Abstract: Provided is a receiver. The receiver according to the inventive concept includes a first filter circuit, a second filter circuit, and an amplifier. The first filter circuit provides a first path for first frequency components below first cutoff frequency of input frequency components and passes second frequency components except for the first frequency components of the input frequency components through second path. The second filter circuit attenuates third frequency components below a second cutoff frequency of the second frequency components. The amplifier amplifies the second frequency components including the attenuated third frequency components.

Abstract: There are disclosed acoustic filters and radios incorporating the acoustic filters. A filter includes a first filter port, a second filter port, and n sub-filters, where n is an integer greater than one. Each sub-filter has a first sub-filter port connected to the first filter port and a second sub-filter port connected to the second filter port. A first acoustic resonator is connected from the first filter port to ground, and a second acoustic resonator is connected from the second filter port to ground. The first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of a passband of the filter.

Abstract: A radio frequency module includes: a module board including a first principal surface and a second principal surface on opposite sides of the module board; an antenna connection terminal; a filter that is on the first principal surface and connected to the antenna connection terminal, wherein the filter includes one or more inductors and one or more capacitors, and is configured to allow a transmission signal and a reception signal to pass through; and a reception low noise amplifier on the second principal surface and configured to amplify the reception signal.

Abstract: A SAW device having a stacked design of functional layers is proposed that is build up on a carrier substrate (SUB) that is chosen to provide a high acoustic velocity. The stack further comprises a thin TCF compensation layer (TCL), a thin film piezoelectric layer (PEL) and a set of interdigital electrodes (IDE) on top of the piezoelectric layer. Energy of the desired mode mainly in the high acoustic velocity material. Despite the high possible operating frequencies the SAW device can reliably be manufactured with present lithographic techniques.

Abstract: Certain aspects provide an integrated circuit (IC) including a resonator. One example IC generally includes a substrate, a first oxide region disposed above the substrate, and a resonator. The resonator may include a piezoelectric layer, a second oxide region disposed below the piezoelectric layer and bonded to the first oxide region, and a cavity in the second oxide region, wherein at least a portion of the second oxide region is below the cavity.

Abstract: An acoustic resonator filter includes at least one series acoustic resonator electrically connected between a first port and a second port in series, through which a radio frequency (RF) signal passes; at least one second shunt acoustic resonator electrically shunt-connected between the at least one series acoustic resonator and a ground; and at least one first shunt acoustic resonator electrically shunt-connected between the at least one series acoustic resonator and a ground and having a resonance frequency higher than a resonance frequency of the at least one second shunt acoustic resonator. At least one shunt acoustic resonator, among the at least one first shunt acoustic resonator and the at least one second shunt acoustic resonator has a temperature coefficient of frequency (TCF) corresponding to resonance frequency sensitivity more insensitive than resonance frequency sensitivity according to a change in temperature of the at least one series acoustic resonator filter.

Abstract: A surface acoustic wave (SAW) filter package structure includes a dielectric substrate having a dielectric layer, a first patterned conductive layer, a second patterned conductive layer, and a conductive connection layer. The conductive connection layer is electrically connected between the first patterned conductive layer and the second patterned conductive layer, which are disposed at opposite sides of the dielectric layer. The second patterned conductive layer has a finger electrode portion. An active surface of a chip is faced toward the finger electrode portion. A polymer sealing frame is disposed between the chip and the dielectric substrate and surrounds the periphery of the chip to form a chamber together with the chip and the dielectric substrate. The mold sealing layer is disposed on the dielectric substrate and covers the chip and the polymer sealing frame. A manufacturing method of the SAW filter package structure is also disclosed.

Abstract: Acoustic wave filter devices is disclosed. The device includes a piezoelectric layer, an input electrode and an output electrode located on a top surface of the piezoelectric layer and physically separated from one another, and a counter electrode having a top surface connected to a bottom surface of the piezoelectric layer. The input and output electrodes each include a base and at least one extension extending from the base. The at least one extension of the input electrode extending alongside and in a generally opposite direction to and separated by a gap width from an adjacent extension of the at least one extensions of the output electrode. In some embodiments, the at least one extension of the input or output electrodes has a width that can changes from a first end of the at least one extension to a second end.

