Abstract: 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.

Abstract: A surface acoustic wave device includes a piezoelectric single crystal substrate and an electrode. The piezoelectric single crystal substrate is made of LiTaO3 or LiNbO3. The electrode includes a titanium film formed on the piezoelectric single crystal substrate and an aluminum film or a film containing aluminum as a main component. The aluminum film or the film is formed on the titanium film. The aluminum film or the film containing aluminum as the main component is a twin crystal film or a single crystal film, the aluminum film or the film has a (111) plane that is non-parallel to a surface of the piezoelectric single crystal substrate with an angle ?, and the aluminum film or the film has a [?1, 1, 0] direction parallel to an X-direction of a crystallographic axis of the piezoelectric single crystal substrate.

Abstract: A surface acoustic wave device includes a quartz layer, a piezoelectric layer, and an Inter Digital Transducer. A rotation in a right-screw direction is assumed as a +-rotation. A three-dimensional coordinate system formed by an x1-axis, a y1-axis, and a z1-axis respectively matching an X-axis, a Y-axis, and a Z-axis as crystallographic axes of a quartz-crystal is rotated from +125.25° in a range of ±3° with the x1-axis as a rotation axis. Subsequently, the three-dimensional coordinate system is rotated from +45° in a range of ±2° with the z1-axis as the rotation axis. Subsequently, the three-dimensional coordinate system is rotated from ?45° in a range of ±2° with the x1-axis as the rotation axis. The quartz layer is cut along a surface as a sectional plane perpendicular to the z1-axis. The quartz layer has a propagation direction of the surface acoustic wave in a direction parallel to the x1-axis.

Abstract: A surface acoustic wave device includes a quartz layer, an amorphous silicon oxide layer, a piezoelectric layer, and an Inter Digital Transducer. The amorphous silicon oxide layer is laminated on the quartz layer. The piezoelectric layer is laminated on the amorphous silicon oxide layer. The Inter Digital Transducer is formed on the piezoelectric layer. The Inter Digital Transducer excites a surface acoustic wave on the piezoelectric layer. Assuming that the surface acoustic wave has a wavelength ?, 0.1?a thickness of the amorphous silicon oxide layer/??1, and 0.08<a thickness of the piezoelectric layer/??1.

Abstract: 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.

Abstract: A surface acoustic wave device includes a piezoelectric material layer, a pair of busbars, a plurality of electrode fingers, and reflectors. The piezoelectric material layer has a thickness that is in a range of 1 to 2.5 times of an acoustic wavelength. A main mode of an elastic wave excited on the piezoelectric material layer by the electrode fingers is a leaky surface acoustic wave. A design variable is set such that a minimum propagation loss frequency where a propagation loss becomes minimum and a frequency of a plate wave spurious formed due to a slow shear wave excited together with the leaky surface acoustic wave are matched. A propagation velocity of a slowest bulk wave of an elastic wave that propagates in a lower layer of the piezoelectric material layer is equal to or more than 1.05 times of a velocity of the leaky surface acoustic wave.

Abstract: A surface acoustic wave device includes a piezoelectric material layer, a pair of busbars, a plurality of electrode fingers, and reflectors. The piezoelectric material layer has a thickness that is in a range of 1 to 2.5 times of an acoustic wavelength. A main mode of an elastic wave excited on the piezoelectric material layer by the electrode fingers is a leaky surface acoustic wave. A design variable is set such that a minimum propagation loss frequency where a propagation loss becomes minimum and a frequency of a plate wave spurious formed due to a slow shear wave excited together with the leaky surface acoustic wave are matched. A propagation velocity of a slowest bulk wave of an elastic wave that propagates in a lower layer of the piezoelectric material layer is equal to or more than 1.05 times of a velocity of the leaky surface acoustic wave.