An acoustic wave device includes a plurality of interdigital transducer electrodes, in a first interdigital transducer electrode, a first electrode finger includes a wide portion having a greater width in the second direction than a center portion. In the first interdigital transducer electrode, for the first electrode finger, a first distance that is a maximum distance in the second direction between a center line of the center portion in a first direction is shorter than a second distance that is a maximum distance in a second direction between the center line of the center portion and an outer edge, away from a second interdigital transducer electrode, of the wide portion.

An acoustic wave device includes an interdigital transducer electrode connected to first and second terminals, and a reflector connected to the second terminal. In a group of electrode fingers of the interdigital transducer electrode, the electrode fingers at one end and another end in a second direction are respectively first and second end electrode fingers, the first end electrode finger includes a wide portion at a distal end portion. The first end electrode finger is located between the reflector and the second end electrode finger in the second direction. An inner busbar portion of one of first and second busbars not connected to the first end electrode finger, is located on an inner side in the second direction relative to the wide portion of the first end electrode finger so as not to overlap the wide portion of the first end electrode finger in a first direction.

A filter includes: a piezoelectric substrate; a first acoustic wave resonator located on the piezoelectric substrate and including a pair of first reflectors including first grating electrodes and a pair of first comb-shaped electrodes that is located between the first reflectors and includes first electrode fingers; and a second acoustic wave resonator that is connected in series or parallel with the first acoustic wave resonator, is located on the piezoelectric substrate, and includes a pair of second reflectors including second grating electrodes and a pair of second comb-shaped electrodes that is located between the second reflectors and includes second electrode fingers, an average value of duty ratios of the second grating electrodes being different from an average value of duty ratios of the first grating electrodes, an average value of pitches of the second electrode fingers being substantially equal to an average value of pitches of the first electrode fingers.

Multi-mode surface acoustic wave filters are disclosed. A multi-mode surface acoustic wave filter can include a plurality of interdigital transducer electrodes that are longitudinally coupled to each other and slanted acoustic reflectors on opposing sides of the plurality of interdigital transducer electrodes. The acoustic reflectors include acoustic reflector fingers with slanted pitches.

Multi-mode surface acoustic wave filters are disclosed. A multi-mode surface acoustic wave filter can include a plurality of interdigital transducer electrodes that are longitudinally coupled to each other and acoustic reflectors on opposing sides of the plurality of interdigital transducer electrodes. The acoustic reflectors include acoustic reflector fingers arranged to suppress a spurious response due to shear horizontal mode of the multi-mode surface acoustic wave filter. For example, the acoustic reflector fingers can include stepped lengths and/or slanted pitches to suppress the spurious response due to shear horizontal mode.

Multi-mode surface acoustic wave filters are disclosed. A multi-mode surface acoustic wave filter can include a plurality of interdigital transducer electrodes that are longitudinally coupled to each other and stepped acoustic reflectors on opposing sides of the plurality of interdigital transducer electrodes. The acoustic reflectors include acoustic reflector fingers with stepped lengths.

An acoustic wave device includes a piezoelectric substrate, an interdigital transducer (IDT) electrode provided on the piezoelectric substrate, and a pair of reflectors provided on both sides of the IDT electrode in a first direction on the piezoelectric substrate, the first direction being a propagation direction of an acoustic wave. The pair of reflectors include a plurality of electrode fingers and a plurality of electrode fingers, respectively, which extend in a second direction, the second direction being perpendicular to the first direction. The electrode finger widths of second end portions are greater than the electrode finger widths of first end portions. The electrode finger width at any given position in the electrode fingers is equal to or greater than the electrode finger width at a position closer than the given position to the first end portions.

Aspects of this disclosure relate to a surface acoustic wave device with a vertical stack over a piezoelectric layer. The vertical stack can include a first acoustic reflector disposed on the piezoelectric layer, a second acoustic reflector disposed on the piezoelectric layer, and an interdigital transducer electrode disposed on the piezoelectric layer and positioned between the first acoustic reflector and the second acoustic reflector. The interdigital transducer electrode has a first side that is closer to the first acoustic reflector and a second side that is closer to the second acoustic reflector. A vertical arrangement of the vertical stack can be configured such that an acoustic wave propagation velocity of a first region between the first side and a first reflector is faster than an acoustic wave propagation velocity of a second region between the first side and the second side.

An acoustic wave device comprises a piezoelectric substrate, interdigital transducer electrodes having an electrode pitch .sub.0, and first and second reflector gratings disposed on opposite respective sides of the interdigital transducer electrodes in a propagation direction of a main acoustic wave through the acoustic wave device, the first reflector grating having a different electrode pitch .sub.1 than an electrode pitch .sub.2 of the second reflector grating to suppress ripples in a conductance curve of the acoustic wave device.

A superconducting device that mixes surface acoustic waves and techniques for fabricating the same are provided. A superconducting device can comprise a first surface acoustic wave resonator comprising a first low-loss piezo-electric dielectric substrate. The superconducting device can also comprise a second surface acoustic wave resonator comprising a second low-loss piezo-electric dielectric substrate. Further, the superconducting device can comprise a Josephson ring modulator coupled to the first surface acoustic wave resonator and the second surface acoustic wave resonator. The Josephson ring modulator is a dispersive nonlinear three-wave mixing element.