Sensitivity enhancement for coupled core fluxgate magnetometer utilizing negative state feedback

Recent theoretical works have shown that spontaneous oscillations can be induced by unidirectionally ring coupling the overdamped bistable nonlinear systems, subject to the proper initial states and coupling strength. These techniques have been adopted in the practical realization of the coupled core fluxgate magnetometer (CCFM) which obtains better magnetic field detection performances with residence times difference (RTD) readout strategy compared with the single core fluxgate magnetometer. In this paper, the effects of negative state feedback on CCFM have been investigated. Numerical simulations and preliminary experimental results, which have a good consistency, show a distinct benefit from the standpoint of sensitivity enhancement for CCFM utilizing negative state feedback.