Transverse acoustic anisotropy of obliquely propagating LSAW in resonator structures on LiTaO3 and LiNbO3 substrates

The transverse anisotropy of LSAW characteristics is numerically analyzed in some orientations of practical interest in LiTaO₃ and LiNbO₃ with Al grating. The detailed analysis of the slowness curves for LSAW propagating in the grating and in the substrate with uniform Al layer helps to estimate the frequency intervals, in which strong radiation of obliquely propagating waves can be expected in the grating and in the busbars, and explains the transversal pattern within the IDT aperture. The numerical results show good agreement with measurements previously reported by Koskela et al. (2001) and Knuuttila et al. (2003).