Analysis of anharmonics in surface skimming bulk wave devices

The anharmonics of surface-skimming-bulk-wave devices on rotated Y-cut quartz are analyzed by the two-dimensional theory developed by P.C.Y. Lee et al. (1987). The problem is solved in closed form, taking into account the electrical and mechanical surface conditions. From this calculation, the dispersion curves of the horizontal shear mode are obtained. The application of these dispersion curves to bulk-wave resonators and surface-skimming-bulk-wave delay lines is compared and discussed. Delay lines have been fabricated and tested on ST-cut quartz with different wavelength-to-thickness ratios. Good agreement between experimental results and theoretical prediction has been obtained