Patents by Inventor James C.M. Hwang

James C.M. Hwang 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-voltage impulse amplifier
    Patent number: 8183933
    Abstract: A circuit includes a first transistor in a common-collector configuration and a heterojunction bipolar transistor (HBT) in a common-emitter configuration. The first transistor has a base coupled to an input node for receiving a pulsed signal. A collector of the first transistor is coupled to a first voltage source node. A base of the HBT is coupled to an emitter of the first transistor. A collector of the HBT is coupled to a second voltage source node configured to bias the HBT normally off. The HBT operating isothermally when the pulsed signal has a short-pulse width and a low duty cycle. The first transistor drives the HBT when the pulsed signal is received at the base of the first transistor to output an amplified pulsed signal at the collector of the HBT.
    Type: Grant
    Filed: April 3, 2009
    Date of Patent: May 22, 2012
    Assignee: Lehigh University
    Inventors: Subrata Halder, Renfeng Jin, James C.M. Hwang
  • HIGH-VOLTAGE IMPULSE AMPLIFIER
    Publication number: 20110006847
    Abstract: A circuit includes a first transistor in a common-collector configuration and a heterojunction bipolar transistor (HBT) in a common-emitter configuration. The first transistor has a base coupled to an input node for receiving a pulsed signal. A collector of the first transistor is coupled to a first voltage source node. A base of the HBT is coupled to an emitter of the first transistor. A collector of the HBT is coupled to a second voltage source node configured to bias the HBT normally off. The HBT operating isothermally when the pulsed signal has a short-pulse width and a low duty cycle. The first transistor drives the HBT when the pulsed signal is received at the base of the first transistor to output an amplified pulsed signal at the collector of the HBT.
    Type: Application
    Filed: April 3, 2009
    Publication date: January 13, 2011
    Applicant: LEHIGH UNIVERSITY
    Inventors: Subrata Halder, Renfeng Jin, James C.M. Hwang