Elastic wave device having pairs of filters that face each other

摘要

In an elastic wave device, a first piezoelectric substrate and a second piezoelectric substrate are joined to each other with a joining portion so as to face each other across a cavity. A first set of a plurality of filters located on a facing surface of the first piezoelectric substrate and a second set of a plurality of filters located on a facing surface of the second piezoelectric substrate define a plurality of pairs of filters and face each other across the cavity. An absolute value of a difference between center frequencies of a filter of the first set of filters and a filter of the second set of filters in each pair of filters is larger than a minimum value among absolute values of differences between center frequencies of pairs of filters selected from a group including the first set of filters and the second set of filters.