Abstract: An acoustic wave device includes a support including a support substrate, a piezoelectric layer on the support and including a lithium niobate layer or a lithium tantalate layer, and an IDT electrode on the piezoelectric layer and including a pair of busbars and electrode fingers. The support includes an acoustic reflector portion overlapping at least a portion of the IDT electrode in plan view. When a thickness of the piezoelectric layer is defined as d and a center-to-center distance between the electrode fingers adjacent to each other is defined as p, d/p is equal to or less than about 0.5. A region located between an intersection region and the pair of busbars is a pair of gap regions. An addition film having a higher dielectric constant and density than silicon oxide is provided in at least one of the pair of gap regions.

Abstract: An acoustic wave device includes a support, a piezoelectric layer on the support, and an IDT electrode on the piezoelectric layer and includes a pair of busbars and electrode fingers. The support includes an acoustic reflection portion overlapping at least a portion of the IDT electrode. d/p is about 0.5 or less. Some of the electrode fingers are connected to one of the busbars, others of the electrode fingers are connected to another of the busbars. When viewed from a direction in which adjacent electrode fingers face each other, a region where the adjacent electrode fingers overlap each other is an intersection region. A region between the intersection region and the pair of busbars includes a pair of gap regions. A mass addition film is provided in at least a portion of at least one of the gap regions.

Abstract: An acoustic wave device includes an IDT electrode on a piezoelectric body and the IDT electrode includes first and second busbars, and first and second electrode fingers. A first dielectric film extends from a region between tip end portions of the first electrode fingers and the piezoelectric body to a region between the second busbar and the piezoelectric body with a first gap in between. The second electrode fingers are in direct contact with the piezoelectric body at a center of an overlap width, and a permittivity of the first dielectric film is lower than a permittivity of the piezoelectric body.

Abstract: In an acoustic wave device, an IDT electrode is located on a piezoelectric layer. A high-acoustic-velocity member is positioned on an opposite side of the piezoelectric layer from the IDT electrode. An acoustic velocity of a bulk wave propagating through the high-acoustic-velocity member is higher than an acoustic velocity of an acoustic wave propagating through the piezoelectric layer. A low-acoustic-velocity film is provided between the high-acoustic-velocity member and the piezoelectric layer. An acoustic velocity of a bulk wave propagating through the low-acoustic-velocity film is lower than the acoustic velocity of the bulk wave propagating through the piezoelectric layer. A dielectric film is located on the piezoelectric layer so as to cover the IDT electrode. In the acoustic wave device, a Young's modulus of the dielectric film is larger than a Young's modulus of the low-acoustic-velocity film.

Abstract: An acoustic wave device includes a support substrate, an intermediate layer on the support substrate, a piezoelectric layer on the intermediate layer, a bonding layer between the support substrate and the piezoelectric layer, a low-resistivity layer between the support substrate and the piezoelectric layer, and an IDT electrode on the piezoelectric layer and including a pair of busbars and first and second electrode fingers. The low-resistivity layer closer to the piezoelectric layer than the bonding layer and includes Al as a main component.

Abstract: A surface acoustic wave element includes a substrate including a LiNbO3 piezoelectric single crystal, a first dielectric layer provided on the substrate, and an IDT electrode provided on the first dielectric layer, and propagates a high-frequency signal on the substrate using a Rayleigh wave.

Abstract: An acoustic wave device includes a piezoelectric substrate including a piezoelectric layer made of lithium tantalate, an IDT electrode on the piezoelectric substrate, and a pair of reflectors on both sides of the IDT electrode on the piezoelectric substrate in an acoustic wave propagation direction. SH waves are used as a principal mode. The IDT electrode includes electrode fingers and the pair of reflectors each including electrode fingers. When a length along a direction orthogonal to a direction in which the electrode fingers extend is a width, each of the reflectors includes first and second electrode fingers having different widths. Four consecutive electrode fingers, which are any four of the electrode fingers of each of the reflectors, include both of the first and second electrode fingers and distances between centers of the four consecutive electrode fingers are equal or substantially equal.

Abstract: An acoustic wave device includes a piezoelectric substrate and an IDT electrode on the piezoelectric substrate. The IDT electrode includes first and second electrode fingers. When the propagation direction of acoustic waves is a first direction and the direction orthogonal or substantially orthogonal to the first direction is a second direction, an intersecting region of the IDT electrode includes a central region located toward the middle in the second direction and first and second edge regions on both sides in the second direction of the central region. The first and second electrode fingers include epitaxially grown oriented films in the central region and portions that do not include the oriented films in the first and second edge regions.

Abstract: An acoustic wave device includes a crystal substrate, a silicon carbide layer on the crystal substrate, a lithium tantalate layer on the silicon carbide layer, and an interdigital transducer electrode on the lithium tantalate layer and including multiple first and second electrode fingers.

