Patents by Inventor Yuji Akatsu

Yuji Akatsu 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).

  • Transimpedance amplifier
    Patent number: 7868701
    Abstract: A gain switching determination circuit (250) compares/determines a comparative input voltage (Vc) from an inter-stage buffer (230) with a first hysteresis characteristic, and outputs a gain switching signal (SEL) based on the comparison/determination result to first and second transimpedance amplifier core circuits (210, 220), thereby switching the gains of the core circuits. This obviates holding a comparison input voltage with long response time in a level holding circuit for gain switching determination, which allows instantaneous gain switching determination and instantaneous response corresponding to burst data.
    Type: Grant
    Filed: August 3, 2005
    Date of Patent: January 11, 2011
    Assignees: Nippon Telephone and Telegraph Corporation, NTT Electronics Corporation
    Inventors: Makoto Nakamura, Yohtaro Umeda, Jun Endou, Yuji Akatsu, Yuuki Imai, Masatoshi Tobayashi, Yoshikazu Urabe, Hatsushi Iizuka, Eiji Hyodo
  • Transimpedance Amplifier
    Publication number: 20080309407
    Abstract: A gain switching determination circuit (250) compares/determines a comparative input voltage (Vc) from an inter-stage buffer (230) with a first hysteresis characteristic, and outputs a gain switching signal (SEL) based on the comparison/determination result to first and second transimpedance amplifier core circuits (210, 220), thereby switching the gains of the core circuits. This obviates holding a comparison input voltage with long response time in a level holding circuit for gain switching determination, which allows instantaneous gain switching determination and instantaneous response corresponding to burst data.
    Type: Application
    Filed: August 3, 2005
    Publication date: December 18, 2008
    Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NITT ELECTRONICS CORPORATION
    Inventors: Makoto Nakamura, Yohtaro Umeda, Jun Endou, Yuji Akatsu, Yuuki Imsi, Masatoshi Tobayashi, Yoshikazu Urabe, Hatsushi Iizuka, Eiji Hyodo
  • Optical wavelength division multiplexing transmission network system using transmitting/receiving apparatuses having 2-input and 2-output optical path switching elements
    Patent number: 6643463
    Abstract: An optical wavelength division multiplexing transmission network system having a star-topology network is disclosed, which comprises an arrayed-waveguide grating type multiplexing/demultiplexing circuit having N input ports and N output ports, and N transmitting/receiving apparatuses, each apparatus including a transmitter, receiver, demultiplexer, multiplexer, and N 2-input and 2-output optical path switching elements corresponding to N wavelengths, so as to cope with a damage to a transmitting or receiving portion corresponding to a specific wavelength. Each switching element is independently switched between first and second connective conditions.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: November 4, 2003
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Senichi Suzuki, Masao Kawachi, Kennosuke Fukami, Yuji Akatsu, Kazutosi Kato, Mitsuru Harada, Junichi Akahani, Atsushi Takahara