WO2017115562A1 - Filtre à ondes acoustiques et duplexeur - Google Patents

Filtre à ondes acoustiques et duplexeur Download PDF

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Publication number
WO2017115562A1
WO2017115562A1 PCT/JP2016/083567 JP2016083567W WO2017115562A1 WO 2017115562 A1 WO2017115562 A1 WO 2017115562A1 JP 2016083567 W JP2016083567 W JP 2016083567W WO 2017115562 A1 WO2017115562 A1 WO 2017115562A1
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WO
WIPO (PCT)
Prior art keywords
inductor
duplexer
resonator
acoustic wave
elastic wave
Prior art date
Application number
PCT/JP2016/083567
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English (en)
Japanese (ja)
Inventor
憲良 太田
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株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2017115562A1 publication Critical patent/WO2017115562A1/fr

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/70—Multiple-port networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source
    • H03H9/72—Networks using surface acoustic waves

Definitions

  • the present invention relates to an elastic wave filter and a duplexer.
  • the duplexer transmission filter described in Patent Document 1 is a ladder-type elastic wave filter.
  • the series arm resonator and the parallel arm resonator of the acoustic wave filter are composed of surface acoustic wave resonators.
  • a bridging inductor is connected in parallel to the series arm resonator connected to the transmission terminal.
  • An object of the present invention is to provide an elastic wave filter and a duplexer which can easily achieve impedance matching and can be miniaturized.
  • An elastic wave filter includes a signal terminal, an elastic wave resonator connected to the signal terminal, a first inductor that is a bridging inductor connected in parallel to the elastic wave resonator, The first inductor has a first end connected to the signal terminal, and a second end opposite to the first end, the first end and the first end A second inductor connected between one of the second ends and the ground potential.
  • the acoustic wave resonator is directly connected to the signal terminal without passing through other circuit elements. In this case, it is easier to perform impedance matching.
  • the second inductor is connected between the second end of the first inductor and a ground potential. In this case, it is easier to perform impedance matching. In addition, since the second inductor can be reduced in size, the elastic wave filter can be reduced in size.
  • the signal terminal is an input terminal.
  • impedance matching can be easily performed, and the resistance to electrostatic breakdown of the elastic wave filter can be effectively increased.
  • the elastic wave filter is a ladder type filter having a series arm resonator and a parallel arm resonator, and the elastic wave resonator is the signal terminal most. It is the said series arm resonator located in the side.
  • the duplexer according to the present invention includes a first bandpass filter that is an elastic wave filter configured according to the present invention, and a second bandpass filter that has a different passband from the first bandpass filter. Is provided.
  • an elastic wave filter and a duplexer that can easily achieve impedance matching and can be miniaturized.
  • FIG. 1 is a circuit diagram of a duplexer according to the first embodiment of the present invention.
  • FIG. 2 is a circuit diagram of a duplexer of a comparative example.
  • FIG. 3 is a schematic plan view showing the electrode configuration of the series arm resonator connected to the input terminal according to the first embodiment of the present invention.
  • FIG. 4 is a schematic plan view showing the electrode configuration of the first and second longitudinally coupled resonator type acoustic wave filters in the first embodiment of the present invention.
  • Time 5 is a Smith chart at the input terminal of the duplexer of the first embodiment of the present invention and the comparative example.
  • FIG. 6 is a circuit diagram of a duplexer according to the second embodiment of the present invention.
  • FIG. 7 is a Smith chart at the input terminals of the duplexers of the first and second embodiments and the comparative example of the present invention.
  • FIG. 8 is a circuit diagram of a duplexer according to the third embodiment of the present invention.
  • FIG. 1 is a circuit diagram of a duplexer according to the first embodiment of the present invention.
  • the duplexer 1 includes a first band pass filter 2a and a second band pass filter 2b having a different pass band from the first band pass filter 2a.
  • the duplexer 1 has an antenna terminal 4 connected to an antenna.
  • the first and second band-pass filters 2 a and 2 b are commonly connected to the antenna terminal 4.
  • the duplexer 1 is not particularly limited, the duplexer 1 is a duplexer whose frequency band is located in Band66. More specifically, the first band-pass filter 2a is a transmission filter having a pass band of 1710 MHz or more and 1780 MHz or less. The second band pass filter 2b is a reception filter having a pass band of 2110 MHz or more and 2200 MHz or less.
  • the first band-pass filter 2a is an elastic wave filter according to an embodiment of the present invention.
  • the first band-pass filter 2a is not particularly limited, but is a ladder filter.
