Abstract: A laterally excited bulk acoustic wave device is disclosed. The laterally excited bulk acoustic wave device can include a first solid acoustic mirror, a second solid acoustic mirror, a piezoelectric layer that is positioned between the first solid acoustic mirror and the second solid acoustic mirror, an interdigital transducer electrode on the piezoelectric layer, and a support substrate arranged to dissipate heat associated with the bulk acoustic wave. The interdigital transducer electrode is arranged to laterally excite a bulk acoustic wave. The first solid acoustic mirror and the second solid acoustic mirror are arranged to confine acoustic energy of the bulk acoustic wave. The first solid acoustic mirror is positioned on the support substrate.

Abstract: Aspects of this disclosure relate to a surface acoustic wave filter with an acoustic velocity adjustment structure. The surface acoustic wave filter can include a first interdigital transducer electrode disposed on a piezoelectric layer, an acoustic reflector disposed on the piezoelectric layer, and a second interdigital transducer electrode disposed on the piezoelectric layer. The second interdigital transducer electrode is longitudinally coupled to the first interdigital transducer electrode and positioned between the first interdigital transducer electrode and the acoustic reflector. The acoustic velocity adjustment structure can be positioned over at least a gap between the first interdigital transducer electrode and the second interdigital transducer electrode.

Abstract: Aspects of this disclosure relate to a surface acoustic wave device with a vertical stack over a piezoelectric layer. The vertical stack can include a first acoustic reflector disposed on the piezoelectric layer, a second acoustic reflector disposed on the piezoelectric layer, and an interdigital transducer electrode disposed on the piezoelectric layer and positioned between the first acoustic reflector and the second acoustic reflector. The interdigital transducer electrode has a first side that is closer to the first acoustic reflector and a second side that is closer to the second acoustic reflector. A vertical arrangement of the vertical stack can be configured such that an acoustic wave propagation velocity of a first region between the first side and a first reflector is faster than an acoustic wave propagation velocity of a second region between the first side and the second side.

Abstract: Aspects of this disclosure relate to a surface acoustic wave device that includes a first reflector over a piezoelectric layer, a second reflector over the piezoelectric layer, and an interdigital transducer electrode structure over the piezoelectric layer and positioned between the first reflector and the second reflector. The surface acoustic wave device includes a velocity adjustment layer arranged to adjust acoustic velocity in a region of the surface acoustic wave device. The velocity adjustment layer can be a high speed layer or a low speed layer.

Abstract: Aspects of this disclosure relate to a multiplexer, such as a duplexer, a quadplexer, a hexaplexer, or the like. The multiplexer includes acoustic wave filters coupled to a common node. A first acoustic wave filter of the acoustic wave filters includes acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node.

Abstract: Aspects of this disclosure relate to an acoustic wave filter with an acoustic wave resonator arranged to concentrate a transverse spurious mode at a frequency. Such an acoustic wave resonator can have a narrow aperture to concentrate the transverse spurious mode. The transverse spurious mode can increase steepness of a skirt of the acoustic wave filter. Related methods, acoustic wave devices, multiplexers, radio frequency front ends, radio frequency modules, and wireless communication devices are disclosed.

Abstract: In some embodiments, a power amplification system can comprise a current source configured to provide a bias current, a current mirror configured to mirror the bias current, a comparator configured to compare the mirrored bias current to a threshold current, and a transistor at an output of the comparator. The transistor can be configured to be activated in response to the mirrored bias current exceeding the threshold current.

Abstract: Aspects of this disclosure relate to an acoustic wave filter with an acoustic wave resonator arranged to concentrate a transverse spurious mode at a frequency. Such an acoustic wave resonator can have a narrow aperture to concentrate the transverse spurious mode. The transverse spurious mode can increase steepness of a skirt of the acoustic wave filter. Related methods, acoustic wave devices, multiplexers, radio frequency front ends, radio frequency modules, and wireless communication devices are disclosed.

Abstract: Embodiments of this disclosure relate to reducing coupling between acoustic wave resonators. An isolation region of a substrate can be located between acoustic wave resonators. The isolation region can reduce capacitive coupling through the substrate between the acoustic wave resonators. In certain embodiments, the isolation region can be located between acoustic wave resonators of different filters to thereby increase isolation between the filters.

Abstract: Embodiments of this disclosure relate to methods of manufacturing acoustic wave components that include acoustic wave resonators that share a substrate. Laser light can be applied to alter a region of the substrate that is located between two of the acoustic wave resonators. Altering the region with laser light can reduce coupling between the two acoustic resonators through the substrate. The substrate can be monolithic after laser the light is applied.

