A new approach to test set for SAW delay line based gas sensors

The paper presents a new switchable test set dedicated to dual delay line surface acoustic wave (SAW) gas sensors. It operates at frequency of 205 MHz utilizing dual delay line fabricated by SAW Components. The sensor detects traces of dimethyl methylphosphonate (DMMP) that is a simulant of combat poisoning agents. The test set described is built of a single oscillator adopting commutation of two SAW delay lines and this way has better thermal properties than commonly used networks consisting of two independent oscillators. Its measured frequency to temperature is ten times lower than obserwed for double oscillator networks. Additonaly due to alteranate operation of the sensors the interaction between delay lines built on common substrate is eliminated. This work was presented at the 53^th Winter School on Wave and Quantum Acoustics [1] February, 24 – 27, 2025, DOI 10.5162/20WWonAE/A7.