A Two-dimensional Analysis of the Effect of Periodic Electrodes on Surface Acoustic Wave Resonators

Among many parameters important in surface acoustic wave resonator analysis and design, accurate prediction of the phase velocity and displacement fields is essential. Since surface acoustic wave analysis usually is done for a semi-infinite elastic solid, simplified methods which have only one spatial coordinate considered are applied to devices which are finite piezoelectric strips serving as a substrate with complications like the presence of periodic electrodes (IDTs). In this study, the authors treat the periodic structure of electrodes on a substrate with the two-dimensional equations, which lead to the direct consideration of effect of electrodes for their layout, size, and material properties. The analytical model and the two-dimensional equations represent the full consideration of electrodes in a much more accurate and systematic manner