Abstract: An acoustic wave device includes a piezoelectric substrate, comb-shaped electrodes, wires, a sealing body, terminal electrodes, and connection electrodes. The comb-shaped electrodes are disposed on the piezoelectric substrate and are connected to the wires. The sealing body is disposed on the piezoelectric substrate in such a manner that the comb-shaped electrodes are sealed between the piezoelectric substrate and the sealing body. The terminal electrodes are disposed on the sealing body. The connection electrodes penetrate the sealing body so as to electrically connect the wires and the terminal electrodes, respectively. A first linear expansion coefficient in a first temperature range below a first glass transition temperature of the sealing body is larger than a second linear expansion coefficient in a second temperature range above the first glass transition temperature.

Abstract: An acoustic wave device includes a piezoelectric substrate made of a lithium niobate material having the Euler angles (?, ?, ?), an electrode disposed on the piezoelectric substrate for exciting a major acoustic wave of a wavelength ?, and a protective layer disposed on the piezoelectric substrate to cover the electrode. The protective layer has a thickness greater than 0.27?. The Euler angles satisfy ?100°????60°; 1.193??2°???1.193?+2°; and either ???2??3° or ?2?+3°??.

Abstract: An antenna duplexer has a first filter passing a signal in a first frequency band and a second filter passing a signal in a second frequency band which is higher than the first frequency band. The first filter includes a first series resonator having a lowest antiresonance frequency and second series resonators. A propagation angle of a main elastic wave of the first series resonator a propagation angle of a main elastic wave of each of the second series resonators are different from each other so that an electromechanical coupling coefficient of the first series resonator is smaller than an electromechanical coupling coefficient of the second series resonators.

Abstract: An object of the present disclosure is to provide an elastic wave resonator having a high Q value, and producing little or no unwanted spurious signals. In order to achieve the object, an elastic wave resonator according to the present disclosure includes a piezoelectric substrate and an IDT electrode. The IDT electrode has an apodization-weighting portion in which a staggered section width decreases toward an end portion of the IDT electrode in an elastic wave propagation direction. The electrode finger pitch of the IDT electrode decreases toward an end portion of the IDT electrode in an end portion, in the elastic wave propagation direction, of a staggered region of the IDT electrode.

Abstract: An acoustic wave device includes a first longitudinally-coupled acoustic wave filter having interdigital transducer (“IDT”) electrodes arranged in a propagation direction of acoustic wave, and a second longitudinally-coupled acoustic wave filter having IDT electrodes arranged in a propagation direction of acoustic wave. In the IDT electrodes of the first longitudinally-coupled acoustic wave filter, a comb-shaped electrode connected to an input port and another comb-shaped electrode connected to an output port are disposed in an in-phase relation. In the IDT electrodes of the second longitudinally-coupled acoustic wave filter, a comb-shaped electrode connected to an input port and another comb-shaped electrode connected to an output port are disposed in an anti-phase relation. This acoustic wave device has an excellent attenuation characteristic while maintaining a preferable insertion loss.

Abstract: An elastic wave device includes an interdigital transducer (IDT) electrode disposed on an upper surface of a piezoelectric substrate, a wiring electrode disposed on the upper surface of the piezoelectric substrate and connected to the IDT electrode, and a first insulator layer disposed on the upper surface of the piezoelectric substrate. The first insulator layer seals the IDT electrode and the wiring electrode and includes a first resin and a first filler. A resin layer including no filler is provided on an upper surface of the first insulator layer. An inductor electrode is disposed on an upper surface of the resin layer. A second insulator layer is disposed on the upper surface of the resin layer and covers the inductor electrode. A terminal electrode is disposed on an upper surface of the second insulator layer. A connecting electrode electrically connects the wiring electrode, the terminal electrode, and the inductor electrode.

Abstract: An antenna duplexer includes first and second filters connected to an antenna terminal. The first filter has a passband of a low frequency band. The second filter has a passband of a high frequency band. The second filter is a ladder-type filter including series-arm resonators and parallel-arm resonators. At least one parallel-arm resonator out of the parallel-arm resonators has a main resonance and an auxiliary resonance. Attenuation poles caused by the main resonance and the auxiliary resonance are within the low frequency band. This antenna duplexer has a high attenuation characteristic and a high isolation characteristic while maintaining a low insertion loss.

Abstract: A reflector of the elastic wave resonator in an elastic wave device has first and second regions. The second region has third and fourth regions. The first region is located near to the IDTs of the reflector, while the second region is located farther from them. The third region is located nearer to the IDTs in the second region, while the fourth region is located farther from them. As a result that the center frequency of the reflection band in the fourth region is lower than that in the third region, an elastic wave device with low energy loss and insertion loss is provided.

Abstract: An elastic wave device includes a piezoelectric substrate, a pair of reflectors disposed on the piezoelectric substrate along the propagation direction of an elastic wave, and first to fifth comb electrode pairs disposed in this order between the pair of reflectors. Ground comb electrodes of adjacent comb electrode pairs are connected by an even number of connection electrode fingers or by an odd number of connection electrode fingers.

Abstract: An electronic device includes a main circuit connected between an input terminal and an output terminal, and an auxiliary circuit connected in parallel to the main circuit between the input terminal and the output terminal. The main circuit includes a filter having a first passband and a stopband. The auxiliary circuit has a passing characteristic that allows a signal having a frequency in a certain frequency band inside the stopband to pass through the auxiliary circuit. The main circuit is configured to output a main signal in response to an input signal. The auxiliary circuit is configured to output an auxiliary signal in response to the input signal. The main signal and the auxiliary signal contain phase components opposite to each other in the certain frequency band inside the stopband. This electronic device has an attenuation amount in the stopband.

