Patents by Inventor Hiroshi Kamizuma

Hiroshi Kamizuma 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).

  • Publication number: 20100052743
    Abstract: The power consumption of a data sampling unit that selects a phase of a clock signal appropriate for sampling payload data is reduced at an input interface. A semiconductor integrated circuit includes an input interface and internal core circuits. The input interface includes a hysteresis circuit and a data sampling unit. The hysteresis circuit detects an input signal between first and second input thresholds as a sleep command. The data sampling unit selects an appropriate phase of a sampling clock signal in accordance with a synchronizing signal and samples payload data. When a sleep command is detected, a sleep signal is also supplied to the internal core circuits and the data sampling unit and they are controlled into a low-power consumption state.
    Type: Application
    Filed: August 14, 2009
    Publication date: March 4, 2010
    Inventors: Hiroshi KAMIZUMA, Taizo YAMAWAKI, Yukinori AKAMINE, Koji MAEDA
  • Publication number: 20090156135
    Abstract: A transceiver includes an oscillator and a plurality of communication blocks. Each of the communication blocks includes frequency dividers and mixers. Frequency dividing number of the frequency divider included in one communication block is set to an even-numbered integer, and transmission local signals supplied from the frequency dividers to the mixer become quadrature signals having a phase difference of 90 degrees. The frequency dividing number of another frequency divider in the another communication block is set to a non-integer, and communication local signals supplied from the frequency divider to the mixers become non-quadrature signals having a phase difference at a predetermined offset angle from 90 degrees. The transceiver further includes a converting unit for giving a compensation offset amount having almost the same absolute value and having a polarity opposite to that of the offset angle to communication analog signals related to the mixer of the another communication block.
    Type: Application
    Filed: December 16, 2008
    Publication date: June 18, 2009
    Inventors: Hiroshi Kamizuma, Satoshi Tanaka, Taizo Yamawaki, Yukinori Akamine, Koji Maeda
  • Publication number: 20080311860
    Abstract: The transmitter of the transceiver includes: a transmitter-side mixers of a transmitter-side modulator; a transmitter-side voltage-controlled oscillator; and a transmitter-side divider. The divider having a dividing factor of a non-integral number is supplied with an oscillating output of the oscillator. A pair of non-quadrature local signals having a phase difference of 90° plus a predetermined offset angle is produced by the divider and supplied to the mixers. The transmitter includes a phase-shift unit which converts a pair of quadrature transmit signals having a phase difference of about 90° on an analog basis into a pair of non-quadrature shifted transmit signals. Consequently, quadrature modulation is performed by the mixers. Use of a similar configuration enables the reduction in interference of an RF signal with local signals supplied to receiver-side mixers of the receiver.
    Type: Application
    Filed: June 8, 2008
    Publication date: December 18, 2008
    Inventors: Satoshi Tanaka, Hiroshi Kamizuma, Koji Maeda, Sungwoo Cha, Yukinori Akamine, Taizo Yamawaki