Abstract: An acoustic wave device includes an antenna terminal, a signal terminal, and a plurality of resonators that are provided on a piezoelectric substrate. The plurality of resonators include a plurality of series arm resonators on a series arm, and the duty of an IDT electrode of the series arm resonator closest to the antenna terminal among the plurality of series arm resonators is smaller than the duty of an IDT electrode of at least one series arm resonator among the other series arm resonators.

Abstract: Embodiments of the present disclosure provide a radio frequency (RF) conductive medium for reducing the undesirable insertion loss of all RF hardware components and improving the Q factor or “quality factor” of RF resonant cavities. The RF conductive medium decreases the insertion loss of the RF device by including one or more conductive pathways in a transverse electromagnetic axis that are immune to skin effect loss and, by extension, are substantially free from resistance to the conduction of RF energy.

Abstract: A filter is provided that includes a set of cascaded resonator stages coupled between a filter input and a first filter output, wherein the filter includes a second filter output coupled to an output of a first or an intermediate one of the set of cascaded resonator stages. Another filter includes a set of cascaded resonator stages coupled between a first filter input and a filter output, wherein the filter includes a second filter input coupled to an input of an intermediate or a last one of the set of cascaded resonator stages. Both filters are configured to apply a first filter frequency response to a first signal propagating via the set of cascaded resonator stages, and apply a second filter frequency response to a second signal propagating via a subset of one or more of the set of cascaded resonator stages.

Abstract: An elastic wave device includes a piezoelectric substrate, and elastic wave elements on the piezoelectric substrate and including IDT electrodes, respectively. The IDT electrode of a first of the elastic wave elements includes first and second busbars, and the IDT electrode of a second of the elastic wave elements includes third and fourth busbars. The second busbar and the third busbar extend parallel or substantially parallel to each other, and are spaced by a gap in a direction perpendicular or substantially perpendicular to an elastic-wave propagating direction. Each of the second and third busbars includes first and second electrode layers at least a portion of which is laminated on the first electrode layer. The second electrode layer of the second busbar is cut in at least one location in a direction crossing the elastic-wave propagating direction.

Abstract: An acoustic wave device includes a piezoelectric substrate, interdigital transducer electrodes including a predetermined number of electrode fingers disposed on an upper surface of the substrate, and a dielectric material layer having a first portion and a second portion. The first portion is disposed on the upper surface of the substrate and between the interdigital transducer electrode fingers. The second portion is disposed above the interdigital transducer electrode fingers. The acoustic wave device further includes at least one thermally conductive bridge disposed within the dielectric material layer and contacting upper surfaces of at least two adjacent interdigital transducer electrode fingers to dissipate heat therefrom.

Abstract: An electronic filter includes a plurality of series arm acoustic wave resonators electrically connected in series between an input port and an output port, a plurality of parallel arm acoustic wave resonators electrically connected in parallel and electrically connected on first sides between respective ones of the plurality of series arm acoustic wave resonators and electrically connected on second sides to ground, and at least one additional acoustic wave resonator electrically connected in parallel to one of one of the plurality of series arm acoustic wave resonators or one of the plurality of parallel arm acoustic wave resonators and having a temperature coefficient of frequency (TCF) lower than a TCF of the acoustic wave resonator to which it is electrically connected in parallel.

Abstract: An acoustic wave filter device includes first and second terminals, an inductor connected to the first terminal, and a longitudinally coupled resonator coupled between the inductor and the second terminal. The longitudinally coupled resonator includes at least one first IDT electrode coupled to the first terminal, and at least one second IDT electrode connected to the second terminal. A total capacitance value of the at least one first IDT electrode is greater than a total capacitance value of the at least one second IDT electrode.

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 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: Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode in the diaphragm. A back-side partial Bragg reflector is formed on the back surface of the diaphragm, and a front-side partial Bragg reflector is formed on the front surface of the diaphragm.

Abstract: A filter device includes a first filter connected between a common terminal and a first individual terminal, and a second filter connected between the common terminal and a second individual terminal. A pass band of the second filter is in a frequency range lower than a pass band of the first filter. The first filter includes SAW resonators, at least one of which includes divided resonators connected in parallel with each other. Each of the divided resonators includes an IDT. A pitch of the IDT of one of the divided resonators is different from that of another of the divided resonators.

Abstract: An acoustic resonator assembly and a filter are disclosed. The acoustic resonator assembly includes at least two acoustic resonators vertically connected to each other. The acoustic resonator includes: an acoustic mirror, a bottom electrode layer, a piezoelectric layer, and a top electrode layer that are arranged on a substrate. An active area of the acoustic resonator is defined by an overlapping area of the acoustic mirror, the bottom electrode layer, the piezoelectric layer, and the top electrode layer. The acoustic resonator further includes a support layer arranged on the substrate or the piezoelectric layer on a periphery of a projection of the acoustic mirror on the substrate. The at least two acoustic resonators are vertically connected to each other through the support layer. The filter significantly reduces the volume and the area of a device, improves design freedom and reduces design difficulty, enhances product performance and greatly reduces costs.

