Elastic wave device

• Main Author: DAIMON KATSUYA
• Format: Patent
• Language: Chinese; English
• Published: 03.05.2024
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS

Provided is an elastic wave device capable of suppressing useless waves at a frequency lower than the resonance frequency and located near the resonance frequency. This elastic wave device (10) is provided with: a support member (13) including a support substrate (16); a piezoelectric layer (14), which is a lithium niobate layer or a lithium tantalate layer, provided on the support member (13); and an IDT electrode (11) provided on the piezoelectric layer (14) and having a pair of bus bars and a plurality of electrode fingers. A sound reflecting portion (cavity portion (10a)) is formed at a position overlapping at least a part of the IDT electrode (11) in a plan view as viewed in a stacking direction of the support member (13) and the piezoelectric layer (14). When the thickness of the piezoelectric layer (14) is d and the distance between the centers of adjacent electrode fingers is p, d/p is 0.5 or less. Some of the plurality of electrode fingers are connected to one bus bar of the IDT electrode (11), the r