TEMPERATURE STABLE PIEZOELECTRIC SUBSTRATES FOR SAW GAS SENSORS

A systematic search of several surface acoustic wave (SAW) substrates and crystallographic orientations has been conducted in an effort to i dentify temperature compensated cuts. As a result of this search, a se quence of crystallographic orientations along the rotated Y-cut (RYC) in quartz has been identified as appropriate for operation over a broa d range of temperatures. Theoretical calculations, in fact, show that different orientations along RYC quartz provide compensation at temper atures ranging from -35 degrees C to over 500 degrees C, thereby allow ing one to select an appropriate temperature stable orientation for a particular application. Experimental measurements performed on selecte d RYCs in quartz have confirmed these predictions of temperature stabi lity.