Low noise amplifier with actively terminated input

摘要

An impedance matching circuit includes a differential amplifier providing a differential output signal across two output terminals. The differential amplifier receives the input signal whose input impedance is to be matched at one of the differential input terminals. The other one of the differential amplifier's input terminals is coupled to ground by a resistor. In one embodiment, feedback signal paths from the output terminals are provided by feedback resistors. In another embodiment, feedback signal paths from the output terminals are currents related by the ratio of the resistance of the resistor to the input impedance.