基于JFET的低噪声感应式磁传感器设计  

Design of low noise inductive magnetic sensor based on JFET

作　　者：李珉[1,2] 柏逢明[1] 

机构地区：[1]长春理工大学电子信息工程学院,吉林长春130022 [2]长春工业大学人文信息学院,吉林长春130122

出　　处：《传感器与微系统》2014年第11期86-88,91,共4页Transducer and Microsystem Technologies

基　　金：国家“863”高技术研究发展计划支持项目（2009AA03Z442）

摘　　要：在航空瞬变电磁（TEM）大深度测量时,由于飞行过程中共模噪声和天电噪声的引入,致使传统感应式磁传感器（IMS）探测灵敏度降低,无法满足地质探测深度的需要。为了增加IMS探测微弱磁场信号的能力,通过理论分析IMS的物理结构和前置放大电路的机理,研究了噪声引入的主要来源,建立了基于结型场效应晶体管（JFET）的IMS等效模型,设计了一种低噪声IMS。通过在屏蔽室内对所研制的IMS性能进行测试,结果表明：其输入噪声为2nV/Hz1/2@10 kHz,3 dB响应带宽达到42 kHz,较3D—3磁传感器信噪比提高了10.04dB,为其在实际项目应用提供了可靠的性能保障。Because common-mode noise and atmospheric noise are introduced to traditional inductive magnetic sensor （ IMS ） while flying in aerial transient electromagnetic measurement （ TEM ） of great depth detection application, detection sensitivity of IMS is reduced, which is unable to meet the requirement of geological exploration depth. In order to enhance the capability of IMS to detect weak magnetic signals, the manuscript through the theoretical analysis for physical structure of IMS and mechanism of pre-amplifier circuit, primary noise sources is studied, equivalent model of IMS based on JFET is built, and a low noise IMS is designed. Performance of IMS is tested in shielded room, and experimental results show that input noise is 2 nV/Hz%^1/2 @ 10 kHz,3 dB response bandwidth is 42 kHz, signal-to-noise ratio is increased by 10.04 dB compared with magnetic sensor 3D-3, which guarantees performance for its real project application.

关 键 词：瞬变电磁 感应式磁传感器 结型场效应晶体管 低噪声 

分 类 号：O657.3[理学—分析化学]