Analysis of longitudinal leaky surface acoustic wave resonance properties on LiNbO₃/Ca₃TaGa₃Si₂O₁₄ bonded structures

Abstract The resonance properties of longitudinal leaky surface acoustic waves excited by an Al interdigital transducer on bonded structures of a Ca 3 TaGa 3 Si 2 O 14 support substrate with two types of LiNbO 3 (LN) thin plate (X-cut and rotated Y-cut) were analyzed. For the X-cut LN thin plate, several optimum conditions such as the propagation angle and the thickness for obtaining an electromechanical coupling factor larger than 11%, a high Q factor, and a large admittance ratio ( AR ) were determined. For the rotated Y-cut LN, optimum conditions for achieving an electromechanical coupling factor larger than 12.3%, high resonance Q, and antiresonance Q factors (622 and 844, respectively), and a high AR of 75.7 dB were determined. For the rotated Y-cut LN, the values of the temperature coefficient of frequency corresponding to the resonance and antiresonance frequencies under the optimum condition were found to be −65.8 and −98.1 ppm/°C, respectively.