Aspects of this disclosure relate to an acoustic wave filter configured to filter a radio frequency signal and a loop circuit coupled to the acoustic wave filter. The loop circuit is configured to generate an anti-phase signal to a target signal at a particular frequency. The loop circuit includes a Lamb wave element. Related radio frequency modules and wireless communication devices are disclosed.

Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device, comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar through a central region of the interdigital transducer electrode towards an edge region of the interdigital transducer electrode, each of the plurality of electrode fingers having a width in a direction perpendicular to the extension of the electrode fingers that is smaller in the edge regions than in the central regions, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

Aspects of this disclosure relate to an acoustic wave device that includes a bulk acoustic wave resonator and a Lamb wave element implemented on a common substrate. In some instances, the bulk acoustic wave resonator can be a film bulk acoustic wave resonator. Related radio frequency modules and wireless communication devices are disclosed.

A method of manufacturing an acoustic wave device is provided. The method of manufacturing the acoustic wave device comprises providing a layer of piezoelectric material, disposing a pair of interdigital transducer electrodes on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and etching trench portions into the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The formation of the trench portions through etching results in an easier fabrication, that is less likely to damage the interdigital transducer electrodes.

An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

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.

Embodiments of this disclosure relate to acoustic wave filters configured to filter radio frequency signals. An acoustic wave filter includes a first bulk acoustic wave resonator on a substrate, a second bulk acoustic wave resonator on the substrate, a conductor electrically connecting the first bulk acoustic wave resonator in anti-series with the second bulk acoustic wave resonator, and an air gap positioned between the conductor and a surface of the substrate. The air gap can reduce parasitic capacitance associated with the conductor. Acoustic wave filters disclosed herein can suppress a second harmonic.

A filter is disclosed. The filter can be a band pass filter or a band rejection filter. The filter can have bulk acoustic wave resonators. The filter can include a shunt bulk acoustic wave resonator and a series bulk acoustic wave resonator. The shunt bulk acoustic wave resonator and the series bulk acoustic wave resonator include different raised frame structures. The different raised frame structures contribute to one of the shunt bulk acoustic wave resonator or the series bulk acoustic wave resonator to have a higher quality factor below a resonant frequency than the other.

Aspects of this disclosure relate to acoustic wave filters that include a Lamb wave resonator and a second acoustic wave resonator that is a different type of acoustic wave resonator than the Lamb wave resonator. The different type of resonator can be a film bulk acoustic wave resonator for example. Some embodiments of this disclosure relate to an acoustic wave filter that includes the Lamb wave resonator and the second acoustic wave resonator. Some embodiments of this disclosure related to different respective acoustic wave filters including the Lamb wave resonator and the second acoustic wave resonator, in which the Lamb wave resonator and the second acoustic wave resonator are implemented on a common substrate.