Patent ID: 6147559
Filing Date: 2000-11-14
Classification: H03F

Abstract:
An amplifier comprising:an input terminal for receiving an input signal to be amplified,a transconductance stage coupled to said input terminal for transforming power of the input signal into current,a cascode stage coupled to said transconductance stage to isolate an output terminal of said amplifier from said transconductance stage, anda frequency dependent shunt-feedback network comprising (i) feedback resistive device coupled between the transconductance stage and said cascode stare and (ii) only a feedback capacitance device coupled between said input and a node between said transconductance stage and said cascode stage, the frequency dependent shunt feedback circuit biasing the transconductance stage in dependence on the frequency of the input signal, to thereby improve noise figure of said amplifier; and a degeneration inductive impedance connected between an emitter of said transconductance stage and a ground terminal.