Patents by Inventor Katuyuki Kurokawa

Katuyuki Kurokawa 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).

  • Differential amplifier for reducing input capacitance without deterorating noise characteristics
    Patent number: 5453718
    Abstract: A differential amplifier (101) includes an input circuit (20), a bias circuit (31) and an output circuit (50). In the input circuit (20), when base potentials of transistors (Q1) and (Q2) change respectively by .DELTA.V and -.DELTA.V thereby changing current flowing through the transistors (Q1) and (Q2) by .DELTA.I and -.DELTA.I, respectively, base-emitter voltages of transistors (Q5) and (Q9) equally increase by .DELTA.V in the bias circuit (31). However, since a base potential of the transistor (Q5) is fixed, an emitter potential of the transistor (Q9) drops by 2.DELTA.V, decreasing a base potential of a transistor (Q4) by 2.DELTA.V. On the other hand, since a current flowing through the transistor (Q4) changes by -.DELTA.I, a base-emitter voltage of the transistor (Q4) accordingly falls by .DELTA.V. This reduces an emitter potential of the transistor (Q4), i.e., a collector potential of the transistor (Q2) by .DELTA.V, and hence, a base-emitter voltage of the transistor (Q2) stays unchanged.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: September 26, 1995
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Company Limited
    Inventors: Katuyuki Kurokawa, Takehiko Umeyama, Masayasu Tanaka