A surface acoustic wave (SAW) device includes a substrate; an interdigital transducer (IDT) having lead-out portions and arrays of interdigital electrodes formed on the substrate, wherein the interdigital electrodes includes central portions, end portions, and intermediate portions between the end portions and the lead-out portions, and a thickness of the interdigital electrodes at the end portions is greater than a thickness of the interdigital electrodes at the central portions and the intermediate portions, thereby forming protruding structures at the end portions of the interdigital electrodes; a protective layer formed on the protruding structures at the end portions of the interdigital electrodes; a first temperature compensation layer formed on the protective layer; a second temperature compensation layer formed on the first temperature compensation layer and on the central portions and the intermediate portions of the interdigital electrodes; and a passivation layer formed on the second temperature compensation layer.

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.

Aspects of this disclosure relate to an acoustic wave resonator with hyperbolic mode suppression. The acoustic wave resonator can include a piezoelectric layer, an interdigital transducer electrode, a temperature compensation layer, and a mass loading strip. The mass loading strip can be a conductive strip. The mass loading strip can overlap edge portions of fingers of the interdigital transducer electrode. A layer of the mass loading strip can have a density that is at least as high as a density of a material of the interdigital transducer electrode. The material of the interdigital transducer can impact acoustic properties of the acoustic wave resonator.

An elastic wave device includes an IDT electrode provided on a piezoelectric substrate and including a first end region including one end of the IDT electrode in an elastic wave propagation direction, a second end region including the other end of the IDT electrode in the elastic wave propagation direction, and an inner region that is located farther toward an inside than the first and second end regions in the elastic wave propagation direction, includes first and second high-acoustic-velocity regions, and a center region and first and second low-acoustic-velocity regions, located in the crossing region. The mass of the IDT electrode in the crossing region in the first and second end regions is smaller than the mass of the IDT electrode in the crossing region in the inner region.

An elastic wave device includes a high-acoustic-velocity member, a low-acoustic-velocity film, a piezoelectric film, and am interdigital transducer electrode stacked in this order. The interdigital transducer electrode includes an intersecting region and outer edge regions. The intersecting region includes a central region located in the middle of the intersecting region in the direction in which electrode fingers extend and the inner edge regions located at the respective outer side portions of the central region. The electrode fingers in the inner edge regions have a larger thickness than in the central region. Each electrode finger has an incrased thickness portion. The increased thickness portion is made of a metal having a density d of about 5.5 g/cm.sup.3 or more and has a film thickenss equal to or smaller than a wavelength-normalized film thickness represented by T (%)=0.1458d+4.8654.

An electro-acoustic transducer and an electro-acoustic component including an electro-acoustic transducer are disclosed. In an embodiment the transducer includes a first and a second bus bar, a plurality of electrode fingers and a plurality of two or more sub tracks, wherein each electrode finger is electrically connected to one of the bus bars, wherein each sub track extends along a longitudinal direction, wherein all sub tracks are arranged one next to another in a transversal direction, wherein at least a first of the sub tracks includes segments of the electrode fingers and has an associated sub track with segments of the electrode fingers, wherein the segments of the electrode fingers of the first sub track are shifted by a distance S=/2 along the longitudinal direction relative to the segments of the electrode fingers of the associated sub track, and wherein is an acoustic wavelength.

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.

Aspects of this disclosure relate to a surface acoustic wave device. The surface acoustic wave device includes a piezoelectric layer and an interdigital transducer. The interdigital transducer electrode includes a pair of electrodes, each electrode having a bus bar and fingers extending from the bus bar. The interdigital transducer electrode has an interdigital region defined by a portion of the fingers of the electrodes that interdigitate with each other. A dielectric layer is disposed over the interdigital transducer electrode outside the interdigital region and configured to reduce a loss of the surface acoustic wave device.

An improved electroacoustic transducer with an improved mode profile is provided. The transducer comprises a 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 surface acoustic wave device includes: comb-shaped electrodes each including electrode fingers and dummy electrode fingers; and additional films located to cover gaps between tips of the electrode fingers of one of the comb-shaped electrodes and tips of the dummy electrode fingers of the other, wherein each of the additional films overlap with at least one of the electrode fingers and the dummy electrode fingers located lateral to the corresponding gap in a first direction in which the electrode fingers extend or in a second direction intersecting with the first direction, and a distance G of the gap is 0<G1.0 and a film thickness h of the additional films is 0<h/(0.146G+0.694076)2/1 where is a wavelength of an acoustic wave, 1 is a density of a material of the additional films, and 2 is a density of aluminum oxide.