| 摘要 |
<p>Provided is an acoustic wave device capable of improving isolation properties and out-of-passband attenuation while achieving miniaturization even if piezoelectric substrates are disposed to face each other across a void. In an acoustic wave device (10), a first piezoelectric substrate (12) and a second piezoelectric substrate (14) are coupled by a junction part (13) so as to face each other across a void (18). A first set of a plurality of filters (22 and 24) formed on a facing surface (12s) for the first piezoelectric substrate (12) and a second set of a plurality of filters (26 and 28) formed on a facing surface (14s) for the second piezoelectric substrate (14) form a plurality of pairs (22 and 26, and 24 and 28) that face each other across the void (18). The absolute value of the difference between center frequencies of a filter of the first set and a filter of the second set for each pair, in each case, is greater than the minimum value among absolute values of differences between center frequencies for two filters selected from the groups (22, 24, 26, and 28) comprising the filters of the first set and the filters of the second set.</p> |
