiating light or the like to the metallic film so as to increase the film's resistivity.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: May 26, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yo Ichikawa, Hideaki Adachi, Kentaro Setsune, Syunichiro Kawashima
  • 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: 5729186
    Abstract: A resonator ladder surface acoustic wave (SAW) filter, which has a wide and flat pass band without spurious signals therein is provided. An input electrode, a serial arm SAW resonator, an output electrode, a parallel arm SAW resonator and a ground electrode are respectively formed on a 41.degree.-rotated Y-cut X-propagation lithium niobate substrate. The serial arm SAW resonator comprises a pair of interdigital transducers (IDTs) to excite SAW, one of which is connected to the input electrode. The output electrode is connected to the other IDT of the serial arm SAW resonator. The parallel arm SAW resonator comprises a pair of IDTs to excite SAW, one of which is connected to the output electrode. And the ground electrode is connected to the other IDT of the parallel arm SAW resonator. The IDTs are metal films of Al or Al-based alloy, and the thickness of the metal films ranges from 2.5% to 7.5% of the electrode cycle of the IDT of the parallel arm SAW resonator.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: March 17, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shun-ichi Seki, Kazuo Eda, Yutaka Taguchi, Keiji Onishi, Hiroki Sato, Osamu Kawasaki
  • Patent number: 5723934
    Abstract: A surface acoustic wave position-sensing device comprising a piezoelectric substrate, a nonpiezoelectric plate, at least two surface acoustic wave transducing units X and Y having N propagation lanes U.sub.Xi (i=1, 2, ...... , N) and U.sub.Yi (i=1, 2, ...... , N), respectively, and a controlling system connected with the units X and Y. Each unit includes input and output interdigital transducers formed on the upper end surface of the piezoelectric substrate. One end surface of the nonpiezoelectric plate is mounted on the upper end surface of the piezoelectric substrate through the interdigital transducers. When an electric signal E.sub.T is applied to the input interdigital transducer, a surface acoustic wave is excited on an area, in contact with the input interdigital transducer, of the upper end surface of the piezoelectric substrate.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: March 3, 1998
    Inventor: Kohji Toda
  • Patent number: 5719536
    Abstract: In a resonator-type surface acoustic wave filter comprising a lithium tantalate substrate, lithium niobate substrate or lithium tetraborate substrate having a cut plane of high velocity, the direction of propagation of surface acoustic waves is set within the range of (40 deg to 90 deg, 40 deg to 90 deg, 0 deg to 60 deg) as expressed in Eulerian angles, and the capacitance Cos of the series resonators and the capacitance Cop of the parallel resonators are set within a predetermined range formulated with the center frequency taken as a parameter. Optimum ranges of the required design parameters are thus clarified to assure the resonator-type surface acoustic wave filter of higher performance.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: February 17, 1998
    Assignees: Sanyo Electric Co., Ltd., Yasutaka Shimizu
    Inventors: Kuniyuki Matsui, Yasuhiro Hirao, Yasumi Kobayashi, Kosuke Takeuchi, Kenichi Shibata, Yusuke Takahashi, Tateo Kondo, Yasutaka Shimizu