Surface acoustic wave (SAW) structures with transverse mode suppression are disclosed. In one aspect, the SAW structure provides digits or fingers with broad interior terminal end shapes. By providing such shapes spurious modes above the resonance frequency of the SAW are suppressed thereby providing desired out of band rejection that helps satisfy design criteria such as keeping a higher Q value, a higher K2 value and better Temperature Coefficient of Frequency (TCF).

An acoustic wave device includes a piezoelectric layer made of lithium niobate or lithium tantalate, and first and second electrodes opposed to each other in a direction that intersects with a thickness direction of the piezoelectric layer. The first and second electrodes are adjacent electrodes, and, when a thickness of the piezoelectric layer is d and a distance between centers of the first and second electrodes is p, d/p is less than or equal to about 0.5.

An acoustic wave device includes a piezoelectric substrate, a first interdigital transducer (IDT) electrode, reflectors on both sides of the first IDT electrode in a propagation direction of an acoustic wave, and a second IDT electrode facing the first IDT electrode with a reflector interposed therebetween. The first and second IDT electrodes include first and second intersecting areas in which electrode fingers overlap in the propagation direction. The first and second intersecting areas overlap in the propagation direction. A third busbar of the second IDT electrode is coupled to a first busbar of the first IDT electrode. A fourth busbar of the second IDT electrode is coupled to a ground potential. A resonant frequency of the second IDT electrode is in a frequency band of an interference wave signal.

Certain aspects of the present disclosure provide an electroacoustic device and methods for signal processing via the electroacoustic device. One example electroacoustic device generally includes a first surface acoustic wave (SAW) resonator comprising a first apodized interdigital transducer (IDT) disposed between a first busbar and a second busbar, and a second SAW resonator comprising a second apodized IDT disposed between the second busbar and a third busbar, wherein the second busbar is at an angle with respect to at least one of the first busbar or the third busbar.

A surface acoustic wave resonator comprises at least one set of interdigital transducer (IDT) electrodes disposed on an upper surface of a piezoelectric substrate between first and second reflector gratings, a layer of silicon nitride disposed over the at least one set of IDT electrodes and the first and second reflector gratings, and a continuous trench formed in the layer of silicon nitride over portions of bus bar electrodes and tips of electrode fingers of the at least one set of IDT electrodes and over portions of bus bar electrodes and electrode fingers of the first and second reflector gratings to reduce acoustic leakage at electrode fingers of the first and second reflector gratings proximate the at least one set of IDT electrodes.

A device includes a die and an interdigital transducer on the die. The interdigital transducer includes a first bus bar, a second bus bar, and a number of electrode fingers. The first bus bar is parallel to the second bus bar. The electrode fingers are divided into a first set of electrode fingers and a second set of electrode fingers. The first set of electrode fingers extend obliquely from the first bus bar towards the second bus bar. The second set of electrode fingers extend obliquely from the second bus bar towards the first bus bar, and are parallel to and interleaved with the first set of electrode fingers. By providing the electrode fingers oblique to the bus bars, spurious transverse modes may be suppressed while maintaining the quality factor, electromechanical coupling coefficient, and capacitance of the device.

A filter body includes a serial arm and one or more parallel resonators in a state where they are connected in a ladder shape. The serial arm includes a plurality of serial resonators connected in series to each other. A difference of resonance frequencies among the plurality of serial resonators is smaller than a half of a difference between the resonance frequency and an antiresonance frequency of each serial resonator. The serial arm includes a first divided arm which extends from one side toward the other side in a predetermined direction on the piezoelectric substrate, and a second divided arm which is folded back from the other side of the first divided arm and extends toward the one side. The shield conductor includes a portion which is located between at least one of the serial resonators included in the first divided arm and at least one of the serial resonators included in the second divided arm.

A surface acoustic wave resonator comprises at least one set of interdigital transducer (IDT) electrodes disposed on an upper surface of a piezoelectric substrate between first and second reflector gratings, a layer of silicon nitride disposed over the at least one set of IDT electrodes and the first and second reflector gratings, and a continuous trench formed in the layer of silicon nitride over portions of bus bar electrodes and tips of electrode fingers of the at least one set of IDT electrodes and over portions of bus bar electrodes and electrode fingers of the first and second reflector gratings to reduce acoustic leakage at electrode fingers of the first and second reflector gratings proximate the at least one set of IDT electrodes.

A filter body includes a serial arm and one or more parallel resonators in a state where they are connected in a ladder shape. The serial arm includes a plurality of serial resonators connected in series to each other. A difference of resonance frequencies among the plurality of serial resonators is smaller than a half of a difference between the resonance frequency and an antiresonance frequency of each serial resonator. The serial arm includes a first divided arm which extends from one side toward the other side in a predetermined direction on the piezoelectric substrate, and a second divided arm which is folded back from the other side of the first divided arm and extends toward the one side. The shield conductor includes a portion which is located between at least one of the serial resonators included in the first divided arm and at least one of the serial resonators included in the second divided arm.

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.