Abstract: 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.

Abstract: A filter with bulk acoustic wave devices is disclosed. The filter includes a first bulk acoustic wave resonator and a second bulk acoustic wave resonator. The first bulk acoustic wave resonator includes a first raised frame structure. The first raised frame structure is a multi-layer raised frame structure. The second bulk acoustic wave resonator includes a second raised frame structure. The first raised frame structure has at least one more raised frame layer than the second raised frame structure.

Abstract: An acoustic wave device comprises a piezoelectric substrate, interdigital transducer electrodes having an electrode pitch ?0, and first and second reflector gratings disposed on opposite respective sides of the interdigital transducer electrodes in a propagation direction of a main acoustic wave through the acoustic wave device, the first reflector grating having a reflector electrode pitch ?1 throughout an entirety of the first reflector grating that is different than a reflector electrode pitch ?2 throughout an entirety of the second reflector grating to suppress ripples in a conductance curve of the acoustic wave device.

Abstract: Provided is a high-speed variant ChRmine protein having faster kinetic properties compared to a parent ChRmine protein, where the high-speed variant ChRmine protein has one or more amino acid substitutions compared to the parent ChRmine protein. Also provided is a red-shifted variant ChRmine protein having a red-shifted spectrum compared to a parent ChRmine protein, where the red-shifted variant ChRmine protein has one or more amino acid substitutions compared to the parent ChRmine protein. Further provided is a nucleic acid encoding for a variant ChRmine protein disclosed herein as well as a genetically modified cell comprising such nucleic acid. Additionally, provided is an optogenetic method that includes genetically modifying a subject to express in the subject's brain cells a variant ChRmine protein disclosed herein, applying stimulating light to the subject's brain, and imaging the subject's brain.

Abstract: Aspects of this disclosure relate to an acoustic wave device having an overtone mode as a main mode. The acoustic wave device is sufficiently asymmetric on opposing sides of a piezoelectric layer over an acoustic reflector such that the main mode of the acoustic wave device is the overtone mode.

Abstract: Aspects of this disclosure relate to acoustic wave filters with bulk acoustic wave resonators configured to excite an overtone mode as a main mode. A bulk acoustic wave resonator of the filter can include a plurality of stacked piezoelectric layers positioned between a pair of electrodes.

Abstract: Aspects of this disclosure relate to an acoustic wave filter that includes a shunt a bulk acoustic wave resonator having a plurality of resonant frequencies that impact a passband of the acoustic wave filter. Related bulk acoustic wave resonators, radio frequency modules, wireless communication devices, and methods of filtering radio frequency signals are disclosed.

Abstract: Aspects of this disclosure relate to bulk acoustic wave devices that have a raised frame structure, and filters that utilize the bulk acoustic wave devices. The raised frame structure can include a first raised frame layer that has a relatively low acoustic impedance. The raised frame structure can include a second raised frame layer that has a relatively high acoustic impedance. The first raised frame layer can extend inward further than the second raised frame layer. A width of the first raised frame layer that overlaps the first and second electrodes is between about 1.5 times to about 4 times larger than the combined thickness of the first electrode, the piezoelectric layer, and the second electrode.

Abstract: Aspects of this disclosure relate to an acoustic wave filter that includes a series a bulk acoustic wave resonator having a plurality of anti-resonant frequencies that impact a passband of the acoustic wave filter. Related bulk acoustic wave resonators, radio frequency modules, wireless communication devices, and methods of filtering radio frequency signals are disclosed.

Abstract: Aspects of this disclosure relate to an acoustic wave filter that includes a shunt a bulk acoustic wave resonator having a plurality of resonant frequencies that impact a passband of the acoustic wave filter. Related bulk acoustic wave resonators, radio frequency modules, wireless communication devices, and methods of filtering radio frequency signals are disclosed.

