An acoustic resonator device includes a conductor pattern formed on a surface of a piezoelectric plate. The conductor pattern includes a first busbar, a second busbar, and n interleaved parallel fingers of an interdigital transducer (IDT), where n is a positive integer. The fingers extend alternately from the first and second busbars. A first finger and an n'th finger are disposed at opposing ends of the IDT. The conductor pattern also includes a first reflector element proximate and parallel to the first finger and a second reflector element proximate and parallel to the n'th finger. When an RF signal is applied between the first and second busbars, the first reflector element is at substantially the same potential as the first finger and the second reflector element is at substantially the same potential as the n'th finger.

A BAW resonator comprises: a substrate comprising an acoustic reflector; a first electrode disposed over the acoustic reflector, and comprising a first electrode layer comprising a comparatively high acoustic impedance material, and a second electrode layer comprising a comparatively low acoustic impedance; a piezoelectric layer disposed over the second electrode layer; and a second electrode disposed over the piezoelectric layer, and comprising a third electrode layer comprising the low acoustic impedance, and a fourth electrode layer comprising the comparatively high acoustic impedance material and being disposed directly on the piezoelectric layer. A total thickness of an acoustic stack of the BAW resonator is approximately λ/2, where λ is a wavelength corresponding to a thickness extensional resonance frequency of the BAW resonator.

An elastic wave device in which an IDT electrode defines an excitation electrode on a piezoelectric layer, an acoustic reflection layer is laminated on a first main surface of the piezoelectric layer, the acoustic reflection layer includes high acoustic impedance layers with a relatively high acoustic impedance and low acoustic impedance layers with a relatively low acoustic impedance, and the acoustic reflection layer has an unwanted wave reflection suppression structure in which reflection of unwanted waves toward the piezoelectric layer side is significantly reduced or prevented.

The present disclosure relates to a tunable Bulk Acoustic Wave (BAW) resonator with a top electrode, a bottom electrode, a piezoelectric layer sandwiched between the top electrode and the bottom electrode, and a reflection region underneath the bottom electrode. The reflection region includes a reflection layer and an ion-conductible structure between the bottom electrode and the reflection layer. Herein, the ion-conductible structure has a first terminal layer coupled to the bottom electrode, a second terminal layer coupled to the reflection layer, and an ion conductor between the first terminal layer and the second terminal layer. The ion conductor is eligible to transport ions between the first terminal layer and the second terminal layer, so as to achieve a mass-loading shift between the first terminal layer and the second terminal layer, and consequently, to tune a resonance frequency of the tunable BAW resonator.

A piezoelectric device includes a foundation structure and a plurality of metal islands distributed over a first area of a top surface of the foundation structure. A piezoelectric film resides over the foundation structure and is formed from a piezoelectric material. The piezoelectric film has a non-piezoelectric portion over the first area and a piezoelectric portion over a second area of the top surface of the foundation structure. Within the non-piezoelectric portion, the piezoelectric film is polarity patterned to have pillars and a mesh. The pillars of the piezoelectric material have a first polar orientation residing over corresponding ones of the plurality of metal islands. The mesh of the piezoelectric material has a second polar orientation, which is opposite that of the first polar orientation, and surrounds the pillars. In one embodiment, the metal islands are self-assembled islands.

A resonance apparatus that processes an electrical loss using a conductive material and a method of manufacturing the resonance apparatus are provided. The resonance apparatus includes a lower electrode formed at a predetermined distance from a substrate, and a piezoelectric layer formed on the lower electrode. The resonance apparatus further includes an upper electrode formed on the piezoelectric layer, and a conductive layer formed on the upper electrode or the lower electrode.

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.

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.

The present invention relates to a wave control apparatus using change of elastic modulus of thermoresponsive material, comprising: a wave modulation member having thermoresponsive material whose elastic modulus changes according to temperature variation, a wave source propagating wave through the wave modulation member, and a heating unit forming a wave modulation region by heating the wave modulation member, wherein the wave propagating through the wave modulation member from the wave source is configured to change wave characteristics when the wave passes through the wave modulation region heated by the heating unit.

Acoustic sensor devices and sensor systems are disclosed. An acoustic sensor device includes a piezoelectric plate having a front surface and a back surface. A floating back-side conductor pattern is formed on the back surface. A first and second front-side conductor patterns are formed on a portion of the front surface opposite the back-side conductor pattern. A sensing layer is formed over all or a portion of the floating back-side conductor pattern.