Patents by Inventor Rowan L. Messham

Rowan L. Messham 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).

  • Aluminum gallium nitride heterojunction bipolar transistor
    Patent number: 5923058
    Abstract: A heat tolerant, frequency responsive transistor for use in the microwave region includes a collector region, a base region overlying the collector region, and an emitter region including an AlGaN layer overlying at least part of said base region, forming a heterojunction between said base region and said emitter region. The emitter region may include two layers. The HBT may be mounted on a SiC or sapphire substrate. The HBT may include a buffer layer between the substrate and the collector region.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: July 13, 1999
    Assignee: Northrop Grumman Corporation
    Inventors: Anant K. Agarwal, Rowan L. Messham, Michael C. Driver
  • Aluminum gallium nitride based heterojunction bipolar transistor
    Patent number: 5641975
    Abstract: A heat tolerant, frequency responsive transistor for use in the microwave region includes a collector region, a base region overlying the collector region, and an emitter region including an AlGaN layer overlying at least part of said base region, forming a heterojunction between said base region and said emitter region. The emitter region may include two layers. The HBT may be mounted on a SiC or sapphire substrate. The HBT may include a buffer layer between the substrate and the collector region.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: June 24, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Anant K. Agarwal, Rowan L. Messham, Michael C. Driver