Numerical Approach for Extraction COM Surface Acoustic Wave Parameters from Periodic Structures Analysis

A numerical approach for extraction COM surface acoustic wave parameters from periodic structures analysis is proposed. COM parameters (velocity, reflection coefficient, effective electromechanical coupling coefficient, attenuation) are extracted from simulations of a set of test structures employing COMSOL Multiphysics. Two types of a periodic structure analysis: eigenfrequency analysis and frequency response analysis of harmonic admittance are presented. A comparison using two methods on the example of extracting and calculating the Q-factor parameter, which is inversely proportional to the losses, showed good agreement. To demonstrate the method we calculated the Q-factor for single electrode structure on 49° YX-cut LiNbO3 as a function of relative electrode thickness.