Acoustic wave element, duplexer, and communication module

Patent metadata

Field	Value
Publication number	US-9806692-B2
Application number	US-201514836782-A
Country	US
Kind code	B2
Filing date	Aug 26, 2015
Priority date	Feb 27, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

An acoustic wave element of the present disclosures has a piezoelectric substrate and an acoustic wave resonator S 1 on a main surface of the piezoelectric substrate. The acoustic wave resonator S 1 is one being divided into a first IDT electrode and a second IDT electrode which are electrically connected to the first IDT electrode. The first IDT electrode includes a first comb-shaped electrode on the signal input side and a second comb-shaped electrode on the signal output side. The second IDT electrode includes a third comb-shaped electrode on the signal input side and a fourth comb-shaped electrode on the signal output side. The direction of arrangement of the third comb-shaped electrode and the fourth comb-shaped electrode from the third comb-shaped electrode toward the fourth comb-shaped electrode is different from the direction of arrangement from the first comb-shaped electrode toward the second comb-shaped electrode.

First claim

The invention claimed is:

1. An acoustic wave element, comprising:
a piezoelectric substrate;
a signal input line;
a signal output line; and
an acoustic wave resonator on a main surface of the piezoelectric substrate, electrically connected to the signal input line and the signal output line, wherein
the acoustic wave resonator is being divided into a first IDT electrode and a second IDT electrode which is electrically connected to the first IDT electrode,
the first IDT electrode comprises a first comb-shaped electrode on a first signal input line side with respect to electrical connection and a second comb-shaped electrode on a first signal output line side with respect to electrical connection, the first signal input line side being a side of the first IDT electrode where the signal input line electrically couples with the first IDT electrode and the first signal output line side being a side of the first IDT electrode where the signal output line electrically couples with the first IDT electrode,
the second IDT electrode comprises a third comb-shaped electrode on a second signal input line side with respect to electrical connection and a fourth comb-shaped electrode on a second signal output line side with respect to electrical connection, the second signal input line side being a side of the second IDT electrode where the signal input line electrically couples with the second IDT electrode and the second signal output line side being a side of the second IDT electrode where the signal output line electrically couples with the second IDT electrode,
a direction of arrangement from the third comb-shaped electrode toward the fourth comb-shaped electrode is different from a direction of arrangement from the first comb-shaped electrode toward the second comb-shaped electrode, the directions of arrangement being directions with respect to the piezoelectric substrate.

2. The acoustic wave element according to claim 1 ,
wherein
the first IDT electrode is electrically connected in parallel to the second IDT electrode by the first comb-shaped electrode being electrically connected to the third comb-shaped electrode and the second comb-shaped electrode being electrically connected to the fourth comb-shaped electrode.

3. The acoustic wave element according to claim 1 ,
wherein
the first IDT electrode is electrically connected in series to the second IDT electrode by the second comb-shaped electrode being electrically connected to the third comb-shaped electrode.

4. The acoustic wave element according to claim 2 , wherein:
in the first IDT electrode,
the first comb-shaped electrode comprises
a first bus bar electrode and
a plurality of first electrode fingers which are connected to the first bus bar electrode and extend toward a side of the second comb-shaped electrode, and

the second comb-shaped electrode comprises
a second bus bar electrode facing the first bus bar electrode and
a plurality of second electrode fingers which are connected to the second bus bar electrode, extend toward a side of the first comb-shaped electrode, and comprise portions adjacent to the first electrode fingers,

in the second IDT electrode,
the third comb-shaped electrode comprises
a third bus bar electrode and
a plurality of third electrode fingers which are connected to the third bus bar electrode and extend toward a side of the fourth comb-shaped electrodes, and

the fourth comb-shaped electrode comprises
a fourth bus bar electrode facing the third bus bar electrode and
a plurality of fourth electrode fingers which are connected to the fourth bus bar electrode, extend toward a side of the third comb-shaped electrode, and comprise portions adjacent to the third electrode fingers.

5. The acoustic wave element according to claim 4 , wherein:
the first IDT electrode comprises
a plurality of first dummy electrode fingers which are connected to the first bus bar electrode and comprise front ends located forming first gaps with respect to a plurality of front ends of the second electrode fingers and
a plurality of second dummy electrode fingers which are connected to the second bus bar electrode and comprise front ends located forming second gaps with respect to a plurality of front ends of the first electrode fingers, and

the second IDT electrode comprises
a plurality of third dummy electrode fingers which are connected to the third bus bar electrode and comprise front ends located forming third gaps with respect to a plurality of front ends of the fourth electrode fingers and
a plurality of fourth dummy electrode fingers which are connected to the fourth bus bar electrode and comprise front ends located forming fourth gaps with respect to a plurality of front ends of the third electrode fingers.

6. The acoustic wave element according to claim 4 , wherein:
the first IDT electrode propagates a first acoustic wave in a direction vertical to a direction of arrangement of the first comb-shaped electrode and the second comb-shaped electrode,
the second IDT electrode propagates a second acoustic wave in a direction vertical to the direction of arrangement of the third comb-shaped electrode and the fourth comb-shaped electrode,
the second IDT electrode is arranged with respect to the first IDT electrode so that the second acoustic wave is along the first acoustic wave, and
between the first IDT electrode and the second IDT electrode, reflector electrode reflecting the first acoustic wave or second acoustic wave is further arranged.

7. The acoustic wave element according to claim 6 , wherein
the reflector electrode comprises
a first reflector electrode arranged on a side of the first IDT electrode and
a second reflector electrode arranged on a side of the second IDT electrode and,

further comprises an interconnect line passing between the first reflector electrode and the second reflector electrode and electrically connected to the first IDT electrode and second IDT electrode.

8. The acoustic wave element according to claim 6 , wherein the first IDT electrode and the second IDT electrode are electrically connected through the reflector electrode.

9. The acoustic wave element according to claim 8 , wherein the first IDT electrode and the second IDT electrode are electrically connected by electrical connection of the first bus bar electrode and the third bus bar electrode to the reflector electrode.

10. The acoustic wave element according to claim 9 , wherein:
the reflector electrode has
a first reflector electrode arranged on a side of the first IDT electrode and
a second reflector electrode arranged on a side of the second IDT electrode and

the acoustic wave element further comprises
a third reflector electrode which is located on an opposite side to the first reflector electrode with respect to the first IDT electrodein the direction of propagation of the first acoustic wave and
a fourth reflector electrode which is located on the opposite side to the second reflector electrode with respect to the second IDT electrode in direction of propagation of the second acoustic wave, and

the second comb-shaped electrode and the fourth comb-shaped electrode are electrically connected through the third reflector electrode.

11. The acoustic wave element according to claim 10 , wherein the fourth comb-shaped electrode and the fourth reflector electrode are electrically connected.

12. The acoustic wave element according to claim 4 , wherein:
the first IDT electrode propagates a first acoustic wave in a direction perpendicular to the direction of arrangement of the first comb-shaped electrode and the second comb-shaped electrode, and
the second IDT elec

Assignees

• Kyocera Corp

Inventors

• Kishino Tetsuya

Classifications

• H01Q1/50

  Structural association of antennas with earthing switches, lead-in devices or lightning protectors · CPC title

• H03H9/02614

  Treatment of substrates, e.g. curved, spherical, cylindrical substrates ensuring closed round-about circuits for the acoustical waves · CPC title

• H03H9/02913

  Measures for shielding against electromagnetic fields (shielding of electrical components in general H05K9/00) · CPC title

• H03H9/725

  Duplexers · CPC title

• H03H9/0033 Primary

  having one acoustic track only · CPC title