A Simple, Portable, Two Channels Correlation Spectrum Analyzer for Low Frequency Noise Measurements

Easy access to affordable and effective instrumentation is a key element for the diffusion, among researchers, of advanced characterization techniques such as those based on low frequency noise measurements. In this paper we demonstrate how it is possible to build a portable two-channel correlation spectrum analyzer by a careful selection of easily available electronics subsystems and minimal efforts in terms of prototyping expertise. We propose an implementation by combining two subsystems based on the AD converter AD1256 (mounted on breakout boards) and on a Raspberry Pi computer board. The entire system can be supplied from a standard 5 V power bank, has a bandwidth from DC to 6 kHz, programmable input gain (from 1 to 64) and input dynamic range, at the lowest gain, in excess of ± 1 V. Results obtained with a prototype demonstrate that the system has more than adequate performances in terms of overall background noise for its application in various fields.