Aspects of this disclosure relate to a bulk acoustic wave device with a floating raised frame structure. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a floating raised frame structure positioned on a same side of the piezoelectric layer as the first electrode and spaced apart from the first electrode. The floating raised frame structure is at a floating potential. The bulk acoustic wave device can suppress a raised frame mode. Related methods, filters, multiplexers, radio frequency front ends, radio frequency modules, and wireless communication devices are disclosed.

Techniques for improving acoustic wave device structures are disclosed, including filters and systems that may include such devices. An apparatus may comprise a first electrical filter including an acoustic wave device. The first electrical may having a first filter band in a Super High Frequency (SHF) band or an Extremely High Frequency (EHF) band to facilitate compliance with a regulatory requirement or a standards setting organization specification. For example, the first electrical filter may comprise a notch filter having a notch band overlapping at least a portion of an Earth Exploration Satellite Service (EESS) band to facilitate compliance with a regulatory requirement or the standards setting organization specification for the Earth Exploration Satellite Service (EESS) band.

The disclosure provides a packaging structure and method of an acoustic device, relating the technical field of semiconductors, including: a substrate and a piezoelectric stack structure located on the substrate, a first organic material layer is disposed on the piezoelectric stack structure, a second organic material layer is disposed on the first organic material layer, the first organic material layer includes a first supporting part and a second supporting part, the second supporting part forms a first acoustic reflection structure, when being transmitted to the first acoustic reflection structure, acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is reduced, and the performance of the acoustic device is improved. The first supporting part is matched with the second organic material layer to form a second acoustic reflection structure, so that when part of acoustic waves are not reflected back by the first acoustic reflection structure and are transmitted to the second acoustic reflection structure, the acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is further reduced, and the performance of the acoustic device is improved.

An acoustic wave device includes a high-acoustic-velocity layer, a piezoelectric layer made of lithium tantalate, and an interdigital transducer electrode that are successively laminated. An acoustic velocity of a bulk wave propagating in the high-acoustic-velocity layer is higher than an acoustic velocity of an acoustic wave propagating in the piezoelectric layer, and an acoustic velocity Vsub of a fast transversal bulk wave propagating in the high-acoustic-velocity layer satisfies Vsh0≤Vsub≤Vsp with respect to an acoustic velocity Vsh0 of an SH0 mode and an acoustic velocity Vsp of a mode becoming a spurious of which acoustic velocity is not lower than the acoustic velocity of the SH0 mode, wherein the acoustic velocity Vsh0 and the acoustic velocity Vsp is obtained from Eq. (1).

The present disclosure provides a bulk acoustic wave resonator, a manufacturing method thereof, and a filter, wherein the bulk acoustic wave resonator includes: a substrate; an acoustic reflection unit on the substrate; a piezoelectric stack structure on the acoustic reflection unit; and a pad on the piezoelectric stack structure; wherein the pad has an overlapping region with the acoustic reflection unit. The acoustic wave resonator, the manufacturing method thereof and the filter of the present disclosure can effectively reduce connection resistance of the bulk acoustic wave resonator, thereby reducing insertion loss of the filter.

An acoustic wave filter device is disclosed. The device includes an acoustic wave filter element, and a first resonator and a second resonator coupled to the acoustic wave filter element. The acoustic wave filter element includes interdigited input electrodes and output electrodes located on a top surface of a piezoelectric layer. Each of the first and the second resonators includes a top electrode on the top surface, and a bottom electrode on the bottom surface of the piezoelectric layer. At least one of each of the first and the second resonators' electrodes is electrically connected to the acoustic wave filter element. The first resonator has a first notch in resonator impedance at a first frequency. The second resonator includes a first mass loading layer on the second resonator electrode such that the second resonator has a second notch in resonator impedance at a second frequency different from the first frequency.

A longitudinally coupled resonator acoustic wave filter includes a piezoelectric substrate, IDT electrodes on the piezoelectric substrate along an acoustic wave propagation direction, and a pair of reflectors on the piezoelectric substrate on both sides of the IDT electrodes in the acoustic wave propagation direction. Each of the reflectors includes first and second reflector busbars, and first reflective electrode fingers connected to at least one of the first reflector busbar and the second reflector busbar. The reflector includes a first portion in which lengths of the first reflective electrode fingers change in the acoustic wave propagation direction.

An acoustic wave device in which a cavity defining an acoustic reflector is formed on a first main surface side of a substrate, an excitation portion is structured above the cavity in a manner that a first electrode, a piezoelectric thin film, and a second electrode are laminated, and a periodic pattern is provided in a normal direction of a side of the excitation portion on at least one of a first extraction electrode and a second extraction electrode.

Techniques for improving Bulk Acoustic Wave (BAW) resonator structures are disclosed, including fluidic systems, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a substrate and a first layer of piezoelectric material. The bulk acoustic wave (BAW) resonator may comprise a top electrode. A sensing region may be acoustically coupled with the top electrode of the bulk acoustic wave (BAW) resonator.

Techniques for improving Bulk Acoustic Wave (BAW) resonator structures are disclosed, including filters, oscillators and systems that may include such devices. First and second layers of piezoelectric material may be acoustically coupled with one another to have a piezoelectrically excitable resonance mode. The first layer of piezoelectric material may have a first piezoelectric axis orientation, and the second layer of piezoelectric material may have a second piezoelectric axis orientation that opposes the first piezoelectric axis orientation of the first layer of piezoelectric material. A top acoustic reflector including a first pair of top metal electrode layers may be electrically and acoustically coupled with the first layer of piezoelectric material to excite the piezoelectrically excitable main resonance mode at a resonant frequency.