Patents by Inventor Kengo Asai

Kengo Asai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070120623
    Abstract: A surface acoustic wave device in the present invention is provided with a piezoelectric substrate, a supporting substrate being jointed to the piezoelectric substrate and including a material different in expansion coefficient from the piezoelectric substrate and an interdigital electrode for exciting a surface acoustic wave, the electrode being arranged on the surface of the piezoelectric substrate. Either the interdigital electrode or the piezoelectric substrate is configured so that the interdigital electrode is 40% or more to 70% or less as long as the piezoelectric substrate in the direction to which a surface acoustic wave propagates.
    Type: Application
    Filed: September 1, 2006
    Publication date: May 31, 2007
    Inventors: Kazuyuki Sakiyama, Kengo Asai, Atsushi Isobe, Kunio Matsumoto, Shinichi Fujiwara
  • Patent number: 7221242
    Abstract: A bulk acoustic wave resonator in which the problem of the technology for forming the diaphragm structure is resolved, which is more compact and improved the frequency accuracy, and the manufacturing method thereof, a filter using the same, a semiconductor integrated circuit device using the same, and a high frequency module using the same are provided. The bulk acoustic wave resonator according to the present invention comprises a substrate having a first surface and a second surface opposite to the first surface, and a staked resonator including a first electrode film in contact with the first surface, a piezoelectric film overlaying the first electrode film and a second electrode film overlaying the piezoelectric film.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: May 22, 2007
    Assignee: Hitachi Media Electronics Co., Ltd
    Inventors: Kengo Asai, Hisanori Matsumoto, Atsushi Isobe, Mitsutaka Hikita
  • Publication number: 20070069606
    Abstract: The present invention provides a film bulk acoustic wave resonator (FBAR) filter that can keep the Q factor high. The FBAR filter comprises a first FBAR with a first resonant frequency and a second FBAR with a second resonant frequency, formed on a same substrate. The FBAR filter has such a structure that a first underlayer is formed between the substrate and a first bottom electrode layer and a second underlayer is formed between the substrate and a second bottom electrode layer, the first underlayer thickness being different from the second underlayer thickness.
    Type: Application
    Filed: November 21, 2006
    Publication date: March 29, 2007
    Inventors: Hisanori Matsumoto, Kengo Asai, Atsushi Isobe, Mitsutaka Hikita
  • Publication number: 20060267710
    Abstract: A bulk acoustic wave resonator which has excellent elasticity and high electromechanical energy conversion efficiency. A bulk acoustic wave resonator comprises a substrate, a lower electrode formed on the substrate, an interlayer formed on the lower electrode layer, a piezoelectric layer formed on the interlayer, and an upper electrode layer formed on the piezoelectric layer.
    Type: Application
    Filed: February 2, 2006
    Publication date: November 30, 2006
    Inventors: Hisanori Matsumoto, Tomio Iwasaki, Kengo Asai, Nobuhiko Shibagaki
  • Publication number: 20060206126
    Abstract: A blade for used in corneal surgery for incising and separating a corneal epithelium into a flap shape, the blade includes: an edge tip portion including a distal end and two upper and lower edge tip surfaces. An angle formed between the two edge tip surfaces is not smaller than 60° and smaller than 140°, and a height of the edge tip portion is not smaller than 3 ?m.
    Type: Application
    Filed: February 1, 2006
    Publication date: September 14, 2006
    Inventors: Masahiro Sugimura, Kengo Asai
  • Publication number: 20060158283
    Abstract: A piezoelectric thin film resonator is formed on a base substrate such as made of Si in which the resonance frequency is substantially determined by the lateral size not by the thickness of the resonator, whereby a resonator for use in TCXO, etc. is provided by the thin film technique, which enables to reduce the thickness of the film and the size of the resonator and integration with Si-based IC incorporating the resonator in one identical substrate.
    Type: Application
    Filed: January 18, 2006
    Publication date: July 20, 2006
    Inventors: Mitsutaka Hikita, Nobuhiko Shibagaki, Atsushi Isobe, Kengo Asai, Hisanori Matsumoto
  • Publication number: 20060139122
    Abstract: A bulk acoustic wave resonator in which the problem of the technology for forming the diaphragm structure is resolved, which is more compact and improved the frequency accuracy, and the manufacturing method thereof, a filter using the same, a semiconductor integrated circuit device using the same, and a high frequency module using the same are provided. The bulk acoustic wave resonator according to the present invention comprises a substrate having a first surface and a second surface opposite to the first surface, and a staked resonator including a first electrode film in contact with the first surface, a piezoelectric film overlaying the first electrode film and a second electrode film overlaying the piezoelectric film.
