Patents by Inventor Tatsuto Okamoto

Tatsuto Okamoto 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: 6836674
    Abstract: Disclosed is a control apparatus capable of more effectively utilizing radio resources. Mobile stations positioned close to each other are treated as one group, and a direction and width (radiation angle) of a beam radiated from an adaptive array antenna 11 is controlled for each group so that one beam capture one group. To be concrete, a plurality of mobile stations are classified into groups by a classification section 19, and an area to which each group moves is estimated by a directivity determination section 20. The adaptive array antenna 11 is controlled by the directivity control section 15 so that one beam can cover an area in which one group is positioned and the area to which this one group moves.
    Type: Grant
    Filed: March 1, 2001
    Date of Patent: December 28, 2004
    Assignees: Hitachi, Ltd., KDDI Corporation
    Inventors: Tsuyoshi Taniguchi, Tatsuto Okamoto, Satoshi Masuda, Toshiro Suzuki, Takashi Inoue, Sumaru Niida
  • Publication number: 20020034967
    Abstract: Disclosed is a control apparatus capable of more effectively utilizing radio resources. Mobile stations positioned close to each other are treated as one group and a direction and width (radiation angle) of a beam radiated from an adaptive array antenna 11 is controlled for each group so that one beam capture one group. To be concrete, a plurality of mobile stations are classified into groups by a classification section 19, and an area to which each group moves is estimated by a directivity determination section 20. The adaptive array antenna 11 is controlled by the directivity control section 15 so that one beam can cover an area in which one group is positioned and the area to which this one group moves.
    Type: Application
    Filed: March 1, 2001
    Publication date: March 21, 2002
    Inventors: Tsuyoshi Taniguchi, Tatsuto Okamoto, Satoshi Masuda, Toshiro Suzuki, Takashi Inoue, Sumaru Niida
  • Patent number: 5774792
    Abstract: This invention is intended to realize a high frequency switch with a low distortion characteristic. In an SPDT switch consisting of a plurality of FETs, the FET on the receiver side through which a received signal passes and the shunt FET on the transmitter side are each formed of series-connected FETs, and a capacitor is connected between the first gate and the source and between the second gate and the drain. An inductance is connected in parallel with a series connection of FETs. This easily realizes a high frequency switch having a low voltage and a low distortion characteristic. The 1 dB compression level, an index of input-output characteristic, can be improved more than 5 dB over the conventional SPDT switch at an input level.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: June 30, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Tanaka, Tatsuto Okamoto, Taro Kitayama, Masao Yamane