Transmission Line Techniques for Description of Microwave Acoustic Resonances in Thin Piezoelectric Disks.

Standard transmission line theory and techniques are used to develop a quantitative description of microwave acoustic resonances in thin piezoelectric disks. An equivalent circuit is derived from basic electromagnetic and acoustic principles for the vibration of such a disk in the gap of a reentrant cavity. The elements of this circuit are given in terms of physical parameters of the disk and cavity. Experimental results confirming the theory are also presented including observation of S-band resonances in X-cut, Y-cut, AC-cut and BC-cut quartz and Z-cut LiNbO3. By using the theoretical model to relate these results back to fundamental quantities, an estimate of the acoustic attenuation is obtained for the various crystal cuts. Author