An acoustic wave device includes a piezoelectric layer and electrodes including at least a pair of electrodes on a first main surface, facing each other in a second direction crossing a first direction, and adjacent to each other. At least three or more of the electrodes are arranged in the second direction. The electrodes include at least two electrodes having different film thicknesses from each other. The electrodes include at least two electrodes having the same or substantially the same film thickness and being adjacent to each other.

An acoustic wave device includes a piezoelectric layer and a pair of electrodes. In a cross-section including first and second directions, at least one electrode of the pair of electrodes includes top, bottom, first side, and second side surfaces, the bottom surface being opposed to the top surface and closer to the piezoelectric layer than the top surface. A first angle between the first side surface and the first main surface is different from a second angle between the second side surface and the first main surface, and at least one of the first angle and the second angle is about 80° or larger.

An acoustic wave device includes a piezoelectric layer including first and second main surfaces and made of lithium niobate or lithium tantalate, and an interdigital transducer electrode on the first main surface and including multiple electrode fingers. d/p is about 0.5 or less where d is a thickness of the piezoelectric layer, and p is a distance between centers of adjacent electrode fingers. The electrode fingers include first and second electrode films, which include first and second surfaces and a side surface. Θ1≠Θ2 is satisfied and W1>W2 is satisfied, where Θ1 and Θ2 are angles between the side surfaces and the first surfaces of the first and second electrode films, and W1 and W2 are widths of the first and second electrode films.

A resonance apparatus that processes an electrical loss using a conductive material and a method of manufacturing the resonance apparatus are provided. The resonance apparatus includes a lower electrode formed at a predetermined distance from a substrate, and a piezoelectric layer formed on the lower electrode. The resonance apparatus further includes an upper electrode formed on the piezoelectric layer, and a conductive layer formed on the upper electrode or the lower electrode.

An elastic wave includes a piezoelectric substrate having a polarization direction denoted by an arrow Px, and first and second IDT electrodes arranged on the substrate in an elastic wave propagation direction with a shared reflector therebetween. A first bus bar of the first IDT electrode and a first end portion bus bar of a second reflector are connected to a wiring electrode to define a first terminal. A second bus bar of the first IDT electrode and a second end portion bus bar of the shared reflector are connected to each other to define a second terminal. A first end portion bus bar and a first bus bar are electrically connected to each other. A second bus bar and a second end portion bus bar are electrically connected to each other, and the first and second IDT electrodes and are connected in parallel between the first and second terminals.

A resonator has a resonator body and a frame at least partially surrounding the resonator body, the resonator body being coupled to the frame by at least one tether. The resonator body, frame and at least one tether comprise silicon carbide. A plurality of interdigitated electrodes are disposed on the silicon carbide resonator body. The resonator body preferably comprises 6H silicon carbide and preferably has a crystalline c-axis oriented generally parallel to a thickness direction of the resonator body.

An acoustic resonator structure comprises: a substrate comprising a cavity having a plurality of sides; a first electrode disposed over the cavity; a first connection portion that connects to the first electrode over only one side of the plurality of sides of the cavity; a piezoelectric layer disposed over at least a portion of the first electrode; a second electrode disposed over the piezoelectric layer; and a second connection portion that connects to the second electrode over only the one side of the plurality of sides. The second connection portion does not overlap the first connection portion, and a contacting overlap of the first electrode, the piezoelectric layer and the second electrode provides an active area of the acoustic resonator.

The present invention provides a piezoelectric film acoustic resonator, which comprises a substrate, a first electrode disposed over the substrate, a piezoelectric film disposed over the substrate and covering at least a portion of the first electrode and a second electrode disposed on a surface of the piezoelectric film away from the first electrode, one end of the first electrode extends in the direction away from the piezoelectric film to form a first extended pad, one end of the second electrode extends in the direction away from the first extended pad to form a second extended pad, the first extended pad comprises a first protruding reflection grating on the surface away from the substrate, the second extended pad comprises a second protruding reflection grating on the surface away from the substrate. The configuration can reduce the impact on acoustic performance while improving the quality factor.

A bulk-acoustic wave resonator includes a substrate, a resonance portion including a first electrode, a piezoelectric layer, and a second electrode, stacked in this order on the substrate, and a seed layer disposed below the first electrode, wherein the resonance portion includes an active portion disposed in a central portion of the resonance portion, and a lateral resonance suppressing portion disposed to surround the active portion, wherein a thickness distribution of the seed layer, the first electrode, the piezoelectric layer, and the second electrode in the lateral resonance suppressing portion is different from a thickness distribution in the active portion.

There are provided an excitation electrode, a quartz crystal vibrator element, a quartz crystal vibrator, a sensor, an oscillator, and a method of manufacturing a quartz crystal vibrator element which are not affected by heat in a process or a use environment to surely prevent a frequency fluctuation from occurring, reduction in size of which can be achieved, and which are low in cost and excellent in productivity. The excitation electrodes are disposed on an outer surface of a quartz crystal plate, apply an electrical field for exciting the quartz crystal plate to the quartz crystal plate, have a single layer structure formed of a two-dimensional layered substance, and are used when arranged as a pair so as to be opposed to each other via the quartz crystal plate.