The vibration substrate having a main surface extending parallel to a first direction and a second direction that are orthogonal to each other, and that includes a main body region having a vibrating portion at least in a part thereof and at least one holding region arranged side by side with the main body region along the first direction. The at least one holding region including a holding portion and a beam portion connecting the holding portion and the main body region. The beam portion includes a first arm portion extending from the holding portion along the first direction, a second arm portion extending along the second direction from an end portion of the first arm portion on a side thereof opposite to the holding portion, and a connection portion connecting the second arm portion and the main body region.

A family of composite resonator devices having improved performance properties for use in electronic circuits. Each composite device includes two or more resonator electrodes on a single crystal or other resonant material. The two resonators may be connected in series or parallel, based on application requirements. The two resonators have different surface areas or some other type of asymmetry, causing the response of the composite device to have suppressed spurious modes, reduced insertion loss, or both. This is accomplished by designing the electrodes to have different frequency response curves, where the responses can be tuned and combined to reduce undesirable modes. Improvements in acceleration sensitivity and temperature sensitivity are also achieved. Both physically-applied and projected electrode types are disclosed, along with several crystal shapes. The family of composite resonator devices includes both passive and active devices, such as resonators, filters and oscillators.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in an order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle b and subsequently bulged, and connected to the second end portion.

A piezoelectric vibrating piece includes a piezoelectric substrate, a first excitation electrode, and a second excitation electrode. The piezoelectric substrate is formed into a flat plate shape and vibrates in a thickness-shear vibration mode. The first excitation electrode is formed on one principal surface of the piezoelectric substrate. The second excitation electrode is formed on another principal surface of the piezoelectric substrate. The first excitation electrode is formed to entirely have an identical thickness. The second excitation electrode has a main thickness portion and an inclined portion. The main thickness portion has a constant thickness. The inclined portion is formed in a peripheral area of the main thickness portion and gradually decreases in thickness from a portion in contact with the main thickness portion to an outermost periphery of the second excitation electrode. The main thickness portion has a thickness larger than the thickness of the first excitation electrode.

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.

The present invention provides tunable film bulk acoustic resonators (FBARs) with the resonant frequency of the acoustic wave to be excited and to be transmitted tuned by digital to analog converters which convert an input digital signal to an output DC voltage and provide DC bias voltages to the FBARs through integrated thin film biasing resistors. The polarity and the value of the output DC voltage are controlled by the input digital signal to achieve selection and tuning of the resonant frequency of the FBARs. A plurality of the tunable FBARs are connected to form microwave filters with tunable bandpass frequencies and oscillators with selectable resonating frequencies by varying the input digital signals applied to the digital to analog converters.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in this order from a side of one short side, in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle b and subsequently bulged, and connected to the second end portion.

A resonator element includes a quartz crystal substrate including a first surface along an X axis which is an electrical axis, a second surface along the X axis, and a side surface, a first excitation electrode, a second excitation electrode, a first coupling electrode, a second coupling electrode, a first extraction electrode that couples the first excitation electrode and the first coupling electrode, and a second extraction electrode that couples the second excitation electrode and the second coupling electrode. In plan view, a virtual extension region is obtained by extending the first excitation electrode along the X axis.

A piezoelectric resonator unit includes a base member having a mounting surface. A piezoelectric resonator is mounted on the mounting surface and a lid member is bonded to the mounting surface such that the piezoelectric resonator is hermetically sealed in an inner space. A heat conductor is connected to a temperature sensor that detects a temperature of the piezoelectric resonator and is connected to a heating element that radiates heat onto the piezoelectric resonator. The heat conductor has a portion that is arranged in the inner space.

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.