Elastic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorMasakazu Mimura
Life of this patent
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Abstract
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 0.62λ or more and about 0.98λ or less, where λ denotes the wavelength, which is determined by the finger pitch of the IDT electrodes.
Claims18
An elastic wave device comprising:
- a piezoelectric body;
- and
- interdigital transducer electrodes on the piezoelectric body;
- wherein
- the interdigital transducer electrodes include:
- opposing first and second busbars;
- a plurality of first electrode fingers connected at one end to the first busbar;
- and
- a plurality of second electrode fingers interdigitated with the first electrode fingers and connected at one end to the second busbar;
- wherein
- when an intersection is defined as an area in which the first and second electrode fingers overlap when viewed in a direction of propagation of an elastic wave, the intersection includes:
- a center region;
- and
- low-acoustic-velocity sections at both sides of the center region in a direction in which the electrode fingers extend, sections in which the acoustic velocity is lower than in the center region;
- and
- a length of a gap between an edge of the first electrode fingers and the second busbar and a length of a gap between an edge of the second electrode fingers and the first busbar are about 0.62λ or more and about 0.98λ or less, where λ denotes a wavelength determined by a finger pitch of the interdigital transducer electrodes.
Dependencies are inferred from the claim text.