Elastic wave device and multiplexer

Abstract

A filter (10) is provided with a plurality of elastic wave resonance circuits, and an elastic wave resonance circuit (11) among the plurality of elastic wave resonance circuits is composed of series arm resonators (111-113) connected in series to each other. Each of the series arm resonators (111-113) has an IDT electrode that is disposed on a piezoelectric substrate (50) and has a plurality of electrode fingers that are parallel to each other. When a region in which two or more electrode fingers having the same duty are continuously arranged is defined as an electrode finger region, the IDT electrode of each of the series arm resonators (111-113) is divided into a plurality of electrode finger regions having different duties D. When the plurality of electrode finger regions are compared, the larger the duty D, the smaller an electrode finger pitch that is the interval between the adjacent electrode fingers.