An AT-cut crystal resonator plate includes: a vibrating part having a rectangular shape in plan view that is disposed on a center of the AT-cut crystal resonator plate and that has excitation electrodes respectively formed on a first and a second main surfaces; a cut-out part having a rectangular shape in plan view that is formed along an outer periphery of the vibrating part; an external frame part having a rectangular shape in plan view that is formed along an outer periphery of the cut-out part; and a connecting part that connects the vibrating part to the external frame part and that extends, in a Z axis direction of the vibrating part, from one end part of a side of the vibrating part along an X axis direction. The connecting part includes wide parts whose widths gradually increase only toward the external frame part.

A vibrator device includes a vibrator having a first and second electrode, and a circuit device having a drive circuit adapted to drive the vibrator, and an output circuit adapted to output a monitor signal corresponding to a vibration characteristic of the vibrator while driven by the drive circuit. The circuit device includes a first terminal electrically connected to the first electrode, and from which an output signal from the drive circuit to the vibrator is output, a second terminal electrically connected to the second electrode, and to which an input signal from the vibrator to the drive circuit is input, a third terminal electrically separated from the first electrode and the second electrode, and a monitor terminal from which the monitor signal is output. The vibrator is supported on an active surface side of the circuit device using conductive bumps respectively to the first, second, and third terminal.

A bulk acoustic wave (BAW) resonator includes: a substrate; an acoustic reflector disposed in the substrate; a first electrode disposed over the acoustic reflector; a second electrode; and a piezoelectric layer between the first and second electrodes. The second electrode is not disposed between the first electrode and the acoustic reflector. The BAW resonator further includes a block disposed over the substrate and beneath the piezoelectric layer. A contacting overlap of the acoustic reflector, the first electrode, the second electrode and the piezoelectric layer defines an active area of the BAW resonator.

A micro-electro-mechanical system (MEMS) device includes a substrate having a cavity and a MEMS structure disposed over the cavity and attached to the substrate. The MEMS structure includes at least one first piezoelectric layer having a first piezoelectric coefficient and two second piezoelectric layers respectively disposed under and above the first piezoelectric layer, where each second piezoelectric layer has a second piezoelectric coefficient higher than the first piezoelectric coefficient. The MEMS structure further includes a first electrode layer and a second electrode layer sandwiching the two second piezoelectric layers.

An acoustic resonator is disclosed. The acoustic resonator comprises a substrate, a first electrode, a second electrode and a piezoelectric layer positioned between the first electrode and the second electrode. An acoustic reflector is positioned between the first electrode and the substrate. An active area comprises a region of contacting overlap of the acoustic reflector, the first electrode, the piezoelectric layer and the second electrode. A gap region extends around the active area.

A bulk acoustic wave resonator includes a substrate, a first electrode and a second electrode disposed on the substrate, and a piezoelectric layer disposed between the first electrode and the second electrode. At least one of the first electrode and the second electrode includes an alloy of molybdenum and tantalum.

A bulk acoustic wave resonator includes a substrate; and a resonator including a first electrode, a piezoelectric layer, and a second electrode sequentially disposed on the substrate. Either one or both of the first electrode and the second electrode includes an alloy of molybdenum (Mo) and tantalum (Ta).

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film; and a wiring layer located on the upper electrode, the wiring layer having a thickness equal to or greater than 0.8 m and equal to or less than 3.0 m, at least a part of the wiring layer overlapping in plan view with a resonance region in which the lower electrode and the upper electrode face each other across the piezoelectric film, a distance between an outline of the resonance region and an edge of a lower surface located within the resonance region and farthest from the outline being greater than 0 m and less than 2 m.

An acoustic wave device includes a piezoelectric layer, an interdigital transducer, and a slow wave propagation overlay over a portion of the interdigital transducer. By providing electrode fingers of the interdigital transducer such that a portion of the width thereof is dependent on an electrode period, a desirable wave mode may be maintained in the acoustic wave device. Further, by varying a width of the slow wave propagation overlay based on the electrode period, the desirable wave mode may be further maintained.

A solid mount bulk acoustic wave resonator, comprises a first electrode; a second electrode; a piezoelectric layer disposed between the first and second electrodes; and an acoustic reflector comprising a plurality of layers and disposed beneath the first electrode, the second electrode and the piezoelectric layer. An overlap of the acoustic reflector, the first electrode, the second electrode and the piezoelectric layer defines an active area of the acoustic resonator, and the piezoelectric layer extends over an edge of the first electrode. The acoustic resonator also comprises a bridge adjacent to a termination of the active area of the acoustic resonator. The bridge overlaps a portion of the first electrode.