An acoustic resonator including a substrate, an active vibration region including, sequentially stacked on the substrate, a lower electrode, a piezoelectric layer, and an upper electrode, and a horizontal resonance suppressing part formed from and disposed in the piezoelectric layer, the horizontal resonance suppressing part having piezoelectric physical properties that are different from piezoelectric physical properties of the piezoelectric layer.

A piezoelectric oscillation device includes a piezoelectric vibration element, a heating element that heats the piezoelectric vibration element, an electronic component that is electrically connected to the piezoelectric vibration element, a substrate on which the piezoelectric vibrator, the heating element, and the electronic component are mounted, and a base member to which the substrate is attached with a prescribed spacing therebetween via a substrate holding member. The substrate holding member includes a conductive part. The conductive part has a lower thermal conductivity than metal.

A crystal vibrator according to the present invention includes a crystal blank generating thickness shear vibration, a pair of excitation electrodes on both surfaces of the crystal blank, and a pair of extraction electrodes respectively extracted from the excitation electrodes. The crystal blank includes a region provided with a plurality of hill parts which are covered by an excitation electrode. Due to hill parts, it is possible to increase adhesion to the excitation electrodes and to provide a highly reliable crystal vibrator.

A method for manufacturing a piezoelectric vibration element that includes preparing a piezoelectric substrate; providing a first electrode layer on a first main surface of the piezoelectric substrate; arranging a mask on a side of the first main surface of the piezoelectric substrate, the mask including a center region and a peripheral region located along a periphery of the center region; and irradiating a radiation beam through the mask toward the first main surface of the piezoelectric substrate such that a larger amount of the radiation beam passes through the peripheral region than the center region of the mask so as to remove a part of the first electrode layer to form a first excitation electrode that decreases in thickness from the center region to the peripheral region of the mask on the first main surface of the piezoelectric substrate.

An acoustic impedance transformation circuit and related apparatus are provided. In aspects discussed herein, the acoustic impedance transformation circuit can be configured to transform an input impedance into an output impedance higher than the input impedance. In this regard, the acoustic impedance transformation circuit can be provided in an apparatus to enable impedance matching between two electrical circuits. As a result, it may be possible to reduce signal reflection resulting from impedance mismatch between the two circuits, thus helping to improve performance of the apparatus.

An AT-cut crystal element is provided. The AT-cut crystal element includes side surfaces intersecting with a Z-axis of a crystallographic axis of a crystal. At least one side surface of the side surfaces is constituted of three surfaces of a first surface to a third surface. Besides, a crystal resonator including the AT-cut crystal element, and a crystal unit including the crystal resonator are provided.

A piezoelectric oscillator includes a base member on which a piezoelectric resonator is mounted, a first lid member that seals the piezoelectric resonator on the base member, and a second lid member that seals the first lid member on the base member. The first lid member and the second lid member are each joined to the base member.

A vibrator device includes a vibration element including a vibration portion and a fixed portion, a supporting member to which the fixed portion is attached to support the vibration element, and a first substrate to which the supporting member is attached, the supporting member includes a attaching portion attached to the first substrate, and A1A2 is satisfied in a case where an area of a rectangular region including the fixed portion is A1 and an area of a rectangular region including the attaching portion is A2 in a plan view seen from a thickness direction of the vibration element.

In a crystal resonator plate (2), a support part (24) extends from only one corner part positioned in the +X direction and in the Z direction of a vibrating part (22) to an external frame part (23) in the Z direction. The vibrating part (22) and at least part of the support part (24) form an etching region (Eg) having a thickness thinner than a thickness of the external frame part (23). A stepped part is formed at a boundary of the etching region (Eg), and a first lead-out wiring (223) is formed over the support part (24) to the external frame part (23) so as to overlap with the stepped part. At least part of the stepped part that is superimposed on the first lead-out wiring (223) is formed so as not to be parallel to the X axis in plan view.

Provided is an oscillator including a resonator which includes a resonator element and a resonator element container accommodating the resonator element, an integrated circuit element which includes an inductor, and a nonconductive spacer member, in which the resonator and the integrated circuit element are stacked above each other, the resonator has a metal member, and the spacer member is provided between the resonator and the integrated circuit element.