Propagation characteristics of longitudinal leaky SAW in Al-grating structure

Author

Isobe, Atsushi ; Hikita, Mitsutaka ; Asai, Kengo

Author_Institution

Dept. of Commun. Syst. Res., Hitachi Ltd., Tokyo, Japan

Volume

46

Issue

4

fYear

1999

fDate

7/1/1999 12:00:00 AM

Firstpage

849

Lastpage

855

Abstract

New orientations for longitudinal leaky SAW with small propagation losses and high velocities in lithium niobate (LN) and lithium tantalate (LT) have been found. Their velocities are 6100 to 6500 m/s in LN and 5200 to 5800 m/s in LT. Their propagation losses are almost negligible only in the case of an Al-grating structure. For example, the Al thickness relative to the SAW wavelength must be 8.4% for 171/spl deg/YZ´-LN; for 133/spl deg/YZ´-LT, the value must be 9.2%. These propagation properties were obtained by using a simulator that combined both finite-element and analytical methods. These results were also well confirmed by measuring the impedance responses of one-port SAW resonators.

Keywords

aluminium; diffraction gratings; finite element analysis; lithium compounds; losses; surface acoustic wave resonators; ultrasonic propagation; ultrasonic velocity; 5200 to 5800 m/s; 6100 to 6500 m/s; Al; Al thickness; Al-grating structure; LiNbO/sub 3/; LiTaO/sub 3/; SAW wavelength; analytical methods; finite-element methods; high velocities; impedance response; lithium niobate; lithium tantalate; longitudinal leaky SAW; one-port SAW resonators; orientations; propagation characteristics; propagation properties; small propagation losses; Acoustic waves; Analytical models; Capacitance; Electrodes; Impedance measurement; Lithium compounds; Lithium niobate; Permittivity; Propagation losses; Surface acoustic waves;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/58.775649

Filename

775649