An electronic device comprises a first surface acoustic wave (SAW) resonator and a second SAW resonator, each including interleaved interdigital transducer (IDT) electrodes, the first and second SAW resonators being formed on a same piezoelectric substrate, the first SAW resonator having IDT electrodes with a different finger pitch than the IDT electrodes of the second SAW resonator; a dielectric material layer disposed on the IDT electrodes of the first and second SAW resonators; and a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes of the first SAW resonator, the second SAW resonator lacking a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes.

A surface elastic wave filter has resonant cavities and comprises a composite substrate formed of a base substrate and a piezoelectric upper layer; at least one input electroacoustic transducer and an output electroacoustic transducer, arranged on the upper layer, and at least one internal reflecting structure, arranged between the input electroacoustic transducer and the output electroacoustic transducer. The internal reflecting structure comprises a first structure comprising at least one reflection grating having a first period and a second structure comprising at least one reflection grating having a second period, the first period being greater than the second period.

A filter device including a first filter having a first passband, and a second filter having a second passband, the first and second filters each being connected between a common contact and a respective signal contact, and the filter device configured to reduce spurious emissions generated in one filter due to propagation of Lamb waves in the other filter. In one example the first filter includes a SAW filter formed on a piezoelectric substrate, a SAW resonator formed on the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film formed over the piezoelectric substrate covering the SAW filter and the SAW resonator. The dielectric film has a first thickness over the SAW filter and a second, lesser, thickness over the SAW resonator, a difference between the first and second thicknesses being selected to suppress spurious emissions in the second passband generated by propagation of a Lamb wave in the SAW filter.

A multiplexer includes a first filter on a first path connecting a common terminal and a first terminal and defined by a band pass filter, a low pass filter, or a high pass filter, and a second resonator on a second path connecting the common terminal and a second terminal and defined by a band elimination filter including at least one elastic wave resonator. A pass band of the first filter and an attenuation band of the second filter overlap with each other, and a ripple of a first resonator closest to the common terminal is generated only outside pass bands of the first filter and the second filter.

An elastic wave filter device includes a ladder filter that includes series arm resonators and parallel arm resonators. In one series arm resonator in which the acoustic velocity in a first and second edge area is lower than in a central area, each first electrode finger includes a large-width portion having a width larger than in remaining portions in the second edge area, and each second electrode finger includes a large-width portion having a width larger than in remaining portions in the first edge area. In at least one of remaining series arm resonators and the parallel arm resonators, each first and second electrode finger includes a large-width portion having a width larger than in remaining portions in both of the first and second edge areas.

An acoustic wave device includes a multilayer substrate including a reverse-velocity surface, a piezoelectric film, a low acoustic velocity material layer, a high acoustic velocity material layer, and an IDT electrode disposed on the piezoelectric film. In the IDT electrode, gap lengths of a first gap between a tip of each of first electrode fingers and a second busbar and a second gap between a tip of each of second electrode fingers and a first busbar are about 0.23 or shorter, the gap lengths extending in an extension direction of the first and second electrode fingers.

A quadplexer includes a first filter and a second filter having a pass band frequency that is higher than a pass band frequency of the first filter. The first filter includes series resonators disposed on a first path and parallel resonators disposed on a path that connects the first path and a ground to each other. A direction that connects ends of a plurality of electrode fingers defining each resonator crosses an elastic wave propagation direction at a predetermined angle. The series resonator nearest to a common terminal does not include first electrode fingers, and the other series resonators include the first electrode fingers.

An elastic wave device includes a piezoelectric film and a high acoustic velocity member in which an acoustic velocity of a bulk wave propagating in the high acoustic velocity member is larger than an acoustic velocity of a main mode elastic wave propagating in the piezoelectric film, the piezoelectric film that is directly or indirectly laminated on the high acoustic velocity member, a first conductive film provided on the piezoelectric film, and a second conductive film that is provided on the piezoelectric film and on at least a portion of the first conductive film. A plurality of IDT electrodes including electrode fingers and busbars are provided on the piezoelectric film, at least electrode fingers of a plurality of IDT electrodes are defined by the first conductive film, and at least a portion of connection wiring with which the plurality of IDT electrodes are connected to each other is defined the second conductive film.

An elastic wave device includes a piezoelectric substrate and IDT electrodes including first and second busbars and first and second electrode fingers. An intersection of the IDT electrodes includes a center region, and low-acoustic-velocity sections at both end portions of the center region in the direction in which the electrode fingers extend in the center region, sections in which the acoustic velocity is lower than in the center region. The length of the gap between the edge of the first electrode fingers and the second busbar and the length of the gap between the edge of the second electrode fingers and the first busbar are about 0.62 or more and about 0.98 or less, where denotes the wavelength, which is determined by the finger pitch of the IDT electrodes.

A SAW transducer and a SAW resonator are proposed composed of consecutively arranged unit cells of length L. Slight geometry or material variations such as variations of the metallization ration or the unit cell length L affecting the pitch) between these unit cells result in improved spurious mode suppression while the main mode performance is unaffected.