Surface acoustic wave device
AssigneeKYOCERA Corporation
InventorMasahisa Shimozono
Life of this patent
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Abstract
A surface acoustic wave SAW (SAW) device has a substrate and a filter provided at the substrate. The filter has a plurality of interdigital transducers (IDT) electrodes arranged along a propagation direction of a SAW. Each of the plurality of IDT electrodes has an electrode finger group including a plurality of electrode fingers which extent in a direction orthogonal to the propagation direction and are arranged along the propagation direction. At least one of the plurality of IDT electrodes has a wide pitch section including an adjacent first and second electrode finger among the plurality of electrode fingers. The interval between the first electrode finger and the second electrode finger is larger than the average value of the intervals between the remaining electrode fingers of the plurality of electrode fingers.
Claims15
A surface acoustic wave device, comprising:
- a piezoelectric substrate and
- a surface acoustic wave filter comprising a plurality of interdigital transducer (IDT) electrodes which are provided on the piezoelectric substrate and are arranged along a propagation direction of a surface acoustic wave, wherein
- each of the plurality of IDT electrodes comprises a group of electrode fingers which extend in a direction orthogonal to the propagation direction and which are arranged along the propagation direction spaced apart from each other at predetermined intervals,
- at least one of the plurality of IDT electrodes comprises
- a first adjacent pitch section in which a plurality of intervals of the electrode fingers group are constant,
- a second adjacent pitch section in which a plurality of intervals of the electrode fingers group are constant and the same as the plurality of intervals of the first adjacent pitch section, and
- a wide pitch section which is between the first adjacent pitch section and the second adjacent pitch section and adjacent to the first adjacent pitch section and the second adjacent pitch section, and has only two intervals of electrode fingers,
- the intervals of the wide pitch section are larger than the intervals of the first adjacent pitch section and the second adjacent pitch section and are larger than the average value of remaining intervals of the electrode fingers group other than the intervals of the wide pitch section in the first IDT electrode.
A surface acoustic wave device, comprising:
- a piezoelectric substrate and
- a surface acoustic wave filter comprising a plurality of interdigital transducer (IDT) electrodes which are provided on the piezoelectric substrate and are arranged along a propagation direction of a surface acoustic wave, wherein
- each of the plurality of IDT electrodes comprises a group of electrode fingers which extend in a direction orthogonal to the propagation direction and which are arranged along the propagation direction spaced apart from each other at predetermined intervals,
- a first IDT electrode included in the plurality of IDT electrodes comprises
- a first adjacent pitch section in which a plurality of intervals of the electrode fingers group are constant,
- a second adjacent pitch section in which a plurality of intervals of the electrode fingers group are constant and the same as the plurality of intervals of the first adjacent pitch section, and
- a first wide pitch section which is between the first adjacent pitch section and the second adjacent pitch section and adjacent to the first adjacent pitch section and the second adjacent pitch section, and has only one interval of electrode fingers,
- the interval of the first wide pitch section is larger than intervals of the first adjacent pitch section and the second adjacent pitch section and is larger than an average value of remaining intervals of the electrode fingers group other than the intervals of the first wide pitch section in the first IDT electrode.
A surface acoustic wave device, comprising:
- a piezoelectric substrate and
- a surface acoustic wave filter comprising three or more interdigital transducer (IDT) electrodes which are provided on the piezoelectric substrate and are arranged along a propagation direction of a surface acoustic wave, wherein
- each of the three or more IDT electrodes comprises a group of electrode fingers which extend in a direction orthogonal to the propagation direction and which are arranged along the propagation direction spaced apart from each other at predetermined intervals,
- one of two IDT electrodes included in the three or more IDT electrodes and located at both ends among the three or more IDT electrodes comprises a wide pitch section which has one or more intervals of the electrode fingers group located inside other than two intervals of the both ends of the one of the two IDT electrodes, being larger than any intervals of any IDT electrodes other than the two IDT electrodes located at both ends and being the largest among all intervals of the three or more IDT electrodes.
Dependencies are inferred from the claim text.