Title :
Natural single-phase unidirectional transducers on a LiNbO3 substrate for SAW sensor applications
Author_Institution :
Coll. of Eng., Tamagawa Univ., Machida
Abstract :
LiNbO3 is the substrate most often used in wireless identification tags because of its large electromechanical coupling constant. A single-phase unidirectional transducer (SPUDT) on LiNbO3 is attractive to realize a wireless SAW sensor with reduced size, low insertion loss, low passband ripple, and high degree of linearity of phase. A natural single-phase unidirectional transducer (NSPUDT) produces the directivity even when the geometry is symmetrical. The NSPUDT is good for high frequency sensor applications because of its simple structure with wide electrode width. In this paper, NSPUDT orientations on a LiNbO3 substrate are described. Analytical results of transduction characteristics and COM parameters of the NSPUDT using coupled-mode and perturbation theories are shown. A useful orientation on Euler angle (0deg, 38deg, psi ) cut is obtained for aluminum and copper electrodes.
Keywords :
aluminium; copper; coupled mode analysis; electrodes; lithium compounds; perturbation theory; radiofrequency identification; surface acoustic wave sensors; surface acoustic wave transducers; Al; Cu; Euler angle; LiNbO3; aluminum electrode; copper electrode; coupled-mode theory; electromechanical coupling constant; high frequency sensor; perturbation theory; single-phase unidirectional transducers; transduction characteristics; wireless SAW sensor; wireless identification tags; Electrodes; Electromechanical sensors; Frequency; Geometry; Insertion loss; Linearity; Passband; Surface acoustic waves; Transducers; Wireless sensor networks;
Conference_Titel :
Frequency Control Symposium, 2008 IEEE International
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-4244-1794-0
Electronic_ISBN :
1075-6787
DOI :
10.1109/FREQ.2008.4622978