作者：仇福伟^1,2, 王劲东¹

作者单位：1. 中国科学院国家空间科学中心 空间天气学国家重点实验室, 北京 100190;
2. 中国科学院大学, 北京 100190

关键词：交流调制法;噪声测量;锁相放大器;电阻类传感器

摘要：

为准确测量电阻类传感器的噪声，克服商用锁相放大器在噪声测试方面准确性难以评估、性能有限的缺点，该文利用低噪声的前置放大器与24位的数据采集卡构建高精度的电阻类传感器噪声测试系统。该系统可有效避免测试电路和数据处理对噪声测试结果的影响，且可通过噪声实测值与理论值对比保证测量结果的准确性。测试结果显示该系统具有0.8 nV/Hz^0.5@1kHz的超低输入噪声（100 mV输入范围），优于商用锁相放大器；噪声理论值与实验值之间的平均偏差仅为0.25%，确保测试系统的准确性。该系统可以满足大多数电阻类传感器的高精度噪声测量需求。

High-precision resistive sensor noise measurement system with ultralow input noise
QIU Fuwei^1,2, WANG Jindong¹
1. State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China;
2. University of Chinese Academy of Sciences, Beijing 100190, China
Abstract: Commercialized lock-in amplifier is not suitable for accurate noise measurement, because the noise component in its output signal cannot be fully determined and its intrinsic performance is limited. In order to accurately measure the noise level of resistive sensors, the authors build a high performance noise characterization system using low noise front-end amplifier and 24-bit data acquisition card. The impact of test circuits and data processing on noise test results is effectively avoided, and the accuracy of the measured results is ensured by comparing the measured values with theoretical ones. Test results show that the system has an ultralow input noise of 0.8 nV/Hz^0.5@1kHz in 100 mV input range, which is much lower than commercialized lock-in amplifiers. The mean error between experimental and theoretical noise values is only 0.25%, which guarantees the accuracy of the measured results. This system can meet the high-precision noise measurement requirements of most resistive sensors.
Keywords: AC method;noise measurement;lock-in amplifier;resistive sensors
2019, 45(9):70-75  收稿日期: 2018-12-28;收到修改稿日期: 2019-03-11
基金项目: 国家自然科学基金（41574177，41404146）
作者简介: 仇福伟(1991-),男,江苏盐城市人,博士研究生,主要研究方向为磁传感器和磁强计
参考文献
[1] RYGER I, HARBER D, STEPHENS M, et al. Noise characteristics of thermistors:Measurement methods and results of selected devices[J]. Review of Scientific Instruments, 2017, 88(2):024707
[2] RUBIOLA E, VERNOTTE F. The cross-spectrum experimental method[J/OL]. arXiv preprint, arXiv:10030113, 2010[2019-06-15]. https://arxiv.org/abs/1003.0113.
[3] SCOFIELD J H. AC method for measuring low-frequency resistance fluctuation spectra[J]. Review of Scientific Instruments, 1987, 58(6):985-993
[4] 贾莲莲, 贺子芸, 曾迪昂, 等. 基于数字锁相放大器测量电阻热噪声[J]. 物理实验, 2018(12):1
[5] 蔡屹. 基于双相锁相放大器的微弱信号矢量测量[J]. 微计算机信息, 2007, 25:111-112
[6] 高晋占. 微弱信号检测[M]. 2版. 北京:清华大学出版社, 2011.
[7] 赵玉玲. 基于光斑位置检测系统的双通道数字锁相放大器研究[D]. 长春:中国科学院长春光学精密机械与物理研究所, 2018.
[8] GERVASONI G, CARMINATI M, FERRARI G. Switched ratiometric lock-in amplifier enabling sub-ppm measurements in a wide frequency range[J]. Review of Scientific Instruments, 2017, 88(10):104704
[9] GERVASONI G. A novel architecture of digital lock-in amplifier for extremely high resolution measurements[D]. Milano:Politecnico di Milano, 2017.
[10] ZÜRICH INSTRUMENTS. HF2LI lock-in amplifier User Manual[CP/DK]. Zürich, Switzerland:Zürich Instruments, 2019[2019-06-15]. https://www.zhinst.com/products/hf2li#.
[11] HOOGE F. 1/f noise sources[J]. IEEE Transactions on Electron Devices, 1994, 41(11):1926-1935
[12] VERBRUGGEN A H, STOLL H, HEECK K, et al. A novel technique for measuring resistance fluctuations independently of background noise[J]. Applied Physics A, 1989, 48(3):233-236
[13] GHOSH A, KAR S, BID A, et al. A set-up for measurement of low frequency conductance fluctuation (noise) using digital signal processing techniques[J/OL]. arXiv preprint, arXiv:cond-mat/0402130, 2004[2019-06-15]. https://arxiv.org/abs/cond-mat/0402130.
[14] DU W Y. Resistive, capacitive, inductive, and magnetic sensor technologies[M]. Boca Raton:CRC Press, 2014.
[15] ANALOG DEVICES. AD8429, AD8421, AD8221, AD8220 datasheets[CP/DK]. Norwood,Massachusetts:Analog Devices, 2019[2019-06-15]. https://www.analog.com/en/products/amplifiers/instrumentation-amplifiers.html.
[16] STUTZKE N A, RUSSEK S E, PAPPAS D P, et al. Low-frequency noise measurements on commercial magnetoresistive magnetic field sensors[J]. Journal of Applied Physics, 2005, 97(10):10Q107
[17] NORDING F, WEBER S, LUDWIG F, et al. Measurement system for temperature dependent noise characterization of magnetoresistive sensors[J]. Review of Scientific Instruments, 2017, 88(3):035006
[18] 多维科技. TMR9002产品规格说明书[CP/DK]. 张家港,江苏:多维科技,2019[2019-06-15]. http://www.dowaytech.com/1885.html.
[19] EGELHOFF W F, PONG P W T, UNGURIS J, et al. Critical challenges for picoTesla magnetic-tunnel-junction sensors[J]. Sensors and Actuators A:Physical, 2009, 155(2):217-225
[20] YUAN Z H, FENG J F, GUO P, et al. Low frequency noise in magnetic tunneling junctions with Co40Fe40B20/Co70.5Fe4.5Si15B10 composite free layer[J]. Journal of Magnetism and Magnetic Materials, 2016, 398:215-219
[21] WISNIOWSKI P, DĄBEK M, SKOWRONSKI W, et al. Reduction of low frequency magnetic noise by voltage-induced magnetic anisotropy modulation in tunneling magnetoresistance sensors[J]. Applied Physics Letters, 2014, 105(8):082404
[22] XU G, TORRES J C, ZHANG Y, et al. Effect of spatial charge inhomogeneity on 1/f noise behavior in graphene[J]. Nano Letters, 2010, 10(9):3312-3317
[23] LU J, PAN J, YEH S-S, et al. Negative correlation between charge carrier density and mobility fluctuations in graphene[J]. Physical Review B, 2014, 90(8):085434