Abstract: An acoustic wave device includes a substrate, as well as a first electrode layer, a piezoelectric layer and a second electrode layer which are sequentially arranged on the substrate. The device further includes a protective layer. The protective layer is at least arranged at a first position above the surface, far away from the substrate, of the second electrode layer. The first position is a position, corresponding to a first overlapping region, above the second electrode layer. The first overlapping region, where an active area of the acoustic wave device is located, is at least a part of a region where the first electrode layer, the second electrode layer and the piezoelectric layer are overlapped. A fabrication method for an acoustic wave device is also provided.

Abstract: In a surface acoustic wave filter according to an embodiment, a thickness of a piezoelectric crystal substrate bonded over a support substrate made of an oxide crystal is 0.05 to 0.5 ?m, and an odd-order harmonic is used.

Abstract: Surface acoustic wave device having mass-loaded electrode. In some embodiments, a surface acoustic wave device for providing resonance of a surface acoustic wave having a wavelength ? can include a quartz substrate and a piezoelectric plate formed from LiTaO3 or LiNbO3 disposed over the quartz substrate. The piezoelectric plate can have a thickness greater than 2?. The surface acoustic wave device can further include an interdigital transducer electrode formed over the piezoelectric plate. The interdigital transducer electrode can have a mass density ? in a range 1.50 g/cm3<??6.00 g/cm3, 6.00 g/cm3<??12.0 g/cm3, or 12.0 g/cm3<??23.0 g/cm3, and a thickness greater than 0.148?, greater than 0.079?, or greater than 0.036?, respectively.

Abstract: The present disclosure provides a bulk acoustic wave resonator, a manufacturing method thereof, and a filter, wherein the bulk acoustic wave resonator includes: a substrate; an acoustic reflection unit on the substrate; a piezoelectric stack structure on the acoustic reflection unit; and a pad on the piezoelectric stack structure; wherein the pad has an overlapping region with the acoustic reflection unit. The acoustic wave resonator, the manufacturing method thereof and the filter of the present disclosure can effectively reduce connection resistance of the bulk acoustic wave resonator, thereby reducing insertion loss of the filter.

Abstract: Acoustic filters are disclosed. A bandpass filter has a passband between a lower band edge and an upper band edge. The bandpass filter includes a plurality of transversely-excited film bulk acoustic resonators (XBARs) connected in a ladder filter circuit. The plurality of XBARs includes at least one lithium tantalate XBAR and at least one lithium niobate XBAR.

Abstract: 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.

Abstract: A bulk-acoustic wave resonator includes: a resonator comprising a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion disposed along a periphery of the central portion; and an insertion layer disposed below the piezoelectric layer in the extension portion to raise the piezoelectric layer. The insertion layer may have a first inclined surface formed along a side surface facing the central portion, and the first electrode may have a second inclined surface extending from a lower end of the first inclined surface of the insertion layer.

Abstract: A duplexer includes elastic wave resonators disposed on a piezoelectric substrate to define a ladder elastic wave filter including shunt-arm resonators and series-arm resonators. The duplexer includes an inductance component connected between an antenna terminal and a ground potential. A transmitting filter includes the ladder elastic wave filter. The inductance component is disposed outside a short side of the piezoelectric substrate such that the electromagnetic coupling between the shunt-arm resonator located closest to a transmitting terminal in the ladder circuit configuration, and the inductance component is stronger than the electromagnetic coupling between the inductance component and the remaining shunt-arm resonators.

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 SAW filter includes a substrate including a piezoelectric substrate, a transmission filter, and an additional resonator. The transmission filter is a ladder-type filter filtering signals from a transmission terminal and outputting the result to an antenna terminal. Further, the transmission filter includes one or more serial resonators and one or more parallel resonators which are connected in a ladder configuration on the piezoelectric substrate. An initial stage resonator is the serial resonator. The additional resonator includes an IDT electrode on the piezoelectric substrate. The IDT electrode is connected to the transmission terminal at a stage before the transmission filter and is connected to any of the one or more GND terminals. In the additional resonator, a resonance frequency and an antiresonance frequency are located outside of a passband of the transmission filter.

Abstract: There are disclosed acoustic diplexers and radios incorporating the acoustic diplexers. A diplexer includes common port, a low band port, a high band port, n low band sub-filters, and n high band sub-filters, where n is an integer greater than one. Each low band sub-filter has a first sub-filter port connected to the common port and a second sub-filter port connected to the low band port. Each high band sub-filter has a first sub-filter port connected to the common port and a second sub-filter port connected to the high band port. A first acoustic resonator is connected from the common port to ground and a second acoustic resonator is connected from the low band port to ground. The first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of a passband of the diplexer.

