An acoustic ring resonator employing a two-dimensional surface phononic crystal is proposed for high-sensitivity detection in binary gas mixtures. Band analyses and frequency-domain simulations via the finite-element method reveal that a single band for spoof surface acoustic waves appears at ultrasonic frequencies around 58 kHz where modification of its dispersion due to varying gas composition results in a linear shift of the resonance frequency. The shift rate is -17.3 and 8.8 mHz/ppm for CO2 and CH4, respectively. The linear shift of resonance frequency is experimentally validated. In addition, the ring resonator can also be employed to track acoustic intensity variation with gas concentration, where exponentially decaying intensity for low concentrations leverages high-sensitivity operation.

中文翻译：

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二维表面声子晶体环形谐振器进行的超声波气体传感。

提出了一种采用二维表面声子晶体的声环谐振器，用于二元气体混合物中的高灵敏度检测。通过有限元方法进行的频带分析和频域模拟显示，欺骗性声表面波的单个频带出现在58 kHz左右的超声频率上，其中由于气体成分的变化而导致其色散的改变导致共振频率线性移动。对于CO2和CH4，移位速率分别为-17.3和8.8 mHz / ppm。共振频率的线性位移已通过实验验证。另外，环形谐振器也可用于跟踪气体浓度的声强变化，其中低浓度的指数衰减强度利用了高灵敏度操作。