Patents by Inventor Akihiko Akasegawa

Akihiko Akasegawa 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).

  • Patent number: 7221238
    Abstract: A compact superconducting filter device can easily change a bandwidth and a center frequency without changing a pattern or shape of the filter. A filter pattern is formed on a substrate made of a dielectric material. The filter pattern is made of a superconductor material. A signal input line and a signal output line are formed on the substrate so as to extend from a periphery of the filter pattern. An adjust plate is located above the filter pattern with a predetermined distance therebetween. The adjust plate is formed of one of an electrically conductive material, a superconductive material and a dielectric material.
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: May 22, 2007
    Assignee: Fujitsu Limited
    Inventors: Teru Nakanishi, Akihiko Akasegawa, Manabu Kai, Kazunori Yamanaka
  • Patent number: 7218184
    Abstract: A superconducting filter including input/output feeders formed on one surface of a dielectric substrate, resonator patterns formed on one surface of the dielectric substrate, and a dielectric plate mounted on the one surface of the dielectric substrate with a plurality of spacers formed on said one surface of the dielectric substrate disposed therebetween. The dielectric plate covers the region including the resonator patterns, and the input/output feeders length-wise over the length within ±20% of positive integer times a ¼ effective wavelength from the sides nearer to the resonator patterns.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: May 15, 2007
    Assignee: Fujitsu Limited
    Inventors: Kazunori Yamanaka, Teru Nakanishi, Manabu Kai, Akihiko Akasegawa
  • Patent number: 6980841
    Abstract: A resonator is formed by forming a microstrip line having an electrical length corresponding to a ?/2 wavelength on a dielectric substrate, forming both side portions of the microstrip line from the center thereof into spiral shapes, making the orientations of the spirals opposite each other, making outer-side portions of the spiral shapes on both sides, inclusive of the central portion of the microstrip line, linear in shape overall, and making linear in shape a portion of prescribed range from the end portion of each spiral shape.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: December 27, 2005
    Assignee: Fujitsu Limited
    Inventors: Manabu Kai, Kazunori Yamanaka, Teru Nakanishi, Akihiko Akasegawa
  • Publication number: 20050272609
    Abstract: A transmission line is provided which has a low loss and can flow large current. A superconductor transmission line has: an internal conductor; and an external conductor surrounding the internal conductor, made of oxide superconductor and having four planes, which four planes have a cross section of a hollow quadrilateral with each corner portion being removed, and adjacent planes of which define a slit narrower than ?/4 (? being a wavelength of a high frequency wave to be transmitted).
    Type: Application
    Filed: August 16, 2005
    Publication date: December 8, 2005
    Applicant: FUJITSU LIMITED
    Inventors: Akihiko Akasegawa, Kazunori Yamanaka, Teru Nakanishi
  • Publication number: 20050261135
    Abstract: The superconducting filter comprises input/output feeders 14a, 14b formed on one surface of a dielectric substrate 10, resonator patterns 16a-16e formed on said one surface of the dielectric substrate 10, and a dielectric plate 24 mounted on said one surface of the dielectric plate 24 with a plurality of spacers 20, 22 formed on said one surface of the dielectric substrate 10. The dielectric plate 24 covers the region including the resonator patterns 16a-16e, and the input/output feeders 14a, 14b length-wise over the length within ±20% of positive integer times a ¼ effective wavelength from the sides nearer to the resonator patterns.
    Type: Application
    Filed: September 27, 2004
    Publication date: November 24, 2005
    Applicant: FUJITSU LIMITED
    Inventors: Kazunori Yamanaka, Teru Nakanishi, Manabu Kai, Akihiko Akasegawa
  • Publication number: 20050256010
    Abstract: A compact superconducting filter device can easily change a bandwidth and a center frequency without changing a pattern or shape of the filter. A filter pattern is formed on a substrate made of a dielectric material. The filter pattern is made of a superconductor material. A signal input line and a signal output line are formed on the substrate so as to extend from a periphery of the filter pattern. An adjust plate is located above the filter pattern with a predetermined distance therebetween. The adjust plate is formed of one of an electrically conductive material, a superconductive material and a dielectric material.
