A precise 1/f noise spectroscopy setup for sensor characterization

Abstract

We investigated the detection limit of a high-resolution modular instrumentation for current noise (1/f noise) spectroscopy. Rejecting amplifier noise as well as the thermal noise of two-pole resistive sensors (TPRS), the setup performs direct measurements of the power spectral density (PDS) of 1/f conductivity fluctuations of such TPRS. This enables the characterization of devices exhibiting very low current noise. Accordingly, expressions based on given measurement conditions are derived for the sensitivity and the accuracy of the method. These features are theoretically limited only by the time available for a measurement. The experimental results fully agree with theoretical predictions and confirm sub-thermal noise sensitivity along with high spectral resolution.