Abstract: According to the present disclosure, a passband filter is provided. The passband filter comprises a first connection, a second connection, and a third connection. One or more resonators of a first type are provided connected in series between the first connection and the second connection; and one or more resonators of a second type are provided connected from between the first connection and the second connection to the third connection. A radio-frequency front end module and wireless mobile device are also provided.

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: A high-frequency filter includes a first output to output a first signal, a first filter, a second filter, and a first matching circuit connected to an output of the first filter and to an output of the second filter. The first signal is provided to the first output from one of the output of the first filter and the output of the second filter via the first matching circuit. The first matching circuit includes a resonator connected in series between the first output and the output of only one of the first filter and the second filter.

Abstract: A filter device having improved attenuation and isolation characteristics. In one example the filter device has a common terminal, a first terminal, and a second terminal, and includes a first filter connected between the common terminal and the first terminal, a second filter connected between the common terminal and the second terminal, and an additional circuit including at least three IDT electrodes each connected to a respective one of a corresponding at least three connection points within the filter device, the at least three connection points being selected from a group consisting of the common terminal, the first terminal, the second terminal, a first node disposed between the plurality of first filter elements along a path extending between the common terminal and the first terminal, and a second node disposed between the plurality of second filter elements along a path extending between the common terminal and the second terminal.

Abstract: An acoustic wave element comprising a lithium tantalate substrate having the Euler angles (?, ?, ?), a first component ? satisfying 10°???50°; and an electrode disposed on the lithium tantalate substrate and configured to excite a main acoustic wave of wavelength ?, the electrode having a density ?M satisfying ?M??Ti where ?Ti represents a density of titanium (Ti), and a thickness hM of the electrode satisfies 0.141×exp(0.075?M)??hM?0.134? Embodiments of the present disclosure minimize a thickness of the electrode and suppress a spurious Rayleigh wave signal.

Abstract: A ladder-type elastic wave filter includes an input terminal, an output terminal, and a ground terminal, a first series resonator and a second series resonator connected in series between the input terminal and the output terminal, and a first parallel resonator having a first terminal electrically connected to the series connection between the first series resonator and the second series resonator and a second terminal electrically connected to the ground terminal. A resonance frequency of the first parallel resonator is higher than a resonance frequency of both of the first series resonator and the second series resonator and lower than an antiresonance frequency of both of the first series resonator and the second series resonator.

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: A ladder-type surface acoustic wave filter assembly includes a plurality of series resonators formed on a substrate and connected between an input terminal and an output terminal. A first series resonator has a lowest resonance frequency among the plurality of series resonator. A parallel resonator formed on the substrate and connected between the plurality of series resonators and the ground terminal. A dielectric film is coupled to at least one of the plurality of series resonators and has an inverse temperature coefficient of frequency to that of the substrate. A film thickness of the dielectric film in a region where the second series resonator is formed is smaller than a film thickness of the dielectric film in a region where the first series resonator is formed.

Abstract: An elastic wave device includes an interdigital transducer (IDT) electrode in contact with a piezoelectric substrate having a bus bar electrode region including one of a first bus bar electrode and a second bus bar electrode of the IDT electrode, an alternately disposed region where first electrode fingers are alternately disposed with second electrode fingers of the IDT electrode, and an intermediate region including one of the first electrode fingers and the second electrode fingers. A dielectric film is formed in at least part of the intermediate region and in contact with an upper surface of the IDT electrode. The dielectric film includes a medium in which an acoustic velocity of a transverse wave propagating in the dielectric film is lower than an acoustic velocity of a main elastic wave of the alternately disposed region. The dielectric film is not formed in the alternately disposed region.

Abstract: An elastic wave filter has an unbalanced signal terminal, first and second balanced signal terminals, and first through fifth IDT electrodes arranged in ordinal order between a pair of grating reflectors. Wiring electrodes of the third and fifth IDT electrodes are disposed adjacent a ground electrode of the fourth IDT electrode, wiring electrodes of the second and third IDT electrodes are disposed adjacent one another, and ground electrodes of the first and second IDT electrodes are disposed adjacent one another. The unbalanced signal terminal is connected to the wiring electrodes of the first, third, and fifth IDT electrodes, and the first and second balanced signal terminals are connected to the wiring electrodes of the second and fourth IDT electrodes, respectively.

