基于巨磁阻抗效应的微磁传感器设计与实现

介绍了非晶带产生巨磁阻抗(GMI)效应的机理,对Co基非晶带进行了磁场后退火处理,磁阻抗比得到显著提高,为179%.在此基础上设计了一种基于GMI效应的磁传感器电路,详述了各个环节的电路设计.通过优化传感器电路相关的工作参数,改善了传感器输出性能并给出了典型结果.在常温下,非晶带激励电流频率为10 MHz时得到了非晶带...     

激励电流对CoFeSiB非晶带GMI效应的影响

利用脉冲电流对Co基非晶带进行退火处理,研究了激励电流频率和幅值对非晶带巨磁阻抗(GMI)效应的影响。结果表明:该非晶带的特征频率为1.4MHz,磁场灵敏度Q在约1MHz下达到最大值1.46%/(A·m–1)。激励电流幅值增加,可以提高GMI变化率的最大值(ZGMI)max,磁场灵敏度却在激励电流幅值为7mA左右时达到最大值2.13%/(A·m–1)。     

新型非晶磁芯巨磁阻抗效应弱电流传感器

近零磁致伸缩系数的Co66.3Fe3.7Si12B18非晶薄带卷制成环形磁芯，在2kA/m横向磁场作用下，用密度为25A／mm^2的脉冲电流退火30s后作为敏感元件，提出了一种利用巨磁阻抗效应制作的新型非接触弱电流传感器。磁芯采用高频脉冲电流励磁，信号处理电路由峰值检波、低通滤波及差动电路构成。分析了传感器的工作原理，对传感器信号处理电路进行了参数设计计算，对测量结果进行了分析。通过对电路参数的优化，提高了传感器的分辨力、线性度及灵敏度。     

基于CoFeNbSiB非晶丝巨磁阻抗效应的新型磁传感器

本文利用CoFeNbSiB非晶丝的巨磁阻抗(GMI)效应制作了一种新型微磁场传感器.该传感器尺寸小,灵敏度高,反应速度快,且不需要预热.文章中具体介绍了非晶丝的特性、传感器的硬件及软件设计.     

巨磁电阻传感器在磁场线性测量领域中的应用

对巨磁电阻传感器进行了研究,介绍了巨磁电阻传感器的结构和屏蔽作用,选取电流检测作为巨磁电阻传感器在线性磁场测量的代表,通过对巨磁电阻传感器测试和电流检测的测试,分析了巨磁电阻传感器在磁场线性测量方面的性能优越性,给出了巨磁电阻传感器在磁场线性测量方面的一些注意事项。     

非晶丝MI效应磁场方位角测量系统

本文利用双轴MI效应设计并制作了一种磁场方位角测量系统。分析了尖脉冲电流激励下MI效应,并设计CMOS多谐振荡电路产生尖脉冲电流对非晶丝激励,制作成灵敏度高、稳定性好、功耗低的磁场传感器。利用LabVIEW软件,方便地实现磁场方位角的计算以及数字化显示。     

巨磁阻抗传感器应用研究最新进展

利用零磁致伸缩非晶丝的巨磁阻抗(GMI)效应,可制得新一类灵敏度高、响应快、功耗低、体积小的微型磁电式传感器。介绍了目前几种基于巨磁阻抗效应的传感器,包括磁场传感器、扭矩传感器、汽车交通监测系统和生物传感器等的工作原理和特性。     

磁流体包覆薄包层光纤光栅磁场传感研究

利用磁流体替代光纤布喇格光栅(FBG)的部分二氧化硅包层,制作了一种磁流体封装薄包层FBG结构的磁场传感器,研究了传感器对磁场和温度的响应特性。结果表明,在5.0～20.0mT的磁场范围内,传感器的波长灵敏度和功率灵敏度分别为34.9pm/mT和-1.063dBm/mT,波长线性响应度达到了99.2%。封装工艺未改变FBG波长随温度线性变化的特性,但受磁流体磁光效应影响,其温度灵敏度减小到9.2pm/℃。该传感器可实现磁场测量中的温度补偿,方法简单、易于实现。     

基于线性霍尔传感器的角度测量的非线性校正方法研究

本文提出了一种基于线性霍尔传感器的角度测量的非线性校正方法,在固定磁铁上绕制一定匝数的线圈,线圈产生的磁场与磁铁产生的磁场垂直,空间磁场为上述两个磁场的叠加,固定霍尔传感器的位置,同时保持控制电流不变,让磁铁绕霍尔传感器旋转产生角度的变换,霍尔传感器输出电压也将产生变化。对增加线圈和不增加线圈两种结构进行理论分析和仿真,从仿真结果看,霍尔电压与夹角的关系曲线明显线性增加,测量范围扩大,在角度测量中具有独特的优点。同时设计了传感器硬件电路,进行了实验测量,仿真和实测结果表明：该方法具有电路简单、实时性好、频率相应快、抗干扰能力强、安装调试方便等特点。     

基于铁基非晶丝巨磁阻抗效应的新型磁传感器

本文叙述了利用铁基非晶丝的磁敏特性和石英晶体振荡器,设计制作了一种新型巨磁阻抗磁敏传感器,并对其性能进行了测试,实验结果表明,该传感器具有良好的性能,可以作为弱磁场探测,在地磁测量、弱电流检测等方面有良好的应用前景.     

