US 9,843,305 B2Granted

Elastic wave resonator, elastic wave filter device, and duplexer

AssigneeMurata Manufacturing Co., Ltd.

InventorRyo Nakagawa

Life of this patent

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Abstract

An elastic wave includes a piezoelectric substrate having a polarization direction denoted by an arrow Px, and first and second IDT electrodes arranged on the substrate in an elastic wave propagation direction with a shared reflector therebetween. A first bus bar of the first IDT electrode and a first end portion bus bar of a second reflector are connected to a wiring electrode to define a first terminal. A second bus bar of the first IDT electrode and a second end portion bus bar of the shared reflector are connected to each other to define a second terminal. A first end portion bus bar and a first bus bar are electrically connected to each other. A second bus bar and a second end portion bus bar are electrically connected to each other, and the first and second IDT electrodes and are connected in parallel between the first and second terminals.

An elastic wave resonator comprising:

a first terminal;
a second terminal;
a piezoelectric substrate having a polarization direction;
first and second interdigital transducer electrodes arranged in an elastic wave propagation direction on the piezoelectric substrate;
a shared reflector located between the first interdigital transducer electrode and the second interdigital transducer electrode;
a first reflector located opposite to the shared reflector with the first interdigital transducer electrode therebetween;
and
a second reflector located opposite to the shared reflector it the second interdigital transducer electrode therebetween;
wherein
a projected polarization direction is perpendicular or substantially perpendicular to the elastic wave propagation direction, the projected polarization direction being a direction obtained by projecting the polarization direction onto a substrate surface of the piezoelectric substrate;
assuming that a leading end side in the projected polarization direction is a first end portion side, and a base end side in the projected polarization direction is a second end portion side, the elastic wave resonator further comprises a wiring electrode electrically connecting respective first end portion side portions of the first reflector, the first interdigital transducer electrode, and the second reflector to one another, the wiring electrode defining the first terminal;
respective second end portion side portions of the first interdigital transducer electrode and the shared reflector are electrically connected to each other and define the second terminal;
respective first end portion side portions of the shared reflector and the second interdigital transducer electrode are electrically connected to each other;
respective second end portion side portions of the second interdigital transducer electrode and the second reflector are electrically connected to each other;
and
the first and second interdigital transducer electrodes are connected in parallel between the first terminal and the second terminal.

13 more elements

Facts

Application

15/014,174Filed 3 Feb 2016 · continuation

Priority

JP 2013-1854216 Sep 2013

Published

US 2016/0149554 A126 May 2016

Granted

12 Dec 2017

Term ends

Not estimatedThe source records don’t support an estimate.

Classification13 codes

H03H 9/725
Networks using surface acoustic waves: duplexers
H03H 9/02755
Intra-transducers grating lines: meandering floating or grounded grating lines
H03H 9/02763
Grating lines having particular arrangements: left and right side electrically coupled reflectors
H03H 9/02992
Of surface acoustic wave devices: details of bus bars, contact pads or other electrical connections for finger electrodes

Abstract

Claims18