Temperature-Dependent Characteristics of Surface Acoustic Wave Resonators Deposited on (0°, 138.5°, $psi$ ) Langasite Cuts

摘要

Surface acoustic wave (SAW) resonators were deposited on (0 degrees, 138.5 degrees, psi) LGS (langasite, La3Ga5SiO14) cuts with different Euler angles psi in this paper. The temperature-dependent characteristics of these SAW resonators were investigated systematically. At room temperature, the (0 degrees,1385 degrees, 26.6 degrees) LGS cut has the maximum SAW velocity of about 2716 m/s. The (0 degrees, 138.5 degrees, 3.4 degrees) LGS cut has the minimum SAW velocity of about 2377 m/s. The first-order and second-order temperature coefficients of frequency in the (0 degrees, 138.5 degrees, 26.6 degrees) and (0 degrees, 138.5 degrees, 33.4 degrees) LGS cuts are nearest to zero. The turnover temperature decreases first when the angle psi varies from 3.4 degrees to 26.6 degrees and increases with the further increase of psi. The results in this paper may help us design LGS SAW temperature sensors and other types of sensors.