Orthogonal fundamental mode fluxgate sensor

Abstract

The invention discloses an orthogonal fundamental mode fluxgate sensor. The sensor includes a cobalt-based amorphous wire, an excitation current source, an induction coil, a clock source, a preamplifier, a band-pass filter, a phase-sensitive detector, a low-pass filter and a feedback channel. The cobalt-based amorphous wire, the excitation current source and the clock source constitute an excitation circuit of the sensor. The induction coil, the preamplifier, the band-pass filter, the phase-sensitive detector, the low-pass filter, the feedback channel and the clock source constitute a measurement circuit of the sensor. The excitation current source is a biased alternating current source, namely, the excitation current source contains both DC components and AC components. The DC amplitude is greater than the AC amplitude, which makes the excitation current source in a mono-polar state. Compared with the traditional bipolar current source, the biased current source can significantly suppress the Barkhausen noise of the magnetic core. Compared with the prior art, the orthogonal fundamental mode fluxgate sensor of the invention has such advantages as small size, low noise, low nonlinear error, wide frequency band and large measurement range.

Description

technical field [0001] The invention belongs to the technical field of weak magnetic signal detection in the fields of geophysics, space exploration, etc., and in particular relates to an orthogonal fundamental mode fluxgate sensor. Background technique [0002] Vector weak magnetic sensors mainly include giant magnetoresistance (GMR), giant magnetoresistance (GMI), tunnel magnetoresistance (TMR), fluxgate, inductive coil, superconducting quantum interference (SQUIDs), spin-free exchange relaxation ( SERF) and other types, among which the fluxgate technology has become a research and development hotspot at home and abroad due to its comprehensive performance of low noise, high sensitivity, small size, and high technology readiness, and has been used in magnetotelluric, magnetic anomaly detection, geomagnetic navigation, nondestructive testing, Electromagnetic tracking and other fields have been widely used. [0003] The fluxgate mostly adopts the second harmonic method of p...

AI Technical Summary

Problems solved by technology

[0008] In order to overcome the deficiencies of the existing parallel field second harmonic fluxgate sensor in terms of noise and volume parameters, the present invention provides an orthogonal fundamental mode fluxgate sensor, the fluxgate sensor is made of cobalt-based amorphous wire As a magnetic core, an excitation current source with a bias is used, which greatly suppresses the Barbett noise of the magnetic core, and has the advantages of low noise, wide frequency band, and small size

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