Cross-correlation on a single channel for resistance noise measurements

TL;DR

This paper introduces a novel AC technique enabling cross-correlation noise measurements using only a single channel, reducing cost and complexity while maintaining accuracy and improving signal-to-noise ratio.

Contribution

The authors propose a single-channel cross-correlation method using dual-frequency modulation, simplifying the measurement setup without sacrificing accuracy.

Findings

Achieves accurate amplitude and noise spectra measurements.

Improves signal-to-noise ratio by 7 decibels.

Longer measurements further enhance noise reduction.

Abstract

Cross-correlation is an established tool to reduce the background in resistance noise measurements. However, the conventional method requires the amplifier, demodulator and digitizer channels to be duplicated, increasing the cost and complexity of the measurement circuit. We propose an alternating-current technique that allows cross-correlation with only a single channel by modulating the device under test with two carrier frequencies simultaneously. Using multiple software-based demodulators, we show that this method produces accurate amplitude measurements and noise spectra. The signal-to-noise-ratio is improved by 7 decibel for standard parameters. Longer measurement durations increase this improvement, which makes the new technique a true cross-correlation method.