Measurements of SAW effective velocity angular-variation under metal strip gratings and their application to ASPW analysis

Measurements of SAW effective velocity angular-variation under metal strip gratings, using a comb-filter method are described. A distinctive characteristic was newly observed at higher frequency; the minimum observed at propagation angle 0° of the above angular-variation of LiNbO
₃
-128° rotYX single crystal. The minimum is originated by SAW dispersion considered to be mainly due to stored energy effect. Moreover, as an example to utilize the above measurement results for an analysis of SAW second order effects, the frequency response of a 480 MHz SAW filter was calculated including SAW diffraction effect using angular spectrum of plane wave (ASPW) method. The simulation result was in good agreement with the experimental one