A hybrid resonator includes an acoustic wave resonator (AWR) having a piezoelectric material; a first electrical contact, electrically conductively connected to the piezoelectric material; and a second electrical contact, electrically conductively connected to the piezoelectric material. The hybrid resonator further includes a first resonant circuit, electrically conductively connected in series or parallel to the acoustic wave resonator via at least one of the first electrical contact and the second electrical contact. The resonant circuit includes a first inductor, and a first capacitor; wherein, if the first resonant circuit is electrically conductively connected to the acoustic wave resonator in series, the first inductor and the first capacitor are electrically conductively connected to one another in parallel, and if the first resonant circuit is electrically conductively connected to the acoustic wave resonator in parallel, the first inductor and the first capacitor are electrically conductively connected to one another in series.

Embodiments of this disclosure relate to bulk acoustic wave resonators on a substrate. The bulk acoustic wave resonators include a first bulk acoustic wave resonator, a second bulk acoustic wave resonator, a conductor electrically connecting the first bulk acoustic wave resonator to the second bulk acoustic wave resonator, and an air gap positioned between the conductor and a surface of the substrate.

A film bulk acoustic wave resonator comprising a piezoelectric film having a central region defining a main active domain in which a main acoustic wave is generated during operation, an upper electrode disposed on a top surface of the piezoelectric film, a lower electrode disposed on a lower surface of the piezoelectric film, a dielectric material layer disposed on a lower surface of the lower electrode, and lower recessed frame regions disposed laterally on opposite sides of the central region, the lower recessed frame regions defined by regions of one of the dielectric material or of the lower electrode having a lesser thickness than the thickness of the one of the dielectric material layer or of the lower electrode in the central region.

A 5 GHz Wi-Fi bandpass filter includes a ladder filter circuit with two or more shunt transversely-excited film bulk acoustic resonators (XBARs) and two or more series XBARs. Each of the two or more shunt XBARS includes a diaphragm having an LN-equivalent thickness greater than or equal to 360 nm, and each of the two or more series XBARS includes a diaphragm having an LN-equivalent thickness less than or equal to 375 nm.

A bulk acoustic resonator filter includes a series part including at least one series acoustic resonator electrically connected between a first and second radio frequency ports; and shunt acoustic resonators electrically connected to each other in series between a first node of the series part and a first ground port, wherein each of the shunt acoustic resonators comprises a resonance portion including a first electrode, a piezoelectric layer, and a second electrode; and an overlap region in which the first electrode, the piezoelectric layer, and the second electrode overlap, the overlap region has an aspect ratio equal to a ratio between a longest length of the overlap region in an extension direction of a longest side of the overlap region and a longest length of the overlap region in a direction perpendicular to the extension direction, and the aspect ratios of the shunt acoustic resonators include different aspect ratios.

An acoustic wave filter package is disclosed. The acoustic wave filter package can include a first acoustic wave filter, a second acoustic wave filter, and a shared node. The first acoustic wave filter is configured to filter a first radio frequency signal. The first acoustic wave filter has a first shunt resonator. The second acoustic wave filter is configured to filter a second radio frequency signal. The second acoustic wave filter having a second shunt resonator. The first and second shunt resonators are electrically coupled to ground at the shared node.

An acoustic wave filter device includes a second filter section connected to a first filter section. The second filter section includes acoustic wave resonators in a ladder circuit configuration. Of the acoustic wave resonators in the first and second filter sections, the acoustic wave resonator having the smallest fractional bandwidth is included in the second filter section. In the second filter section, inductors are respectively connected between parallel arm resonators and a reference potential. Attenuation near a pass band in the second filter section is larger than attenuation near a pass band in the first filter section.

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

Aspects of this disclosure relate to acoustic wave filters with bulk acoustic wave resonators. An acoustic wave filter can include a first bulk acoustic wave resonator configured to excite an overtone mode as a main mode and a second bulk acoustic wave resonator having a fundamental mode as a main mode.

An acoustic wave device includes a support substrate, a piezoelectric layer on the support substrate, a functional electrode on the piezoelectric layer, and first and second electrode films on the piezoelectric layer, facing each other, and having different electric potentials from each other. When a region between the first and second electrode films in a plan view is an inter-electrode film region, and a region overlapping with the first electrode film or the second electrode film in a plan view is an electrode film underlying region, a thickness of the piezoelectric layer in at least a portion of the inter-electrode film region is smaller than a thickness of the piezoelectric layer in the electrode film underlying region.