TEMPERATURE COMPENSATED AUTOMATIC OUTPUT CONTROL CIRCUITRY FOR RF SIGNAL POWER AMPLIFIERS WITH WIDE DYNAMIC RANGE

摘要

AbstractImproved temperature compensated, automatic outputcontrol (AOC) circuitry for RF signal power amplifiers isdescribed that maintains the output power within one-halfdB of a selected one of eight power levels varying fromnine milliwatts to five watts, a dynamic range oftwenty-eight dB. The amplification of the RF signalamplifier is proportional to a drive current signalprovided by a current amplifier. A half-wave rectifieris coupled to the output of final amplifiers forgenerating an output power signal that has a magnitudeproportional to the output power. The half-waverectifier is temperature compensated for and biased by adiode coupled to the rectifier by one resistor andcoupled to supply voltage by another resistor. Theoutput power voltage is further coupled to an amplifierhaving an amplification factor selected by level controlsignals. The amplified output power signal is coupled toa comparator which varies the drive current provided bythe current amplifier in response to the voltagedifference between the amplified output power signal anda reference voltage.