CHEN Lei, XU Chun-guang, ZHOU Shi-yuan, et al. Research on resonant frequency measurement in SAW strain sensing[J]. 2009, 28(2): 32-34. DOI: 10.13873/j.1000-97872009.02.033.
SAW应变测量中谐振频率提取技术研究
摘要
声表面波(SAW)应变测量中
所要处理的回波信号具有瞬时、中频、窄带的特点
传统的傅立叶变换(FFT)频谱分析法的频率分辨率受信号采样长度的制约
无法满足SAW应变测量的精度要求。通过对SAW谐振器工作原理的分析
采用基于数字下变频技术测量回波信号频率
仿真验证和对实测信号的测量证明了该测量方法的可行性与有效性。
Abstract
The echo signals in SAW strain sensing have characteristics of instantness
intermediate frequency and narrowband.The frequency resolution of the tradition FFT analytical method is restricted by signal sampling length.The resolution can’t fit precision in SAW strain sensing.Through analyzing the theory of SAW resonator
digital down conversion is used to mearsure the frequency of echo signal.The feasibility and validity of the method is proved by simulation and experiment.