Finite difference time domain analysis of two-dimensional piezoelectric phononic crystals

Phononic crystals (PCs) have promising band gaps, in which Surface Acoustic Wave (SAW) propagating is prohibited. Several numerical methods have already been developed and applied to analyze piezoelectric PCs, most of them have various disadvantages, as they cannot calculate the transmission characteristic of the limited structure or cannot provide the propagation process for SAW in time domain. The finite-difference time-domain (FDTD) technique solving these problems is adopted to analyze the piezoelectric characteristics of PCs. Propagation in the PCs is studies by experience with direct generation and detection of SAW using interdigital transducers (IDT´s). The simulation data agrees with the measurement data. Therefore the FDTD method is an effective method of simulating piezoelectric PCs structure in which a square array of parallel cylindrical aluminum placed on a 128°YX LiNbO₃ substrate.