Characteristics of fundamental acoustic wave modes in thin piezoelectric plates

S G Joshi; B D Zaitsev; I E Kuznetsova; A A Teplykh; A Pasachhe

doi:10.1016/j.ultras.2006.05.013

Characteristics of fundamental acoustic wave modes in thin piezoelectric plates

Ultrasonics. 2006 Dec 22:44 Suppl 1:e787-91. doi: 10.1016/j.ultras.2006.05.013. Epub 2006 Jun 2.

Authors

S G Joshi¹, B D Zaitsev, I E Kuznetsova, A A Teplykh, A Pasachhe

Affiliation

¹ EECE Department, Marquette University, Milwaukee, WI 53201, USA. shri.joshi@mu.edu <shri.joshi@mu.edu>

PMID: 16806378
DOI: 10.1016/j.ultras.2006.05.013

Abstract

The characteristics of the three lowest order plate waves (A(0), S(0), and SH(0)) propagating in piezoelectric plates whose thickness h is much less than the acoustic wavelength lambda are theoretically analyzed. It is found that these waves can provide much higher values of electromechanical coupling coefficient K(2) and lower values of temperature coefficient of delay (TCD) than is possible with surface acoustic waves (SAWs). For example, in 30Y-X lithium niobate, the SH(0) mode has K(2)=0.46 and TCD=55 ppm/degrees C. The corresponding values for SAW in the widely used, strong coupling material of 128Y-X lithium niobate are K(2)=0.053 and TCD=75 ppm/degrees C. Another important advantage of plate waves is that, unlike the case of SAWs, they can operate satisfactorily in contact with a liquid medium, thus making possible their use in liquid phase sensors.