Abstract: Piston mode Lamb wave resonators are disclosed. A piston mode Lamb wave resonator can include a piezoelectric layer, such as an aluminum nitride layer, and an interdigital transducer on the piezoelectric layer. The piston mode Lamb wave resonator has an active region and a border region, in which the border region has a velocity with a lower magnitude than a velocity of the active region. The border region can suppress a transverse mode.

Abstract: 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.

Abstract: A film bulk acoustic wave resonator (FBAR) comprises a recessed frame region including an undulating perimeter.

Abstract: Aspects of this disclosure relate to an elastic wave device. The elastic wave device includes a sub-wavelength thick piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and a high velocity layer configured to inhibit an elastic wave from leaking from the piezoelectric layer at anti-resonance.

Abstract: An acoustic wave device with a bent section is disclosed. The acoustic wave device includes a piezoelectric layer and an interdigital transducer electrode on the piezoelectric layer. The bent section is arranged to create a curvature in a waveguide of the acoustic wave device to suppress a transverse spurious mode of the acoustic wave device.

Abstract: 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.

Abstract: 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.

Abstract: Phase shift circuits including two or more slanted-finger IDT electrodes, and filters, duplexers, or other electronic devices incorporating same. In one example a filter includes a main filter circuit connected between an input and an output and having a first phase characteristic, and a phase shift circuit connected in parallel with the main filter circuit, the phase shift circuit including first and second capacitor elements and a pair of acoustic wave elements connected in series between the first and second capacitor elements, the pair of acoustic wave elements including a pair of slanted-finger IDT electrodes disposed apart from each other on a single acoustic wave path along which acoustic waves propagate through the acoustic wave elements, the phase shift circuit having a second phase characteristic opposite to the first phase characteristic in an attenuation band that corresponds to at least a portion of a stopband of the main filter circuit.

Abstract: Piston mode Lamb wave resonators are disclosed. A piston mode Lamb wave resonator can include a piezoelectric layer, such as an aluminum nitride layer, and an interdigital transducer on the piezoelectric layer. The piston mode Lamb wave resonator has an active region and a border region, in which the border region has a velocity with a lower magnitude than a velocity of the active region. The border region can suppress a transverse mode.

Abstract: Aspects of this disclosure relate to an elastic wave device. The elastic wave device includes a sub-wavelength thick piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and a high velocity layer with a higher bulk velocity than the velocity of an elastic wave.

Abstract: Aspects of this disclosure relate to an elastic wave device. The elastic wave device includes a sub-wavelength thick piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and a high velocity layer configured to inhibit an elastic wave from leaking from the piezoelectric layer at anti-resonance.

Abstract: A fence system may include stably coupleable posts, railings, and pickets. A post may include components configured to snap fit such as a post housing and post cover. A post cover may include a hole to snap fit to an end of a railing. A railing may include components configured to snap fit such as a railing housing and railing cover. Railing components may include holes positioned to correspond when the components are snap fit. The corresponding holes may be dimensioned to snap fit an end of a picket. Railings, pickets, or both may be pivoted when snap fit with a respective post or railing.

Abstract: Phase shift circuits including two or more slanted-finger IDT electrodes, and filters, duplexers, or other electronic devices incorporating same. In one example a filter includes a main filter circuit connected between an input and an output and having a first phase characteristic, and a phase shift circuit connected in parallel with the main filter circuit, the phase shift circuit including first and second capacitor elements and a pair of acoustic wave elements connected in series between the first and second capacitor elements, the pair of acoustic wave elements including a pair of slanted-finger IDT electrodes disposed apart from each other on a single acoustic wave path along which acoustic waves propagate through the acoustic wave elements, the phase shift circuit having a second phase characteristic opposite to the first phase characteristic in an attenuation band that corresponds to at least a portion of a stopband of the main filter circuit.