    Type: Application
    Filed: January 27, 2005
    Publication date: November 17, 2005
    Applicant: FUJITSU LIMITED
    Inventors: Teru Nakanishi, Akihiko Akasegawa, Manabu Kai, Kazunori Yamanaka
  • Publication number: 20050256008
    Abstract: A compact superconducting filter device can easily change a bandwidth and a center frequency without changing a pattern or shape of the filter. A filter pattern is formed on a substrate made of a dielectric material. The filter pattern is made of a superconductor material. A signal input line and a signal output line are formed on the substrate so as to extend from a periphery of the filter pattern. An adjust plate is located above the filter pattern with a predetermined distance therebetween. The adjust plate is made of an electrically conductive material.
    Type: Application
    Filed: September 23, 2004
    Publication date: November 17, 2005
    Applicant: FUJITSU LIMITED
    Inventors: Teru Nakanishi, Akihiko Akasegawa, Manabu Kai, Kazunori Yamanaka
  • Patent number: 6889068
    Abstract: A superconducting signal transmission apparatus provided with a vacuum container 11, a superconducting electronic device 12 provided in the vacuum container 11, an input side transmission line 13 and output side transmission line 14 for connection to the superconducting electronic device 12 through the vacuum container 11, and a cooling mechanism (15, 16, 17) for cooling the superconducting electronic device 12 and further having a heat cutoff signal transmission unit 20 inserted at least at part of the input side and output side transmission lines 13 and 14. The heat cutoff signal transmission unit 20 is comprised of a substrate 31 and a flat circuit body 30 provided with a signal transmission line 32 and ground layer (33, 33-1, 33-2). The substrate 31 is comprised of a dielectric material having a small heat conductivity. The conductor portions forming the signal transmission line 32 and the ground layer are formed with thin thicknesses enabling suppression of the inflow of heat from the outside.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: May 3, 2005
    Assignee: Fujitsu Limited
    Inventors: Manabu Kai, Toru Maniwa, Kazunori Yamanaka, Akihiko Akasegawa
  • Publication number: 20050020452
    Abstract: A coaxial connector 10 to be connected to a coaxial cable comprising a surface coating layer 20 of indium or an indium alloy being formed on the surface of a terminal 12 which is a central conductor. Since indium similar to an indium-based solder material is used as the material of the surface coating layer 20, a reaction product is prevented from being produced in indium-based solder by the reaction between the material of the surface coating layer 20 and the material of the indium-based solder material. Accordingly, deterioration of the flexibility of the indium-based solder can be prevented, and a superconducting device which can endure the repeated temperature changes between the room temperature and lower temperatures can be provided.
    Type: Application
    Filed: August 19, 2004
    Publication date: January 27, 2005
    Applicant: Fujitsu Limited
    Inventors: Teru Nakanishi, Akihiko Akasegawa, Kazunori Yamanaka
  • Publication number: 20050009709
    Abstract: A resonator is formed by forming a microstrip line having an electrical length corresponding to a ?/2 wavelength on a dielectric substrate, forming both side portions of the microstrip line from the center thereof into spiral shapes, making the orientations of the spirals' opposite each other, making outer-side portions of the spiral shapes on both sides, inclusive of the central portion of the microstrip line, linear in shape overall, and making linear in shape a portion of prescribed range from the end portion of each spiral shape.
    Type: Application
    Filed: August 12, 2004
    Publication date: January 13, 2005
    Inventors: Manabu Kai, Kazunori Yamanaka, Teru Nakanishi, Akihiko Akasegawa
  • Patent number: 6823201
    Abstract: A superconducting microstrip filter capable of achieving an improvement of power resistance without enlarging the overall size and while maintaining steep cut characteristics. This filter has a resonator section including at least one resonator. This resonator forms a current density reduction part in one part of its line pattern. Also, the filter has an input line section arranged adjoining the resonator of an initial stage. Current density reduction parts are formed in one part of this input line section. Alternatively, the input line section is comprised of a normal conductor.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: November 23, 2004
    Assignee: Fujitsu Limited
    Inventors: Manabu Kai, Toru Maniwa, Kazunori Yamanaka, Akihiko Akasegawa
  • Publication number: 20040041656
    Abstract: A dielectric waveguide which comprises a first single crystal magnesium oxide block having a surface of face (001), (100) or (010) and a first copper oxide superconducting film formed on the above-described surface in a c-axis crystal orientation perpendicular to the surface, and a method of production thereof are provided.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 4, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Kazunori Yamanaka, Akihiko Akasegawa, Masafumi Shigaki, Isao Nakazawa
  • Patent number: 6690957
