SAW pressure sensors

The design and performance of two types of SAW pressure sensors have been considered. SAW resonator oscillators with metal strip gratings designed for operation at 200 and 360 MHz have been used in both type devices to study the opportunity of the mechanical pressure measurement became of mechanical loading on Rayleigh surface wave propagation. Such electrical characteristics of SAW resonator as amplitude and phase response are discussed, as well as a geometrical dimensions of the sensitive element and a disposition of SAW structures on it. The sensitivity and the non linearity of both sensors with a sensitive element shaped as an integral crystal diaphragm and sensor with mechanically loaded quartz plates measured and discussed too. Experimental data clearly show that sensitivity and threshold are not independent parameters for this kind of pressure sensor. We studied the opportunity to optimize this parameters for a given pressure range. Finally, recommendations are made for optimal configuration of SAW pressure sensor according to pressure and dynamic range demands. These results are important for the design of SAW pressure sensors intended for operation in gaseous or liquid media