High-Speed Reader for Contactless Resonant Surface Acoustic Wave Sensors
Ying Zou, Zheng Zhao, Fanbing Hu, Lina Cheng, Xufeng Xue, Wen Wang
Abstract
The wireless and passive surface acoustic wave (SAW) sensing system comprises SAW sensors and a SAW reader. In dynamic application scenarios, such as strain, torque, and vibration measurements, there is a critical need for high sensing speeds. However, the existing high-speed readers encounter challenges related to limited sensing range and reduced demodulation accuracy, which impede the broader adoption of SAW wireless passive sensing technology. This article presents a time-domain simulation model for SAW echo signals and explores the amplitude–frequency response characteristics of the reader to optimize its excitation time. Additionally, a noise model is developed based on actual data to assess the sensor bandwidth coverage provided by a single reader excitation, thereby optimizing the reader’s interrogation frequency. Experimental platforms for wireless temperature and strain sensing are also constructed. Experimental results indicate that the developed high-speed reader achieves a measurement speed of 13 kHz while maintaining practical measurement accuracy and distance for the SAW sensor.