Practical Method for Drastic Improvement of Output Offset Stability in Bias-Switched Fundamental Mode Orthogonal Fluxgate
Practical Method for Drastic Improvement of Output Offset Stability in Bias-Switched Fundamental Mode Orthogonal Fluxgate
复制标题
大幅提高偏置切换基模正交磁通门输出失调稳定性的实用方法
DOI：
10.1109/jsen.2021.3089693
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发表时间：
2021
影响因子：
4.3
通讯作者：
Matsuoka Ayako
中科院分区：
文献类型：
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作者：
Murata Naofumi;Matsuoka Ayako
采用偏置开关技术的基模正交磁通门（FM-OFG）是一种很有前途的小型、低噪声磁强计，可用于直流和低频磁场的精确测量。然而，其输出失调稳定性不足以在温度变化较大的环境中进行测量。在这项研究中，我们已经实验研究的原因，剩余的偏移量和它的漂移发现偏置开关FM-光纤光栅。然后，我们提出了一个简单而有效的方法，大大提高了传感器的温度特性的FM-OFG在实际的反馈设计与模拟电路。理想情况下，由非晶线芯的单轴各向异性引起的感应电压在翻转的激励极性下变得对称，并且因此它们通过平均而被抵消。但由于丝材磁性能的不对称性，导致它们之间存在一定的不平衡，在最终输出中产生了残余分量。所提出的方法实现了感应电压解调过程中不平衡分量的平衡，以最大限度地减少最终平均输出中的残余失调及其漂移。实验验证了该方法的有效性，在−60°C ~+70 ° C温度范围内，失调稳定度达到0.013 nT/°C，重复性良好。
Fundamental mode orthogonal fluxgate (FM-OFG) adopting the bias switching technique is a promising compact and low-noise magnetometer for precise DC and low frequency magnetic field measurement. Yet, its output offset stability is insufficient for measurements in the environment with large temperature variations. In this research we have experimentally investigated the cause of the residual offset and its drift found in the bias-switched FM-OFG. Then we proposed a simple and effective method to drastically improve the sensor temperature characteristics of the FM-OFG in a practical feedback design with analog circuitry. Ideally, the induced voltages arisen by the uniaxial anisotropy of an amorphous wire core become symmetrical under flipped excitation polarities, and thus they are canceled by averaging. However, it was revealed that there was certain imbalance between them due to the asymmetry in wire’s magnetic properties, producing remnant component in the final output. The proposed method achieves equilibration of the imbalance component within the demodulation process of the induced voltages to minimize the residual offset and its drift in the final, averaged output. The method was verified by the experiment, and the offset stability of 0.013 nT/°C within the temperature range from −60°C to +70°C was achieved with good repeatability.