阻抗型无线无源声表面波传感器的研究

介绍了一种新型的阻抗负载型无线无源传感器,该传感器由声表面波器件与作为负载的外接传感器构成,采用声表面波器件进行信号传输。在工作时,外接传感器阻抗值的变化使声表面波器件反射回波特性也得到改变,通过检测该回波特性的变化,实现无线无源传感。基于耦合模模型的分析方法,得出了其级联P矩阵形式。针对电阻型和电容型两种不同类型的负载,分别对传感器进行了仿真分析和实际测试。试验结果表明,当电容型传感器作为负载时,可以以相位作为探测基准。

Study on Impedance loaded Wireless Passive SAW Sensors

This paper introduces a new impedance loaded wireless passive sensor. The sensor consists of a SAW device and an external sensor as the impedance load, the SAW device is used for signal transmission. When the sensor is working, the echo wave character will change with the variaty of sensor impadence, so the amplitude and phase of echo wave can correspond to the change of the target detection.We obain the cascaded P matrix based on the theory of coupling of mode. Aiming at the two kinds of capacitive and resistive impedance load, the simulation analysis and test of SAW sensors are carried out respectively. The test results show that when the capacitive sensor is used as the load, the phase can be used as a detection reference.