Patents by Inventor Tomohiro Nagai

Tomohiro Nagai 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: 7212087
    Abstract: H plane and E plane of a second rectangular waveguide element are inclined at an angle of 45° with respect to H plane and E plane of a first rectangular waveguide element. A connection element disposed between the first and second rectangular waveguide elements has an inner periphery that surrounds a central axis extending in a direction of electromagnetic-wave propagation. The inner periphery includes surfaces parallel to H plane and E plane of the first rectangular propagation path element, and these surfaces form a staircase such that abutting sections between the surfaces parallel to H plane and the surfaces parallel to E plane constitute projections. The staircase is inclined in a direction corresponding to a direction in which H plane of the second rectangular propagation path element is inclined.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: May 1, 2007
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Tomohiro Nagai
  • Publication number: 20070075801
    Abstract: A waveguide conversion device including a rectangular waveguide connected to a circular waveguide, and an unnecessary-wave suppression groove provided at a mode conversion part between the rectangular waveguide and the circular waveguide. The unnecessary-wave suppression groove prevents an unnecessary transmission mode from being excited at the mode conversion part between the rectangular waveguide and the circular waveguide.
    Type: Application
    Filed: October 20, 2004
    Publication date: April 5, 2007
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventors: Takeshi Okano, Tomohiro Nagai
  • Publication number: 20070035461
    Abstract: An antenna device having a primary radiator that includes a transmitting section formed of a cylindrical waveguide extending parallel to a direction in which the front of the antenna device faces (front direction), and a rectangular horn-shaped radiant section extending perpendicular to the front direction. A waveguide whose central axis in the extending direction corresponds to that of the transmitting section of the primary radiator is connected to an end of the transmitting section via a rotary joint so as to be rotatable. A first reflector is of an offset parabolic type, and is disposed above the primary radiator in a predetermined position with respect to the primary radiator such that a predetermined directivity is obtained. A second reflector is parabolic in the vertical direction, and is toric in the horizontal direction. The second reflector is disposed below the primary radiator in a predetermined position with respect to the primary radiator such that a predetermined directivity is obtained.
    Type: Application
    Filed: October 19, 2006
    Publication date: February 15, 2007
    Inventor: Tomohiro Nagai
  • Publication number: 20060202909
    Abstract: A design process first determines a desired aperture distribution, then converts the electric power conservation law, Snell's law on the rear face side of a dielectric lens, and the formula representing light-path-length constraint, into simultaneous equations, and computes the shapes of the surface and rear face of the dielectric lens depending on the azimuthal angle ? of a primary ray from the focal point of the dielectric lens to the rear face of the dielectric lens, and then reduces the light path length in the formula showing light-path-length constraint by an integral multiple of the wavelength when the coordinates on the surface of the dielectric lens reach a predetermined restriction thickness position. A dielectric lens is designed by sequentially changing the lazimuthal angle ? from its initial value, and also repeating the second and third steps.
    Type: Application
    Filed: March 22, 2006
    Publication date: September 14, 2006
    Inventor: Tomohiro Nagai
  • Publication number: 20060158382
    Abstract: A conductor member contains a linear feed waveguide extending in a fixed direction and a plurality of horn antennas coupled to the feed waveguide and set at an interval of about one half of a wavelength in the extending direction of the feed waveguide. The horn antennas are formed by horns and coupling waveguides, and the coupling waveguides are set so as to partially enter the feed waveguide. When the size of the spatial coupling portion formed by the entrance is changed, the degree of coupling between the feed waveguide and each of the coupling waveguides changes.
    Type: Application
    Filed: November 22, 2005
    Publication date: July 20, 2006
    Inventor: Tomohiro Nagai
  • Patent number: 7064726
    Abstract: An antenna apparatus includes two circular waveguides including a fixed-side circular waveguide and a rotation-side circular waveguide, each having a propagation mode in a TM01 mode, and being arranged coaxially with each other while a waveguide-side choke is provided between the two waveguides. A rectangular waveguide is connected to the fixed-side circular waveguide. Thereby, the high-frequency signal fed from the rectangular waveguide to the fixed-side circular waveguide can be radiated from a primary radiator to which the rotation-side circular waveguide is connected. While the circular waveguides and the waveguide-side choke can constitute a rotary joint, by rotating the primary radiator together with the rotation-side circular waveguide, scanning can be carried out with a high-frequency signal radiated from the primary radiator.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: June 20, 2006
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobumasa Kitamori, Tomohiro Nagai
  • Publication number: 20060097816
    Abstract: H plane and E plane of a second rectangular waveguide element are inclined at an angle of 45° with respect to H plane and E plane of a first rectangular waveguide element. A connection element disposed between the first and second rectangular waveguide elements has an inner periphery that surrounds a central axis extending in a direction of electromagnetic-wave propagation. The inner periphery includes surfaces parallel to H plane and E plane of the first rectangular propagation path element, and these surfaces form a staircase such that abutting sections between the surfaces parallel to H plane and the surfaces parallel to E plane constitute projections. The staircase is inclined in a direction corresponding to a direction in which H plane of the second rectangular propagation path element is inclined.
    Type: Application
    Filed: August 5, 2004
    Publication date: May 11, 2006
    Inventor: Tomohiro Nagai
  • Publication number: 20050270247
    Abstract: An antenna apparatus includes two circular waveguides including a fixed-side circular waveguide and a rotation-side circular waveguide, each having a propagation mode in a TM01 mode, and being arranged coaxially with each other while a waveguide-side choke is provided between the two waveguides. A rectangular waveguide is connected to the fixed-side circular waveguide. Thereby, the high-frequency signal fed from the rectangular waveguide to the fixed-side circular waveguide can be radiated from a primary radiator to which the rotation-side circular waveguide is connected. While the circular waveguides and the waveguide-side choke can constitute a rotary joint, by rotating the primary radiator together with the rotation-side circular waveguide, scanning can be carried out with a high-frequency signal radiated from the primary radiator.
    Type: Application
    Filed: August 13, 2003
    Publication date: December 8, 2005
    Inventors: Nobumasa Kitamori, Tomohiro Nagai
  • Patent number: 6433741
    Abstract: A directional coupler including a first transmission line and a second transmission line adjacent to the first transmission line, the relative positions of the first transmission line and the second transmission line being changeable, an antenna element connected to a part of the directional coupler, and a driving mechanism for driving the directional coupler and the antenna element.
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: August 13, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Toru Tanizaki, Ikuo Takakuwa, Tomohiro Nagai, Kazutaka Higashi
  • Publication number: 20010052876
    Abstract: A directional coupler including a first transmission line and a second transmission line adjacent to the first transmission line, the relative positions of the first transmission line and the second transmission line being changeable, an antenna element connected to a part of the directional coupler, and a driving mechanism for driving the directional coupler and the antenna element.
    Type: Application
    Filed: July 2, 1999
    Publication date: December 20, 2001
    Inventors: TORU TANIZAKI, IKUO TAKAKUWA, TOMOHIRO NAGAI, KAZUTAKA HIGASHI