新型驻波模式的声表面波MEMS-IDT陀螺仪

Novel Surface Acoustic Wave MEMS-IDT Gyroscope Based on Standing Wave Mode

文中提出了一种新型基于驻波模式的声表面波(SAW)MEMS-IDT陀螺仪,包括一个谐振腔内驻波反节点位置分布金属点阵的两端SAW谐振器和一组平行于谐振器设置的双延迟线型SAW振荡器。SAW谐振器形成稳定的驻波,由于旋转利用分布的金属点阵产生Coriolis力并激发垂直于旋转方向的二次SAW,并与SAW延迟线上传播的SAW产生相干效应,以此改变声波速度,从而导致延迟线型振荡器的频率输出发生变化。双延迟线振荡器结构有效地降低由于外围温度等干扰的影响。单相单向换能器(SPUDT)以及梳状换能器结构用于构建SAW延迟线,以改善振荡器的频率稳定性。所研制的用于构建陀螺仪的80 MHz两端谐振器以及延迟线器件的测试结果表现出低损耗等特点。利用旋转台对所研制的SAW陀螺仪进行性能评价,在0～1 000 deg/s范围内表现出良好的灵敏度(119 Hz/(deg·s))以及线性度性能。

This paper presented a novel microelectromechanical systems （MEMS） interdigital transducer （IDT） surface acoustic wave （SAW） gyroscope with 80MHz central frequency on a 128° YX LiNbO3 . The developed MEMS - IDT gyroscope was composed of two-pert SAW resonator, dual delay line oscillator, and metallic dots. The SAW resonator provides a stable standing wave, and the vibrating metallic dot at an antinode of the standing wave induces the second SAW in the normal direction of its vibrating axis. The dual delay line oscillators detect the Coriolis force by comparing the resonant frequencies between two oscillators through the interference effect. In the electrical testing by the network analyzer, the fabricated SAW resonator and delay lines showed low insertion loss and similar operation frequency between resonator and delay lines. When the device was rotated, the resonant frequency differences between two oscillators were linearly varied due to the Coriolis force. Obtained sensitivity was approximately 119 Hz/ （deg · s） in the angular rate range of 0 - 1 000 deg/s. Satisfactory linearity and superior directivity were also observed in the testing.