Advanced Dual-Resonance Modeling and Stability Design of Induction Magnetometer With Magnetic Flux Negative Feedback

This study addresses the high-frequency limitations of conventional single-resonance models for induction magnetometers (IMs) with magnetic flux negative feedback. At frequencies beyond the first resonance, parasitic capacitive effects become dominant, necessitating a more physically complete model. We therefore develop a dual-resonance equivalent circuit that incorporates a second resonance point to accurately characterize this high-frequency behavior. The stability of this extended model is rigorously investigated using the Routh-Hurwitz criterion, establishing critical stability conditions for the feedback system. Experimental validation via frequency-response testing confirms the model’s superior accuracy in predicting sensor response across a wide bandwidth. The research ultimately delivers a verified dual-resonance model and practical stability criteria, providing foundational insights for IM circuit design and enabling the development of high-stability, high-precision sensors for advanced applications.