Abstract: A multiplexer includes a transmit filter circuit, a receive filter circuit, and an additional circuit connected in parallel with a portion of the transmit filter circuit. The transmit filter circuit includes series resonators on a signal path connecting a common terminal and a first terminal, and parallel resonators on the signal path between a node and ground. The series resonator closest to the first terminal includes split resonators. The additional circuit includes a capacitor and a resonator group. The resonator group includes IDT electrodes side by side in the direction of acoustic wave propagation. A first end of the resonator group is connected to the common terminal with the capacitor interposed therebetween. A second end of the resonator group is connected to the signal path between two of the split resonators such that no capacitor is interposed between the second end and the signal path.

Abstract: A duplexer includes a duplexer package having a transmit terminal, an antenna terminal, a receive terminal and at least one package ground terminal, a transmit filter disposed within the duplexer package, and a receive filter disposed within the duplexer package. Coupled first and second inductors, the first inductor connected to the transmit filter and the second inductor connected to the receive filter, are configured to cancel, at least in part, RF signal leakage between the transmit filter and the receive filter.

Abstract: A filter circuit has a first frequency band as a pass band and a second frequency band as an attenuation band. The filter circuit includes a 90-degree hybrid coupler, a first filter that is connected to the 90-degree hybrid coupler and has the first frequency band as a pass band, and a second filter that is connected to the 90-degree hybrid coupler and has the second frequency band as a pass band. The second filter includes a first inductor, a resonant circuit, and a second inductor connected in series in this order, a first capacitive element connected between a node on a signal path connecting the first inductor and the resonant circuit and a ground electrode, and a second capacitive element connected between a node on a signal path connecting the second inductor and the resonant circuit and a ground electrode.

Abstract: An antenna module includes a multilayer substrate having a first main surface and a second main surface opposing to each other, a patch antenna formed on a side of the first main surface of the multilayer substrate and configured with a radiation electrode and a ground electrode, an RFIC formed on a side of the second main surface of the multilayer substrate, a first filter, and a second filter different from the first filter, wherein the patch antenna has a first feed point and a second feed point provided at different positions in the radiation electrode, the first feed point is electrically connected to the RFIC via the first filter, the second feed point is electrically connected to the RFIC via the second filter, and the first filter and the second filter are formed in the multilayer substrate.

Abstract: A high-frequency device includes: a circuit substrate including dielectric layers that are stacked, wiring patterns located on at least one of the dielectric layers, and a passive element formed of at least one of the wiring patterns, the circuit substrate having a first surface that is a surface of an outermost dielectric layer in a stacking direction of the dielectric layers; a terminal for connecting the high-frequency device to an external circuit, the terminal being located on the first surface and electrically connected to the passive element through a first path in the circuit substrate; and an acoustic wave element located on the first surface and electrically connected to the passive element through a second path in the circuit substrate.

Abstract: Acoustic wave devices are disclosed. An acoustic wave device can include a first filter and a second filter coupled to a common node. The second filter includes acoustic wave resonators of a first type (e.g., bulk acoustic wave resonators) and a series acoustic wave resonator of the second type (e.g., a surface acoustic wave resonator) that is coupled between the acoustic wave resonators of the first type and the common node. The acoustic wave device can further include a loop circuit coupled to the first filter, in which the loop circuit is configured to generate an anti-phase signal to a target signal at a particular frequency. In certain embodiments, the first filter is a receive filter and the second filter is a transmit filter.

Abstract: A communication module includes an input/output switch, a duplexer, a transmit filter, and a receive filter. In the duplexer, a second side is disposed at a position farther from the input/output switch than a first side in a second direction orthogonal to a first direction. Any one of the transmit filter and the receive filter is disposed adjacent to the input/output switch in the first direction.

Abstract: An acoustic wave device includes a first acoustic wave element including a first substrate having piezoelectricity at least in a portion thereof, a first functional electrode provided on a first surface of the first substrate, and a first wiring conductor electrically connected to the first functional electrode. The first acoustic wave element further includes a relay electrode on the first surface of the first substrate and electrically connected to a second wiring conductor, and a ground electrode on the first surface of the first substrate and electrically connected to the first functional electrode. The ground electrode is between at least one of the first functional electrode and the first wiring conductor, and the relay electrode, and is electrically insulated from the relay electrode.

