Patents by Inventor Michael F. Landherr

Michael F. Landherr 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: 6049704
    Abstract: According to the apparatus of the present disclosure, dual gate control and dual gain control uses variable voltages on the gates of first stage (302) and a second stage (304) to control the output power. In alternate embodiments, dual drain control is also employed using a variable voltage supply on the drains of the first stage (302) and the second stage (304). In particular, a level shifter circuit (421) is employed to convert a positive voltage gate control signal to negative voltage with respect to ground. Drain current limiting circuits (417, 419) are used to sample drain currents and generate gate voltages to maintain a desired current ratio between stages of a multi-stage amplifier. When dual drain control is also employed, a 1:1 ratio of drain control voltages is employed at low power levels, with a single drain control at higher power levels.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: April 11, 2000
    Assignee: Motorola, Inc.
    Inventors: David S. Peckham, Michael F. Landherr, Armin W. Klomsdorf, Mark A. Pennock