A7 - An Improved Test set with Switchable Oscillator for Dual-Delay lineSAW Gas sensors
- Event
- 20th Jubilee Winter Workshop
on Acoustoelectronics
2024-02-24 - 2024-02-27
Szczyrk, Beskidy Mountains (Poland) - Chapter
- Acoustoelectronics
- Author(s)
- J. Wrotniak, M. Magnuski, W. Jakubik - Silesian University of Technology,
Gliwice (Poland) - Pages
- 18 - 19
- DOI
- 10.5162/20WWonAE/A7
- ISBN
- 978-3-910600-05-8
- Price
- free
Abstract
The paper presents a new switchable test set dedicated to dual delay line SAW gas sensors. The
described network is a switchable oscillator operating at frequency of approx. 205 MHz adopting dual
delay line fabricated by SAW Components. It was successfully applied to detect traces of DMMP
(Dimethyl methylphosphonate) being the simulator of combat poisoning agents in the air. The
oscillator discussed in the paper adopts a single active network, multi-state phase shifter and
electronics switches to alternate excitation of two delay lines, so that it offers much better temperature
properties in comparation to the existing solutions using two separate temperature sensitive
oscillators. The measured frequency to temperature sensitivity of the discussed test set is 10 times
lower than the one built of two separated oscillators. Moreover, the proposed circuit, thanks to its
alternate operation, eliminates the interaction between two delay lines placed on the same substrate.