Large k2 and good temperature stability for SAW on new double-rotated cut of α-quartz with gold film

LST-cut α-quartz offers good temperature stability and small propagation loss. It has been also observed that if thickness cannot be ignored compared with SAW wavelength, propagation loss increases. We investigated the relation between the rotation angles of LST-cut quartz and SAW propagation characteristics theoretically and experimentally. We found that if the thickness of Au film electrodes was optimized, ranges of double-rotation angles could exist, where the compatibility of both small propagation loss and zero temperature coefficient was achieved, The maximum value of their coupling factors was 0.5%, which is very large for α-quartz