| 摘要 |
<p>A longitudinally coupled resonator acoustic wave filter device that utilizes an inter-IDT resonance mode with a further low loss is provided. In a longitudinally coupled resonator acoustic wave filter device (100) that utilizes an inter-IDT resonance mode, the apodization weights are assigned in first to third IDTs (111 to 113) having narrow pitch electrode finger portions (111A, 111B, 112A and 113A), but other than the narrow pitch electrode finger portions, in such a manner that the electrode finger overlap width sequentially varies in an acoustic wave propagating direction in which an acoustic wave propagates and portions of the IDTs, located at ends adjacent to the narrow pitch electrode finger portions (111A, 111B, 112A and 113A), have a maximum electrode finger overlap width.</p> |
