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.

Abstract: An acoustic wave device includes a material layer which has Euler angles and an elastic constant at the Euler angles, a piezoelectric body which includes first and second principal surfaces opposing each other, is laminated directly or indirectly on the material layer so that the second principal surface is on the material layer side and has Euler angles, and whose elastic constant at the Euler angles, and an IDT electrode which is disposed on at least one of the first principal surface and the second principal surface of the piezoelectric body. At least one elastic constant among elastic constants C11 to C66 of the material layer not equal to 0 and at least one elastic constant among elastic constants C11 to C66 of the piezoelectric body not equal to 0 have opposite signs to each other.

Abstract: An acoustic wave device includes a support substrate, a silicon nitride film stacked on the support substrate, a silicon oxide film stacked on the silicon nitride film, a piezoelectric body stacked on the silicon oxide film and made of lithium tantalite, and an IDT electrode provided on one main surface of the piezoelectric body. For a wavelength normalized film thickness of the piezoelectric body, an Euler angle of the piezoelectric body, a wavelength normalized film thickness of the silicon nitride film, a wavelength normalized film thickness of the silicon oxide film, and a wavelength normalized film thickness of the IDT electrode, values are set so that at least one of a response intensity of a first higher order mode, corresponding to the response intensity of a second higher order mode, and of a response intensity of a third higher mode is greater than about ?2.4.

Abstract: In an acoustic wave device, an antenna end resonator that is electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is about 3.5? or less when a wavelength of an acoustic wave is denoted as ?. The first acoustic wave resonator and the second acoustic wave resonator satisfy at least one of a first condition, a second condition, and a third condition. The first condition is a condition that the first acoustic wave resonator further includes a dielectric film provided between the piezoelectric layer and an interdigital transducer electrode, and the second acoustic wave resonator does not include the dielectric film.

Abstract: In a multiplexer, at least one acoustic wave filter includes a piezoelectric body made of lithium tantalate having Euler angles (?LT=0°±5°, ?LT, ?LT=0°±15°), a support substrate, and an interdigital transducer (IDT) electrode. A frequency fh1_t(n) of a first higher-order mode satisfies below Formulas (3) and (4) in all acoustic wave filters (m) having a higher pass band than at least one acoustic wave filter (n) (n<m?N) in at least one acoustic wave resonator among a plurality of acoustic wave resonators. fh1_t(n)>fu(m) Formula (3). fh1_t(n)<fl(m) Formula (4). Here, fu(m) and fl(m) represent the frequencies of the high-frequency end and the low-frequency end of the pass band in the m acoustic wave filters in Formulas (3) and (4).

Abstract: An acoustic wave device includes a material layer with Euler angles and an elastic constant at the Euler angles represented by Expression 1, a piezoelectric body including opposing first and second principal surfaces, is laminated directly or indirectly on the material layer and has Euler angles, and whose elastic constant at the Euler angles is represented by the Expression 1 below, and an IDT electrode on at least one of first and second principal surfaces of the piezoelectric body, and in which a wave length determined by an electrode finger pitch is ?.

Abstract: An acoustic wave device includes a high-acoustic-velocity film, a low-acoustic-velocity film provided on the high-acoustic-velocity film, a piezoelectric layer provided on the low-acoustic-velocity film, and an IDT electrode provided on the piezoelectric layer. An acoustic velocity of bulk waves propagating through the high-acoustic-velocity film is higher than an acoustic velocity of acoustic waves propagating through the piezoelectric layer. An acoustic velocity of bulk waves propagating through the low-acoustic-velocity film is lower than an acoustic velocity of bulk waves propagating through the piezoelectric layer. The low-acoustic-velocity film includes a material including hydrogen atoms.

Abstract: An acoustic wave device includes a piezoelectric substrate, a first interdigital transducer (IDT) electrode, reflectors on both sides of the first IDT electrode in a propagation direction of an acoustic wave, and a second IDT electrode facing the first IDT electrode with a reflector interposed therebetween. The first and second IDT electrodes include first and second intersecting areas in which electrode fingers overlap in the propagation direction. The first and second intersecting areas overlap in the propagation direction. A third busbar of the second IDT electrode is coupled to a first busbar of the first IDT electrode. A fourth busbar of the second IDT electrode is coupled to a ground potential. A resonant frequency of the second IDT electrode is in a frequency band of an interference wave signal.

Abstract: An elastic wave device includes a SiNx layer stacked directly or indirectly on a supporting substrate made of a semiconductor material, a piezoelectric film stacked on directly or indirectly the SiNx layer, and an interdigital transducer electrode stacked directly or indirectly on at least one main surface of the piezoelectric film. In the SiNx layer, x is about 1.34 or more and about 1.66 or less.

Abstract: A multiplexer includes N acoustic wave filters each including one end connected in common and having a different pass band, in which when the N acoustic wave filters are in order from a side of a lower frequency of the pass band, at least one n-th acoustic wave filter among the N acoustic wave filters excluding an acoustic wave filter having the highest frequency of the pass band includes one or more acoustic wave resonators including a support substrate, a silicon nitride film laminated on the support substrate, a silicon oxide film laminated on the silicon nitride film, a piezoelectric body laminated on the silicon oxide film, and an IDT electrode provided on the piezoelectric body. All acoustic wave filters having a pass band in a higher frequency than a frequency of a pass band of the n-th acoustic wave filter satisfy fh1_t(n)>fu(m) or fh1_t(n)<fl(m).

