Fujitsu Corporation

Fujitsu Media Devices Limited

Yoshiro Fujiwara

Masanori Ueda

Sumio Yamada

Osamu Kawachi

Noboru Wakatsuki

Gou Endoh

Yuji Kojima

Masaaki Ono

Hiroshi Hoshino

Hiroshi Ishikawa

Yoshio Satoh

Masanori Yachi

Kazushi Hashimoto

Masanobu Yanagisawa

Osamu Ikata

Michiko Endo

Hideki Ohmori

Kazunari Komenou

Shigeo Tanji

Kiyoshi Satoh

Takumi Kooriike

Kuninori Kawaura

Akira Hirano

A surface acoustic wave device includes: interdigital transducers; first electrode pads that are connected to the interdigital transducers through wire patterns; and a piezoelectric substrate on which the interdigital transducers, the first electrode pads, and the wire patterns, are formed. In this surface acoustic wave device, at least one of the first electrode pads is not connected to a ground pattern, and the piezoelectric substrate has a conductivity in the range of 10/&#x3a9;&#xb7;cm to 10/&#x3a9;&#xb7;cm.

Surface acoustic wave device and method of producing the same

A tuning-fork vibratory gyro has first and second arms and a base integrally connected to the first and second arms. The gyro includes drive electrodes used to generate tuning-fork vibrations due to a piezoelectric transversal effect, and detection electrodes provided on the first and second arms and used to output a detection voltage due to an angular velocity.

Tuning-fork vibratory gyro

A surface acoustic wave device supported by a package body. At least one surface acoustic wave element having interdigital electrodes disposed on a propagation path of a surface acoustic wave on the piezoelectric substrate. These interdigital electrodes include an input-side interdigital electrode connected to a ground pad on the package body and an output-side interdigital electrode connected to another ground pad on the package body.

Surface-acoustic-wave device having an improved pass-band characteristic and an improved degree of freedom for setting input and output impedances

Tuning fork vibratory gyro utilizing a piezoelectric transversal effect

A filter device includes at least two filter elements provided in a package, each of the filter elements passing only signals within a predetermined frequency band, the predetermined frequency bands of the filter elements having center frequencies which are distinct from each other. An input terminal is connected to and shared by respective inputs of the filter elements. An output terminal is connected to and shared by respective outputs of the filter elements.

Filter device and dual-band radio system in which the filter device is

A piezoelectric substrate having two reflectors along a propagation path of a surface acoustic wave and three interdigital electrodes provided on said piezoelectric substrate consecutively between the reflectors. A primary side electrode is connected to an input/output terminal and a secondary side electrode is connected to a second input/output terminal. Each interdigital electrode includes include pairs of electrode fingers, where the pair of electrodes for one interdigital electrode is different than a pair of electrodes for another interdigital electrode.

Surface-acoustic-wave device having an improved pass-band characteristic

A double-mode surface-acoustic device having a piezoelectric substrate with two reflectors placed on the piezoelectric substrate and first through third interdigital electrodes placed on the substrate consecutively between the two reflectors. Each electrode containing first through third number of pairs of electrode fingers, respectively.

Surface-acoustic-wave three interdigital electrodes with different

This invention relates to an acoustic surface wave device suitably used in a high-frequency circuit, in which high attenuation characteristics are provided. The present invention includes an acoustic surface wave element, a ceramic package having a ceramic substrate of a multi-layer structure, the ceramic substrate having a die-attach portion on which the acoustic surface wave element is mounted, the ceramic package having an input terminal and an output terminal connected to the acoustic surface wave element, the ceramic package having an opening located above the ceramic substrate, each of the input terminal and the output terminal having a ground terminal, and a metallic cap sealing the opening of the ceramic package. The metallic cap is electrically connected to one of the ground terminal of the input terminal and the ground terminal of the output terminal.

