RF AMPLIFIER WITH CURRENT MIRROR BIAS-BOOSTING

摘要

An amplifier circuit comprises an input stage and an output stage. The input stage is biased by means of a circuit, such as a current mirror, that senses the input signal level. As the input signal increases the average current of the sensing circuit also increases. This current is fed forward to the output stage to boost its bias. The bias boosting is thus proportional to the input signal. One of the advantages of the bias scheme presented is that it allows amplifiers to be biased with a lower quiescent current without being pushed into saturation at higher output power levels.