Cathode Impedance Feedback Patents (Class 330/87)
  • Patent number: 7863978
    Abstract: An RF amplifier system having closed cavity containing an amplifying device that includes at least a cathode, an anode and a grid and wherein the amplifying device exhibits an internal grid-to-anode capacitance. Apparatus is presented for use in neutralizing the internal capacitance. This includes a feedback circuit including an external capacitor of fixed value and a phase inverting transformer having a transformer primary winding connected in series with the capacitor to the cathode. The transformer has a secondary winding connected between the cathode and the grid for supplying a phase inverted negative feedback voltage to the grid for neutralizing the cavity by the feedback voltage. The transformer coupling is adjustable to vary the magnitude of the feedback voltage.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: January 4, 2011
    Assignee: Harris Corporation
    Inventors: David Christopher Danielsons, Geoffrey Norman Mendenhall
  • Patent number: 3952259
    Abstract: A circuit for providing AC gain control while minimizing the change in AC impedance and eliminating any effects on DC biasing of following stages.
    Type: Grant
    Filed: April 28, 1975
    Date of Patent: April 20, 1976
    Assignee: Rockwell International Corporation
    Inventor: Vernon R. Cunningham