100 Hz~1 MHz感应式磁传感器的低噪声前置放大电路设计  

Low Noise Amplifier Design for 100 Hz~1 MHz Induction Magnetometers

作　　者：唐尧 晏茂珊[1,2] 

机构地区：[1]中南大学地球科学与信息物理学院,湖南 长沙 [2]中南大学有色金属成矿预测教育部重点实验室,湖南 长沙

出　　处：《传感器技术与应用》2023年第3期222-231,共10页Journal of Sensor Technology and Application

摘　　要：感应式磁传感器常用于大地电磁法勘探中,降低感应式磁传感器的噪声水平可改善采集的磁场数据信噪比,进而提高大地电磁法的勘探精度。本文从感应式磁传感器的原理出发,分析了感应式磁传感器的噪声源分布,采用低噪声JFET (JFE2140)和高速集成运算放大器(OPA211)设计并制作了一款低噪声前置放大电路,该前置放大电路的电压噪声为1.8 nV/√Hz@100kHz,电流噪声为2.9 fA/√Hz@100kHz,固定增益为60 dB,带宽为30 Hz~500 kHz。测量结果表明,该低噪声前置放大电路适用于100 Hz~1 MHz感应式磁传感器中的微弱磁场信号放大。Induction Magnetometers (IM) are commonly used in geomagnetic exploration. Reducing the noise of Induction Magnetometers can improve the signal-to-noise ratio of the collected magnetic field data, which in turn can improve the exploration accuracy of geomagnetic exploration. In this paper, the noise source distribution of IM is analyzed. A low-noise JFET (JFE2140) and a high- speed integrated operational amplifier (OPA211) were used to design and fabricate a low-noise amplifier with a voltage noise of 1.8 nV/√Hz@100kHz and a current noise of 2.9 fA/√Hz@100kHz, a fixed gain of 60 dB and a bandwidth of 30 Hz~500 kHz. The measurement results show that this low-noise amplifier is suitable for am-plifying weak magnetic field signals in 100 Hz~1 MHz Induction Magnetometers.

关 键 词：大地电磁法勘探 感应式磁传感器 低噪声 前置放大电路 

分 类 号：TN7[电子电信—电路与系统]