Abstract: An acoustic wave device includes a support substrate including silicon, a piezoelectric layer in which a rotated Y-cut X-propagation lithium tantalate is included, and an IDT electrode. A film thickness of the piezoelectric layer is less than or equal to about 1?. When ?111 is an angle between a directional vector k111, and a direction of silicon and n is an arbitrary integer, the angle ?111 is in a range of about 0°+120°×n??111?45°+120°×n or in a range of about 75°+120°×n??111?120°+120°×n when the IDT electrode is on a positive surface of the piezoelectric layer and the angle ?111 is in a range of about 15°+120°×n??111?105°+120°×n when the IDT electrode is on the negative surface of the piezoelectric layer.

Abstract: An acoustic wave device includes a support substrate having a central region and a surrounding region located around the central region, a silicon oxide film that is located in the central region directly or indirectly and that has a side surface, a piezoelectric layer that is provided on the silicon oxide film and that has a first principal surface and a second principal surface, an excitation electrode provided on at least one of the first principal surface and the second principal surface, a cover film provided to cover the entire side surface of the silicon oxide film, a resin layer that is provided in the surrounding region and that is provided to cover the side surface of the silicon oxide film from above the cover film, and a wiring electrode that is electrically connected to the excitation electrode and that extends from the piezoelectric layer to the resin layer.

Abstract: An acoustic wave device includes a high-acoustic-velocity film, a piezoelectric layer provided directly or indirectly on the high-acoustic-velocity film, an IDT electrode provided on the piezoelectric layer, and a dielectric film provided on the piezoelectric layer to cover the IDT electrode. An acoustic velocity of bulk waves propagating through the high-acoustic-velocity film is higher than an acoustic velocity of acoustic waves propagating through the piezoelectric layer. The dielectric film includes a material including hydrogen atoms.

Abstract: In an acoustic wave device, an antenna end resonator electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is equal to or less than about 3.5?. A cut angle of the piezoelectric layer of the first acoustic wave resonator is within a range of ?B±4°. The cut angle of the piezoelectric layer of the second acoustic wave resonator has a larger difference from ?B (°) than the cut angle of the piezoelectric layer of the first acoustic wave resonator.

Abstract: An elastic wave device includes a piezoelectric thin film provided on a low acoustic velocity film and an IDT electrode provided on the piezoelectric thin film, wherein the piezoelectric thin film is made of a piezoelectric single crystal and includes a first principal surface that is a positive surface in a polarization axis direction and a second principal surface that is a negative surface in the polarization axis direction. The first principal surface of the piezoelectric thin film faces the low acoustic velocity film, and the second principal surface faces the IDT electrode.

Abstract: In an acoustic wave device, an antenna end resonator electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is equal to or less than about 3.5?. A cut angle of the piezoelectric layer of the first acoustic wave resonator is within a range of ?B±4°. The cut angle of the piezoelectric layer of the second acoustic wave resonator has a larger difference from ?B (°) than the cut angle of the piezoelectric layer of the first acoustic wave resonator.

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.

Abstract: In an acoustic wave device, an antenna end resonator that is electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is about 3.5? or less when a wavelength of an acoustic wave is denoted as ?. The first acoustic wave resonator and the second acoustic wave resonator satisfy at least one of a first condition, a second condition, and a third condition. The first condition is a condition that the first acoustic wave resonator further includes a dielectric film provided between the piezoelectric layer and an interdigital transducer electrode, and the second acoustic wave resonator does not include the dielectric film.

Abstract: Of a plurality of acoustic wave resonators, the acoustic wave resonator electrically closest to a first terminal is an antenna end resonator, the antenna end resonator is a first acoustic wave resonator and at least one acoustic wave resonator other than the antenna end resonator of the plurality of acoustic wave resonators is a second acoustic wave resonator. An acoustic wave device satisfies a first condition. The first condition is a condition that a high acoustic velocity layer of the first acoustic wave resonator and a high acoustic velocity layer of the second acoustic wave resonator each include a silicon substrate, a surface closer to a piezoelectric layer in the silicon substrate of the first acoustic wave resonator is a plane or a plane, and a surface closer to a piezoelectric layer in the silicon substrate of the second acoustic wave resonator is a plane.

Abstract: An elastic wave device includes a multilayer film including a piezoelectric thin film laminated on a support substrate. In a region outside a region in which an IDT electrode is provided, the multilayer film is not disposed. A first insulating layer extends from at least a portion of the region to a region on the piezoelectric thin film. A wiring electrode extends to a region on the first insulating layer from a region on the piezoelectric thin film and to extend to a region on a portion of the first insulating layer located in the region. A support layer including a cavity defining a hollow space is provided on the support substrate. The support layer includes, on the wiring electrode, a portion extending from the region to a region above an inner end of the first insulating layer.