Temperature sensors based on GaPO/sub 4/

Results of investigations of temperature sensors using singly rotated Gallium Orthophosphate (GaPO/sub 4/) Y-cut resonators are presented in this paper. Depending on rotating angle the most important parameters - sensitivity, resolution and linearity differ in a wide range. Theoretical calculations leads to cuts owning nearly a linear response with sensitivity between 44.5 ppm//spl deg/C and 46.5 ppm//spl deg/C within a temperature range from room temperature to 600/spl deg/C with a high resolution of about 10/sup -6//spl deg/C. First measurements confirm the theoretically predicted sensitivity. The broad thermal stability range of GaPO/sub 4/ can also be used for temperature sensors based on surface acoustic wave devices. By theoretical calculations, suitable orientations with high temperature coefficients are identified.