海洋电场信号程控增益超低噪声采集系统设计  

Design of ultra low noise acquisition system with programmable gain for marine electric field signal

作　　者：刘兰军[1,2] 周亚涛 陈家林 黎明[1,2] 强嘉晨 谢鹏[1] Liu Lanjun;Zhou Yatao;Chen Jialin;Li Ming;Qiang Jiachen;Xie Peng(College of Engineering,Ocean University of China,Qingdao 266100,China;Shandong Engineering Research Center of Marine Intelligent Equipment and Technology,Qingdao 266100,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100 [2]山东省海洋智能装备技术工程研究中心,山东青岛266100

出　　处：《电子技术应用》2022年第2期91-95,100,共6页Application of Electronic Technique

基　　金：国家重点研发计划项目(2019YFC1408101);青岛海洋科学与技术试点国家实验室开放基金项目(QNLM2016ORP0414);国家高技术发展计划项目(2012AA09A201)。

摘　　要：针对海洋电磁勘探中微弱动态电场信号的宽测量范围需求,提出了一种电场信号程控增益超低噪声采集(Programmable Gain Ultra-Low Noise Acquisition,PGULNA)方法,给出了系统设计实现。设计的程控增益超低噪声采集电路以低噪声运算放大器为核心,将D/A转换器内部电阻网络作为可编程反馈电阻,通过改变D/A转换器数字控制量进行电路增益调整。给出了所设计的PGULNA电路的理论噪声分析,本底噪声密度理论分析结果为1.84 nV/√Hz@1 Hz。开展了实验室环境测试,测试结果表明,电路通道之间一致性良好,本底噪声密度约为2.6 nV/√Hz@1 Hz,程控增益为1~128倍8挡可调,能够满足海洋电磁勘探中微弱电场信号的宽测量范围采集需求。Aiming at the wide measurement range of weak dynamic electric field signals in marine electromagnetic exploration,a method of Programmable Gain Ultra Low Noise Acquisition(PGULNA)for electric field signals is proposed in this paper,and the system design and implementation are given.The designed programmable gain ultra-low noise acquisition circuit takes the low-noise operational amplifier as the core,takes the internal resistance network of the D/A converter as the programmable feedback resistor,and adjusts the circuit gain by changing the digital control quantity of the D/A converter.The theoretical noise analysis of the designed PGULNA circuit is given,and the theoretical analysis result of background noise density is 1.84 nV/√Hz@1 Hz.The laboratory environment test results show that the consistency between circuit channels is good,the background noise density is about 2.6 nV/√Hz@1 Hz,and the programmable gain can be adjusted from 1 to 128 times by 8 levels,which can meet the requirements of collecting weak electric field signals in a wide measurement range in Marine electromagnetic exploration.

关 键 词：海洋电磁 电场信号 程控增益 超低噪声放大 测量范围 本底噪声密度 

分 类 号：P631.3[天文地球—地质矿产勘探]