MAGNETIC-FIELD MEASUREMENTS USING AN INTEGRATED RESONANT MAGNETIC-FIELD SENSOR

The present paper introduces a magnetic-field sensor based on a resona ting single-crystal silicon structure. The excitation of the resonator is achieved by the Lorentz force generated by a sinusoidal current fl owing through a rectangular coil deposited on the surface of the struc ture. The amplitude of the vibration, which is proportional to the mag netic field, is detected by sensing capacitors. Because of the high-qu ality factor of the resonator, a lower detection limit of 1 nT, or eve n smaller might be realised when the device is vacuum-packaged. This p aper describes the working principle, the fabrication procedure as wel l as open- and closed-loop measurement results. (C) 1998 Elsevier Scie nce S.A. All rights reserved.