An acoustic wave device includes an IDT electrode and reflector electrodes on or above a piezoelectric substrate. A region in which first and second electrode fingers of the IDT electrode overlap each other in an acoustic wave propagation direction defines an intersection region. The intersection region includes a center region and first and second edge regions on both sides of the center region. Dielectric films extend from the first and second edge regions to outer side regions in the acoustic wave propagation direction of the reflector electrodes via the reflector electrodes.

A low velocity surface acoustic wave device, and a method of reducing the velocity of a surface acoustic wave generated by a surface acoustic wave device are described, the device including a piezoelectric layer, an interdigital transducer disposed on the piezoelectric substrate and configured to generate a surface acoustic wave in response to an electrical, and a temperature coefficient of frequency compensation layer disposed partially on the interdigital transducer and partially on the piezoelectric substrate, the temperature coefficient of frequency compensation layer having a low velocity layer disposed within it configured to reduce the velocity of a surface acoustic wave generated by the interdigital transducer, the method including disposing a wave velocity adjustment layer, the wave velocity adjustment layer being a low velocity layer, within a temperature compensation layer of the surface acoustic wave device.

An acoustic wave device includes a multilayer substrate including a reverse-velocity surface, a piezoelectric film, a low acoustic velocity material layer, a high acoustic velocity material layer, and an IDT electrode disposed on the piezoelectric film. In the IDT electrode, gap lengths of a first gap between a tip of each of first electrode fingers and a second busbar and a second gap between a tip of each of second electrode fingers and a first busbar are about 0.23λ or shorter, the gap lengths extending in an extension direction of the first and second electrode fingers.

An acoustic wave device is disclosed. The acoustic waved device can be a shear horizontal mode surface acoustic wave device. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, and a temperature compensation layer over the interdigital transducer electrode. The piezoelectric layer can be a lithium niobate layer with a cut angle in a range of −20° YX to 25° YX. The interdigital transducer electrode includes a first layer having a first thickness and a second layer having a second thickness. The first layer affects acoustic properties of the acoustic wave device and the second layer affects electrical properties of the acoustic wave device. The first layer is positioned between the piezoelectric layer and the second layer. The first thickness is configured such that a frequency response of the acoustic wave device includes a Rayleigh mode response at a frequency higher than a shear horizontal mode response resonance. The first thickness can be greater than the second thickness.

A surface acoustic wave device includes a piezoelectric substrate and a pair of interdigital transducer electrodes. The pair of interdigital transducer electrodes include an alternating region as a region where the electrode fingers connected to one busbar and the electrode fingers connected to the other busbar are alternately provided. When a region on an end portion side of the alternating region and a region including distal end portions of the plurality of electrode fingers is referred to as an edge region, a propagation velocity of a surface acoustic wave in the edge region is slower than a propagation velocity of a surface acoustic wave in the alternating region. A propagation velocity of a surface acoustic wave in a busbar region as a region where the busbar is disposed is faster than the propagation velocity of the surface acoustic wave in the alternating region.

An improved electroacoustic transducer with an improved mode profile is provided. The transducer comprises a transversal velocity profile with a periodic structure and an edge structure flanking the periodic structure. The velocity profile also allows to suppress the SH wave mode. A dielectric material with a periodic structure contributes to the formation of the periodic structure of the velocity profile.

An acoustic wave resonator includes: a piezoelectric substrate; and an IDT that is located on the piezoelectric substrate and includes first regions and second regions alternately arranged in an extension direction of electrode fingers, which excite an acoustic wave, in an overlap region in which the electrode fingers overlap, at least one electrode finger of the electrode fingers in the second regions having a different width from the at least one electrode finger in the first regions, a width of an outer second region of the second regions in the extension direction differs from a width of an inner second region of the second regions.

A surface acoustic wave device includes a piezoelectric substrate and a pair of IDT electrodes. The pair of IDT electrodes includes a pair of busbars and multiple electrode fingers. The pair of busbars are formed on the piezoelectric substrate. The electrode fingers extend in a comb shape from each of the busbars toward the opposing busbar. The pair of IDT electrodes has an intersection region as a region where the electrode fingers connected to one busbar and the electrode fingers connected to another busbar are intersected when viewed along an arrangement direction of the electrode fingers. The electrode finger in a non-intersection region outside the intersection region has a thickness thinner than a thickness of the electrode finger in the intersection region.

An acoustic wave device includes a piezoelectric substrate, an interdigital transducer electrode on the piezoelectric substrate, and reflectors. The interdigital transducer electrode includes first and second busbars including first and second cavities in a first direction, and first and second edge regions and first and second gap regions. The first and second edge regions include low acoustic velocity regions. Regions in which the first and second cavities are provided include high acoustic velocity regions. The reflector includes first and second reflector busbars and first reflection electrode fingers each including a second end portion that faces the second reflector busbar. The first reflection electrode fingers overlap the entire or substantially the entire second gap region when viewed in the first direction.

Aspects of the disclosure relate to an electroacoustic device that includes a piezoelectric material and an electrode structure that includes a first busbar and a second busbar along with electrode fingers arranged in an interdigitated manner and including a first plurality of fingers connected to the first busbar and a second plurality of fingers connected to the second busbar. The electrode structure further includes a first conductive structure disposed between each of the first plurality of fingers and disposed between the first busbar and the second plurality of fingers. The electrode structure further includes a second conductive structure disposed between each of the second plurality of fingers and disposed between the second busbar and the first plurality of fingers. The first conductive structure and the second conductive structure each have a height that is less than a height of the second plurality of fingers.