ملخص: In this study, the first chapter is reserved to the development of gas sensors, the use of SAWS for gas analysis, the SAW characteristics, its generation on the substrate and its velocity perturbation using Auld's approach. The second chapter treatsthe design of oscillators, which includes the definition of an oscollator, Barkhausen Criterion, oscillator type, SAW delay line oscillator principles and "Q" factor. The third chapter deals with the devices used in the design of the dual SAW delay line oscillator, which contains the RF amplifier, the dual SAW delay line device, the mixer, the active low pass filter and the power supply unit. A dual SAW delay line oscillator has been achieved, operating in fundamental mode at 158 MHz and having a narrow bandwidth of 0.7 MHz. It exhibits no auto-oscillation, good long term stability, approximately 1 Hz/4 mn, and a short term stability of about +- 5 Hz for both the delay line oscillators. Both oscillators have clean, low noise spectral output. This RF oscillator can be used for gas analysis by measuring the changes of its frequencies when the coated SAW delay line is subject to gas absorption of desorption. The final chapter comprises the conclusion and some suggestions to further develop the dual SAW delay line oscillator.

طبعة: Manchester: University of Manchester
لغة: إنجليزية
الوصف المادي: 70 p. ill. ;30 cm
الشهادة: Master
مؤسسة مناقشة الرسالة: University of Manchester

ملاحظة: Bibliogr.pp.[1-2]