Temperature compensated automatic output control circuitry for RF signal power amplifiers with wide dynamic range

摘要

Improved temperature compensated, automatic output control (AOC) circuitry for RF signal power amplifiers is described that maintains the output power within one-half dB of a selected one of eight power levels varying from nine milliwatts to five watts, a dynamic range of twenty- eight dB. The amplification of the RF signal amplifier is proportional to a drive current signal provided by a current amplifier. A half-wave rectifier is coupled to the output of final amplifiers for generating an output power signal that has a magnitude proportional to the output power. The half-wave rectifier is temperature compensated for and biased by a diode coupled to the rectifier by one resistor and coupled to supply voltage by another resistor. The output power voltage is further coupled to an amplifier having an amplification factor selected by level control signals. The amplified output power signal is coupled to a comparator which varies the drive current provided by the current amplifier in response to the voltage difference between the amplified output power signal and a reference voltage.