Acoustic surface wave device

A surface-acoustic-wave device includes at least first and second surface-acoustic-wave elements formed on a common piezoelectric substrate and cascaded with each other, each of the first and second surface-acoustic-wave elements including a plurality of interdigital electrodes having a plurality of electrode fingers overlapping with each other in correspondence to a path of a surface acoustic wave on the piezoelectric substrate, wherein the width of overlapping of the electrode fingers is changed between the first surface-acoustic-wave element and the second surface-acoustic-wave element.

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. In the device, a ratio of the number of pairs of the electrode fingers in one of the front transducer and the rear transducer to the number of pairs of the electrode fingers in the middle transducer is in a range between 55% and 80%.

Surface acoustic wave filter device on 40.degree. to 42.degree. rotated

An acoustic surface wave element having an oscillation frequency stable against temperature changes, and a wide range of oscillation frequency adjustment, is provided by an acoustic surface wave element comprising: a substrate of a 36.degree. rotated Y-cut single crystal lithium tantalate having X, Y and Z crystal axes and a top surface and side walls; electrodes formed on the top surface of the substrate such that an acoustic surface wave is propagated in a direction of the X-axis of the substrate and an oscillation of the acoustic surface wave occurs at a predetermined frequency, the electrodes having a thickness equal to 1 to 4% of a wavelength of the acoustic surface wave at the oscillation; and a plasma CVD-deposited layer of silicon dioxide covering the electrodes and the substrate, the silicon dioxide layer having a refractive index of 1.445 to 1.486 and a thickness equal to 16 to 26% of the wavelength of the acoustic surface wave at the oscillation.

Acoustic surface wave element

A position detector having a magnetic sensor for measuring linear or angular displacement, or detecting a position of a body without contact thereto. The detector has a closed circuit including magnets and yokes. The magnetic leakage flux which emanates from the inside surfaces of the yokes is utilized to detect the position of the body. The magnetic sensor is transferred along the inside surfaces of the yokes by a transferring circuit, which senses the magnetic field intensity of the leakage flux distributed thereon. This enables the detector to have a longer measuring range than that of a prior art detectors. An output signal is stable due to the shielding effect of the yokes. The magnetic closed circuit has many magnetic and mechanical configurations. For example, for the magnet, a permanent magnet and an electromagnet can be used. Further, improvements are proposed for enhancing the linearity of the output signal voltage with respect to the transferring distance of the sensing element and for compensating the offset drift of an amplifier or changing the coercive force of permanent magnets.

Position detecting apparatus using a magnetic sensor and a closed

A piezoelectric resonator includes a base plate and a strip-type, energy trapping piezoelectric resonator chip mounted on the base plate. The piezoelectric resonator chip includes a piezoelectric chip plate and a pair of electrode patterns formed on the opposed main surfaces of the piezoelectric chip plate. One main surface of the piezoelectric chip plate faces the base plate and is parallel therewith, and a conductive layer is formed on each end of the main surface facing the base plate. The thickness of the conductive layer is greater than that of the electrode pattern so that the electrode pattern is separated from the base plate. The conductive layer is directly mounted onto a conductive portion of the base plate, so as to electrically connect the electrode pattern and the conductive portion of the base plate.

Method for producing a piezoelectric resonator

A piezoelectric resonator with a rectangular parallelepiped resonator. A lithium niobate single crystal is used as the resonator chip material. Each of the opposed main surfaces of the resonator chip is arranged to be a surface of a rotated Y-cut plate which is rotated 165.+-.5 degrees about an X-axis. The angle of the longitudinal direction of the resonator chip is arranged to be 90.+-.5 degrees with respect to the X-axis of the rotated Y-cut plate.

Piezoelectric resonator using 165.degree. Y-cut LiNbO.sub.3

A piezoelectric resonator chip which includes a piezoelectric chip plate and a pair of electrode patterns which is formed on the opposite surfaces of the piezoelectric chip plate, the electrode patterns face each other through the piezoelectric chip plate. At least one of the electrode patterns has an adjuster pattern which includes a narrow cutting pattern and a separation pattern which is connected to the electrode pattern through the cutting pattern and which faces the other electrode pattern.

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Kawasaki, Japan

Yoshiro Fujiwara