Elastic wave resonator including a constant pitch region with a tapering width
AssigneeSkyworks Panasonic Filter Solutions Japan Co., Ltd.
InventorsHidehito Shimizu, Hiroyuki Nakamura
Life of this patent
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Abstract
An object of the present disclosure is to provide an elastic wave resonator having a high Q value, and producing little or no unwanted spurious signals. In order to achieve the object, an elastic wave resonator according to the present disclosure includes a piezoelectric substrate and an IDT electrode. The IDT electrode has an apodization-weighting portion in which a staggered section width decreases toward an end portion of the IDT electrode in an elastic wave propagation direction. The electrode finger pitch of the IDT electrode decreases toward an end portion of the IDT electrode in an end portion, in the elastic wave propagation direction, of a staggered region of the IDT electrode.
Claims20
An elastic wave resonator comprising:
- a piezoelectric substrate;
- and
- an inter-digital transducer (IDT) electrode provided on the piezoelectric substrate,
- the IDT electrode having a staggered region in which electrode fingers of a comb electrode alternate with electrode fingers of an opposite comb electrode, the staggered region having a width in an electrode finger extending direction that tapers toward an end portion of the staggered region in an elastic wave propagation direction, the staggered region including, in a central portion, a constant pitch region in which an electrode finger pitch is substantially constant, and, on outer sides of the constant pitch region, reduced pitch regions in which an electrode finger pitch is less than the electrode finger pitch in the constant pitch region, a width of the constant pitch region in the electrode finger extending direction tapering toward an end portion of the constant pitch region in the elastic wave propagation direction.
An elastic wave resonator comprising:
- a piezoelectric substrate;
- and
- an inter-digital transducer (IDT) electrode provided on the piezoelectric substrate,
- the IDT electrode having a staggered region in which electrode fingers of a comb electrode alternate with electrode fingers of an opposite comb electrode, the staggered region having a width in an electrode finger extending direction that tapers toward an end portion of the staggered region in an elastic wave propagation direction, the staggered region including, in a central portion, a constant pitch region in which an electrode finger pitch is substantially constant, and, on outer sides of the constant pitch region, reduced pitch regions in which an electrode finger pitch is less than the electrode finger pitch in the constant pitch region, a width of the constant pitch region in the elastic wave propagation direction tapering toward an end portion of the constant pitch region in an electrode finger extending direction.
Dependencies are inferred from the claim text.