Abstract: An acoustic wave filter includes a series-arm resonator, a first parallel-arm resonator, and a second parallel-arm resonator. The series-arm resonator is disposed on a path connecting first and second input/output terminals. The first parallel-arm resonator is disposed on a path that connects ground with a node, which is located on a path connecting the series-arm resonator with the first input/output terminal. The second parallel-arm resonator is disposed on a path that connects ground with a node, which is located on a path connecting the series-arm resonator with the second input/output terminal. The parallel-arm resonator has a resonant frequency lower than the resonant frequency of the second parallel-arm resonator. The first parallel-arm resonator has an anti-resonant frequency higher than the anti-resonant frequency of the second parallel-arm resonator. The second parallel-arm resonator has the highest resonant frequency of all the parallel-arm resonators.

Abstract: Aspects of this disclosure relate to a surface acoustic wave resonator. The surface acoustic wave resonator includes a piezoelectric substrate, interdigital transducer electrodes disposed on an upper surface of the piezoelectric substrate, a dielectric temperature compensation layer disposed on the piezoelectric substrate to cover the interdigital transducer electrodes, and a dielectric passivation layer over the temperature compensation layer. The passivation layer may include an oxide layer configured to have a sound velocity greater than that of the temperature compensation layer to suppress a transverse signal transmission.

Abstract: An acoustic wave resonator includes an IDT electrode that is on or above a piezoelectric plate and includes a periodic withdrawal weighted portion in each of a plurality of regions for at least two or more periods in an acoustic wave propagation direction. A periodic withdrawal weighted portion in at least one of the regions is different from a periodic withdrawal weighted portion in at least one of the other regions.

Abstract: An elastic wave filter device includes a ladder filter that includes series arm resonators and parallel arm resonators. In one series arm resonator in which the acoustic velocity in a first and second edge area is lower than in a central area, each first electrode finger includes a large-width portion having a width larger than in remaining portions in the second edge area, and each second electrode finger includes a large-width portion having a width larger than in remaining portions in the first edge area. In at least one of remaining series arm resonators and the parallel arm resonators, each first and second electrode finger includes a large-width portion having a width larger than in remaining portions in both of the first and second edge areas.

Abstract: An elastic wave filter apparatus includes at least one excitation electrode, a first electrode land, and second electrode lands provided on a first main surface of a device substrate including a piezoelectric layer. A signal terminal and metal members are provided on a second main surface of the device substrate. The first electrode land and the signal terminal are connected to a signal potential, and the second electrode lands and the metal members are connected to a ground potential. A first connection electrode connects the first electrode land and the signal terminal, and a second connection electrode connects at least one of the second electrode lands and at least one of the metal members. The at least one metal member connected to the second connection electrode overlaps at least a portion of the at least one excitation electrode across the device substrate.

Abstract: A shielded bridge for a coplanar waveguide (CPW) includes a signal bridge extending from a first terminal of the CPW to a second terminal of the CPW. The signal bridge has a raised central portion that extends over a separate signal conductor. The shielded bridge for the CPW also includes a ground bridge extending from a first ground plane on a first side of the separate signal conductor to a second ground plane on a second side of the separate signal conductor. The ground bridge is positioned between the signal bridge and the separate signal conductor.

Abstract: Aspects of this disclosure relate to a surface acoustic wave resonator that may include a piezoelectric substrate, interdigital transducer (IDT) electrodes disposed on an upper surface of the piezoelectric substrate, and a dielectric film covering the piezoelectric substrate and the IDT electrode for temperature compensation. The IDT electrodes may include bus bar electrode regions spaced apart from each other in a transverse direction perpendicular to a propagation direction of a surface acoustic wave to be excited, an overlapping region sandwiched between the bus bar regions, and gap regions defined between respective bus bar electrode regions and the overlapping region in the transverse direction. Each of the gap regions may include a dummy electrode in a dummy electrode region extending from the bus bar electrode region in the transverse direction. The dielectric film may include an open region exposing a respective bus bar electrode region and dummy electrode region.

Abstract: Certain aspects of the present disclosure provide a filter. The filter generally includes a series resonator coupled between a first port of the filter and a second port of the filter, and a shunt resonator coupled between a node of the filter and a reference potential node of the filter, the node being coupled between the first port and the second port. The shunt resonator typically includes a first piezoelectric substrate, a first plurality of reflectors disposed above the first piezoelectric substrate, and a first plurality of interdigital transducers (IDTs) disposed above the first piezoelectric substrate and between the first plurality of reflectors, wherein the shunt resonator is configured as a dual mode structure (DMS).