  • the first band-pass filter 2a includes series arm resonators S1 to S5 and parallel arm resonators P1 to P4.
  • the series arm resonators S1 to S5 and the parallel arm resonators P1 to P4 are all acoustic wave resonators.
  • the first band-pass filter 2a has an input terminal 3 as a signal terminal.
  • the series arm resonators S 1 to S 5 are connected in series between the input terminal 3 and the antenna terminal 4.
  • the series arm resonator S 1 is a series arm resonator located closest to the input terminal 3 and is directly connected to the input terminal 3.
  • the series arm resonator S1 is directly connected to the input terminal 3 without passing through other circuit elements.
  • the first band-pass filter 2a has a first inductor L1, which is a bridging inductor connected in parallel to the series arm resonator S1.
  • the first inductor L1 has a first end L1a connected to the input terminal 3, and a second end L1b opposite to the first end L1a.
  • the second end L1b is connected to the series arm resonator S2 side of the series arm resonator S1.
  • a second inductor L2 is connected between the second end L1b and the ground potential.
  • the second inductor L2 is an inductor for adjusting impedance.
  • the inductance of the second inductor L2 is not particularly limited, but is 9 nH.
  • a parallel arm resonator P1 is connected between the connection point between the series arm resonator S1 and the series arm resonator S2 and the ground potential.
  • a parallel arm resonator P2 is connected between a connection point between the series arm resonator S2 and the series arm resonator S3 and the ground potential.
  • a parallel arm resonator P3 is connected between a connection point between the series arm resonator S3 and the series arm resonator S4 and the ground potential.
  • a parallel arm resonator P4 is connected between a connection point between the series arm resonator S4 and the series arm resonator S5 and the ground potential.
  • the parallel arm resonators P1 to P4 are commonly connected to the ground potential. More specifically, the first bandpass filter 2a includes an inductor L3. The ends on the ground potential side of the parallel arm resonators P1 to P4 are commonly connected to the inductor L3. The inductor L3 is connected to the ground potential.
  • the first band-pass filter 2a may not include the inductor L3.
  • the configuration in which the parallel arm resonators P1 to P4 are commonly connected to the ground potential is not particularly limited.
  • the number of series arm resonators and parallel arm resonators of the first bandpass filter 2a is not particularly limited.
  • the second band-pass filter 2 b has an output terminal 5.
  • the second band pass filter 2b includes first and second longitudinally coupled resonator type acoustic wave filters 6a and 6b connected in parallel between the antenna terminal 4 and the output terminal 5. Further, the second band pass filter 2b has an acoustic wave resonator S11 connected between the antenna terminal 4 and the first and second longitudinally coupled resonator type acoustic wave filters 6a and 6b.
  • the first and second longitudinally coupled resonator type acoustic wave filters 6a and 6b are 3IDT type longitudinally coupled resonator type acoustic wave filters.
  • the configuration of the second bandpass filter 2b is not particularly limited.
  • the feature of this embodiment is that the first inductor L1 is connected in parallel to the acoustic wave resonator connected to the signal terminal, and between the second end L1b of the first inductor L1 and the ground potential.
  • the second inductor L2 is connected to the second inductor L2.
  • FIG. 2 is a circuit diagram of a duplexer of a comparative example.
  • the duplexer 31 is different from the first embodiment in that the first band-pass filter 32a does not have an inductor connected between the end of the first inductor L1 and the ground potential. In other respects, the duplexer 31 has the same configuration as the duplexer 1 of the first embodiment.
  • each elastic wave resonator in the first embodiment and the comparative example specifically has a configuration shown in FIG. In FIG. 3, the configuration of the series arm resonator S1 is shown as a representative.
  • FIG. 3 is a schematic plan view showing an electrode configuration of the series arm resonator connected to the input terminal in the first embodiment.
  • the serial arm resonator S1 has an IDT electrode 7 provided on a piezoelectric body. Reflectors 8 are provided on both sides of the IDT electrode 7 in the elastic wave propagation direction.
  • the series arm resonators S2 to S5, the parallel arm resonators P1 to P4, and the elastic wave resonator S11 shown in FIGS. 1 and 2 also have the same configuration as the series arm resonator S1.
  • first and second longitudinally coupled resonator type acoustic wave filters 6a and 6b have a configuration shown in FIG.
  • FIG. 4 is a schematic plan view showing an electrode configuration of the first and second longitudinally coupled resonator type acoustic wave filters in the first embodiment.
  • the first longitudinally coupled resonator type acoustic wave filter 6a includes IDT electrodes 6a1 to 6a3. Reflectors 9 are provided on both sides of the IDT electrodes 6a1 to 6a3 in the elastic wave propagation direction.
  • the second longitudinally coupled resonator type acoustic wave filter 6b includes IDT electrodes 6b1 to 6b3. Reflectors 10 are provided on both sides of the IDT electrodes 6b1 to 6b3 in the elastic wave propagation direction.