Abstract: A electronic component includes a connection electrode on a wiring layer. An electrically conductive layer is connected to the wiring layer via the connection electrode. A protective film covers a cover portion and the electrically conductive layer. A solder bump is electrically connected to the electrically conductive layer via an opening. An alloy layer is between the solder bump and the electrically conductive layer in a thickness direction to join the solder bump to the electrically conductive layer and differs in composition and/or elements from the solder bump. The connection electrode does not overlap the solder bump. The surface of the electrically conductive layer that is located on a protective film side is in contact with the protective film between the alloy layer and an edge of the electrically conductive layer that is located on a connection electrode side.

Abstract: Provided is a multiplexer that includes a first filter (first transmission filter), a second filter (second reception filter), a third filter (third reception filter), a first inductor, and a second inductor. The first inductor is connected in series with one parallel arm resonator (second parallel arm resonator) of the first filter between the one parallel arm resonator and ground. The second inductor is connected in series with another parallel arm resonator (third parallel arm resonator) of the first filter between the other parallel arm resonator and ground. The first inductor and the second inductor have the same winding direction as each other from the first filter side toward the ground side thereof.

Abstract: Techniques are disclosed for forming integrated circuit film bulk acoustic resonator (FBAR) devices having multiple resonator thicknesses on a common substrate. A piezoelectric stack is formed in an STI trench and overgrown onto the STI material. In some cases, the piezoelectric stack can include epitaxially grown AlN. In some cases, the piezoelectric stack can include single crystal (epitaxial) AlN in combination with polycrystalline (e.g., sputtered) AlN. The piezoelectric stack thus forms a central portion having a first resonator thickness and end wings extending from the central portion and having a different resonator thickness. Each wing may also have different thicknesses from one another. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate. The end wings can have metal electrodes formed thereon, and the central portion can have a plurality of IDT electrodes patterned thereon.

Abstract: An acoustic wave filter device includes a plurality of acoustic wave resonators. Each of the acoustic wave resonators includes a piezoelectric layer and an IDT electrode provided on the piezoelectric layer. On a surface opposite to a surface of the piezoelectric layer on which the IDT electrode is provided, a low-acoustic-velocity film and a substrate made of a semiconductor are stacked. A routing line electrically connected to an antenna terminal is provided on an insulating film provided on the piezoelectric layer.

Abstract: A transmission filter includes a transmission filter circuit and an additional circuit. The transmission filter circuit defines a first signal path connecting a first terminal and a second terminal. The additional circuit is connected to a first node located between the first terminal and the transmission filter circuit on the first signal path and a second node located between the second terminal and the transmission filter circuit on the first signal path and defines a second signal path connecting the first node and the second node. The additional circuit includes, on the second signal path, a resonator group, a capacitive element, and an inductance element. The inductance element is electromagnetically coupled to the transmission filter circuit.

Abstract: An acoustic wave filter includes: a series-arm resonator disposed on a path that connects input/output terminals; and a parallel-arm circuit connected to a node on the path and a ground. The parallel-arm circuit includes a parallel-arm resonator and a capacitor connected in parallel to each other. The capacitor includes a comb-shaped electrode that includes electrode fingers. A frequency at which impedance of the capacitor has a local maximum value is located outside a passband of the acoustic wave filter. The comb-shaped electrode has at least two different electrode finger pitches or at least two different electrode finger duty ratios.

Abstract: Embodiments of the invention include an acoustic wave resonator (AWR) module. In an embodiment, the AWR module may include a first AWR substrate and a second AWR substrate affixed to the first AWR substrate. In an embodiment, the first AWR substrate and the second AWR substrate define a hermetically sealed cavity. A first AWR device may be positioned in the cavity and formed on the first AWR substrate, and a second AWR device may be positioned in the cavity and formed on the second AWR substrate. In an embodiment, a center frequency of the first AWR device is different than a center frequency of the second AWR device. In additional embodiment of the invention, the AWR module may be integrated into a hybrid filter. The hybrid filter may include an AWR module and other RF passive devices embedded in a packaging substrate.

Abstract: A phased antenna array system is provided that includes a beamforming integrated circuit and beamforming elements in communication with the integrated circuit disposed on a substrate. The beamforming integrated circuit includes multiple radio frequency (RF) signal ports. One or more of the RF signal ports includes an RF signal pad disposed between an edge of the integrated circuit and an internal RF ground pad. The RF signal pad and the internal RF ground pad of the RF signal port are oriented perpendicular with respect to the edge of the integrated circuit. Specifically, the RF signal pad has a first side disposed on or adjacent to the edge of the integrated circuit and an opposing second side that is adjacent to the internal RF ground pad. A method of controlling the phased antenna array system is also provided.

