Highly-Sensitive MEMS Micro-Fluxgate Magnetometer

Fluxgate magnetometers have been widely applied in many fields, such as magnetic anomaly detection, e-compass, etc. In this work, a micro-fluxgate magnetometer based on the implementation of the MEMS technology is proposed. The core of the fluxgate was fabricated by using an amorphous Co-based magnetic material, which shows a good degree of linearity below 0.5 Oe. Moreover, a mixed-signal lock-in circuit was designed to drive and capture signals. Magnetic noise density of such a device was limited to the value of 500 pT/
$\surd $
Hz at 1 Hz, while the capability of sensing a DC magnetic field of 6 nT was demonstrated, which presents a good development prospect in the weak signal detection domain.