Enhanced Sensitivity of Surface Acoustic Wave-Based Rate Sensors Incorporating Metallic Dot Arrays

Sensors

Wen Wang¹  Xiuting Shao²  Xinlu Liu²  Jiuling Liu² 

[1] State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, No.21, BeiSiHuan West Road, Beijing 100190, China;

关键词: Coriolis force;    delay line;    metallic dot array;    oscillator;    SAW rate sensor;   

DOI  :  10.3390/s140303908

来源: mdpi

【 摘 要 】

A new surface acoustic wave (SAW)-based rate sensor pattern incorporating metallic dot arrays was developed in this paper. Two parallel SAW delay lines with a reverse direction and an operation frequency of 80 MHz on a same X-112°Y LiTaO₃ wafer are fabricated as the feedback of two SAW oscillators, and mixed oscillation frequency was used to characterize the external rotation. To enhance the Coriolis force effect acting on the SAW propagation, a copper (Cu) dot array was deposited along the SAW propagation path of the SAW devices. The approach of partial-wave analysis in layered media was referred to analyze the response mechanisms of the SAW based rate sensor, resulting in determination of the optimal design parameters. To improve the frequency stability of the oscillator, the single phase unidirectional transducers (SPUDTs) and combed transducer were used to form the SAW device to minimize the insertion loss and accomplish the single mode selection, respectively. Excellent long-term (measured in hours) frequency stability of 0.1 ppm/h was obtained. Using the rate table with high precision, the performance of the developed SAW rate sensor was evaluated experimentally; satisfactory detection sensitivity (16.7 Hz·deg·s⁻¹) and good linearity were observed.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.