Patents by Inventor Yoshizumi Kawaoka

Yoshizumi Kawaoka 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).

  • Variable gain amplifier
    Patent number: 6630861
    Abstract: A variable gain amplifier includes at least two amplifiers for amplifying a signal, the at least two amplifiers being connected in series with one another, and a variable resistor having a resistance that is controlled in accordance with a voltage applied to a control terminal, the variable resistor being connected between the outputs of two of the at least two amplifiers having opposite output phases. As a result, the variable gain amplifier is capable of a low-gain operation and an attenuating operation in a high-frequency amplifier used in a communications device for transmitting and receiving high-frequency signals.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: October 7, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Yoshizumi Kawaoka
  • Variable gain amplifier
    Publication number: 20020050857
    Abstract: A variable gain amplifier includes at least two amplifiers for amplifying a signal, the at least two amplifiers being connected in series with one another, and a variable resistor having a resistance that is controlled in accordance with a voltage applied to a control terminal, the variable resistor being connected between the outputs of two of the at least two amplifiers having opposite output phases. As a result, the variable gain amplifier is capable of a low-gain operation and an attenuating operation in a high-frequency amplifier used in a communications device for transmitting and receiving high-frequency signals.
    Type: Application
    Filed: September 25, 2001
    Publication date: May 2, 2002
    Applicant: Murata Manufacturing Co., Ltd
    Inventor: Yoshizumi Kawaoka