US 12,633,899 B2Granted

Resonator and filter device

AssigneeMurata Manufacturing Co., Ltd.

InventorsSeima Kondo, Takayuki Okude

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Abstract

A resonator includes a resonant electrode on a substrate having piezoelectricity. The resonant electrode includes a first comb-shaped electrode including a first busbar electrode and first electrode fingers, and a second comb-shaped electrode including a second busbar electrode and second electrode fingers. The substrate includes first and second overlap regions. The first region includes of pairs of first and second electrode fingers arranged alternately at a first pitch. The second region includes pairs of first and second electrode fingers arranged alternately at a second pitch different from the first pitch. An electrostatic capacitance of the first comb-shaped electrode and the second comb-shaped electrode in the first region is about 0.9 times or more and about 1.1 times or less an electrostatic capacitance of the first comb-shaped electrode and the second comb-shaped electrode in the second region.

Claims20

Dependent claims

A resonator comprising:

a substrate having piezoelectricity;
and
a resonant electrode on the substrate, wherein
the resonant electrode includes:
a first busbar electrode and a second busbar electrode facing each other;
a plurality of first electrode fingers extending in a comb shape from the first busbar electrode toward the second busbar electrode;
and
a plurality of second electrode fingers extending in a comb shape from the second busbar electrode toward the first busbar electrode such that the plurality of first electrode fingers and the plurality of second electrode fingers are alternately arranged in a first direction;
a first comb-shaped electrode includes the first busbar electrode and the plurality of first electrode fingers;
a second comb-shaped electrode includes the second busbar electrode and the plurality of second electrode fingers;
the substrate includes an overlap region where the plurality of first electrode fingers and the plurality of second electrode fingers overlap when the substrate is viewed in the first direction;
the overlap region includes:
a first region including a plurality of pairs of the first electrode fingers and the second electrode fingers alternately arranged in the first direction at a first pitch;
and
a second region including a plurality of pairs of the first electrode fingers and the second electrode fingers alternately arranged in the first direction at a second pitch different from the first pitch;
and
an electrostatic capacitance of the first comb-shaped electrode and the second comb-shaped electrode in the first region is about 0.9 times or more and about 1.1 times or less an electrostatic capacitance of the first comb-shaped electrode and the second comb-shaped electrode in the second region.

14 more elements

A resonator comprising:

a substrate having piezoelectricity;
and
a resonant electrode on the substrate;
wherein
the resonant electrode includes:
a first busbar electrode and a second busbar electrode facing each other;
a plurality of first electrode fingers extending in a comb shape from the first busbar electrode toward the second busbar electrode;
and
a plurality of second electrode fingers extending in a comb shape from the second busbar electrode toward the first busbar electrode such that the first electrode fingers and the second electrode fingers are alternately arranged in a first direction;
a first comb-shaped electrode includes the first busbar electrode and the plurality of first electrode fingers;
a second comb-shaped electrode includes the second busbar electrode and the plurality of second electrode fingers;
the substrate includes an overlap region where the first electrode fingers and the second electrode fingers overlap when the substrate is viewed in the first direction;
the overlap region includes:
a first region including J pairs of the first electrode fingers and the second electrode fingers alternately arranged in the first direction at a first pitch with a first gap where J is an integer of two or more;
and
a second region including K pairs of the first electrode fingers and the second electrode fingers alternately arranged in the first direction at a second pitch different from the first pitch with a second gap where K is an integer of two or more;
a first value obtained by dividing the first pitch by the first gap is about 0.9 times or more and about 1.1 times or less a second value obtained by dividing the second pitch by the second gap;
and
a value obtained by multiplying the J by the first value is about 0.9 times or more and about 1.1 times or less a value obtained by multiplying the K by the second value.

16 more elements

A resonator comprising:

a substrate having piezoelectricity;
and
a resonant electrode on the substrate;
wherein
the resonant electrode includes:
a first busbar electrode and a second busbar electrode facing each other;
a plurality of first electrode fingers extending in a comb shape from the first busbar electrode toward the second busbar electrode;
and
a plurality of second electrode fingers extending in a comb shape from the second busbar electrode toward the first busbar electrode such that the first electrode fingers and the second electrode fingers are alternately arranged in a first direction;
a first comb-shaped electrode includes the first busbar electrode and the plurality of first electrode fingers;
a second comb-shaped electrode includes the second busbar electrode and the plurality of second electrode fingers;
the substrate includes an overlap region where the first electrode fingers and the second electrode fingers overlap when the substrate is viewed in the first direction;
the overlap region includes:
a first region including J pairs of the first electrode fingers and the second electrode fingers alternately arranged in the first direction at a first pitch with a first gap where J is an integer of two or more;
and
a second region including K pairs of the first electrode fingers and the second electrode fingers alternately arranged in the first direction at a second pitch different from the first pitch with a second gap where K is an integer of two or more;
a first value obtained by dividing the first pitch by the first gap is about 0.9 times or more and about 1.1 times or less a second value obtained by dividing the second pitch by the second gap;
and
the J is about 0.9 times or more and about 1.1 times or less the K.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/603,327Filed 13 Mar 2024
Priority: JP 2023-05127528 Mar 2023
Published: US 2024/0333253 A13 Oct 2024
Granted: 19 May 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H03H 9/17
Constructional features of resonators consisting of piezoelectric or electrostrictive material: having a single resonator
H03H 9/135
Driving means, e.g. electrodes, coils: for networks consisting of magnetostrictive materials
H03H 9/568
Electric coupling means therefor: consisting of a ladder configuration
H03H 9/6483
Coupled resonator filters: ladder SAW filters