Patents by Inventor Don P. Roehrs

Don P. Roehrs 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).

  • Apparatus and method for combining output signals from parallelly coupled power field effect transistors in high frequency amplifiers
    Patent number: 4994760
    Abstract: Apparatus and method for parallel operation of radio frequency transistor amplifier circuits in a Class D mode of operation at radio frequency signal ranges without the use of frequency limiting components is disclosed. A driver circuit provides the input signals for each radio frequency transistor amplifier circuit. A transformer is disclosed that combines the output signals of the radio frequency transistor amplifier circuits while matching the amplifier circuit impedance and the transformer load impedance (i.e., the antenna impedance). The transformer eliminates the need for DC blocking capacitors between the primary and secondary windings of the transformer. The transformer/power combiner includes a plurality of (1:1) transformer units having the unit input terminals (power amplifier output signals) coupled in parallel and having unit output terminals coupled in series.
    Type: Grant
    Filed: June 7, 1989
    Date of Patent: February 19, 1991
    Assignee: Signal One Corporation
    Inventor: Don P. Roehrs
  • Apparatus and method for paralleling power field effect transistors in high frequency amplifiers
    Patent number: 4899116
    Abstract: Switching power amplifier circuits for use in a frequency range from 0.5 MHz to 100 MHz are described. The power amplifier circuits have power field effect transistor (FET) devices as output components and the FET devices are driven by bipolar transistor devices without frequency limiting components. The power amplifier circuits can be coupled in parallel and the coupled amplifier circuits can be operated in a push-pull mode of operation for increased power. The systems using these amplifier devices can operate in a Class A, B, C, D, E, F and S modes. In particular, a Class D amplifier system is described that uses the switching power amplifier circuits in the extended frequency range.
    Type: Grant
    Filed: March 17, 1988
    Date of Patent: February 6, 1990
    Assignee: Signal One Corporation
    Inventors: Don P. Roehrs, Helge O. Granberg
  • Apparatus and method for paralleling power field effect transistors in high frequency amplifiers
    Patent number: 4733194
    Abstract: Switching power amplifier circuits for use in a frequency range from 0.5 MHz to 100 MHz are described. The power amplifier circuits have power field effect transistor (FET) devices as output components and the FET devices are driven by bipolar transistor devices without frequency limiting components. The power amplifier circuits can be coupled in parallel and the coupled amplifier circuits can be operated in a push-pull mode of operation for increased power. The systems using these amplifier devices can operate in a Class A, B, C, D, E, F and S modes. In particular, a Class D amplifier system is described that uses the switching power amplifier circuits in the extended frequency range.
    Type: Grant
    Filed: May 26, 1987
    Date of Patent: March 22, 1988
    Assignee: Signal One Corporation
    Inventors: Don P. Roehrs, Helge O. Granberg