Giant magneto-impedance magnetic sensor based on magneto-electro-mechanical double-resonance mode

Abstract

The invention discloses a giant magneto-impedance magnetic sensor based on a magneto-electro-mechanical double-resonance mode, which is composed of a multi-layer variable cross-section shuttle-shapediron-based nanocrystalline soft magnetic film, a first laminated planar coil, a second laminated planar coil, a piezoelectric/giant magnetostrictive laminate array and a MEMS adjustable capacitor driven by a piezoelectric beam. The optimal working frequency can be effectively reduced to below MHz, the magnetic conductivity limitation of the soft magnetic material is broken through, and the sensitivity of the magnetic domain motion changing along with the magnetic field is further increased through the external magnetic field and the magnetic force changing along with the magnetic field. By adjusting the input of the direct current voltage to the piezoelectric driving layer, double resonance of a magnetic machine and capacitance and inductance of the GMI magnetic sensor is caused at the same time, and the detection sensitivity is further improved.

Description

technical field [0001] The invention relates to a DC magnetic field sensor, in particular to a giant magneto-impedance (GMI) magnetic sensor based on a magneto-electromechanical double resonance type. Background technique [0002] High-resolution weak magnetic field sensors are of great significance to the fields of national defense engineering, medicine, biology, aerospace engineering and industry. In order to meet the real-time weak magnetic field measurement, it is necessary to meet the indicators of high resolution (<1nT), fast response speed (>1kHz), small size and low power. At present, the accuracy of the magnetic induction sensor can reach up to 10 -14 T, but it is complicated to make and cannot measure static or slowly changing magnetic fields. The superconducting quantum interferometer is currently the most sensitive magnetic field measuring instrument, and the resolution limit can reach 10 -11 Oe, but it must work normally below the liquid helium temperat...

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Problems solved by technology

On the other hand, the single-layer rectangular film above the critical thickness produces a significant demagnetization field, and at the same time, the interval between the soft magnetic films and the magnetic poles on the end faces of the film in the sandwich structure produce serious AC flux leakage.

This results in low sensitivity

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