Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China.
Sensors (Basel). 2019 Nov 20;19(23):5058. doi: 10.3390/s19235058.
In this paper, the performance of orthogonal fluxgate sensors with meander-shaped cores is studied in fundamental mode. The meander-shaped cores are made by micro-patterning technology based on a Co-based amorphous ribbon. The main advantage of this structure is that the linear operating range of the sensor can be adjusted simply by changing the number of strips, without affecting the excitation mechanism. Experiments show that a linear range of 560 μT is obtained by a meander-shaped core sensor with 12 strips. The changes in the number of strips can also increase sensitivity and reduce noise of the sensor. We can achieve a sensitivity of 600 V/T and a noise level of 0.64 nT/√Hz at 1 Hz for a meander-shaped core sensor with eight strips. Compared with the performance of the sensors built using a single strip core having the same equivalent cross-sectional area, the use of meander-shaped core can provide a higher sensitivity and linearity, and a lower noise level. We also compare the performance of an eight-strip meander-shaped core orthogonal fluxgate operated in the fundamental and second-harmonic modes. Similar sensitivity for the two modes can be obtained by adjusting the excitation current. In this case, we find that the noise of sensor operating in fundamental mode is about five times lower than that of the sensor operating in second-harmonic mode. This can be interpreted as the suppression of Barkhausen noise by unipolar bias in the fundamental mode.
本文研究了基于 Co 基非晶带材的蜿蜒型磁芯正交磁通门传感器在基频模式下的性能。蜿蜒型磁芯采用微图案化技术制作，其主要优点是通过改变磁芯的条带数量可以简单地调整传感器的线性工作范围，而不会影响激励机制。实验表明，采用 12 条带的蜿蜒型磁芯传感器可获得 560 μT 的线性范围。条带数量的变化还可以提高传感器的灵敏度并降低其噪声水平。对于采用 8 条带的蜿蜒型磁芯传感器，我们可以实现 600 V/T 的灵敏度和 0.64 nT/√Hz 的噪声水平，频率为 1 Hz。与使用具有相同等效横截面积的单条带磁芯的传感器的性能相比，使用蜿蜒型磁芯可以提供更高的灵敏度和线性度，以及更低的噪声水平。我们还比较了工作在基频和二次谐波模式下的八边形蜿蜒型磁芯正交磁通门的性能。通过调整激励电流，可以获得两种模式下相似的灵敏度。在这种情况下，我们发现工作在基频模式下的传感器的噪声比工作在二次谐波模式下的传感器低约五倍。这可以解释为在基频模式下，单极偏置抑制了 Barkhausen 噪声。
