基于斩波技术的低噪声前置放大器研究  

Research on Low Noise Preamplifier Based on Chopper Technology

作　　者：云震 吴永鹏 YUN Zhen;WU Yongpeng(Hainan Branch,CNOOC(China)Ltd.,Haikou 570100,China;Southern Marine Science and Engineering Guangdong laboratory(Zhanjiang),Zhanjiang 524000,China)

机构地区：[1]中海石油(中国)有限公司海南分公司,海南海口570100 [2]南方海洋科学与工程广东省实验室(湛江),广东湛江524000

出　　处：《电工技术》2023年第1期34-37,共4页Electric Engineering

摘　　要：磁传感器(IMS)是频率域电磁法(FEM)中使用最广泛的磁传感器,通常由感应线圈和前置放大器组成。为了增加IMS探测深度和微弱磁场信号的能力,基于磁通负反馈技术,获得了低频段平坦的灵敏度曲线,拓宽了观测频带。采用斩波前置放大技术,降低了1/f噪声对IMS的影响,对IMS的输出噪声进行了压制。通过在屏蔽室内对所研制的IMS性能进行测试,表明其频带范围为0.001 Hz~10 kHz,输入噪声为2 nV/Hz^(1/2),为实际项目应用提供了可靠的性能保障。Inductive magnetic sensors(IMS)are the most widely used magnetic sensors in the frequency domain electromagnetic method(FEM)and typically consist of an induction coil and a preamplifier.In order to increase the ability of IMS to detect depth and weak magnetic field signals,a flat sensitivity curve in low frequency bands is obtained based on magnetic flux negative feedback technology,and the observation frequency band is broadened.The chopper preamplification technology is used to reduce the influence of 1/f noise on IMS and suppress the output noise of IMS.By testing the developed IMS performance in the shielded room,it is shown that its frequency band range is 0.001 Hz~10 kHz and the input noise is 2 nV/Hz^(1/2),which provides a reliable performance guarantee for practical project applications.

关 键 词：磁传感器 磁通负反馈 斩波前置放大 1/f噪声 

分 类 号：TN722.3[电子电信—电路与系统]