Patents by Inventor Charles Weitzel

Charles Weitzel 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).

  • pHEMT with barrier optimized for low temperature operation
    Publication number: 20060220062
    Abstract: In one embodiment, a semiconductor device (500) includes a buffer layer (504) formed over a substrate (502). An AlxGa1-xAs layer (506) is formed over the buffer layer (504) and has a first doped region (508) formed therein. An InxGa1-xAs channel layer (512) is formed over the AlxGa1-xAs layer (506). An AlxGa1-xAs layer (518) is formed over the InxGa1-xAs channel layer (512), and the AlxGa1-xAs layer (518) has a second doped region formed therein. A GaAs layer (520) having a first recess is formed over the AlxGa1-xAs layer (518). A control electrode (526) is formed over the AlxGa1-xAs layer (518). A doped GaAs layer (524) is formed over the undoped GaAs layer (520) and on opposite sides of the control electrode (526) and provides first and second current electrodes. When used to amplify a digital modulation signal, the semiconductor device (500) maintains linear operation over a wide temperature range.
    Type: Application
    Filed: April 5, 2005
    Publication date: October 5, 2006
    Inventors: Bruce Green, Olin Hartin, Ellen Lan, Philip Li, Monte Miller, Matthias Passlack, Marcus Ray, Charles Weitzel
  • Recessed semiconductor device
    Publication number: 20060043416
    Abstract: A semiconductor structure includes a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, a third semiconductor layer over the second semiconductor layer, and a fourth semiconductor layer over the third semiconductor layer. A first conductive portion is coupled to the first semiconductor layer, and a second conductive portion is formed over the first semiconductor layer.
    Type: Application
    Filed: August 25, 2004
    Publication date: March 2, 2006
    Inventors: Hsin-Hua P. Li, Bruce Green, Olin Hartin, Ellen Lan, Charles Weitzel
  • InGaP pHEMT device for power amplifier operation over wide temperature range
    Publication number: 20050104087
    Abstract: In one embodiment, a semiconductor device (500) includes a buffer layer (504) formed over a substrate (502). An AlxGa1-xAs layer (506) is formed over the buffer layer (504) and has a first doped region (508) formed therein. An InxGa1-xAs channel layer (512) is formed over the AlxGa1-xAs layer (506). An InxGa1-xP barrier layer (518) is formed over the InxGa1-xAs channel layer (512), the InxGa1-xP layer (518) has a second doped region formed therein. A control electrode (526) is formed over the InxGa1-xP layer (518). An undoped GaAs layer (520) is formed over the InxGa1-xP layer (518) adjacent to the control electrode (526). A doped GaAs layer (524) is formed over the undoped GaAs layer (520) and on opposite sides of the control electrode (526) and provides first and second current electrodes. When used to amplify a digital modulation signal, the semiconductor device (500) maintains linear operation over a wide temperature range.
    Type: Application
    Filed: June 30, 2004
    Publication date: May 19, 2005
    Inventors: Ellen Lan, Monica De Baca, Bruce Green, Monte Miller, Charles Weitzel