Surface acoustic wave device comprising langasite single crystal substrate

摘要

A surface acoustic wave device including a substrate and an electrode structure formed on the substrate, said substrate being made of a doubly rotated Y-cut ( alpha X-&thetas;Y cut) Langasite (La3Ga5SiO14), a rotation angle alpha from the X axis being substantially 50 DEG +/-5 DEG and a rotation angle &thetas; from the Y axis being substantially 19 DEG +/-30 DEG . The device further includes a normal type electrode structure which reveals a natural single-phase unidirectional transducer property together with an anisotropy of the substrate. The device further has a double electrode type electrode structure which cancels the directionality, or a floating type electrode structure which reverses the directionality, the electrode structure is formed to constitute a surface acoustic wave filter having a low insertion loss and an excellent phase property. <IMAGE>