DocumentCode :
3016085
Title :
Optimal cut of lithium niobate with suppressed Rayleigh-type mode for application in resonator SAW filters
Author :
Naumenko, Natalya ; Abbott, Benjamin
Author_Institution :
Moscow Steel & Alloys Inst., Moscow
fYear :
2008
fDate :
2-5 Nov. 2008
Firstpage :
1013
Lastpage :
1017
Abstract :
Results of resonators constructed on rotated YX lithium niobate (LiNbO3), to provide minimum coupling of the spurious Rayleigh-type mode are reported. The resonator employs non-leaky waves which result when the metal grating´s electrodes are sufficiently heavy to suppress attenuation of leaky waves. The coupling of two SAW modes propagating in rotated YX cuts was estimated as function of cut angle and electrode thickness, with Al or Cu as electrode material. The optimal orientation, 19degYX for Al grating or 20degYX for Cu grating, is compared with previously reported 15degYX cut. If the electrode thickness is optimized to suppress the spurious mode, in 15degYX the coupling of this mode grows fast with variation of frequency or electrode thickness because of close proximity between the velocities of two modes. In 19degYX cut the resonance of the spurious mode is located in the middle of the interval between the resonance and anti-resonance of non-leaky SAW mode. The spurious mode is made less sensitive to variations of frequency or metal thickness and provides better performance of resonator filters. This conclusion is confirmed experimentally..
Keywords :
Rayleigh waves; acoustic wave propagation; aluminium; copper; electrodes; electromechanical effects; lithium compounds; surface acoustic wave resonator filters; Al; Cu; LiNbO3; Rayleigh-type mode suppression; SAW propagation; electromechanical coupling coefficient; lithium niobate crystal; metal grating electrode thickness; nonleaky waves; resonator SAW filter; surface acoustic waves; Attenuation; Electrodes; Frequency estimation; Gratings; Lithium niobate; Resonance; Resonator filters; SAW filters; Surface acoustic waves; Surface waves; SAW; SAW resonator; non-leaky wave; rotated YX cuts of LiNbO3; spurious mode;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 2008. IUS 2008. IEEE
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-2428-3
Electronic_ISBN :
978-1-4244-2480-1
Type :
conf
DOI :
10.1109/ULTSYM.2008.0245
Filename :
4803182
Link To Document :
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