设计了一种新的超磁致伸缩材料和声表面波谐振器构成的复合磁传感器.该传感器将超磁致伸缩材料在磁场中产生的应力应变传递到声表面波谐振器上,改变其谐振频率,通过对谐振频率的检测进行磁场测量.该传感器可以用于静态和动态磁场测量,并且可用作无源、无线磁传感器.主要分析了该结构用于静态磁场测量的原理,给出了实验结果.传感器谐振频率的变化对于静态磁场变化的灵敏度可达132Hz/Oe,谐振频率测量分辨率在1Hz时,磁场测量分辨率可达10^-7T数量级.
A new composite magnetic sensor using giant magnetostriction material and surface acoustic wave resonator is presented. The stress and strain of giant magnetostriction material generated by magnetic field are transfered to surface acoustic wave resonator and the resonant frequency of resonator is influenced. Magnetic field strength can be measured through the detection of resonant frequency. The magnetic sensor can be used to static or dynamic magnetic field measurement, and it also can work as a passive and wireless magnetic sensor. This paper focuses on theoretical analysis of static magnetic field measurement, and experiment results show that the sensitivity of frequency shift to magnetic field variation could achieve 132 Hz/Oe, and the resolution of magnetic field measurement could reach 10^-7 Tesla when the resolution of frequency detection is 1Hz.