Low Loss Acoustic Waveguide Based On 128° Y-cut Lithium Niobate

In this study, we investigate the simulation and fabrication of overlay-type Surface Acoustic Wave (SAW) waveguides on 128° Y-cut Lithium Niobate (LiNbO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>) substrates. A thin metallic layer is deposited on the 128° Y-cut LiNbO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> substrate to serve as the waveguide region. Finite Element Analysis (FEA) is employed to investigate the impact of different metal types and waveguide widths on SAW propagation, with the goal of minimizing propagation loss. Simulation results guide the determination of the optimal waveguide width by analyzing the energy confinement ratio for different modes. Finally, the proposed devices are fabricated using manufacturing processes, and their frequency responses are measured to validate the earlier simulation results. This research offers valuable insights into the design and optimization of SAW waveguides for diverse applications.