Patents by Inventor Tetsuya Umemoto

Tetsuya Umemoto 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).

  • Power amplifier including an impedance matching circuit and a switch FET
    Patent number: 5548246
    Abstract: A power amplifier comprises opposite input and output terminals, a first amplifier circuit connected between the input terminal and the output terminal and comprising a first amplifier FET and a first matching circuit, and a second amplifier circuit connected between the input terminal and the output terminal and comprising a second amplifier FET, a second matching circuit, and a switching circuit. In this power amplifier, the first amplifier circuit outputs an output signal of a first power level when the first amplifier FET is operated while the second amplifier FET is not operated and the switching circuit is turned off, and the second amplifier circuit outputs an output signal of a second power level when the first amplifier FET is not operated while the second amplifier FET is operated and the switching circuit is turned on.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: August 20, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuya Yamamoto, Noriyuki Tanino, Tetsuya Umemoto