Abstract: A high-frequency filter including first and second signal terminals, a filter circuit having a passband and a stopband and being connected between the first signal terminal and the second signal terminal, and an additional circuit connected in parallel with the filter circuit between the first signal terminal and the second signal terminal. The filter circuit is configured to provide a first output signal responsive to receipt of an input signal. The additional circuit has an attenuation band within the stopband, and is configured to provide a second output signal responsive to receiving the input signal, the first and second output signals having phase components opposite to each other in the attenuation band.

Abstract: In an acoustic wave device, an unnecessary high-order transverse mode wave is suppressed. The acoustic wave device includes a piezoelectric substrate, at least one pair of interdigital transducer (IDT) electrodes formed on the piezoelectric substrate, and a dielectric film which covers at least a part of the piezoelectric substrate and the IDT electrodes. The IDT electrodes each have a plurality of electrode fingers interleaved with each other. An acoustic velocity of an acoustic wave in the area in which the electrode fingers are interleaved with each other is greater than an acoustic velocity of an acoustic wave in an edge area including end portions of the electrode fingers.

Abstract: A filter device having improved attenuation and isolation characteristics. In one example the filter device has a common terminal, a first terminal, and a second terminal, and includes a first filter connected between the common terminal and the first terminal, a second filter connected between the common terminal and the second terminal, and an additional circuit including at least three IDT electrodes each connected to a respective one of a corresponding at least three connection points within the filter device, the at least three connection points being selected from a group consisting of the common terminal, the first terminal, the second terminal, a first node disposed between the plurality of first filter elements along a path extending between the common terminal and the first terminal, and a second node disposed between the plurality of second filter elements along a path extending between the common terminal and the second terminal.

Abstract: A high-frequency filter including first and second signal terminals, a filter circuit having a passband and a stopband and being connected between the first signal terminal and the second signal terminal, and an additional circuit connected in parallel with the filter circuit between the first signal terminal and the second signal terminal. The filter circuit is configured to provide a first output signal responsive to receipt of an input signal. The additional circuit has an attenuation band within the stopband, and is configured to provide a second output signal responsive to receiving the input signal, the first and second output signals having phase components opposite to each other in the attenuation band.

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 multimode elastic wave device includes a pair of reflectors, and a first interdigital transducer (IDT) electrode through a fifth IDT electrode arranged between the pair of reflectors. In this configuration, each of the average of electrode-finger pitches in the first IDT electrode and the average of electrode-finger pitches in the fifth IDT electrode is smaller than both of the average of electrode-finger pitches in the second IDT electrode and the average of electrode-finger pitches in the fourth IDT electrode.

Abstract: In a ladder-type elastic wave filter, a resonance frequency of a second parallel resonator is higher than that of a series resonator and lower than an antiresonance frequency of a series resonator. With this configuration, an attenuation pole is formed by the second parallel resonator at a frequency region lower than an attenuation pole formed by the series resonator in a frequency region higher than the passband of the ladder-type elastic wave filter.

Abstract: In a ladder-type elastic wave filter, a resonance frequency of a second parallel resonator is higher than that of a series resonator and lower than an antiresonance frequency of a series resonator. With this configuration, an attenuation pole is formed by the second parallel resonator at a frequency region lower than an attenuation pole formed by the series resonator in a frequency region higher than the passband of the ladder-type elastic wave filter.

Abstract: An acoustic wave element comprising a lithium tantalate substrate having the Euler angles (?, ?, ?), a first component ? satisfying 10°???50°; and an electrode disposed on the lithium tantalate substrate and configured to excite a main acoustic wave of wavelength ?, the electrode having a density ?M satisfying ?M??Ti where ?Ti represents a density of titanium (Ti), and a thickness hM of the electrode satisfies 0.141×exp(0.075?M)??hM?0.134? Embodiments of the present disclosure minimize a thickness of the electrode and suppress a spurious Rayleigh wave signal.

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°??.