Two-channel amplifier for high-sensitivity voltage noise measurements

In this paper we propose a new method for the measurement of a voltage noise source that allows, at least in principle, the complete elimination of the noise introduced by the amplifiers used for the measurements. This measurement procedure does not require the measurement of the DUT impedance and the estimation of the amplifier noise sources. Its main advantage with respect to our previous methods is that it requires only two amplifier channels. SPICE simulations and noise measurements on a prototype circuit demonstrate the validity of the proposed approach.