基于延迟线理论的无源声表面波气体传感器

Study of Passive Surface Acoustic Wave Gas Sensors Based on the Delay Line Theory

针对单输入、单输出及双输入、双输出换能器构成的声表面波(SAW)气体传感器存在的缺陷,研究一种无线无源、温度可测的气体传感器。基于声表面波的延迟线理论,利用叉指换能器的转换能量原理,对叉指换能器及反射器进行合理布局,并使3个反射器之间互为参考反射器,获得一种新型的声表面波气体传感器。该设计减少了传感器中信号间及环境温度等因素对测量的干扰,提高了传感器的灵敏度和测量准确度。该传感器具有结构简单、无线无源等特点,适合在不宜接触的复杂工程环境下工作。

In view of some shortcomings existing in the surface acoustic wave gas sensor composed of the single input-output and the double input-output transducers,a type of wireless and passive gas sensor that can also measure temperature was studied. The sensor was designed by applying the transition energy principle of inter digital transducers to set up a rational layout of inter digital transducers and reflectors based on the surface acoustic wave delay line theory,and taking the three reflectors as reflecting reference each other. The proposed scheme can reduce the effect of the interior signals of sensor and the environment temperature on the signal measurement,and enhance the sensor sensitivity and measurement accuracy. The sensor has characteristics such as simple structure, wireless and passive, suitable for working in complex engineering environment unsuited for contacting.