Patents by Inventor Heung B. Lee

Heung B. Lee 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).

  • Patent number: 5331290
    Abstract: Variable-gain amplifier stages, such as may be used in a television receiver intermediate-frequency (IF) amplifier, each comprise a pair of transistors connected as an emitter-coupled differential amplifier with resistive collector loads. An electrically controlled conductance is connected between the collector electrodes of the transistors, to shunt the resistive collector loads in controllable amount to set the voltage gain of the stage. The electrically controlled conductance in each variable-gain amplifier stage is constructed so as not to change the DC operating conditions of the emitter-coupled differential amplifier and its resistive collector loads with variation in the conductance of the electrically controlled conductance. Front end portions of television receivers or video tape recorders are described each of which uses separate intermediate-frequency (IF) amplifiers for the FM sound carrier and vestigial-AM picture carrier.
    Type: Grant
    Filed: September 8, 1992
    Date of Patent: July 19, 1994
    Assignee: SamSung Electronics Co., Ltd.
    Inventors: Jack R. Harford, Heung B. Lee