New method of change in temperature coefficient delay of acoustic waves in thin piezoelectric plates

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 53; no. 11; pp. 2113 - 2120
• Main Authors: Zaitsev, B.D., Kuznetsova, I.E., Joshi, S.G., Kuznetsova, A.S.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.11.2006; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustic coupling; Acoustic devices; Acoustic materials; Acoustic waves; Acoustics; Coefficients; Delay effects; Devices; Joining; Permittivity; Piezoelectric materials; Piezoelectricity; Plates; Propagation delay; Surface acoustic wave devices; Surface acoustic waves; Temperature
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2006.151

As is well-known, the development of highly effective and thermostable acoustic devices assumes using the acoustic waves with high coefficient of electromechanical coupling (K 2 ) and low temperature coefficient of delay (TCD). At present, it also is well-known that fundamental shear horizontal (SH 0 ) acoustic waves in thin piezoelectric plates possess significantly more electromechanical coupling compared to surface acoustic waves (SAW) in the same material. However, although the value of TCD of SH 0 waves is insignificantly less than for SAW, this is not enough for development of thermostable devices. This paper suggests a new way of decreasing TCD of SH 0 waves in piezoelectric plates at a high level of electromechanical coupling. This way assumes to use the structure containing the piezoelectric plate and liquid with the special dependence of permittivity on temperature. Theoretical and experimental investigation showed that, for SH 0 wave in YX LiNbO 3 plate at hf=700 m/s (h=plate thickness, f=wave frequency) the presence of butyl acetate can decrease the value of TCD by six times at K 2 =30%. In a whole the obtained results open the wide prospect of using SH 0 wave in thin piezoelectric plate for development of highly effective and thermo-stable acoustic devices