A quantitative model for the nonlinear response of fluxgate magnetometers

An analytical nonlinear hysteresis model was developed to describe the hysteresis loops of different magnetic materials, which was capable of fitting Permalloy films as an example. As a case study this model was applied in the sensitivity analysis of the fluxgate magnetometers where accurately capturing the nonlinear behavior of the magnetic core is crucial. Straightforward analytical equation of the output voltage signal as well as its harmonic decomposition was obtained for the fluxgate magnetometer as a function of hysteresis loop parameters. Sensitivity values predicted by the model were found to be consistent with the measured values published previously. The model allows the harmonic content distribution in the output signal of the fluxgate magnetometer to be studied analytically as a function of various device parameters, and thereby very useful in the selection of core materials in fluxgate devices.