Patent ID: 8781427

Claim:
A signal receiving circuit, comprising: an amplifier, comprising: an input stage, for receiving an input signal to generate a first signal; a gain stage, coupled to the input stage, for generating an output signal according to the first signal; and an output stage, coupled to the gain stage, for adjusting a spectral response of the amplifier according to a first adjusting signal; a mixer, coupled to the gain stage, for generating a converted signal according to the output signal; and a first controlling circuit, coupled to the mixer, for detecting the converted signal to generate the first adjusting signal to adjust the spectral response of the amplifier; wherein the gain stage comprises: a trans-conducting circuit, for providing a transferring gain upon the first signal to generate the output signal at an output terminal of the gain stage; the output stage comprises: an inductive circuit, having a first terminal coupled to the output terminal of the gain stage and a second terminal coupled to a first reference voltage; a capacitive circuit, having a first terminal coupled to the output terminal of the gain stage and a second terminal coupled to the first reference voltage; and a variable resistive circuit, having a first terminal coupled to the output terminal of the gain stage and a second terminal coupled to the first reference voltage; wherein the first controlling circuit is arranged to adjust a resistance of the variable resistive circuit for adjusting the spectral response of the amplifier.