    Type: Application
    Filed: February 28, 2005
    Publication date: June 29, 2006
    Inventors: Kengo Asai, Hisanori Matsumoto, Atsushi Isobe, Mitsutaka Hikita
  • Publication number: 20050168102
    Abstract: The present invention provides a film bulk acoustic wave resonator (FBAR) filter that can keep the Q factor high. The FBAR filter comprises a first FBAR with a first resonant frequency and a second FBAR with a second resonant frequency, formed on a same substrate. The FBAR filter has such a structure that a first underlayer is formed between the substrate and a first bottom electrode layer and a second underlayer is formed between the substrate and a second bottom electrode layer, the first underlayer thickness being different from the second underlayer thickness.
    Type: Application
    Filed: August 3, 2004
    Publication date: August 4, 2005
    Inventors: Hisanori Matsumoto, Kengo Asai, Atsushi Isobe, Mitsutaka Hikita
  • Publication number: 20050099252
    Abstract: An inexpensive MEMS switch which stably operates at low voltage and its fabrication method are provided. The switch comprises: a first anchor 7-2-1 formed over a substrate 3; a first spring 7-3-1 connected to the first anchor; an upper electrode 7-1 which is connected to the first spring and makes a motion above the substrate, elastically deforming the first spring; a lower electrode 1 formed over the substrate, positioned under the upper electrode; a second spring 7-3-2 connected to the upper electrode; and a second anchor 7-2-2 connected to the second spring. When voltage is applied to between the upper electrode and the lower electrode and the upper electrode makes a downward motion, the second anchor is brought into contact with the substrate. As a result, the second spring is elastically deformed. When the upper electrode is subsequently brought into contact with the lower electrode, thereby the upper electrode and the lower electrode are electrically connected with each other.
    Type: Application
    Filed: July 30, 2004
    Publication date: May 12, 2005
    Inventors: Atsushi Isobe, Akihisa Terano, Kengo Asai, Hiroyuki Uchiyama, Hisanori Matsumoto
  • Patent number: 6346761
    Abstract: A surface acoustic wave device which includes a piezoelectric substrate, and an interdigital transducer formed on a planar surface of the piezoelectric substrate, and having first and second bus bars, a first plurality of electrode fingers connected to the first bus bar, and a second plurality of electrode fingers connected to the second bus bar. The first and second plurality of electrode fingers of the interdigital transducer have an electrode cross region in which the first and second plurality of electrode fingers are arranged alternatively. Each boundary between the first and second bus bars and a grating region of the first and second plurality of electrode fingers is arranged such that the boundary is not substantially parallel, with a transmission direction of surface acoustic waves excited by the interdigital transducer.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: February 12, 2002
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventors: Atsushi Isobe, Mitsutaka Hikita, Kengo Asai, Atsushi Sumioka
  • Patent number: 5814917
    Abstract: Aluminum is used for the interdigital transducer mounted on a piezoelectric substrate to realize a surface acoustic wave transducer having a small capacity ratio, no spurious resonance, and a low loss. A .theta. rotated Y cut lithium niobate single crystal piezoelectric substrate is used for the piezoelectric material, a metal film of which principal ingredient is aluminum is used for the interdigital transducer, the direction of the interdigital transducer is made parallel to the X-axis of the lithium niobate single crystal, and thick h and electrode pitch P of the interdigital transducer have the following relationship:(.theta.+5).sup.2 /300+11/12.ltoreq.h/P.times.100-8.ltoreq.-0.0001.times.(.theta.+5).sup.3 +0.1625.times.(.theta.+5)+5.5and-30.ltoreq..theta..ltoreq.20.
    Type: Grant
    Filed: July 10, 1996
    Date of Patent: September 29, 1998
    Assignee: Hitachi Media Electronics Co., Ltd.
    Inventors: Atsushi Isobe, Mitsutaka Hikita, Chisaki Takubo, Kengo Asai
  • Patent number: 5604059
    Abstract: A mask structure has two (or more) groups of device patterns formed on one transparent support plate. Each of the device patterns has a transparent partial pattern. One or both of the groups of device patterns are provided with phase shifting patterns for improvement of the resolution in the lithography. The transparent partial pattern in each of the device patterns in each of the device pattern groups is determined such that each of the transparent partial patterns held by one of the device pattern groups is adapted for combination with one transparent partial pattern held by the other device pattern group by two or more times of transmission of an exposure beam through the mask structure. Manufacturing of solid-state devices is possible by use of the mask structure, in which exposure of a photo-sensitive film on a substrate to an exposure beam through the mask structure is repeated two or more times with a relative position between the mask structure and the substrate being changed.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: February 18, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Ryo Imura, Yoshinori Hoshina, Kengo Asai, Mitsutaka Hikita, Atsushi Isobe, Ryo Suzuki, Kohji Oda, Kazuyuki Sakiyama