Resolution limit of anisotropic magnetoresistance based vector magnetometer
Resolution limit of anisotropic magnetoresistance based vector magnetometer
复制标题
基于各向异性磁阻的矢量磁力计分辨率极限
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
张艺腾
中科院分区：
文献类型：
--
作者：
仇福伟;王劲东;张艺腾
为分离有效载荷计划开发了基于 AMR 的矢量磁力计，以探索地球极区的场对准电流。它具有体积小、质量兼容 CubeSat 平台的优点，同时仍保持足够的分辨率。为了确定基于 AMR 的磁力计的分辨率极限，我们测量了传感器的固有噪声。这一特性与我们的原型磁阻磁力计相冲突，因为相敏检测（PSD）只能抑制来自接口电路的噪声，而不影响待测量的信号。我们相信，除了周期性地翻转磁化方向之外，设置/重置技术还可以起到磁场调制的作用。传感器工作在调制频率下，其噪声水平远低于低频时的噪声水平。对该技术进行了理论分析，并从频率角度进行了描述。通过将信号调制到传感器和放大器的转角频率之外，传感器和接口电路都工作在白噪声区域。然后我们计算了基于HMC1001的磁力计的理论分辨率极限，结果表明在5 V偏置和适当匹配的放大器下，本底噪声为24.9 pT/Hz0.5@1 Hz。
An AMR based vector magnetometer was developed for the Separated Payload program to explore thefield-aligned currents in Earth polar region. It has the advantages of low volume and CubeSat platformcompatible mass while still maintains adequate resolution. In order to determine the resolution limit ofAMR based magnetometer, we measured the sensor’s intrinsic noise. This characteristic was in conflictwith our prototype magnetoresistive magnetometer since phase sensitive detection(PSD) could onlyreject noise from interfacing circuit without affecting the signal to be measured. We believe that besidesflipping the magnetization direction periodically, the set/reset technique also functions as a modulationto the magnetic field. The sensor operates at the modulation frequency and its noise level is much lowerthan that at low frequency. This technique is analyzed theoretically and a description from frequencyperspective is given. By modulating the signal beyond corner frequency of the sensor and amplifier, boththe sensor and interfacing circuit work in white noise region. Then we calculate the theoretical resolutionlimit of HMC1001 based magnetometer and the result shows that the noise floor is 24.9 pT/Hz0.5@1 Hzunder 5 V bias with proper-matched amplifier.