| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave (SAW) filter and a communication device which exhibits excellent characteristics even when a passband is wide. SOLUTION: A plurality of interdigital electrode parts 203, 204 and 205 having couples of interdigital electrodes 203a, 204a, 205a and interdigital electrodes 203b, 204b and 205b along the propagating direction of SAW are provided on a piezoelectric substrate. In at least one interdigital electrode part, the duty ratio in one interdigital electrode is different from the duty ratio in the other interdigital electrode. COPYRIGHT: (C)2004,JPO
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