Abstract: An elastic wave device includes a support substrate, a piezoelectric layer disposed on the support substrate, and an IDT electrode disposed on a piezoelectric layer and including first and second electrode fingers that are interdigitated. A region where the first and second electrode fingers overlap each other as seen in a direction of propagation of elastic waves is an excitation region. Edge portions where an acoustic velocity is lower than an acoustic velocity in a central portion are disposed on opposite sides of a central portion in the excitation region. A first busbar and second busbar include inner busbar portions, central busbar portions, and outer busbar portions. First and second offset electrode fingers extend from the inner busbar portions toward the leading ends of the second electrode fingers or first electrode fingers.

Abstract: An acoustic wave device including a piezoelectric layer including lithium tantalate or lithium niobate, a dielectric film on the piezoelectric layer, and an IDT electrode on the dielectric film. The dielectric film includes one dielectric substance selected from the group consisting of TiO2, TaO2, MnO2, GeO2, RuO2, OsO2, IrO2, SnO2, and PbO2.

Abstract: An acoustic wave device includes a crystal substrate, a silicon nitride film on the crystal substrate, a lithium tantalate layer on the silicon nitride film, and an interdigital transducer electrode on the lithium tantalate layer and including multiple first and second electrode fingers.

Abstract: An acoustic wave device includes a crystal substrate, a polycrystalline silicon layer on the crystal substrate, a lithium tantalate layer on the polycrystalline silicon layer, and an interdigital transducer electrode on the lithium tantalate layer and including multiple first and second electrode fingers.

Abstract: An acoustic wave device includes a crystal substrate, an aluminum oxide layer on the crystal substrate, a lithium tantalate layer on the aluminum oxide layer, and an interdigital transducer electrode on the lithium tantalate layer and including multiple first and second electrode fingers.

Abstract: An acoustic wave element includes a piezoelectric substrate, an IDT electrode on the piezoelectric substrate, and a reflector. The IDT electrode includes plural electrode fingers, and the reflector includes plural reflector electrode fingers. In a case where IRGAP is an IDT-reflector gap that is a distance between a center of the electrode finger located closest to the reflector and a center of the reflector electrode finger located closest to the IDT electrode, and ?REF is a reflector wave length that is twice a repetition pitch of the reflector electrode fingers, a ratio of about 0.25?IRGAP/?REF?about 0.44 is satisfied, and the reflector wave length is longer than an IDT wave length that is a repetition pitch of the electrode fingers.

Abstract: An acoustic wave device includes a silicon substrate, a polysilicon layer provided on the silicon substrate, a silicon oxide layer directly or indirectly provided on the polysilicon layer, a piezoelectric layer directly or indirectly provided on the silicon oxide layer, and an interdigital transducer electrode provided on the piezoelectric layer. A plane orientation of the silicon substrate is any one of (100), (110), and (111), and, where a wave length that is defined by an electrode finger pitch of the interdigital transducer electrode is ?, a thickness of the piezoelectric layer is less than or equal to about 1?.

Abstract: An acoustic wave device includes a piezoelectric layer including lithium tantalate or lithium niobate, a dielectric film on the piezoelectric layer, the dielectric film including a dielectric material having a higher dielectric constant than that of the lithium tantalate or lithium niobate, and an IDT electrode on the dielectric film.

Abstract: An acoustic wave device includes a piezoelectric substrate including a piezoelectric layer, an IDT electrode provided on the piezoelectric substrate and including electrode fingers, and a dielectric film between the piezoelectric substrate and the IDT electrode. A portion of the IDT electrode in which the electrode fingers overlap with each other when seen in a propagation direction of an acoustic wave is an intersecting range. The intersecting range includes a central range and a first range and a second range sandwiching the central range in an electrode finger extending direction. Permittivity and density of the dielectric film are lower than that of the piezoelectric layer. When seen in plan view, the dielectric film is provided at a portion overlapping with the central range, and not provided at a portion overlapping with one of the first range and the second range.

Abstract: An acoustic wave device includes a high-acoustic-velocity layer, a piezoelectric layer made of lithium tantalate, and an interdigital transducer electrode that are successively laminated. An acoustic velocity of a bulk wave propagating in the high-acoustic-velocity layer is higher than an acoustic velocity of an acoustic wave propagating in the piezoelectric layer, and an acoustic velocity Vsub of a fast transversal bulk wave propagating in the high-acoustic-velocity layer satisfies Vsh0?Vsub?Vsp with respect to an acoustic velocity Vsh0 of an SH0 mode and an acoustic velocity Vsp of a mode becoming a spurious of which acoustic velocity is not lower than the acoustic velocity of the SH0 mode, wherein the acoustic velocity Vsh0 and the acoustic velocity Vsp is obtained from Eq. (1).

Abstract: An acoustic wave device is provided between a first terminal that is an antenna terminal and a second terminal that is different from the first terminal, and includes a plurality of acoustic wave resonators. The plurality of acoustic wave resonators include a plurality of series arm resonators and a plurality of parallel arm resonators. When the acoustic wave resonator electrically closest to the first terminal among the plurality of acoustic wave resonators is an antenna end resonator, the antenna end resonator is a SAW resonator or a BAW resonator. At least one acoustic wave resonator other than the antenna end resonator among the plurality of acoustic wave resonators is a first acoustic wave resonator.