| 摘要 |
<p>An elastic boundary wave device using an SH elastic boundary wave and exhibiting an electro-mechanical coupling coefficient suitable for a narrow-band filter and a resonator and achieved without using a troublesome process. An elastic boundary wave device (1) comprises a lithium borate-based piezoelectric single crystal substrate (2), an IDT (4) formed on the lithium borate-based piezoelectric single crystal substrate (2), and a dielectric body (3) covering the IDT (4). The elastic boundary wave device (1) uses a Stoneley wave which is a P+SV elastic boundary wave propagating along the boundary between the lithium borate-based piezoelectric single crystal substrate (2) and the dielectric body (3). The Euler angles (f, ?, ?) of the lithium borate-based piezoelectric single crystal substrate (2) are on the line representing that the electro-mechanical coupling coefficient K<SUP>2</SUP> is 0.4% or in the region where the electro-mechanical coupling coefficient K<SUP>2</SUP> is higher than the line in Figs. 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58, 62, 66, 70, or 74.</p> |
