Patents by Inventor Masahiro Kumagawa

Masahiro Kumagawa 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).

  • High frequency variable gain amplification device, control device, high frequency variable gain frequency-conversion device, and communication device
    Patent number: 7245890
    Abstract: A high frequency variable gain amplification device 100 includes: a feedback circuit 103 capable of changing a feedback impedance to adjust the gain of an amplifier 101 in accordance with a control signal from a control device 200; and a current consumption adjustment circuit 102 capable of adjusting current consumption of the amplifier 101. The control device 200 controls the feedback impedance and the current consumption based on a desired signal power level and an undesired signal power level. If the desired signal power level exceeds a predetermined value, the control device 200 reduces the feedback impedance to increase the amount of a feedback signal, thereby allowing the amplifier 101 to operate with low gain so as to prevent the distortion characteristic from being reduced and to reduce the current consumption.
    Type: Grant
    Filed: July 21, 2004
    Date of Patent: July 17, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masahiro Kumagawa, Toshifumi Nakatani, Hisashi Adachi
  • High frequency variable gain amplification device, control device, high frequency variable gain frequency-conversion device, and communication device
    Publication number: 20050020227
    Abstract: A high frequency variable gain amplification device 100 includes: a feedback circuit 103 capable of changing a feedback impedance to adjust the gain of an amplifier 101 in accordance with a control signal from a control device 200; and a current consumption adjustment circuit 102 capable of adjusting current consumption of the amplifier 101. The control device 200 controls the feedback impedance and the current consumption based on a desired signal power level and an undesired signal power level. If the desired signal power level exceeds a predetermined value, the control device 200 reduces the feedback impedance to increase the amount of a feedback signal, thereby allowing the amplifier 101 to operate with low gain so as to prevent the distortion characteristic from being reduced and to reduce the current consumption.
    Type: Application
    Filed: July 21, 2004
    Publication date: January 27, 2005
    Inventors: Masahiro Kumagawa, Toshifumi Nakatani, Hisashi Adachi