无源声表面波谐振器的无线温度传感系统

介绍了一种基于声表面波谐振器的无源无线温度传感系统。作为传感器的谐振器受到正弦脉冲串的无线激励。因激励信号的中心频率不同于谐振器的谐振频率,所以回波信号是一调幅信号,其包络的主频就是谐振器的谐振频率和激励信号中心频率的差频。给出了传感系统的电路设计以及信号处理方法。实验数据和器件的温度系数吻合。
关键词: 传感器; 声表面波谐振器; 无源无线检测
Abstract : An passive and wireless sensor system using a surface acoustic wave ( SAW) resonator is described. Functioning as a temperature sensor ,the passive SAW resonator is excited by the wireless interrogating sinusoidal bursts with a fixed frequency which is different from the natural oscillating frequency of the resonator. So the re2 sponse is an AM signal. Consequently the primary frequency of the envelope in the AM signal is the difference
frequency of the two frequencies. The design of circuits and signal processing concerning this sensing system are presented. The experimental data show that the sensing results correspond with the resonator’s temperature coef2 ficients well.
Key words : sensor ; SAW resonator ; passive and wireless sensing