摘要 |
A boundary acoustic wave device by which SH type boundary acoustic wave can be utilized while employing an inexpensive quartz substrate, and physical properties such as electromechanical coupling coefficient K2 and characteristics can be enhanced. In the boundary acoustic wave device (1) where at least an IDT (4) is formed on a quartz substrate (2), a dielectric (3) is formed to cover the IDT (4) and a boundary acoustic wave propagates on the interface between the quartz substrate (2) and the dielectric (3), thickness of the IDT (4) is set such that an SH type boundary wave has a sound velocity lower than those of slow transverse waves respectively propagating through the quartz substrate (2) and the dielectric (3), and the Eulerian angles of the quartz substrate (2) fall within shaded regions in Fig. 13.
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