  • the duplexer of the first embodiment was manufactured.
  • the logarithm, cross width, and electrode finger pitch of the electrode fingers of the IDT electrodes of the series arm resonators S1 to S5, the parallel arm resonators P1 to P4, and the acoustic wave resonator S11 shown in FIG. I made it.
  • the number of electrode fingers and the electrode finger pitch of each reflector are as shown in Table 1.
  • the number of electrode fingers and the electrode finger pitch of each reflector 9, 10 are as shown in Table 2.
  • a comparative duplexer was also produced.
  • the configurations of the acoustic wave resonators and the longitudinally coupled resonator type acoustic wave filters in the comparative example are the same as those of the acoustic wave resonators and the longitudinally coupled resonator type acoustic wave filters in the first embodiment.
  • FIG. 5 is a Smith chart at the input terminals of the duplexers of the first embodiment and the comparative example.
  • Solid line A shows the result of the first embodiment
  • alternate long and short dash line B shows the result of the comparative example.
  • each thick line part of a continuous line and a dashed-dotted line is corresponded to the pass band of the duplexer of 1st Embodiment and a comparative example. The same applies to FIG. 7 described later.
  • the impedance in the pass band of the duplexer of the comparative example is far from the characteristic impedance (50 ⁇ ).
  • the impedance in the pass band of the duplexer of the first embodiment is sufficiently close to 50 ⁇ .
  • the spread of the thick line portion of the solid line A is smaller than the spread of the thick line portion of the one-dot chain line B. Therefore, in the first embodiment, it is easy to perform impedance matching of the duplexer.
  • the series arm resonator S1 is connected to the input terminal 3, and the burden at the time of voltage application is larger than the other series arm resonators S2 to S5.
  • the input terminal 3 is connected to the ground potential via the first inductor L1 and the second inductor L2. Therefore, the electrostatic breakdown of the series arm resonator S1 hardly occurs. Accordingly, the resistance of the duplexer 1 to electrostatic breakdown can be effectively increased.
  • the second inductor L2 is connected to the second end L1b of the first inductor L1. Thereby, the inductance of the second inductor L2 for impedance matching can be further reduced. Therefore, the second inductor L2 can be reduced in size. Therefore, the duplexer 1 can be reduced in size.
  • FIG. 6 is a circuit diagram of the duplexer according to the second embodiment.
  • the duplexer 11 is the first implementation in the first band-pass filter 12a in that the second inductor L12 is connected between the first end L1a of the first inductor L1 and the ground potential. Different from form. In other respects, the duplexer 11 has the same configuration as the duplexer 1 of the first embodiment.
  • the inductance of the second inductor L12 is 12 nH.
  • the input terminal 3 is connected to the series arm resonator S1, and is also connected to the ground potential via the second inductor L12. Therefore, as in the first embodiment, electrostatic breakdown of the series arm resonator S1 hardly occurs.
  • FIG. 7 is a Smith chart at the input terminals of the duplexers of the first and second embodiments and the comparative example.
  • a broken line C indicates the result of the second embodiment, and a thick line portion of the broken line C corresponds to the passband of the duplexer of the second embodiment.
  • the impedance in the passband of the duplexer of the second embodiment is closer to 50 ⁇ than the comparative example. Therefore, it can be understood that impedance matching of the duplexer can be easily performed.
  • the second inductor L2 is connected to the second end L1b of the first inductor L1. This makes it easier to achieve impedance matching.
  • FIG. 8 is a circuit diagram of a duplexer according to the third embodiment.
  • the duplexer 21 is different from the first embodiment in the arrangement of the first inductor L21 and the second inductor L22 connected to the first inductor L21.
  • the duplexer 21 also differs from that of the first embodiment in that it includes an acoustic wave resonator S22 connected between the first and second longitudinally coupled resonator type acoustic wave filters 6a and 6b and the output terminal 5.
  • the duplexer 21 has the same configuration as the duplexer 1 of the first embodiment.
  • the first inductor L21 is connected in parallel to the acoustic wave resonator S22.
  • the first end L21a of the first inductor L21 is connected to the output terminal 5.
  • a second inductor L22 is connected between the second end L21b opposite to the first end L21a of the first inductor L21 and the ground potential. Note that the first band-pass filter 22a does not have a bridging inductor.
  • impedance matching at the output terminal 5 is easy to be performed, and electrostatic breakdown of the acoustic wave resonator S22 hardly occurs.
  • the second band-pass filter 22b is an elastic wave filter according to an embodiment of the present invention. As described above, the present invention can also be suitably applied to an elastic wave filter other than a ladder type filter.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

