Title :
Interaction between leaky surface acoustic waves in periodic gratings of thick metal electrodes
Author :
Grigorievski, Valeri I.
Author_Institution :
Inst. of Radio Eng. & Electron., Acad. of Sci., Fryazino, Russia
Abstract :
It is shown that effective permittivity function in the complex plane of slowness for 36-42 degrees rotated lithium tantalate substrates apart from the well-known LSAW exhibits an additional singular point. The pole is located between "fast shear" and "longitudinal" branch points and can be numerically found out when appropriate branch line is drawn from the "fast shear" branch point. The effective propagation velocity of this leaky mode on 36 degrees rotated lithium tantalate equals 4723 m/s that is 1.1 times larger than the velocity of fast shear SSBW propagating in the same direction. The intrinsic attenuation of this mode is extremely high and equal to 6.93 dB/wavelength. The previously reported PSAW-like mode in periodic system of metal electrodes is associated with this new mode.
Keywords :
acoustic wave propagation; acoustic wave velocity; lithium compounds; permittivity; piezoelectric materials; surface acoustic wave filters; surface acoustic waves; LiTaO3; additional singular point; complex plane of slowness; effective permittivity function; effective propagation velocity; fast shear; intrinsic attenuation; leaky surface acoustic waves; longitudinal branch points; periodic gratings; thick metal electrodes; Acoustic propagation; Acoustic waves; Acoustical engineering; Attenuation; Dielectric substrates; Electrodes; Gratings; Lithium compounds; Permittivity; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE
Print_ISBN :
0-7803-7582-3
DOI :
10.1109/ULTSYM.2002.1193415
