Acoustic wave devices and interdigital transducer (IDT) arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein that provide sharp transitions between passband frequencies and frequencies that are outside of desired passbands. A SAW device may include several IDTs arranged between reflective structures on a piezoelectric material and one or more additional IDTs or electrode pairs that are configured to modify the influence of parasitic capacitance, or other internal device capacitance, thereby improving steepness on the upper side of a passband as well as improving rejection for frequencies outside of the passband. The one or more additional IDTs or electrode pairs may be configured as at least one of a capacitor, an IDT capacitor, an IDT with a floating electrode, or combinations thereof.

An acoustic wave device includes first to third acoustic wave resonators connected in series, and the first acoustic wave resonator and the third acoustic wave resonator are respectively disposed on one side and another side of the second acoustic wave resonator. In the first to third acoustic wave resonators, a first common busbar is connected to one of reflectors of the first and second acoustic wave resonators, and a second common busbar is connected to one of reflectors of the second and third acoustic wave resonators.

An acoustic wave element includes an IDT electrode includes pluralities of electrode fingers, and reflector electrodes on the two sides of the IDT electrode. The IDT electrode includes a major part and at least one end part which is located between the major part and one of the reflector electrodes and is arranged along a direction of propagation of an acoustic wave together with the major part. the at least one end part includes a pitch of the plurality of electrode fingers substantially the same as a pitch of the plurality of electrode fingers in the major part, is electrically connected in parallel with respect to the major part, and is divided into two or more sections which are electrically connected in series with each other.

Acoustic wave devices and interdigital transducer (IDT) arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein that provide sharp transitions between passband frequencies and frequencies that are outside of desired passbands. A SAW device may include several IDTs arranged between reflective structures on a piezoelectric material and one or more additional IDTs or electrode pairs that are configured to modify the influence of parasitic capacitance, or other internal device capacitance, thereby improving steepness on the upper side of a passband as well as improving rejection for frequencies outside of the passband. The one or more additional IDTs or electrode pairs may be configured as at least one of a capacitor, an IDT capacitor, an IDT with a floating electrode, or combinations thereof.

An acoustic wave device includes a first acoustic wave filter including a first piezoelectric substrate and first resonators on the first piezoelectric substrate, and a second acoustic wave filter including a second piezoelectric substrate and second resonators on the second piezoelectric substrate. The first and second resonators are opposed to each other with a gap therebetween. The first and second resonators each include a heat-generation resonator in which a heat generation range has a highest temperature at a time of signal application. The heat generation ranges of the heat-generation resonators do not overlap each other in plan view.

An acoustic wave device includes first to third acoustic wave resonators connected in series, and the first acoustic wave resonator and the third acoustic wave resonator are respectively disposed on one side and another side of the second acoustic wave resonator. In the first to third acoustic wave resonators, a first common busbar is connected to one of reflectors of the first and second acoustic wave resonators, and a second common busbar is connected to one of reflectors of the second and third acoustic wave resonators.

Acoustic wave device includes: a piezoelectric substrate; a first IDT located on the piezoelectric substrate; and a second IDT located on the piezoelectric substrate and connected in series to the first IDT, wherein the first IDT and the second IDT share a single common bus bar as a first bus bar of two bus bars of the first IDT and a first bus bar of two bus bars of the second IDT, and the common bus bar has a width not more than two times a wavelength of an acoustic wave propagating through the first and second IDTs, the common bus bar connects to no dummy electrode finger facing a tip of an electrode finger connected to a second bus bar of the two bus bars of the first IDT and the second IDT across a gap.

An elastic wave resonator includes series divided resonators on a piezoelectric substrate, first and second outer busbars, a first interstage busbar, first to fourth electrode fingers and first and second dummy electrode fingers. Third dummy electrode fingers are not provided at at least one of a side where the second electrode fingers are provided and a side where the third electrode fingers are provided or third dummy electrode fingers having a length smaller than lengths of the first and second dummy electrode fingers are provided at at least one of a side where the second electrode fingers are provided and a side where the third electrode fingers are provided. The third electrode fingers are arranged on an extension to which the second electrode fingers extend.

A filter body has a series arm including a plurality of series resonators connected in series with one another and one or more parallel resonators in such a manner that the series arm and the parallel resonators are connected in a ladder form. The series arm has a bent part, and when viewed from an elastic wave propagation direction, a series resonator located closest to a first terminal from a circuit perspective among the plurality of series resonators and a parallel resonator located closest to the first terminal from a circuit perspective among the plurality of parallel resonators do not overlap a series resonator located closest to a second terminal from a circuit perspective among the plurality of series resonators and a parallel resonator located closest to the second terminal from a circuit perspective among the plurality of parallel resonators.

An elastic wave resonator includes a first, second and third reflectors. The first reflector is between a portion including a first IDT electrode and a third IDT electrode and a portion including a second IDT electrode and a fourth IDT electrode and is shared by the first to fourth IDT electrodes. The second reflector is shared by the first and third IDT electrodes. The third reflector is shared by the second and fourth IDT electrodes. The first and third IDT electrodes share a first common busbar. The second and fourth IDT electrodes share a second common busbar. The first and second common busbars are connected to the first reflector. A first busbar, a second busbar, a third busbar, and a fourth busbar of the respective first to fourth IDT electrodes are electrically connected to each other.