La présente invention concerne un filtre à ondes acoustiques avec lequel une harmonie d'impédance peut être facilement exécutée et avec lequel une réduction de taille peut être obtenue. Ce filtre à ondes acoustiques est pourvu : d'une borne d'entrée 3 (borne de signal) ; d'un résonateur de branche série S1 (résonateur à ondes acoustiques) connecté à la borne d'entrée ; d'une première inductance L1, qui est une inductance de dérivation connectée en parallèle avec le résonateur de branche série S1 ; d'une première partie d'extrémité L1a où la première inductance L1 est connectée à la borne d'entrée 3 ; d'une seconde partie d'extrémité L1b du côté opposé à la première partie d'extrémité L1a ; d'une deuxième inductance L2 connectée entre la première partie d'extrémité L1a ou la seconde partie d'extrémité L1b et un potentiel de masse.
PCT/JP2016/083567 2015-12-28 2016-11-11 Filtre à ondes acoustiques et duplexeur WO2017115562A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015255811 2015-12-28
JP2015-255811 2015-12-28

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WO2017115562A1 true WO2017115562A1 (fr) 2017-07-06

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021020102A1 (fr) * 2019-07-30 2021-02-04 京セラ株式会社 Dispositif à ondes élastiques et dispositif de communication

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008011151A (ja) * 2006-06-29 2008-01-17 Kyocera Kinseki Corp バンドパスフィルタ
JP5510694B1 (ja) * 2012-08-30 2014-06-04 株式会社村田製作所 弾性波フィルタ装置及びデュプレクサ

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008011151A (ja) * 2006-06-29 2008-01-17 Kyocera Kinseki Corp バンドパスフィルタ
JP5510694B1 (ja) * 2012-08-30 2014-06-04 株式会社村田製作所 弾性波フィルタ装置及びデュプレクサ

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021020102A1 (fr) * 2019-07-30 2021-02-04 京セラ株式会社 Dispositif à ondes élastiques et dispositif de communication

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