High frequency amplifier circuit with noise figure improvement

摘要

A high frequency, negative feedback amplifier is coupled at its input to an inductance network which together with the input capacitance of the negative feedback amplifier forms a resonance circuit. The resonance frequency of the resonance circuit is set within the desired reception band of the amplifier, to thereby form a band pass filter having a pass band corresponding to the desired reception band. The resonance circuit assures only a real input to the amplifier thereby reducing the input noise attributable to the input source.