三分量磁通门传感器非正交性误差校正

静态磁场测量中,由于三分量磁通门传感器的非正交性,使得高分辨率测量要求不能得到满足,必须校正其测量误差。通过分析三分量磁通门传感器非正交性误差,给出其数学模型描述,提出了一种基于实数编码遗传算法的校正方法。应用于三分量磁通门传感器非正交性误差的校正,提高了传感器磁场测量的准确度。实验表明,该算法提高了三分量磁通门传感器非正交误差的校正效果。     

基于Sagnac干涉仪的光纤直流磁场传感研究

将磁致伸缩材料粘贴单模光纤构成的光纤磁传感探头接入Sagnac光纤环的一端,外加交流磁场将探头周围的直流磁场加载到4.9kHz的高频信号上,建立了基于Sagnac干涉仪的光纤直流磁场传感实验系统.采用锯齿波相位调制的方法,将干涉仪系统相位偏置在π/2附近,通过测量所加高频信号的幅度,实现了对直流磁场的测量.实验得到系统信号稳定性为0.4%,磁场分辨率为4.3nT,并给出36.75g铁块经过磁传感探头时系统的响应信号.     

Novel magnetic field sensor based on magnetic fluids infiltrated dual-core photonic crystal fibers

Novel magnetic field sensor based on magnetic fluids infiltrated dual-core Photonic Crystal Fibers (PCFs) is proposed in this paper. Inside the cross-section of the designed PCFs, the two fiber cores filled with magnetic fluids (Fe₃O₄) are separated by an air hole, and then form two independent waveguides with mode coupling. The mode coupling under different magnetic field strength is investigated theoretically. A novel and simple magnetic field sensing system is proposed and its sensing performances have been studied numerically. The results show that the magnetic field sensor with 15-cm PCFs has a large sensing range and high sensitivity of 4.80 pm/Oe. It provides a new feasible method to design PCF-based magnetic field sensor.     

MEMS magnetic field sensor based on silicon bridge structure

A MEMS piezoresistive magnetic field sensor based on a silicon bridge structure has been simulated and tested.The sensor consists of a silicon sensitivity diaphragm embedded with a piezoresistive Wheatstone bridge,and a ferromagnetic magnet adhered to the sensitivity diaphragm.When the sensor is subjected to an external magnetic field, the magnetic force bends the silicon sensitivity diaphragm,producing stress and resistors change of the Wheatstone bridge and the output voltage of the sensor.Good agreeme...     

Yield improvement of a large area magnetic field sensor array usingredundancy schemes

The circuit design of a large area magnetic field sensor array (LAMSA) is described. This prototype is developed for applications in magnetic field mapping and tactile sensor arrays. To enable the production of such a large sensor system, redundancy schemes are implemented and a laser interconnection post fabrication technique is used for fault repairs. The design restructurable capabilities rely on local redundancy schemes for the sensor grid and global redundancy schemes for the surrounding control circuits. Experimental results obtained on a laser restructurable subarray of magnetic field sensor cells are shown. A study of the robustness of the local sensor grid redundancy schemes is presented     

Fiber-optic magnetic gradiometer utilizing the magnetictranslational force

A fiberoptic AC/DC magnetic gradiometer utilizing magnetic translational force is proposed, and its working principle is verified. The minimum gradient of an AC magnetic field of 4×10^-2 is detected with 100 mm of Sm-Co-coated sensor fiber built into an interferometer. This gradiometer is intrinsically insensitive to spatially uniform magnetic fields but is sensitive to their gradients. Therefore, the dynamic range and S/N ratio of measurements with the proposed sensor are not restricted by the magnitude of background magnetic field, including the geologic magnetic field. Spatial resolution is <1 mm     

Fundamental characteristics of a magnetoresistive sensor using Y1Ba2Cu3O7-x ceramicsuperconducting films

The fundamental characteristics of a magnetic sensor fabricated from a Y₁Ba₂Cu₃O_7-x ceramic superconducting film are investigated. The operation principle of the sensor is based on the magnetoresistive properties of the material. The Y₁Ba₂Cu₃O_7-x ceramic film was prepared by the spray pyrolysis method. An element of the magnetic sensor consists of the film patterned to a meander shape. the sensitivity is discussed in connection with the noise measurement of the element. A magnetic field resolution of 2×10^-6 G/(Hz) ^1/2 at 100 Hz was obtained in the 0.1-100 G range. The sensitivity is much higher than that of a conventional semiconductor magnetic sensor. With an AC modulation provided by a magnetic field, phase detection of the magnetic field can be performed using a lock-in amplifier. An improvement in the low-frequency (<1 Hz) magnetic field resolution of about one order of magnitude was obtained using this method     

双光纤布拉格光栅磁场传感器

载流导线在磁场中产生的电磁力使等腰三角形悬臂梁变形,从而导致安装在悬臂梁两边的光纤布拉格光栅(FBG)的布拉格波长漂移.通过检测2个FBG的波长漂移差,得到被测磁场的磁感应强度.双FBG通过补偿温度效应,解决了FBG传感器的交叉敏感问题.垂直放置的等腰三角形悬臂梁,确保FBG在传感过程中不出现啁啾现象,又避免了自身重量和导线重量对测量结果的影响,从而减少了测量误差.该系统传感灵敏度为1.11 nm/T,与理论值的相对误差为4.31%,结果表明,该传感器结构是可行的.     

新型Spindt阴极阵列磁敏传感器的研究

提出了一种检测三维磁场的真空微电子磁敏传感器。该传感器采用Ｓｐｉｎｄｔ阴极阵列作为电子源,阳极分为五个区域,以便检测发射电子在磁场作用下的偏移。通过不同阴极电压下电子束流的偏移量的国赤出器件所在位置磁场的三个分量。对传感器的灵敏度和误差进行了模拟计算,并研究了它们与阳极电压、阴－阳极间距及阳极电压变化步长的关系。结果表明该传感器的灵敏度约为８００％,相对误差为３％。