On the Influence of Electrode Thickness in the Spurious Mode Reduction of Lithium Niobate-On-Insulator SH₀ Acoustic Wave Resonators

This work demonstrates manufactured microacoustic resonators exploiting the shear horizontal (SH₀) mode on a 30° YX-cut lithium niobate-on-insulator (LNOI) structure. Moreover, the work shows how the careful selection of electrode thickness is key to avoid the excitation of spurious longitudinal modes above the anti-resonance frequency. The manufactured resonators are in the 1.5 GHz frequency range and exhibit an electromechanical coupling coefficient of 14.3% and a quality factor of 615.