Abstract: A high-frequency module includes an antenna terminal, a transmission signal terminal, a reception signal terminal, a plurality of earth terminals, a switch, a transmission filter, a reception filter, and a multilayer board. The multilayer board includes a ground electrode arranged between the transmission filter and the reception filter. The plurality of earth terminals include a first earth terminal and a second earth terminal. When the high-frequency module is viewed in a direction perpendicular to a principal surface of the multilayer board, the reception signal terminal is provided between the antenna terminal and the transmission signal terminal, the first earth terminal is provided between the antenna terminal and the reception signal terminal, and the second earth terminal is provided between the reception signal terminal and the transmission signal terminal.

Abstract: An acoustic wave device includes a semiconductor substrate having a first main surface and a second main surface, a piezoelectric thin film provided directly on or indirectly above the first main surface of the semiconductor substrate, and an IDT electrode provided on the piezoelectric thin film. A semiconductor defining the semiconductor substrate is a high acoustic velocity material in which an acoustic velocity of a bulk wave propagating therethrough is higher than an acoustic velocity of an acoustic wave propagating through the piezoelectric thin film. The semiconductor substrate includes a first region including the first main surface and a second region which is a region other than the first region and includes the second main surface. An electric resistance of the first region is lower than an electric resistance of the second region.

Abstract: A filter device having a pass band and a stop band on a lower frequency side than the pass band includes a filter having a pass band including the pass band, a series arm resonator connected in series to the filter, a first inductor directly connected in series to the series arm resonator, and a parallel arm resonator connected between a node on a path connecting the filter and the series arm resonator and the ground. The parallel arm resonator constitutes a resonance circuit having a resonant frequency at which an attenuation pole corresponding to a high frequency end of the first stop band, and the series arm resonator and the inductor constitute a resonance circuit having an anti-resonant frequency on a lower frequency side than the pass band and having a sub-resonant frequency higher than a resonant frequency of the resonance circuit.

Abstract: One aspect of the present disclosure provides a quantum circuit assembly that includes a substrate with one or more qubit devices, and at least one demultiplexer included in a single chip with the qubit device(s). The demultiplexer is configured to receive a combined signal from external electronics, the combined signal including a combination of a plurality of signals in different frequency ranges, and to demultiplex said plurality of signals within the combined signal. The demultiplexer is further configured to apply different demultiplexed signals to different lines of a single qubit device, or/and to different qubit devices. Providing such demultiplexers on-chip with the qubit devices advantageously allows reducing the number of input/output lines coupling the chip with qubit devices and the external electronics.

Abstract: An acoustic wave device includes a first and second element substrates each having piezoelectricity, and bonding layers bonding the first and second element substrates to each other. First and second IDT electrodes and first and second wiring electrodes are respectively provided on the first and second element substrates. The first and second wiring electrodes are disposed one above the other with the bonding layer interposed therebetween to define a wiring electrode overlapped portion. In each of the wiring electrode overlapped portions, the first wiring electrode and the second wiring electrode are provided in one of combinations in which one wiring electrode is a signal wiring electrode and the other wiring electrode is a ground wiring electrode, both of the wiring electrodes are ground wiring electrodes, and both of the wiring electrodes are signal wiring electrodes at the same potential.

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: A filter device includes a piezoelectric substrate, first and second functional elements provided on a surface of the piezoelectric substrate, a first conductive layer provided on the surface of the piezoelectric substrate, the first conductive layer connecting the first and second functional elements to each other, an insulating layer provided at least on the first conductive layer, a cover that faces the surface of the piezoelectric substrate, a support layer located between the surface of the piezoelectric substrate and the cover, the support layer defining hollow portions, in which the first and second functional elements are provided, between the piezoelectric substrate and the cover, and a first conductor that connects the insulating layer to the cover.

Abstract: A detector arrangement, for selective detection of vibrations on a component, comprises a film fitted with at least one piezoelectric element. The film is attached to the component in such a way that occurring mechanical vibrations act on the piezoelectric element, such that an electrical charge with a frequency correlating with the mechanical vibration is generated at the connection electrodes of the piezoelectric element. An electrical filter is connected to the piezoelectric element and filters out the component of the supplied charge which corresponds to a predefined frequency. An electrical charge storage means which is connected to the filter is used to accumulate the filtered-out charge components. A signaling means is also provided, which generates an electrical signal as soon as a predetermined charge limit value is reached on the charge storage means.

