Study on low-loss surface acoustic wave sensor installed in sensor network

我们已经研究了一种新型的SAW气体传感器，用于检测患者或病房中的气味和未来燃料电池汽车的氢气泄漏。研制的传感器将安装在传感器网络中。在车库中用作传感器节点必须保证-40到80°C的大温度范围，这就需要将自温度补偿特性作为基本特性。此外，传感器节点必须在一块电池下工作数年，这要求声表面波传感器具有非常低的功耗和非常低的损耗特性。在本研究中，(1)我们实现了自温度补偿特性，消除了石英等压电晶体衬底的局限性；(2)我们开发了一种新型的晶格电路型低损耗传感器，它可以包括在传感器节点中；(3)为了提高传感灵敏度，我们提出了一种双反射式SAW谐振器，有效地扩大了对传感气体反应的相互作用区域。给出了实验和仿真结果。

We have studied a novel SAW gas sensor for odors from patients or in sickrooms and hydrogen-gas leakage from future fuel-cell cars. The developed sensor will be installed in sensor network. The use in a garage as sensor nodes must guarantee large temperature range from -40 to 80 °C, which requires the self-temperature-compensation characteristics as an essential feature. Moreover, the sensor nodes must operate over couples of years under a single battery, which requires very low-power consumption and very low-loss characteristics for SAW sensors. In this study(1) we achieved the self-temperature-compensation characteristics which removed the limitation for piezoelectric crystal substrates such as a Quartz substrate;(2) we developed a new lattice-circuit type low-loss sensor consisting of SAW resonators which could make it possible to be included in sensor nodes;(3) in order to increase the sensing sensitivity we proposed a double-reflection type SAW resonators which had effectively expanded the interaction areas reactive to sensing gas. Experimental and simulation results are presented.