A 5.5 GHz S3 Mode Plate Acoustic Wave Resonator Using Lithium Tantalate Thin Film

Acoustic wave resonators using plate acoustic wave in the lithium tantalite (LiTaO 3 ) thin film shows the potential of relating high frequency with a suitable quality factor (Q). The effect of the LiTaO 3 thickness on the plate wave characteristics is investigated in this work. A high frequency resonator using third symmetric lamb wave (S 3 ) mode in a composite plate of 36° YX-cut LiTaO 3 and silicon dioxide (SiO 2 ) has been fabricated as a wave-length (λ) is 4 μm. The series resonant frequency (f s ), Q s and Q p of the proposed resonator are 5.5 GHz, 419 and 816, respectively. This work demonstrated that the S 3 mode based composite thin film of LiTaO 3 and SiO 2 is suitable for high-frequency devices with high Q.