Abstract: Film bulk acoustic resonator having suppressed lateral mode. In some embodiments, a film bulk acoustic resonator can include a piezoelectric layer having a first side and a second side, a first electrode having a first lateral shape implemented on the first side of the piezoelectric layer, and a second electrode having a second lateral shape implemented on the second side of the piezoelectric layer. The first and second lateral shapes can be selected and arranged to provide a resonator shape defined by an outline of an overlap of the first and second electrodes. The resonator shape can include N curved sections joined by N vertices of an N-sided polygon. The resonator shape can be configured to have no axis of symmetry.

Abstract: Acoustic resonators, such as bulk acoustic wave (BAW) resonators, are disclosed that include mode suppression structures. Acoustic resonators, including stacked crystal filters (SCFs), are disclosed that include spurious mode suppression by modifying a piezoelectric coupling profile within one or more layers of an SCF. Mode suppression configurations may include structures with one or more inverted polarity piezoelectric layers, one or more non-piezoelectric layers, one or more thicker electrodes of the SCF, and combinations thereof. Symmetric input and output electrical response for SCFs with mode suppression configurations may be exhibited by including piezoelectric materials with different electromechanical coupling values and/or by dividing stress profiles differently by configuring different thicknesses for input and output sides of SCFs.

Abstract: A filter (10) has a first passband and a second passband on a higher frequency side than the first passband and includes a series arm circuit (11) and a parallel arm circuit (12), wherein the parallel arm circuit (12) includes a parallel arm resonator (p1) connected between a node (x1) and ground and having a resonant frequency frp located between a first passband and a second passband, an inductor (L1) connected between the node (x1) and the ground, and an inductor (L2) connected between the node (x1) and the ground and connected in series to the parallel arm resonator (p1), and a circuit in which the parallel arm resonator (p1) and the inductor (L2) are connected in series is connected in parallel to the inductor (L1).

Abstract: An acoustic wave device includes a support substrate, an acoustic reflection film on the support substrate, a piezoelectric layer on the acoustic reflection film, the piezoelectric layer including first and second primary surfaces, and first and second flat-plate electrodes on the first and second primary surfaces of the piezoelectric layer. The acoustic reflection film includes high acoustic impedance layers and low acoustic impedance layers alternately stacked together. At least one layer of the high acoustic impedance and low acoustic impedance layers is a stack of layers of first and second materials having equal or substantially equal acoustic impedances for at least one of longitudinal acoustic impedance and transversal acoustic impedance. The interface between the layers of first and second materials has irregularities.

Abstract: A filter includes: series resonators disposed between an input terminal and an output terminal; and shunt resonators disposed at different nodes between the input terminal and the output terminal, wherein a resonance frequency and an antiresonance frequency of at least one series resonator among the series resonators are respectively located within a reference frequency range of a resonance frequency and an antiresonance frequency of the shunt resonators.

Abstract: A multiplexer includes first and second filters connected to a common terminal. The second filter has a pass band on a higher frequency side with respect to a pass band of the first filter. The first filter includes a series arm circuit, and a parallel arm circuit having a resonant frequency on a lower frequency side with respect to a frequency at a low frequency end of a pass band of the first filter, and the series arm circuit includes a series arm resonator having a resonant frequency in the pass band of the first filter and a series arm resonator that is electrically connected in parallel to the series arm resonator and that has a resonant frequency on a higher frequency side with respect to a frequency at a high frequency end of the pass band of the first filter.

Abstract: A vertically integrated circuit assembly may include a substrate including a plurality of electrical traces, and a first circuit assembly layer disposed on the substrate. In embodiments, the first circuit assembly layer includes a first set of integrated circuit components, and a plurality of electrical interconnects configured to route signals through the first circuit assembly layer. In embodiments, the vertically integrated circuit assembly further includes a second circuit assembly layer coupled to the top surface of the first circuit assembly layer. The second circuit assembly layer may include a second set of integrated circuit components, and a plurality of electrical interconnects configured to route signals through the second circuit assembly layer. In embodiments, an electrical interconnect arrangement on a top surface of the first circuit assembly layer is configured to interface with an electrical interconnect arrangement on the bottom surface of the second circuit assembly layer.