Abstract: A vehicle system to produce audible sound includes at least one auxiliary motor to mechanically operate of a vehicle component based on a control signal and to produce an audible sound without mechanically operating the vehicle component, and a controller to output a motion control signal to control operation of the at least one auxiliary motor and to output an auditory control signal to actuate the at least one auxiliary motor to produce the audible sound. A waveguide is provided in communication with the at least one auxiliary motor and in sonic resonance with sound produced by the auxiliary motor to amplify and/or to modify the audible sound.

Abstract: Circuits with filters and acoustic resonators. In some embodiments, a radio-frequency circuit can include a plurality of nodes and a common node. The radio-frequency circuit can further include a signal path implemented between each of the plurality of nodes and the common node. Each corresponding signal path can include a filter having a first Q-factor value and a respective resonator having a second Q-factor value higher than the first Q-factor value.

Abstract: Aspects of this disclosure relate to a multiplexer, such as a duplexer, a quadplexer, a hexaplexer, or the like. The multiplexer includes acoustic wave filters coupled to a common node. A first acoustic wave filter of the acoustic wave filters includes acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node.

Abstract: A non-contact obstacle detection (NCOD) system for an opening in a vehicle includes a cover panel, such as a glass pane, slidable between opened and closed positions within the opening. The system includes one or more infrared time-of-flight (IR-TOF) sensors which measure the length of a beam of infrared light by measuring the time that the infrared light in the beam takes to travel the length of the beam and to reflect back to the sensor. The IR-TOF sensors may be configured to provide a beam of light along either the side edge of the frame parallel to the sliding direction or a terminal edge generally transverse to the sliding direction. Methods are provided for detecting obstacles within the opening of the frame by controllers using the lengths of beams from each of those different beam configurations, and for self-calibrating the system.

Abstract: In some embodiments, a power amplification system can comprise a current source configured to provide a bias current, a current mirror configured to mirror the bias current, a comparator configured to compare the mirrored bias current to a threshold current, and a transistor at an output of the comparator. The transistor can be configured to be activated in response to the mirrored bias current exceeding the threshold current.

Abstract: A non-contact obstacle detection (NCOD) system for an opening in a vehicle includes a cover panel, such as a glass pane, slidable between opened and closed positions within the opening. The system includes one or more infrared time-of-flight (IR-TOF) sensors which measure the length of a beam of infrared light by measuring the time that the infrared light in the beam takes to travel the length of the beam and to reflect back to the sensor. The IR-TOF sensors may be configured to provide a beam of light along either the side edge of the frame parallel to the sliding direction or a terminal edge generally transverse to the sliding direction. Methods are provided for detecting obstacles within the opening of the frame by controllers using the lengths of beams from each of those different beam configurations, and for self-calibrating the system.

Abstract: An acoustic wave device includes 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 resonator having a piezoelectric layer and an interdigital transducer electrode disposed on the piezoelectric layer. The piezoelectric layer includes free edges. An edge of the piezoelectric layer is configured to one of suppress or scatter reflections of acoustic waves generated by the interdigital transducer electrode from the edge of the piezoelectric layer.

Abstract: Aspects of this disclosure relate to a multiplexer, such as a duplexer, a quadplexer, a hexaplexer, or the like. The multiplexer includes acoustic wave filters coupled to a common node. A first acoustic wave filter of the acoustic wave filters includes acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node.

Abstract: Multiplexers having hybrid circuits with resonators. In some embodiments, a multiplexer for processing radio-frequency signals can include a plurality of nodes, a common node, and a signal path implemented between each of the plurality of nodes and the common node. Each signal path can include a filter, and each of at least some of the signal paths can further include a resonator coupled with the corresponding filter. A signal path with the resonator provides a sharper notch profile for a radio-frequency signal than a signal path without the resonator.

Abstract: A multiplexing system can include a first diplexer and a second diplexer. The first diplexer can have a first transmit terminal, a first receive terminal, and a first common terminal. The first diplexer can be configured to filter a first transmit signal to a first cellular frequency band and output the filtered first transmit signal. The first diplexer can be further configured to filter a first receive signal to a second cellular frequency band and output the filtered first receive signal. The second diplexer can have a second transmit terminal, a second receive terminal, and a second common terminal. The second diplexer can be configured to filter a second transmit signal to the second cellular frequency band and output the filtered second transmit signal. The second diplexer can be further configured to filter a second receive signal to the first cellular frequency band and output the filtered second receive signal.