High-frequency stability oscillator for surface acoustic wave gas sensor

Acoustical Science and Technology

Yong Pan¹  Minghua Liu²  Shitang He²  Shunzhou Li²  Wen Wang² 

[1] Research Institute of Chemical Defense;Institute of Acoustics, Chinese Academy of Sciences

关键词: Delay line;    Frequency stability;    Gas sensor;    Oscillator;    Surface acoustic wave;    Sensitivity;   

DOI  :  10.1250/ast.30.7

学科分类：声学和超声波

来源: Acoustical Society of Japan

【 摘 要 】

References(7)Cited-By(1)We present a 300 MHz surface acoustic wave (SAW) oscillator for gas sensor application. As the oscillator element, SAW delay lines on an ST-X quartz substrate with low insertion loss and single-mode-selection capability were developed. And they were structured by Electrode Width Control Single Phase Unidirectional Transducer (EWC/SPUDT) configuration and comb transducer. The coupling of modes (COM) model was used to predict device performance prior to fabrication. The measured frequency response S12 showed a good agreement with simulated results; a low insertion loss of less than 9 dB and a linear phase in the 3 dB bandwidth were observed. The experimental results show that the baseline noise of the fabricated oscillators was typically up to ∼0.7×10−7 in a laboratory environment with temperature control. The oscillator was successfully applied to a gas sensor coated with fluoroalcoholpolysiloxane (SXFA) as the sensor material for O-isopropyl methyphosphonofluoridate (GB) detection, and a superior threshold detection limit was obtained (<<0.4 mg/m3).

【 授权许可】

Unknown