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 an insertion film inserted in the piezoelectric film, located in at least a part of an outer peripheral region within a resonance region where the lower electrode and the upper electrode face each other across the piezoelectric film, and not located in a center region of the resonance region, wherein a difference between a total film thickness of the piezoelectric film and the insertion film in a first region, in which the insertion film is inserted, within the resonance region and a film thickness of the piezoelectric film in a second region, in which the insertion film is not inserted, is less than a film thickness of the insertion film.

A bulk acoustic wave resonator (BAWR) includes a bulk acoustic resonance unit and at least one compensation layer. The bulk acoustic resonance unit includes a first electrode, a second electrode, and a piezoelectric layer disposed between the first electrode and the second electrode. The first electrode, the second electrode, and the piezoelectric layer each include a material that modifies a resonance frequency based on a temperature, and the at least one compensation layer includes a material that adjusts the resonance frequency modified based on the temperature in a direction opposite to a direction of the modification.

A method for generating high order harmonic frequencies includes: providing a piezoelectric resonant film; and inputting a driving signal with a single tone frequency for driving the piezoelectric resonant film to oscillate in a non-linear region so as to generate a plurality of high order harmonic frequencies. Therefore, the quantity of the high order harmonic frequencies can be adjusted by applying an electrical controlling method.

A resonator that includes a vibrating portion that has a piezoelectric film, and a lower and upper electrodes that face each other with the piezoelectric film interposed therebetween. Moreover, a holding portion is provided at least around a maximum displacement region of the vibrating portion and has an insulating film. A holding arm connects the vibrating portion and the holding portion, and include a conductive portion that is in contact with the insulating film of the holding portion in at least a region that faces the maximum displacement region of the vibrating portion. In addition, the conductive portion is electrically connected to the lower electrode or the upper electrode or is grounded.

A resonator that includes a vibrating portion that has a piezoelectric film, and a lower and upper electrodes that face each other with the piezoelectric film interposed therebetween. Moreover, a holding portion is provided at least around a maximum displacement region of the vibrating portion and has an insulating film. A holding arm connects the vibrating portion and the holding portion, and include a conductive portion that is in contact with the insulating film of the holding portion in at least a region that faces the maximum displacement region of the vibrating portion. In addition, the conductive portion is electrically connected to the lower electrode or the upper electrode or is grounded.

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 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.

Techniques for improving acoustic resonators and resonator structures are disclosed, including filters, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a plurality of piezoelectric layers including first and second piezoelectric layers acoustically coupled with one another and arranged over the substrate. The first and second piezoelectric layers may have respective piezoelectric axis orientations. The first and second piezoelectric layers may have respective thicknesses. An example system may comprise an oscillator circuit coupled with the bulk acoustic wave (BAW) resonator. For example, a radar system may comprise the oscillator circuit coupled with the bulk acoustic wave (BAW) resonator.

Techniques for improving acoustic resonators and resonator structures are disclosed, including filters, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a plurality of piezoelectric layers including first and second piezoelectric layers acoustically coupled with one another and arranged over the substrate. The first and second piezoelectric layers may have respective piezoelectric axis orientations. The first and second piezoelectric layers may have respective thicknesses. An example system may comprise an oscillator circuit coupled with the bulk acoustic wave (BAW) resonator. For example, a radar system may comprise the oscillator circuit coupled with the bulk acoustic wave (BAW) resonator.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.