Sensors based on shear-horizontal surface acoustic waves in layered quartz/SiO/sub 2/ and LiTaO/sub 3//SiO/sub 2/ structures

Acoustic wave devices based on waveguide modes with shear-horizontal polarization, i.e. Love modes, are very promising for sensor application, especially in liquid environments. They can be used for determination of liquid density and viscosity as well as for chemical sensors. Up to now, several systems have been reported based on standard ST-quartz. Those devices lack temperature stability which is essential for field application. Thus, temperature compensated systems based on different Y-rotated quartz and lithium tantalate (LiTaO₃) plates with SiO₂ waveguiding films have been investigated. Temperature behavior as well as relevant acoustic properties are compiled. Furthermore, experimentally determined values for device sensitivity are compared with theoretical predictions from numerical computation.