Maximum energy transfer conditions in parametric amplification of current-output fluxgate sensors

► We analyze the physical process of energy transfer of the current-output fluxgates. ► Maximum energy transfer conditions are described by simple equations. ► Estimate of the tuning capacitance is at a deviation of 5%. ► Phase matching of the output current results in the most sensitive case. This paper analyzes the process of energy transfer between the excitation and the detection circuit of the current-output fluxgates. A physically instructive explanation of the energy transfer process is given by utilizing a “mechanically excited” model, and the phase matching equations of the maximum energy transfer conditions are derived. The calculated value of the tuning capacitor fit the experimental value well with a deviation of 5%. The experimental results have confirmed that the derivation of the maximum energy transfer conditions provides a simple model in which the excitation characteristics are associated with the detection circuit of fluxgate sensors.