Patents by Inventor Yumihiko ANNAKA

Yumihiko ANNAKA 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).

  • Radio communication apparatus and antenna calibration method
    Patent number: 10541760
    Abstract: A radio communication apparatus configured to perform frequency conversion on a first transmission signal modulated at a frequency in a specific frequency band into a second transmission signal having a frequency in a transmission frequency band, in which the apparatus includes: a circuit configured to generate a first calibration signal having a frequency higher than a highest frequency in the specific frequency band, and a second calibration signal having a frequency lower than a lowest frequency of the specific frequency band; a circuit configured to add the first and second calibration signals to the first transmission signal; a circuit configured to estimate a phase at a center frequency in the specific frequency band of the first transmission signal, and output a phase correction coefficient corresponding to the estimated phase; and a circuit configured to correct the phase of the first transmission signal, based on the phase correction coefficient.
    Type: Grant
    Filed: November 30, 2018
    Date of Patent: January 21, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Akihiko Komatsuzaki, Shinichiro Kobayashi, Ryo Koizumi, Toshiyuki Takada, Yumihiko Annaka, Hiroshi Yasui
  • RADIO COMMUNICATION APPARATUS AND ANTENNA CALIBRATION METHOD
    Publication number: 20190199454
    Abstract: A radio communication apparatus configured to perform frequency conversion on a first transmission signal modulated at a frequency in a specific frequency band into a second transmission signal having a frequency in a transmission frequency band, in which the apparatus includes: a circuit configured to generate a first calibration signal having a frequency higher than a highest frequency in the specific frequency band, and a second calibration signal having a frequency lower than a lowest frequency of the specific frequency band; a circuit configured to add the first and second calibration signals to the first transmission signal; a circuit configured to estimate a phase at a center frequency in the specific frequency band of the first transmission signal, and output a phase correction coefficient corresponding to the estimated phase; and a circuit configured to correct the phase of the first transmission signal, based on the phase correction coefficient.
    Type: Application
    Filed: November 30, 2018
    Publication date: June 27, 2019
    Applicant: FUJITSU LIMITED
    Inventors: Akihiko Komatsuzaki, Shinichiro Kobayashi, Ryo KOIZUMI, Toshiyuki Takada, Yumihiko ANNAKA, HIROSHI YASUI