【摘要】 介绍了无源无线声表面波传感器系统,通过对声表面波的回波窄带信号的分析,阐述了基于数字方式解调回波窄带信号的数学原理.应用matlab仿真对回波窄带信号进行解调,分析相位误差产生的原因,论证了数字正交检波技术的优越性、可行性.在给出仪器系统硬件框图的基础上,根据虚拟仪器技术构建灵活、便携、开发成本低等优点,提出了应用LabVIEW实现数字正交检波技术的硬件方案.更多还原

【Abstract】 A passive wireless SAW sensor system is introduced.The narrow-band reflected signal by SAW is analyzed.The math theory of how to demodulate the narrow-band reflected signal by SAW,and that is based on the digital is introduced.Matlab software is applied on demodulating the narrow-band reflected signal by SAW,the reason of phase error is brought forward.The excellence and application of the digital quadrature demodulation is proveded.The hardware block of the instrument is presented.The system is based on the flexity and lower cost of vitural instrument.At last,the method of hardware to realize the digital quadrature demodulation by LabVIEW is advanced.更多还原