【作者】 苗鑫； 张晨睿； 韩韬；

【Author】 MIAO Xin;ZHANG Cheng Rui;HAN Tao;School of Electronic,Information & Electrical Engineering,Shanghai Jiao Tong University;

【机构】 上海交通大学电子信息与电气工程学院；

【摘要】 无线无源声表面波(Surface Acoustic Wave,SAW)传感器具有诸如:纯无源(无需供能)、无线、适用温度范围(-2001000℃)、耐用性强、体积小等优良特性,使其在学术研究和工程应用领域备受关注。现有的SAW无线测量技术仍然存在一些亟待解决的问题,其中之一就是谐振式SAW传感器普遍使用快速傅里叶变化(FFT)方法计算回波信号的频率,完成无线测量。FFT方法本身存在频率估计方差性能较差(结果起伏剧烈)的固有缺点,束缚了测量系统对待测变量的分辨率。此外,FFT方法估计非整周期截断的正弦信号频率时,所获结果是有偏估计。所以,SAW传感器测量的准确度和分辨率都有待提高。本文将基于调制FFT-Chirp-Z算法与传统使用的二次插值FFT算法进行了比较,表明了在运用调制FFT-Chirp-Z算法后,能够提高频率估计算法的精确度。更多还原

【Abstract】 The passive wireless surface acoustic wave(SAW) resonant sensor have attracted much attention in academic research and engineering application because sensors can be passive, wireless, wide temperature range, rugged, radiation hard and small. The traditional wireless measurement technologies based on resonant SAW sensors have some urgent problems; one of them is that in most published papers on wireless resonant SAW sensors, Fast Fourier Transform(FFT) calculations are still commonly used for response frequency estimation. The poor variance performance(high fluctuation in results) is the natural defects of FFT method, which reduces the measurement resolution. In addition, the FFT method would give a biased estimation when it comes to a non-integral period truncated signal. So, the measurement accuracy and resolution of SAW sensor need to be improved. The comparison between modulation FFT finite search Chirp-Z algorithm and the classical quadratic interpolation FFT method in this research. It demonstrates that modulation FFT finite search Chirp-Z algorithm can improve the accuracy of frequency estimation algorithm.更多还原