Abstract: A ladder-type surface acoustic wave filter includes a first series resonator having the lowest resonance frequency among a plurality of series resonators; and a second series resonator having a resonance frequency higher than the first series resonator. The film thickness of a dielectric film in the region where the first series resonator is formed is larger than that of a dielectric film in the region where the second series resonator is formed.

Abstract: An elastic wave filter includes first and second longitudinally coupled elastic wave filters. The first filter includes a first pair of grating reflectors, first to fifth IDT electrodes arranged in ordinal order between the grating reflectors along a propagation direction of elastic waves, a first unbalanced terminal, and first and second balanced terminals. The second filter has a second unbalanced terminal, and third and fourth balanced terminals, the first and second unbalanced terminals being electrically connected to each other, the first and third balanced terminals being electrically connected to a first JO terminal, and the second and fourth balanced terminals being electrically connected to a second JO terminal. The first and second balanced terminals, and the third and fourth balanced terminals, output signals opposite in phase to each other. A first signal at the first JO terminal is opposite in phase to a second signal at the second IO terminal.

Abstract: An elastic wave device includes a first unbalanced terminal, a second unbalanced terminal, a first balanced terminal, a second balanced terminal, a first filter part, and a second filter part. A phase of an electric signal transmitted from first unbalanced terminal to the first balanced terminal in the first filter part is different from a phase of an electric signal transmitted from the second unbalanced terminal to the first balanced terminal in the second filter part. A phase of an electric signal transmitted from the first unbalanced terminal to the second balanced terminal in the first filter part is different from a phase of an electric signal transmitted from the second unbalanced terminal to the second balanced terminal in the second filter part.

Abstract: Assigning multiple functions to a PA and simplifying wiring and circuits are achieved without using switches in a transmission-and-reception system using a high-frequency filter that supports multiple bands. Provided is a high-frequency filter including: first and second transmission filters; first and second reception filters; and a matching circuit connected to input sides of the first and second transmission filters. Transmission signals are inputted to the first and second transmission filters via the matching circuit. A resonator forming the matching circuit is serially connected to an input side of, among the first and second transmission filters, a filter whose passband is a higher frequency band.

Abstract: An acoustic wave device is provided with a low-frequency side filter having a low-frequency side passband, a high-frequency side filter having a high-frequency side passband, and first and second balanced terminals. The low-frequency side filter is connected to a first unbalanced terminal. The low-frequency side passband is a frequency band from a first minimum frequency to a first maximum frequency. The high-frequency side filter is connected to a second unbalanced terminal. The high-frequency side passband is a frequency band from a second minimum frequency to a second maximum frequency. The low-frequency side filter includes a first longitudinally-coupled acoustic wave resonator and a first one-terminal pair acoustic wave resonator connected in series to the first longitudinally-coupled acoustic wave resonator. An antiresonant frequency of the first one-terminal pair acoustic wave resonator is set to be higher than the first maximum frequency and lower than the second minimum frequency.

Abstract: An elastic wave element includes a piezoelectric substrate, an IDT electrode, and a first dielectric film. The IDT electrode includes a first bus bar electrode, a second bus bar electrode, first electrode fingers, and second electrode fingers. The piezoelectric substrate includes a bus bar electrode region, an alternately disposed region, and an intermediate region. The first dielectric film is formed in at least a part of the intermediate region, and formed of a medium in which acoustic velocity of a transverse wave propagating in the first dielectric film is lower than acoustic velocity of a main elastic wave in the alternately disposed region.

Abstract: An elastic wave device includes a piezoelectric substrate, an IDT electrode disposed on the piezoelectric substrate, a wiring electrode disposed on the piezoelectric substrate and connected to the IDT electrode, a first insulator disposed on the piezoelectric substrate to seal the IDT electrode and the wiring electrode, a resin layer provided on the first insulator, an inductor electrode disposed on the resin layer, a second insulator disposed on the resin layer to cover the inductor electrode, a terminal electrode disposed on the second insulator, and a connecting electrode passing through the first insulator, the second insulator, and the resin layer to electrically connect the wiring electrode, the terminal electrode, and the inductor electrode. The first insulator includes a resin and filler dispersed in the resin. A density of filler in the resin layer is smaller than an average density of the filler in the first insulator.

Abstract: The present invention is an acoustic wave device including first and second acoustic wave resonators. A first tilt angle that is an angle formed between a direction perpendicular to a direction in which electrode fingers of the first acoustic wave resonator extend and a direction along which the electrode fingers are arranged is different from a second tilt angle that is an angle formed between a direction perpendicular to a direction in which electrode fingers of the second acoustic wave resonator extend and a direction along which the electrode fingers are arranged.

Abstract: In a filter module capable of handling multiple bands, cross wiring with an RF-IC is to be solved. The filter module includes: an antenna terminal; first and second transmission filters; first and second reception filters; a first switch circuit connected to the antenna terminal, and selectively connected to the first and second transmission filters; a second switch circuit connected to the antenna terminal, and selectively connected to the first and second reception filters; a first matching circuit connected between the first switch circuit and the first transmission filter or between the second switch circuit and the first reception filter; and a second matching circuit connected between the first switch circuit and the second transmission filter or between the second switch circuit and the second reception filter.

Abstract: An acoustic wave device includes a piezoelectric substrate, a first wiring disposed on an upper surface of the piezoelectric substrate, an organic insulator covering at least a portion of the first wiring, a second wiring disposed on a first portion of the upper surface of the organic insulator, and an inorganic insulator covering at least a second portion of an upper surface of the organic insulator. The second portion of the upper surface of the organic insulator faces an oscillation space across the inorganic insulator. The acoustic wave device has preferable high-frequency characteristics and high long-term reliability.