TMR磁传感器磁通调制结构温度稳定性研究

Study on temperature stability of magnetic flux modulation structure of TMR magnetic sensor

隧道磁电阻(TMR)磁传感器在生物磁场、目标探测、地磁导航、无损检测等领域均有极大的发展潜力,但1/f噪声极大限制了其低频磁场探测能力。基于压电谐振的磁通调制结构能够将1/f噪声降低近2个量级,但其调制效率受温度影响明显。为提高调制结构的温度稳定性,提出了一种相幅双闭环温补控制方法。测试结果表明:调制结构在0~40℃的变温范围内振幅波动约为0.01%/℃,远低于补偿前的0.19%/℃,稳定性提升约19倍。

Tunnel magnetoresistance(TMR)magnetic sensor has great development potential in the fields of biological magnetic field, target detection, geomagnetic navigation, nondestructive detection and so on.However, 1/f noise greatly limits its low-frequency magnetic field detection ability.Magnetic flux modulation structure based on piezoelectric resonance can reduce 1/f noise by nearly two orders of magnitude, but its modulation efficiency is significantly affected by temperature.In order to improve the temperature stability of the modulation structure, a phase amplitude double closed loop temperature compensation control method is proposed.The test results show that the amplitude fluctuation of the modulation structure is about 0.01 %/℃ in the temperature range of 0~40 ℃,which is much lower than the 0.19 %/℃ before compensation, and the stability is improved about 19 times.