Improved surface acoustic wave structures (or elements) that can be used to realize any of a wide variety of dispersive or non-dispersive transversal SAW filters that are distinct from prior known means for producing such filters are disclosed. The devices and structures may include stepped acoustic wave delay modification elements that can be used to implement transversal filter impulse response functions in a manner analogous to the use of interdigital transducers. The structures disclosed are of particular usefulness to implement SAW devices at high frequencies where normal photolithographic resolution would prove limiting. Aspects and embodiments of the present invention would be useful to produce SAW devices for use in a wide variety of applications, including as components in cell phones, in radar and other communications and electronic systems, and as wired or wireless sensors or sensor-tags.

An acoustic wave device includes an IDT electrode with an inclined IDT structure on a piezoelectric substrate. An intersection region, where a first electrode finger and a second electrode finger overlap each other when viewed in an acoustic wave propagation direction, includes a central region and first and second low acoustic velocity regions on both sides of the central region. The first and second low acoustic velocity regions have an asymmetric shape about a central axis extending in a length direction of the first and second electrode fingers.

An acoustic wave device can include a substrate, a piezoelectric layer, a first electrode that includes a first bus bar and a first plurality of fingers extending from the first bus bar, and a second electrode that includes a second bus bar and a second plurality of fingers extending from the second bus bar. The second plurality of fingers can be interdigitated with the first plurality of fingers. The acoustic wave device can include a raised frame structure. The raised frame structure can be configured to suppress a transverse mode. The fingers can have widths that are greater than the distances between the fingers. The acoustic wave device can include a bus bar that includes a main section and a secondary section that are electrically connected by gap lines, which can have smaller width than the fingers. The acoustic wave device can include dummy fingers.

A surface acoustic wave device can have a piezoelectric layer and at least one interdigital transducer electrode thereon with a trapezoidal shape. This can be useful to fill dead space or voids between nonparallel elements on the layer. For example, an array with ranks of slanted interdigital transducer electrodes may not be aligned with non-slanted elements (e.g., a surface acoustic wave filter). This can leave voids or openings with unused portions of the piezoelectric layer. Trapezoidal elements such as those described here can solve this problem and help suppress transverse modes.

Acoustic wave device is disclosed. the acoustic wave device can include a piezoelectric layer and an interdigital transducer electrode over the piezoelectric layer. The interdigital transducer electrode having a non-zero tilt angle. The non-zero tilt angle can between 5° to 15°. The interdigital transducer electrode is configured to shift stopband of the acoustic wave device and to reduce a slanted stopband.

An acoustic wave filter device includes a piezoelectric layer, a high-acoustic-velocity member, a low-acoustic-velocity film between the high-acoustic-velocity member and the piezoelectric layer, and first and second IDT electrodes on the piezoelectric layer to define acoustic wave resonators. An acoustic wave resonator of a series-arm resonator portion closest to an antenna end and/or an acoustic wave resonator of a parallel-arm resonator portion closest to the antenna end includes the first IDT electrode including first and second electrode fingers, and the remaining acoustic wave resonators include the second IDT electrode including third and fourth electrode fingers. In the first IDT electrode, a central area, first and second low-acoustic-velocity areas, and first and second high-acoustic-velocity areas extend along a direction perpendicular or substantially perpendicular to an acoustic wave propagating direction. First and second envelopes connecting the tips of the third and fourth electrode fingers of the second IDT electrode are inclined.

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.

There are disclosed acoustic resonators and method of fabricating acoustic resonators. An acoustic resonator includes a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to a surface of a substrate except for portions of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern on the front surface includes an interdigital transducer (IDT) with interleaved fingers of the IDT disposed on the diaphragm. A periodic array of holes is provided in the diaphragm.

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.

An electro acoustic resonator compatible with thin piezoelectric films and providing additional degrees of freedom is provided. The resonator comprises an IDT section with two bus bars (ES,BB) and electrode fingers (ES,EF). The IDT section is slanted by an angle α through shearing and rotated as a whole by an angle β with respect to the piezoelectric axis (PA).