An electronic device according to an embodiment includes: an antenna, a filter configured to pass a signal of a specific frequency band among signals transmitted and received through the antenna, and a processor configured to control the filter to pass the signal of the specific frequency band. The filter includes: a first substrate, a second substrate facing the first substrate, a first group of electrodes disposed inside the first substrate, a second group of electrodes disposed inside the second substrate, a first transducer electrode including a first group of lines, a second transducer electrode including a second group of lines disposed to alternate with the first group of lines, and a power supply configured to apply voltages to the first group of electrodes and the second group of electrodes. The processor is configured to cause at least one of the second group of lines to be separated from the first substrate, by controlling the power supply based on a frequency of a signal to be passed through the filter.

Aspects of this disclosure relate to an acoustic wave device with transverse mode suppression. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode, a temperature compensation layer, and a mass loading strip. The mass loading strip can overlap edge portions of fingers of the interdigital transducer electrode. The mass loading strip can have a sidewall that is tapered inwardly from a bottom side of the mass loading strip to a top side of the mass loading strip. The top side can be shorter than the bottom side.

An acoustic wave filter includes at least three segmented resonator devices connected in series to one another and aligned in a direction that crosses an acoustic wave propagation direction and each including an InterDigital Transducer (IDT) electrode, and centers of respective IDT electrodes of an adjacent pair of the at least three segmented resonator devices in the acoustic wave propagation direction are not aligned when seen from a direction orthogonal to the acoustic wave propagation direction.

An elastic wave device includes a piezoelectric substrate made of LiNbO.sub.3, an IDT electrode on the piezoelectric substrate, and a dielectric film on the piezoelectric substrate and covering the IDT electrode. The IDT electrode includes a first electrode layer on or above the piezoelectric substrate and including W or an alloy including W, and a second electrode layer on or above the first electrode layer. A thickness of the first electrode layer is not smaller than 0.062λ, λ being a wavelength determined by a pitch of electrode fingers of the IDT electrode. The piezoelectric substrate has Euler angles of (0°± about 5°, θ, 0°± about 10°), ↓ being not smaller than 8° and not larger than 32°.

A multiplexer includes: a first filter connected between a common terminal and a first terminal; and a second filter connected between the common terminal and a second terminal, a passband of the second filter being higher than a passband of the first filter, the second filter including series resonators connected in series and parallel resonators connected in parallel between the common terminal and the second terminal, each of the parallel resonators including a pair of comb-shaped electrodes including electrode fingers and a pair of reflectors sandwiching the pair of comb-shaped electrodes therebetween and including grating bars, PR1>PD1 where PR1 represents an average pitch of the grating bars of a parallel resonator closest to the common terminal among the parallel resonators and PD1 represents an average pitch of the electrode fingers of the parallel resonator closest to the common terminal.

An acoustic wave device includes: a piezoelectric substrate: a pair of comb-shaped electrodes located on the piezoelectric substrate, each of the comb-shaped electrodes including a plurality of electrode fingers; a support substrate having protruding portions and/or recessed portions in a region overlapping with the pair of comb-shaped electrodes in plan view, the protruding portions and/or recessed portions being regularly arranged; and an insulating layer directly or indirectly bonded between the piezoelectric substrate and the support substrate, a boundary face between the insulating layer and the support substrate being provided along the protruding portions and/or the recessed portions.

An apparatus is disclosed for a surface-acoustic-wave filter with an electrical conductor having a floating potential. In an example aspect, the apparatus includes a surface-acoustic-wave filter with a piezoelectric layer and an electrode structure disposed on a surface of the piezoelectric layer. The electrode structure includes a first comb-shaped structure and a second comb-shaped structure. The electrode structure also includes at least one electrical conductor positioned between the first comb-shaped structure and the second comb-shaped structure such that a gap separates the at least one electrical conductor from the first comb-shaped structure and the second comb-shaped structure.

An acoustic wave device that includes a spinel layer, a piezoelectric layer and an interdigital transducer electrode on the piezoelectric layer is disclosed. The piezoelectric layer is disposed between the interdigital transducer electrode and the spinel layer. The acoustic wave device is configured to generate an acoustic wave having a wavelength of λ. The piezoelectric layer can have a thickness than is less than A. In some embodiments, the acoustic wave device can include a temperature compensating layer that is disposed between the piezoelectric layer and the spinel layer.

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.

An acoustic wave filter includes a longitudinally coupled resonator including IDT electrodes and a reflector. A standard deviation of a pitch deviation rate of at least one of the reflector and the IDT electrodes is greater than or equal to about 1.4%.