In an acoustic wave device, a piezoelectric body is directly or indirectly provided on a high acoustic velocity material layer, an interdigital transducer electrode is directly or indirectly provided on the piezoelectric body, the interdigital transducer electrode includes a first busbar, a second busbar spaced away from the first busbar, a plurality of first electrode fingers, and a plurality of second electrode fingers, and a weighting is applied to the interdigital transducer electrode by providing a floating electrode finger not electrically connected to the first busbar or the second busbar or applied by providing an electrode finger formed by metallizing a gap between the first electrode fingers or a gap between the second electrode fingers to integrate the first electrode fingers or the second electrode fingers.

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 acoustic wave device is disclosed. The acoustic wave device is configured to generate a surface acoustic wave having a wavelength L. The acoustic wave device can include a piezoelectric layer. The piezoelectric layer has a thickness in a range of 0.1 L to 0.3 L. The acoustic wave device can include an interdigital transducer electrode that is positioned over the piezoelectric layer, and a support substrate that is bonded to the piezoelectric layer such that the piezoelectric layer is positioned between the interdigital transducer electrode and the support substrate. The support substrate has a cut angle configured to provide a velocity of the surface acoustic wave calculated by multiplying the wavelength L by a particular frequency to be greater than 4800 m/s.

An elastic wave device includes an interdigital transducer electrode, a dielectric film, and a frequency adjustment film are disposed on a LiNbO.sub.3 substrate. When Euler Angles of the LiNbO.sub.3 substrate are within a range of about 0°±5°, within a range of about θ±1.5°, within a range of about 0°±10°, the interdigital transducer electrode includes a main electrode, a film thickness of the main electrode normalized by a wavelength determined in accordance with an electrode finger pitch of the interdigital transducer electrode is denoted as T, and a density ratio of a material of the main electrode to Pt is denoted as r, the film thickness of the main electrode and θ of the Euler Angles satisfy θ=−0.05°/(T/r−0.04)+31.35°.

A method of manufacturing an acoustic wave device is disclosed. The method includes attaching a support layer to a ceramic layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The method also includes bonding a piezoelectric layer to a surface of the ceramic layer. The method further includes forming an interdigital transducer electrode over the piezoelectric layer.

A surface acoustic wave resonator device comprises a substrate supporting: a gateable, electrically conducting layer; an interdigital transducer (IDT); a reflector grating that comprises a plurality of electrically separated fingers; a main ohmic contact; and a gate element. The IDT is configured to be connectable to a ground. The conducting layer is configured to be connectable to the ground via the main ohmic contact, while each of said fingers is electrically connected to a lateral side of the conducting layer. This defines a gateable channel, which extends from the fingers to the ground via the conducting layer and the main ohmic contact. The gate element is electrically insulated from the conducting layer. The gate element is configured to allow an electrical impedance of the gateable channel to be continuously tuned by applying a voltage bias to this gate element with respect to the ground, in operation of the device.

An elastic wave device includes an interdigital transducer electrode, a dielectric film, and a frequency adjustment film are disposed on a LiNbO.sub.3 substrate. When Euler Angles of the LiNbO.sub.3 substrate are within a range of about 0° ± 5°, within a range of about θ ± 1.5°, within a range of about 0° ± 10°, the interdigital transducer electrode includes a main electrode, a film thickness of the main electrode normalized by a wavelength determined in accordance with an electrode finger pitch of the interdigital transducer electrode is denoted as T, and a density ratio of a material of the main electrode to Pt is denoted as r, the film thickness of the main electrode and θ of the Euler Angles satisfy θ = -0.05°/(T/r - 0.04) + 31.35°.

An end-surface-reflection surface acoustic wave device, which reflects a surface acoustic wave between first and second end surfaces facing each other, includes a support substrate, an intermediate layer, a piezoelectric layer, and an IDT electrode. The first end surface is located at one end portion in a surface-acoustic-wave propagation direction and extends from a main surface of the piezoelectric layer to at least a portion of the intermediate layer. The second end surface is located at the other end portion in the surface-acoustic-wave propagation direction and extends from the main surface of the piezoelectric layer to at least a portion of the intermediate layer. The support substrate includes support substrate portions that are located outside the first and second end surfaces in the surface-acoustic-wave propagation direction.

An elastic wave device includes a piezoelectric substrate, IDT electrodes disposed on the piezoelectric substrate, a first wiring line, an insulating layer covering at least a portion of the first wiring line, a second wiring line at least a portion of which is disposed on the insulating layer to provide a three-dimensional crossing portion, a peripheral support including a cavity surrounding the IDT electrodes, the first and second wiring lines, and the insulating layer, a partition support disposed in the cavity, and a cover disposed on the peripheral support and the partition support to cover the cavity. The second wiring line includes a step portion electrically connecting a portion of the second wiring line located on the piezoelectric substrate and a portion of the second wiring line located on the insulating layer to each other. The partition support covers the step portion.

An acoustic wave resonator includes: a piezoelectric substrate; and a pair of grating electrodes that is formed on the piezoelectric substrate, one of the pair of grating electrodes including a plurality of first electrode fingers having electric potentials equal to each other, another of the pair of grating electrodes including a plurality of second electrode fingers having electric potentials that differ from the electric potentials of the plurality of first electrode fingers and are equal to each other, two second electrode fingers of the plurality of second electrode fingers being located between at least a pair of adjacent first electrode fingers of the plurality of first electrode fingers, Pg differing from λ/4 where λ represents a wavelength of an acoustic wave excited by the plurality of first electrode fingers and the plurality of second electrode fingers and Pg represents a distance between centers of the two second electrode fingers.