Surface acoustic wave device having a trapezoidal electrode
AssigneeSkyworks Solutions, Inc.
InventorsRei Goto, Keiichi Maki, Yuya Hiramatsu
Life of this patent
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Abstract
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.
Claims21
A surface acoustic wave device comprising:
- a piezoelectric layer forming a plane with a propagation axis;
- a plurality of slanted interdigital transducer electrodes arranged on the piezoelectric layer in ranks that are not aligned with the propagation axis;
- arranged on the piezoelectric layer in the same plane, at least one non-slanted surface acoustic wave filter having an elongate axis that parallels the propagation axis;
- and
- arranged on the piezoelectric layer in the same plane, at least one trapezoid interdigital transducer electrode having one side aligned with the propagation axis and one side aligned with the ranks of slanted interdigital transducer electrodes.
A surface acoustic wave device comprising:
- a multilayer piezoelectric substrate including a support substrate and a piezoelectric layer over the support substrate, the piezoelectric layer forming a planar surface;
- and
- at least one trapezoid interdigital transducer electrode over the piezoelectric layer having a trapezoidal shape when viewed from above the planar surface and configured for positioning in a tessellating manner adjacent to but not in contact with slanted and non-slanted elements on the same planar surface.
A surface acoustic wave filter comprising:
- a piezoelectric layer having a straight edge;
- an array of slanted elements forming at least one rank on the piezoelectric layer that is slanted with respect to the straight edge;
- at least one parallel element on the piezoelectric layer having an elongate axis that is parallel to the straight edge;
- and
- at least one interdigital transducer electrode over the piezoelectric layer, the at least one interdigital transducer electrode being a trapezoid interdigital transducer electrode and having at least one side parallel to the straight edge and one side parallel to the at least one slanted rank such that the trapezoid interdigital transducer electrode efficiently fills space on the piezoelectric layer between the array and the parallel element.
A radio frequency module comprising:
- a power amplifier configured to provide a radio frequency signal;
- and
- a surface acoustic wave filter configured to filter the radio frequency signal, the surface acoustic wave filter including a piezoelectric layer, an array of elements over the piezoelectric layer having trapezoidal voids therebetween, and at least one trapezoidal interdigital transducer electrode over the piezoelectric layer configured to efficiently occupy at least one of the trapezoidal voids.
Dependencies are inferred from the claim text.