基于多条耦合器的双声路声表面波气体传感器  

Dual track surface acoustic wave gas sensor based on multistrip coupler

作　　者：文常保[1,2] 朱长纯[2] 刘君华[2] 巨永锋[1] 许宏科[1] 

机构地区：[1]长安大学电子与控制工程学院,西安710064 [2]西安交通大学电子与信息工程学院,西安710049

出　　处：《仪器仪表学报》2008年第12期2543-2547,共5页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(60476037,60806043);高等学校博士学科点专项科研基金(20020698014)资助项目

摘　　要：针对目前声表面波气体传感器在消除外界因素干扰及抑制体声波中存在的问题,提出一种基于多条耦合器的双声路声表面波气体传感器结构。由于该传感器中的双声路结构关于输入小波换能器左右对称,且具有相同的设计参数,所以该传感器可以消除由于外界测量条件改变而引起的扰动量。同时,由于将具有体声波抑制功能的多条耦合器应用到传感器中,所以能够对造成假响应信号的体声波进行有效地抑制。此外,该传感器中的输入换能器采用了小波函数包络进行加权,所以与传统等指长、等周期的均匀换能器相比提高了对频率响应曲线中旁瓣的抑制效果。中心频率为101.764 MHz SO2气体传感器的实现和测量结果表明,该气体传感器在测量范围内,对各种浓度的SO2气体具有好的响应特性:传感器在0.5×10-6到20×10-6浓度范围内,SO2气体浓度与输出频率参量信号之间具有比较理想的线性特性,测量的灵敏度约为6.5 kHz/10-6。To solve environment disturbance and bulk acoustic wave （BAW） problems in current gas sensor using surface acoustic wave （SAW） device, a novel dual track SAW gas sensor based on multistrip coupler （MSC） is proposed. Because MSC and dual track receiving structure are incorporated into the sensor, the effects of environment disturbance quantities on the measurement signal are eliminated, and the false responses caused by BAW are suppressed. In addition, the output interdigital transducer （IDT） in dual track SAW wavelet gas sensor based on MSC is apodized by wavelet function, so the side lode rejection is better than that of SAW sensors with uniform IDT. An experiment of implementing SO2 gas sensor with a dual track SAW device is presented, and the centre frequency of the gas sensor is 101. 764 MHz. Experiment results confirm that the gas sensor has excellent response performance for different concentration SO2 gas in the measurement range. The sensor has good linearity and the sensitivity is approximately 6.5 kHz/10^-6 in the concentration range from 0.5 × 10^-6 to 20 × 10^-6.

关 键 词：声表面波器件 多条耦合器 气体传感器 小波 体声波 

分 类 号：TN65[电子电信—电路与系统] TP212[自动化与计算机技术—检测技术与自动化装置]