Modeling And Simulation Of Surface Acoustic Wave Gas Sensor

Since terrorist attacks are more and more rampant, explosive detection technology attracts extensive attention worldwide. Surface Acoustic Wave(SAW) technology has become a public focus because of its high sensitivity, high ability of anti-radiation and short wavelength.The purpose of the dissertation is to investigate the high frequency SAW gas sensors for high sensitivity detection of TNT. Firstly, the response mechanism of the SAW sensor for explosive vapors is studied by a perturbational approach. The glassy–rubbery PDMS is suitable for the TNT sensor by choosing the initial film thickness with h0=htrd/10. Secondly,the delay-line and resonant sensors with 200 MHz are simulated by FEM software. The results show that Rayleigh wave is obtained. At last, the insertion loss and sensitivity of two types of sensors are calculated at TNT concentrations of 500 ppb. It's indicated that the insertion loss(-24.5dB) of the resonant SAW sensor is less and the sensitivity(94.8Hz/ppb) of it is higher.