×

Radio frequency power amplifier having variable output power

  • US 5,276,912 A
  • Filed: 04/01/1993
  • Issued: 01/04/1994
  • Est. Priority Date: 02/06/1990
  • Status: Expired due to Fees
First Claim
Patent Images

1. A radio-frequency amplifier circuit for providing an amplified radio-frequency signal to a load having a load impedance, the radio-frequency amplifier circuit comprising:

  • amplifier means for amplifying an input signal to produce the amplified radio-frequency signal to the load, the amplifier means operating in a high efficiency switching mode and having an input for receiving the input signal, and having an output to provide the amplified radio-frequency signal, the amplified radio-frequency signal having variable output power;

    transformation means for transforming the load impedance of the load to a transformed impedance at the output of the amplifier means responsive to a control signal, the transformation means having a control input for receiving the control signal to set a selected power level for the amplified radio-frequency signal, the transformation means having a predetermined transforming characteristic for transforming the load impedance to allow the amplifier means to remain saturated at the selected power level, the saturation of the amplifier means provides for operation at maximum efficiency and not just maximum power transfer available with matched impedance and;

    control means for providing the control signal.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×