一种过零非对称高灵敏GMI磁敏传感器

A Zero-Crossing Asymmetric GMI Magnetic Sensor with High Sensitivity

针对Fe73.5Cu1Nb3Si13.5B9非晶合金薄带具有高灵敏GMI效应,但在微弱磁场下表现出不灵敏且线性度低问题提出内偏置解决方案。根据电磁感应,调节电路参数使流过电感线圈的电流改变,导致电感线圈两端的磁场发生相应变化;通过计算非晶薄带GMI特性曲线的高灵敏线性区间,调整偏置电流大小,使零点偏置到线性区间的中心。利用此方法,传感器输出特性呈现出一种过零非对称形式,并在正负微弱磁场下具有更高灵敏度。本文介绍了Fe基合金薄带的巨磁阻抗特性、传感器的电路原理以及调节偏置电流后的测得的实验数据分析。通过实验结果显示传感器输出特性重复性好、基本无磁滞、线性度高,尤其在微弱磁场下灵敏度达22.53 mV/(A∙m−1)。

Aiming at the problem that Fe73.5Cu1Nb3Si13.5B9 amorphous alloy ribbon has high sensitivity GMI effect, but it is insensitive and has low linearity under weak magnetic field, an internal bias solution is proposed. According to electromagnetic induction, the circuit parameters are adjusted to change the current flowing through the inductance coil, which leads to the corresponding change of the magnetic field at both ends of the inductance coil;By calculating the highly sensitive linear interval of GMI characteristic curve of amorphous ribbon, the bias current is adjusted to bias the zero point to the center of the linear interval. By using this method, the output characteristics of the sensor show a zero-crossing asymmetry form, and it has higher sensitivity under positive and negative weak magnetic fields. This paper introduces the giant magneto-impedance characteristics of Fe-based alloy ribbon, the circuit principle of the sensor and the analysis of the experimental data measured after adjusting the bias current. The experimental results show that the output characteristics of the sensor have good repeatability, basically no hysteresis and high linearity, especially in weak magnetic field, the sensitivity reaches 22.53 mV/(A∙m−1).