A bulk-acoustic wave resonator may include: a substrate; a resonator unit including a first electrode disposed on the substrate, a piezoelectric layer disposed on the first electrode, and a second electrode disposed on the piezoelectric layer; and a protective layer disposed on a surface of the resonator unit. The protective layer is formed of a diamond film, and a grain size of the diamond film is 50 nm or more.

A system for filter enhancement, preferably including one or more analog taps and a controller, and optionally including one or more couplers. The system is preferably configured to integrate with a filter, such as a passband filter or other frequency-based filter. The system can be configured to integrate with an RF communication system, an RF front end, or any other suitable RF circuitry. A method for filter enhancement, preferably including configuring one or more analog taps, and optionally including calibrating a system for filter enhancement and/or receiving temperature information.

Structures for suppressing parasitic acoustic waves in semiconductor structures and integrated circuit devices are described. Such integrated circuit devices can, typically, produce undesirable acoustic wave resonances, and the acoustic waves can degrade the performance of the devices. In that context, some embodiments described herein relate to spoiling a conductive path that participates in the generation of acoustic waves. Some embodiments relate to spoiling acoustic characteristics of an acoustic resonant structure that may be present in the vicinity of the device. Combined embodiments that spoil the conductive path and acoustic characteristics are also possible.

An acoustic wave device is provided comprising a substrate and at least one resonator structure of a first type and at least one resonator structure of a second type mounted on the substrate. The resonator structures of the first type are configured to operate as capacitors and have a first thickness, causing the resonator structures to have a first passband frequency range. The resonator structures of the second type have a second thickness that is different from the first thickness, causing the resonator structures to have a second passband frequency range. A method for forming such an acoustic wave device is also provided. A die comprising such an acoustic wave device, a filter comprising such an acoustic wave device, a radio-frequency module comprising such an acoustic wave device, and a wireless mobile device comprising such an acoustic wave device are also provided.

A bulk acoustic wave resonator includes a substrate; a central portion including a first portion of a first electrode, a first portion of a piezoelectric layer, and a first portion of a second electrode laminated in order on the substrate; and a reflective region disposed laterally of the central portion and including a second portion of the first electrode, an insertion layer, a second portion of the piezoelectric layer, and a second portion of the second electrode. A side surface of the insertion layer adjacent to the central portion has an inclined surface, the first portion of the second electrode and the second portion of the second electrode are coplanar, and an end of the second electrode overlaps the inclined surface of the insertion layer in the reflective region.

Techniques for improving Bulk Acoustic Wave (BAW) reflector and resonator structures are disclosed, including filters, oscillators and systems that may include such devices. A Bulk Acoustic Wave (BAW) resonator of this disclosure may comprise a substrate and an active piezoelectric resonant volume. The active piezoelectric resonant volume of the Bulk Acoustic Wave (BAW) resonator may have a main resonant frequency. The active piezoelectric resonant volume of the Bulk Acoustic Wave (BAW) resonator may comprise first and second piezoelectric layers having respective piezoelectric axis that substantially oppose one another. A first patterned layer may be disposed within the active piezoelectric volume. This may, but need not facilitate suppression of spurious modes. The main resonant frequency of the Bulk Acoustic Wave (BAW) resonator may be in a super high frequency (SHF) band. The main resonant frequency of the Bulk Acoustic Wave (BAW) resonator may be in an extremely high frequency (EHF) band.

A bulk-acoustic wave resonator comprises a substrate, a resonant portion comprising a first electrode, a piezoelectric layer, and a second electrode sequentially stacked on the substrate, and further comprising a center portion and an extension portion that is disposed along a periphery of the center portion, and an insertion layer that is disposed in the extension portion between the first electrode and the piezoelectric layer, and the insertion layer is formed of an aluminum alloy containing scandium (Sc).

A thin-film heater according to one or more embodiments may include an insulated substrate and metal wiring patterned thereon to extend between both terminals of the metal wiring. The metal wiring has a resistance of 10Ω or less between the terminals. The metal wiring includes a heat-generating layer made of a material that recrystallizes at a temperature of 200° C. or lower.

A resonator device includes a resonator element, a base which has a first surface and a second surface that are in front-back relation, and in which the resonator element is arranged at the first surface, an integrated circuit provided to the base, a lid which has an inner surface opposed to the resonator element, and an outer surface in a front-back relationship with the inner surface, and which is bonded to the base so as to house the resonator element, and a radiation layer which is arranged at the inner surface of the lid, and is higher in emissivity than the lid.

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 A1≥A2 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.