| 摘要 |
An elastic wave filter device 11 in which are laminated: a high-acoustic-velocity support substrate 2, which acts as a high-acoustic-velocity member through which bulk waves propagate at a higher acoustic velocity than the acoustic velocity at which main-mode elastic waves propagate through a piezoelectric film 4; the piezoelectric film 4, which is directly or indirectly laminated onto the high-acoustic-velocity support substrate 2; and a plurality of IDT electrodes 5, which are provided so as to contact the piezoelectric film 4. At least one series arm resonator S11, S12 and at least one parallel arm resonator P11 are configured from the plurality of IDT electrodes. At the IDT electrodes that configure the at least one series arm resonator S11, S12 and the at least one parallel arm resonator P11, the direction that connects tips of a plurality of first and second electrode fingers forms an angle of inclination of ν with respect to the propagation direction ψ of elastic waves that are excited by the IDT electrodes. When the angle of inclination at the at least one series arm resonator S11, S12 is ν1 and the angle of inclination at the at least one parallel arm resonator P11 is ν2, ν1 and ν2 are different. |
