A transmission filter is arranged in a first filter region and has one or more acoustic wave resonators, a plurality of terminal electrodes, and a plurality of wires. A reception filter is arranged in a second filter region and has one or more acoustic wave resonators, a plurality of terminal electrodes, and a plurality of wires. The first filter region and the second filter region are arranged adjacently to each other and have at least sides constituting a pair and opposing to each other. At least either one of the first filter region and the second filter region has no wire extending along one side in a forbidden region that is defined by a width including a terminal electrode nearest to the one side, along the one side and over the one side opposing to the other filter region.

A transducer structure for a surface acoustic wave device, comprising a pair of inter-digitated comb electrodes, wherein the pair of inter-digitated comb electrodes comprises neighboring electrode means belonging to different comb electrodes and having a pitch p being defined as the edge-to-edge electrode means distance between two neighboring electrode means, the pitch p satisfying the Bragg condition; characterized in that the pair of inter-digitated comb electrodes comprises at least one region in which two or more neighboring electrode means belong to the same comb electrode while having an edge-to-edge distance to each other corresponding to the pitch p. The present disclosure relates also to a surface acoustic wave filter device.

A surface acoustic wave resonator device comprises a substrate supporting: a gateable, electrically conducting layer; an interdigital transducer (IDT); a reflector grating that comprises a plurality of electrically separated fingers; a main ohmic contact; and a gate element. The IDT is configured to be connectable to a ground. The conducting layer is configured to be connectable to the ground via the main ohmic contact, while each of said fingers is electrically connected to a lateral side of the conducting layer. This defines a gateable channel, which extends from the fingers to the ground via the conducting layer and the main ohmic contact. The gate element is electrically insulated from the conducting layer. The gate element is configured to allow an electrical impedance of the gateable channel to be continuously tuned by applying a voltage bias to this gate element with respect to the ground, in operation of the device.

An acoustic wave resonator includes: a piezoelectric substrate; and a pair of grating electrodes that is formed on the piezoelectric substrate, one of the pair of grating electrodes including a plurality of first electrode fingers having electric potentials equal to each other, another of the pair of grating electrodes including a plurality of second electrode fingers having electric potentials that differ from the electric potentials of the plurality of first electrode fingers and are equal to each other, two second electrode fingers of the plurality of second electrode fingers being located between at least a pair of adjacent first electrode fingers of the plurality of first electrode fingers, Pg differing from λ/4 where λ represents a wavelength of an acoustic wave excited by the plurality of first electrode fingers and the plurality of second electrode fingers and Pg represents a distance between centers of the two second electrode fingers.

A surface acoustic wave device includes a piezoelectric substrate and a pair of interdigital transducer electrodes. The pair of interdigital transducer electrodes include an alternating region as a region where the electrode fingers connected to one busbar and the electrode fingers connected to the other busbar are alternately provided. When a region on an end portion side of the alternating region and a region including distal end portions of the plurality of electrode fingers is referred to as an edge region, a propagation velocity of a surface acoustic wave in the edge region is slower than a propagation velocity of a surface acoustic wave in the alternating region. A propagation velocity of a surface acoustic wave in a busbar region as a region where the busbar is disposed is faster than the propagation velocity of the surface acoustic wave in the alternating region.

Aspects of the disclosure relate to an electroacoustic device that includes a piezoelectric material and an electrode structure that includes a first busbar and a second busbar along with electrode fingers arranged in an interdigitated manner and including a first plurality of fingers connected to the first busbar and a second plurality of fingers connected to the second busbar. The electrode structure further includes a first conductive structure disposed between each of the first plurality of fingers and disposed between the first busbar and the second plurality of fingers. The electrode structure further includes a second conductive structure disposed between each of the second plurality of fingers and disposed between the second busbar and the first plurality of fingers. The first conductive structure and the second conductive structure each have a height that is less than a height of the second plurality of fingers.

An elastic wave device includes a piezoelectric substrate, a first elastic wave element on the piezoelectric substrate and including at least one first interdigital transducer electrode and a first reflector in an area of the first interdigital transducer electrode at one side in a propagation direction of elastic waves, and a second elastic wave element on the piezoelectric substrate and including at least one second interdigital transducer electrode and a second reflector in an area of the second interdigital transducer electrode at one side in the propagation direction of elastic waves. The first and second reflectors are disposed side by side in the propagation direction. A reflection member, between the first and second reflectors, reflects elastic waves in at least a direction different from the propagation direction.

An acoustic wave filter includes series arm resonators and parallel arm resonators each including an acoustic wave resonator including an IDT electrode including a pair of comb-shaped electrodes each including electrode fingers and a busbar electrode. An electrode finger connected to neither of the busbar electrodes of the pair of comb-shaped electrodes is a floating withdrawal electrode, and of all the electrode fingers of the pair of comb-shaped electrodes, the electrode finger that is connected to a same busbar electrode to which the electrode fingers on both sides thereof are connected is a polarity-reversing withdrawal electrode, and, of the series arm resonators, the series arm resonator having a lowest anti-resonant frequency includes an IDT electrode including the floating withdrawal electrodes, and the series arm resonator includes an IDT electrode including the polarity-reversing withdrawal electrodes.

Aspects of the disclosure relate to an electroacoustic device that includes a piezoelectric material and an electrode structure. The electrode structure includes a first busbar and a second busbar. The electrode structure further includes electrode fingers arranged in an interdigitated manner and including a first plurality of fingers connected to the first busbar and a second plurality of fingers connected to the second busbar. A first distance between the first busbar and the second plurality of fingers and a second distance between the second busbar and the first plurality of fingers both being less than a pitch of the electrode fingers. The electrode fingers have a central region with a first trap region and a second trap region respectively located on boundaries of the central region. A structural characteristic of the electroacoustic device is different in the first trap region and the second trap region relative to the central region.

Aspects of the disclosure relate to an electroacoustic device that includes a piezoelectric material and an electrode structure. The electrode structure includes a first busbar and a second busbar. The electrode structure further includes a first conductive structure connected to the first busbar and a second conductive structure connected to the second busbar. The first conductive structure and the second conductive structure is disposed between the first busbar and the second busbar. The first conductive structure and the second conductive structure each include a plurality of conductive segments separated from each other and extending towards one of the first busbar or the second busbar. The electrode structure further includes electrode fingers arranged in an interdigitated manner and each connected to either the first conductive structure or the second conductive structure. The electrode fingers have a pitch that is different than a pitch of the plurality of conductive segments.