Patents by Inventor Carl E. Lindholm

Carl E. Lindholm 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: 4176356
    Abstract: A directional antenna system is disclosed which selectively couples two radiating antenna elements to a transceiver through a selective phase, magnitude and matching network which is controlled by the output of a logic circuit. The network provides for equal magnitude current coupling between the transceiver and the two antennas while simultaneously selectively producing either positive or negative approximately 90.degree. phase shifts between the two antennas to produce either of two discrete directive cardioid radiation patterns directed in substantially opposite directions. The logic circuit, in conjunction with a manual step switch, provides for a manually selecting either of the two cardioid radiation patterns, as well as producing a figure eight or an omnidirectional radiation pattern. For generating a transceiver omnidirectional pattern, one antenna is used and the other is connected to a standard broadcast band receiver.
    Type: Grant
    Filed: June 27, 1977
    Date of Patent: November 27, 1979
    Assignee: Motorola, Inc.
    Inventors: L. Curtis Foster, Carl E. Lindholm