Analysis of leaky surface acoustic waves on LiNbO_3 or LiTaO_3 thin plate bonded to similar-material substrates

摘要

To obtain a bonded structure with low attenuation for leaky surface acoustic waves (LSAWs), the propagation and resonance properties of LSAWs on a similar-material thin plate bonded to a LiTaO3 (LT) or LiNbO3 (LN) support substrate were theoretically analyzed. It was found that zero attenuation can be simultaneously obtained for free and metallized surfaces by utilizing the similar-material bonded structure but not when using a single structure. For a 10 degrees YX-LN/66 degrees YX-LN structure, the antiresonance Q(a) and the admittance ratio of the bonded structure were 1570 and 99 dB, respectively, even taking into consideration a mechanical loss of 1/Q(m) = 10(-3), and were higher than those of a single LN structure. For a YX-LT/36 degrees YX-LT structure, we observed the same or less attenuation and an approximately 1.3 times higher coupling factor than those for a single 36 degrees YX-LT structure. The LT similar-material bonded structure had slightly superior resonance properties to the single structure. (C) 2020 The Japan Society of Applied Physics