The principle of a virtual multi-channel lock-in amplifier and its application to magnetoelectric measurement system

TL;DR

This paper introduces a virtual multi-channel lock-in amplifier based on cross-correlation, enabling precise magnetoelectric measurements without traditional analog lock-in amplifiers, capturing detailed coupling behaviors.

Contribution

It presents a novel digital lock-in amplifier method and demonstrates its application in a versatile magnetoelectric measurement system.

Findings

Successful implementation of a virtual lock-in amplifier

High precision measurement of magnetoelectric coupling

Rich data on coupling strength and phase lag

Abstract

This letter presents principles and applications of a virtual multi-channel lock-in amplifier that is a simple but effective method to recover small ac signal from noise with high presison. The fundamentals of this method are based on calculation of cross-correlation function. Via this method, we successfully built up a magnetoelectric measurement system which can perform precise and versatile measurements without any analog lock-in amplifier. Using the virtual multi-channel lock-in amplifier, the output of the magnetoelectric measurement system is extensively rich in magnetoelectric coupling behaviors, including coupling strength and phase lag, under various dc bias magnetic field and ac magnetic field.