Back to results
US 8,803,402 B2Granted
Elastic wave device
AssigneePanasonic Corporation
InventorSatoru Ikeuchi
Life of this patent
Estimating the term…
Abstract
An elastic wave device includes an elastic wave resonator which includes a comb-shaped electrode pair including a pair of com-shaped electrodes interdigitating with each other and provided on a piezoelectric substrate and which is configured to trap energy of the elastic wave therein. Each of the pair of comb-shaped electrodes includes interdigital electrode fingers connected to a common. A pitch of the interdigital electrode fingers changes along a direction perpendicular to a propagation direction of elastic wave. The elastic wave device has a small insertion loss and operates efficiently.
Claims22
An elastic wave device comprising:
- a piezoelectric substrate having a reciprocal velocity plane which is concave in a propagating direction in which an elastic wave propagates;
- and
- an elastic wave resonator including a comb-shaped electrode pair which includes a first comb-shaped electrode and a second comb-shaped electrode both provided on the piezoelectric substrate, the first comb-shaped electrode and the second comb-shaped electrode interdigitating with each other, comb-shaped electrode pair being configured to trap energy of the elastic wave therein,
- wherein the first comb-shaped electrode includes a first common electrode and a plurality of first interdigital electrode fingers connected to the first common electrode,
- wherein the second comb-shaped electrode includes a second common electrode and a plurality of second interdigital electrode fingers connected to the second common electrode, the plurality of second interdigital electrode fingers interdigitaing with the plurality of first interdigital electrode fingers, and
- wherein the elastic wave resonator has:
- a first region in which the plurality of first interdigital electrode fingers interdigitate with the plurality of second interdigital electrode fingers, and a pitch of the first interdigital electrode fingers and the second interdigital electrode fingers is constant along a direction perpendicular to the propagating direction,
- a second region provided between the first region and the first common electrode, and a pitch of the first interdigital electrode fingers and the second interdigital electrode fingers in the second region is wider than the pitch in the first region, and
- a third region provided between the first region and the second common electrode, and a pitch of the first interdigital electrode fingers and the second interdigital electrode fingers in the third region is wider than the pitch in the first region.
6 more elements
An elastic wave device comprising:
- a piezoelectric substrate having a reciprocal velocity plane which is concave in a propagating direction in which an elastic wave propagates;
- and
- an elastic wave resonator including first and second reflecting electrodes and a comb-shaped electrode pair disposed between the first and second reflecting electrodes, the first and second reflecting electrodes and the comb-shaped electrode pair being disposed on the piezoelectric substrate provided, the elastic wave resonator being configured to trap energy of the elastic wave therein,
- wherein each of the first reflecting electrode and the second reflecting electrode includes a first common electrode, a second common electrode, and a plurality of reflecting electrode fingers disposed between the first and second common electrodes and connected to the first and second common electrodes,
- wherein each of the first reflecting electrode and the second reflecting electrode has:
- a first region in which a pitch of the plurality of reflecting electrode fingers is constant along a direction perpendicular to the propagating direction,
- a second region provided between the first region and the first common electrode, and a pitch of the plurality of reflecting electrode fingers in the second region is wider than the pitch in the first region, and
- a third region disposed between the first region and the second common electrode, and a pitch of the plurality of reflecting electrode fingers in the third region are wider than the pitch in the first region.
5 more elements
Dependencies are inferred from the claim text.