Patent ID: 7633345

Claim:
An amplifier amplifying an input signal to generate an output current, comprising: an impedance matching network receiving the input signal to perform impedance matching thereon, comprising a first resistor, receiving the input signal to generate a matched signal; a first transistor coupled to the first resistor, having a channel thermal noise to establish a first noise voltage; a second resistor coupled to the first resistor and transistor, receiving the channel thermal noise to establish a second noise voltage; and a transconductor amplifier coupled to the impedance matching network, comprising: a first transconductor circuit with first transconductance, coupled to the first resistor and transistor, receiving the first noise voltage to generate a first noise current; a second transconductor circuit with second transconductance, coupled in parallel to the first transconductor circuit and in series to the load, receiving the second noise voltage to generate a second noise current such that the first and second noise currents mutually cancel each other out to reduce a noise component in the output current to the load; and wherein the first and second transconductance have the opposite signs, and the first and second transconductor circuits are operated in a current mode.