In an acoustic wave device, a piezoelectric layer is provided directly or indirectly on a support substrate, an IDT electrode is provided on the piezoelectric layer, an overlap region includes a middle region and first and second edge regions, and first and second conductive layers are provided on a second main surface of the piezoelectric layer to overlap at least some portions of the first and second edge regions in plan view and at least some portions of first and second busbars in plan view.

There are disclosed acoustic resonators and method of fabricating acoustic resonators. An acoustic resonator includes a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to a surface of a substrate except for portions of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern on the front surface includes an interdigital transducer (IDT) with interleaved fingers of the IDT disposed on the diaphragm. A periodic array of holes is provided in the diaphragm.

An acoustic wave device includes a piezoelectric substrate including a crystal axis and an IDT electrode. When an acoustic wave propagation direction is a first direction and a direction perpendicular to the first direction is a second direction, the crystal axis of the piezoelectric substrate is inclined toward the second direction with respect to the thickness direction. The IDT electrode includes first and second electrode fingers interdigitated with each other. The portion where the first and second electrode fingers overlap in the first direction is a crossing region. The crossing region includes a center region that is centrally located in the second direction and first and second low-acoustic-velocity regions that are located on both sides of the center region in the second direction and in which the acoustic velocity is lower than the acoustic velocity in the center region. The first and second low-acoustic-velocity regions are asymmetrical.

A ladder filter includes series-arm resonators each including an IDT electrode and a reflector, and a parallel-arm resonator. In at least one of the series-arm resonators, where a wavelength that is determined by an electrode finger pitch of the IDT electrode is λ, an electrode finger center-to-center distance between an electrode finger located closest to the reflector among electrode fingers of the IDT electrode and an electrode finger located closest to the IDT electrode among electrode fingers of the reflector is less than about 0.5λ, and an anti-resonant frequency of the at least one of the series-arm resonators is higher than an anti-resonant frequency of at least another one of the series-arm resonators.

Aspects of the disclosure relate to an electroacoustic device that includes a piezoelectric material and an electrode structure. The electrode structure includes a first busbar and a second busbar. The electrode structure further includes 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. A first distance between the first busbar and the second plurality of fingers and a second distance between the second busbar and the first plurality of fingers both being less than a pitch of the electrode fingers. The electrode fingers have a central region with a first trap region and a second trap region respectively located on boundaries of the central region. A structural characteristic of the electroacoustic device is different in the first trap region and the second trap region relative to the central region.

Aspects of the disclosure relate to an electroacoustic device that includes a piezoelectric material and an electrode structure. The electrode structure includes a first busbar and a second busbar. The electrode structure further includes a first conductive structure connected to the first busbar and a second conductive structure connected to the second busbar. The first conductive structure and the second conductive structure is disposed between the first busbar and the second busbar. The first conductive structure and the second conductive structure each include a plurality of conductive segments separated from each other and extending towards one of the first busbar or the second busbar. The electrode structure further includes electrode fingers arranged in an interdigitated manner and each connected to either the first conductive structure or the second conductive structure. The electrode fingers have a pitch that is different than a pitch of the plurality of conductive segments.

An acoustic wave device includes a piezoelectric substrate and an IDT electrode provided on the piezoelectric substrate and includes a main electrode layer. In the IDT electrode, a central region, first and second low acoustic velocity regions and first and second high acoustic velocity regions are disposed in this order. A duty ratio in the first low acoustic velocity region of first electrode fingers and the second low acoustic velocity region of second electrode fingers is larger than a duty ratio in the central region. The main electrode layer includes any one of Au, Pt, Ta, Cu, Ni, and Mo as a main component.

Surface acoustic wave (SAW) structures with transverse mode suppression are disclosed. In one aspect, the SAW structure provides digits or fingers with broad interior terminal end shapes. By providing such shapes spurious modes above the resonance frequency of the SAW are suppressed thereby providing desired out of band rejection that helps satisfy design criteria such as keeping a higher Q value, a higher K2 value and better Temperature Coefficient of Frequency (TCF).

An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, a temperature compensation layer over the interdigital transducer electrode, and a dielectric layer positioned partially between the piezoelectric layer and the interdigital transducer electrode. The dielectric layer is positioned in an area under a first portion of the interdigital transducer electrode. An area under a second portion different from the first portion is free from the dielectric layer.

An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, a temperature compensation layer over the interdigital transducer electrode, and a dielectric layer positioned partially between the piezoelectric layer and the interdigital transducer electrode. The interdigital transducer electrode includes an active region that has a center region and an edge region, a bus bar, and a gap region between the active region and the bus bar. At least a portion of the center region is in direct contact with the piezoelectric layer.