Dual transduction Gas sensor based on a surface acoustic wave resonator

This paper presents a novel dual transduction gas sensor providing both resistance and mass modalities for single sensor gas identification. The proposed sensor relies on a configurable dual mode frequency/resistance readout circuit, which enables the use of a single conventional surface acoustic wave (SAW) device. Unlike prior works which all rely on custom-made gas sensors, the proposed sensor is based on off-the-shelf SAW devices, making it low cost and easy to implement. Reported results validate the functionality of the proposed dual transduction gas sensor. The introduction of control switches for the dual mode readout is shown to only deteriorate the phase noise performance of the SAW oscillator by 4 dBc/Hz at 10 MHz offset and not affect the low offset part. This demonstrates that the mass sensing resolution of the SAW device is not reduced while including the resistive sensing feature.