Title :
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
fDate :
7/1/1999 12:00:00 AM
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;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