    Abstract: A high temperature superconductor film which is Y—Ba—Cu—O-based and formed on a dielectric substrate 10, and has a Cu composition ratio to the Ba near the upper surface of the film which is higher than a Cu composition ratio to the Ba inside the film. The YBCO-based high temperature superconductor film is formed with a Cu composition on the film surface maintained higher with respect to the stoichiometric composition, whereby the Cu oxide can be easily produced while the production of the yttrium oxides can be depressed. The yttrium oxides cannot be easily produced, which makes it difficult for pores and crystal strains to be generated while the Cu oxide functions as a flux for advancing the crystal growth, whereby the YBCO-based high temperature superconductor film can have good film quality and single crystal. The superconducting elements can be formed of the YBCO-based high temperature superconducting film of such good film quality.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: February 10, 2004
    Assignee: Fujitsu Limited
    Inventors: Akihiko Akasegawa, Kazunori Yamanaka, Teru Nakanishi
  • Publication number: 20030073584
    Abstract: A high temperature superconductor film which is Y—Ba—Cu—O-based and formed on a dielectric substrate 10, and has a Cu composition ratio to the Ba near the upper surface of the film which is higher than a Cu composition ratio to the Ba inside the film. The YBCO-based high temperature superconductor film is formed with a Cu composition on the film surface maintained higher with respect to the stoichiometric composition, whereby the Cu oxide can be easily produced while the production of the yttrium oxides can be depressed. The yttrium oxides cannot be easily produced, which makes it difficult for pores and crystal strains to be generated while the Cu oxide functions as a flux for advancing the crystal growth, whereby the YBCO-based high temperature superconductor film can have good film quality and single crystal. The superconducting elements can be formed of the YBCO-based high temperature superconducting film of such good film quality.
    Type: Application
    Filed: March 20, 2002
    Publication date: April 17, 2003
    Applicant: Fujitsu Limited
    Inventors: Akihiko Akasegawa, Kazunori Yamanaka, Teru Nakanishi
  • Publication number: 20030016094
    Abstract: A superconducting microstrip filter capable of achieving an improvement of power resistance without enlarging the overall size and while maintaining steep cut characteristics. This filter has a resonator section including at least one resonator. This resonator forms a current density reduction part in one part of its line pattern. Also, the filter has an input line section arranged adjoining the resonator of an initial stage. Current density reduction parts are formed in one part of this input line section. Alternatively, the input line section is comprised of a normal conductor.
    Type: Application
    Filed: July 26, 2002
    Publication date: January 23, 2003
    Inventors: Manabu Kai, Toru Maniwa, Kazunori Yamanaka, Akihiko Akasegawa
  • Publication number: 20020187902
    Abstract: A superconducting signal transmission apparatus provided with a vacuum container 11, a superconducting electronic device 12 provided in the vacuum container 11, an input side transmission line 13 and output side transmission line 14 for connection to the superconducting electronic device 12 through the vacuum container 11, and a cooling mechanism (15, 16, 17) for cooling the superconducting electronic device 12 and further having a heat cutoff signal transmission unit 20 inserted at least at part of the input side and output side transmission lines 13 and 14. The heat cutoff signal transmission unit 20 is comprised of a substrate 31 and a flat circuit body 30 provided with a signal transmission line 32 and ground layer (33, 33-1, 33-2). The substrate 31 is comprised of a dielectric material having a small heat conductivity. The conductor portions forming the signal transmission line 32 and the ground layer are formed with thin thicknesses enabling suppression of the inflow of heat from the outside.
    Type: Application
    Filed: July 29, 2002
    Publication date: December 12, 2002
    Inventors: Manabu Kai, Toru Maniwa, Kazunori Yamanaka, Akihiko Akasegawa
  • Patent number: 6367266
    Abstract: A heat insulation chamber according to the present invention is a heat insulation chamber which is made of heat insulating material and forms an inner chamber for accommodating an electronic part. This heat insulation chamber achieves coupling between the electronic part accommodated in the inner chamber formed within a cabinet and the outside of the cabinet by a radio transmission path or a coupling path by static coupling or inductive coupling. A thermostatic chamber and a cryostat according to the present invention comprise the aforementioned heat insulation chamber, a heat exchanger mounted in the heat insulation chamber, and a thermoregulator which maintains the temperature of the inner chamber accommodating the electronic part at an operating temperature of the electronic part through the heat exchanger.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: April 9, 2002
    Assignee: Fujitsu Limited
    Inventors: Kazuhiko Kobayashi, Kazunori Yamanaka, Akihiko Akasegawa, Yoshiharu Tozawa, Fumihiko Kobayashi, Ichiro Abeno