Abstract: Aspects of this disclosure relate to an acoustic wave resonator having at least two resonant frequencies. An acoustic wave filter can include series acoustic wave resonators and shunt acoustic wave resonators together arranged to filter a radio frequency signal. A first shunt resonator of the shunt acoustic wave resonators can include an interdigital transducer electrode and have at least a first resonant frequency and a second resonant frequency. Related acoustic wave resonators, multiplexers, wireless devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to bulk acoustic wave devices that have a raised frame structure, and filters that utilize the bulk acoustic wave devices. The raised frame structure can include a first raised frame layer that has a relatively low acoustic impedance. The raised frame structure can include a second raised frame layer that has a relatively high acoustic impedance. The first raised frame layer can extend inward further than the second raised frame layer. A width of the first raised frame layer that overlaps the first and second electrodes is between about 1.5 times to about 4 times larger than the combined thickness of the first electrode, the piezoelectric layer, and the second electrode.

Abstract: Aspects of this disclosure relate to multiplexers with that include an acoustic wave resonator. The acoustic wave filter includes a plurality of acoustic wave resonators of a first type and a shunt acoustic wave resonator of a second type. The shunt acoustic wave resonator of the second type has lower second harmonic distortion than the acoustic wave resonators of the first type. The shunt acoustic wave resonator of the second type has a resonant frequency in a passband of another filter of the multiplexer. Related radio frequency modules, wireless communication devices, and methods are also disclosed.

Abstract: An acoustic wave filter with different bulk acoustic wave devices is disclosed. The filter includes a first bulk acoustic wave resonator and a second bulk acoustic wave resonator. The first bulk acoustic wave resonator includes a first raised frame structure. The first raised frame structure is a multi-layer raised frame structure. The second bulk acoustic wave resonator includes a second raised frame structure. The first raised frame structure has at least one more raised frame layer than the second raised frame structure.

Abstract: An acoustic resonator module has and first and second bulk acoustic wave devices with a common shared air cavity structure between a piezoelectric layer and a substrate.

Abstract: A surface acoustic wave resonator that has at least a first resonant frequency and a second resonant frequency is disclosed. The surface acoustic wave resonator can include an interdigital transducer electrode that is positioned over a piezoelectric layer. The interdigital transducer electrode includes fingers having a first pitch. The surface acoustic wave resonator can also include a first set of reflectors that is positioned over the piezoelectric layer. The first set of reflectors includes a first number of reflectors having a second pitch. The first pitch is greater than the second pitch. The surface acoustic wave resonator can also include a second set of reflectors that is positioned over the piezoelectric layer. The second set of reflectors includes a second number of reflectors having a third pitch. The second number of reflectors is different from the first number of reflectors.

Abstract: A wafer-level package module includes a first substrate having a first bulk acoustic wave (BAW) device mounted thereon with a first aluminum nitride piezoelectric layer. The wafer-level package module further includes a second substrate having a second BAW device mounted thereon with a second aluminum nitride piezoelectric layer. The first BAW device has a electromechanical coupling coefficient (kt2) different from the second BAW device.

Abstract: Aspects of this disclosure relate to acoustic wave filter. The acoustic wave filter can include different types of acoustic wave resonators. The acoustic wave filter can include shunt acoustic wave resonator that has lower second harmonic distortion than other acoustic wave resonators of the acoustic wave filter. In certain embodiments, the shunt acoustic wave resonator can be a surface acoustic wave resonator. Related multiplexers, radio frequency modules, wireless communication devices, and methods are also disclosed.

Abstract: Aspects of this disclosure relate to multiplexers with acoustic wave resonators. The multiplexer includes a first filter and a second filter. The first filter includes a plurality of bulk acoustic wave resonators and a shunt surface acoustic wave resonator. The shunt acoustic wave resonator can have a resonant frequency in a passband of the second filter. The passband of the second filter is below a passband of the first filter. In certain applications, the first filter is a receive filter and the second filter is a transmit filter.

Abstract: Aspects of the disclosure provide a front-end module for a wireless device comprising a front-end module for a wireless device. The front end module includes at least one transmit path configured to receive a first transmit signal, at least one receive path configured to receive a first receive signal, at least one transmit/receive path, coupled to the at least one receive path and the at least one transmit path, an antenna switching module coupled between the at least one transmit/receive path and an antenna port, and a first transmit filter located in the at least one receive path and configured to reduce harmonic content from the first transmit signal.