Patents by Inventor Nobuhiro Kuga

Nobuhiro Kuga 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: 8558533
    Abstract: According to a reception passive intermodulation measurement method of the present invention, a device under test is set to the mismatching condition, and a standing wave is generated on a transmission line where the sample is connected. Since the tip of the transmission line is short-circuited using the sample, the sample is positioned at the anti-node of the standing wave, and test signals are applied at a high current density. System noise is calibrated with the tip of the transmission line being open. Since impedance matching is not required and terminators are not employed, a large measurement dynamic range is obtained without being affected by passive intermodulation that is generated in terminators. The sample is very small, and an arbitrary shape can be selected. The property measurement is enabled for a wide range of materials, regardless of a conductive material, an insulating material and a magnetic material.
    Type: Grant
    Filed: February 23, 2007
    Date of Patent: October 15, 2013
    Assignee: Yokohama National University
    Inventors: Nobuhiro Kuga, Yasuyuki Yamamoto
  • Publication number: 20100295533
    Abstract: According to a reception passive intermodulation measurement method of the present invention, a device under test is set to the mismatching condition, and a standing wave is generated on a transmission line where the sample is connected. Since the tip of the transmission line is short-circuited using the sample, the sample is positioned at the anti-node of the standing wave, and test signals are applied at a high current density. System noise is calibrated with the tip of the transmission line being open. Since impedance matching is not required and terminators are not employed, a large measurement dynamic range is obtained without being affected by passive intermodulation that is generated in terminators. The sample is very small, and an arbitrary shape can be selected. The property measurement is enabled for a wide range of materials, regardless of a conductive material, an insulating material and a magnetic material.
    Type: Application
    Filed: February 23, 2007
    Publication date: November 25, 2010
    Applicant: YOKOHAMA NATIONAL UNIVERSITY
    Inventors: Nobuhiro Kuga, Yasuyuki Yamamoto, Mitsuru Doi, Atsunori Endo
  • Patent number: 7582569
    Abstract: A distributor (30) includes a square waveguide (31) to be connected to a microwave oscillator (20) and a square waveguide (41) having a plurality of openings (43) formed in a narrow wall (41B). The square waveguide (31) is hollow. A wave delaying member (53) having a relative dielectric constant ?r is arranged in the square waveguide (41). Narrow walls (31A, 41A) of the two square waveguides (31, 41) are brought into contact with each other, and a communication hole (32) through which the two waveguides (31, 41) communicate with each other is formed in the narrow walls (31A, 41A). The widths of the two waveguides (31, 41) do not become narrow at their connecting portion even if the width of the communication hole (32) is decreased. Thus, a band of a frequency that can pass through the connecting portion is suppressed from becoming narrow. Consequently, reflection loss that occurs when the frequency of electromagnetic waves to be input to the distributor (30) changes can be decreased.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: September 1, 2009
    Assignees: Tokyo Electron Limited
    Inventors: Tadahiro Ohmi, Naohisa Goto, Nobuhiro Kuga, Akihiko Hiroe
  • Publication number: 20070133919
    Abstract: A distributor (30) includes a square waveguide (31) to be connected to a microwave oscillator (20) and a square waveguide (41) having a plurality of openings (43) formed in a narrow wall (41B). The square waveguide (31) is hollow. A wave delaying member (53) having a relative dielectric constant ?r is arranged in the square waveguide (41). Narrow walls (31A, 41A) of the two square waveguides (31, 41) are brought into contact with each other, and a communication hole (32) through which the two waveguides (31, 41) communicate with each other is formed in the narrow walls (31A, 41A). The widths of the two waveguides (31, 41) do not become narrow at their connecting portion even if the width of the communication hole (32) is decreased. Thus, a band of a frequency that can pass through the connecting portion is suppressed from becoming narrow. Consequently, reflection loss that occurs when the frequency of electromagnetic waves to be input to the distributor (30) changes can be decreased.
    Type: Application
    Filed: March 10, 2004
    Publication date: June 14, 2007
    Applicants: TOKYO ELECTRON LIMITED
    Inventors: Tadahiro Ohmi, Naohisa Goto, Nobuhiro Kuga, Akihiko Hiroe
  • Publication number: 20030019653
    Abstract: A contact surface structure including furring layers made of non-magnetic nickel formed by an electroless plating of nickel and gold plating layers applied on the furring layers is provided on contact surfaces of male and female metal members constituting a central conductor of coaxial connector. A coaxial connector having an intermodulation distortion suppressed effectively, a high mechanical strength, a high ruggedness, and can be manufactured at a low cost is realized by providing an intermetallic contact surface structure.
    Type: Application
    Filed: April 25, 2002
    Publication date: January 30, 2003
    Applicant: NGK Insulators, Ltd.
    Inventors: Nobuhiro Kuga, Syuhei Ishikawa, Yoshiki Ishibashi