| 摘要 |
PROBLEM TO BE SOLVED: To prevent a reduction of a Q value and an increase of an attenuation in a passband of a filter. SOLUTION: A surface acoustic wave element 20 comprises an IDT 24 composed of a pair of interdigital electrodes 26(26a, 26b) in a piezoelectric substrate 22, and reflectors 36(36a, 36b) disposed in a propagation direction of a surface acoustic wave excited by the piezoelectric substrate 22 across the IDT 24. Each of the interdigital electrodes 26 has cross electrodes 28(28a, 28b) which excite the surface acoustic wave by the piezoelectric substrate 22 in cooperation with the other interdigital electrode, and dummy electrodes 30(30a, 30b) disposed opposite at a leading edge of the cross electrode 28 of the other interdigital electrode. Each of the reflectors 36 has an opening B which is equal to or more than a cross width W of a cross electrode 34 of the IDT 24, and is smaller than a width W0 of a waveguide formed in the IDT 24. COPYRIGHT: (C)2008,JPO&INPIT
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