Patent attributes
An amplifier circuit for amplifying an input signal to generate an output signal is provided. The amplifier circuit has a stacked main amplifier, a parallel sub-amplifier, and a signal combiner. The stacked main amplifier includes a first amplifier unit for outputting a first amplified signal generated from processing the input signal; and a second amplifier unit for outputting a second amplified signal generated from processing the first amplified signal. The first amplifier unit and the second amplifier unit share bias current. The parallel sub-amplifier is coupled to the stacked main amplifier according to a parallel connection fashion, and outputs a third amplified signal generated from processing the input signal. The signal combiner combines the second amplified signal and the third amplified signal to generate the output signal.