WO2017208856A1 - Acoustic wave filter device - Google Patents

Acoustic wave filter device Download PDF

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Publication number
WO2017208856A1
WO2017208856A1 PCT/JP2017/018834 JP2017018834W WO2017208856A1 WO 2017208856 A1 WO2017208856 A1 WO 2017208856A1 JP 2017018834 W JP2017018834 W JP 2017018834W WO 2017208856 A1 WO2017208856 A1 WO 2017208856A1
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Prior art keywords
wave filter
acoustic wave
inductor
filter device
elastic wave
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PCT/JP2017/018834
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French (fr)
Japanese (ja)
Inventor
一郎 松田
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株式会社村田製作所
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Publication of WO2017208856A1 publication Critical patent/WO2017208856A1/en

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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
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/145—Driving means, e.g. electrodes, coils for networks 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
    • H03H9/25—Constructional features of resonators 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
    • H03H9/46—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 device having first and second filters having different passbands.
  • Patent Document 1 discloses a duplexer used in a mobile phone or the like.
  • each of the transmission filter and the reception filter includes an elastic wave filter.
  • the pass band of the reception filter is higher than the pass band of the transmission filter.
  • This reception filter has a circuit in which a longitudinally coupled resonator type acoustic wave filter and a ladder type filter are connected.
  • An object of the present invention is to provide an elastic wave filter device with improved isolation characteristics.
  • An elastic wave filter device has a first passband, and includes a longitudinally coupled resonator type elastic wave filter and at least one of a series arm resonator and a parallel arm resonator.
  • a second filter having a second passband located on a lower frequency side than the first passband of the first filter, one end of the first filter, and the second One end of the filter is commonly connected, and is provided between the ground terminal connected to the ground potential, the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter, and the ground terminal.
  • an inductor is used to the ground terminal.
  • the first filter includes the longitudinally coupled resonator type elastic wave filter, and a ladder type filter having the series arm resonator and the parallel arm resonator. Including.
  • the first and second filters are configured as one elastic wave filter chip.
  • the acoustic wave filter device can be downsized.
  • the inductor is provided in the elastic wave filter chip.
  • the inductor can be formed with high accuracy by a thin film forming method or the like. Accordingly, variation in characteristics can be reduced.
  • the acoustic wave filter chip has a piezoelectric substrate, and the inductor is provided on the piezoelectric substrate.
  • the inductor can be formed with high accuracy by a thin film formation method or the like, and the variation in characteristics can be effectively reduced.
  • the acoustic wave filter device further includes a package substrate on which the acoustic wave filter chip is mounted, and the ground terminal and the inductor are provided on the package substrate.
  • a package substrate on which the acoustic wave filter chip is mounted, and the ground terminal and the inductor are provided on the package substrate.
  • an inductor having a desired inductance value can be easily formed in the package substrate.
  • the parallel arm resonator is connected to a side opposite to the commonly connected one end side of the longitudinally coupled resonator type acoustic wave filter.
  • the inductor is connected between the end of the parallel arm resonator on the ground potential side and the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter. In this case, the number of terminals connected to the ground potential can be reduced.
  • the elastic wave filter device of the present invention it is possible to improve the isolation characteristics in the second pass band.
  • FIG. 1 is a circuit diagram of an elastic wave filter device according to a first embodiment of the present invention.
  • FIG. 2 is a front sectional view of the acoustic wave filter device according to the first embodiment of the present invention.
  • FIG. 3 is a plan view schematically showing the electrode structure on the lower surface of the piezoelectric substrate used in the first embodiment of the present invention.
  • FIG. 4 is a schematic plan view for explaining the package substrate of the acoustic wave filter device according to the first embodiment of the present invention.
  • FIG. 5 is a schematic plan view showing an electrode structure on the lower surface of the package substrate used in the acoustic wave filter device according to the first embodiment of the present invention.
  • FIG. 1 is a circuit diagram of an elastic wave filter device according to a first embodiment of the present invention.
  • FIG. 2 is a front sectional view of the acoustic wave filter device according to the first embodiment of the present invention.
  • FIG. 3 is a plan view schematically showing the electrode structure on the lower surface of
  • FIG. 6 is a diagram showing the isolation characteristics of the elastic wave filter device of the first embodiment of the present invention and the elastic wave filter device of the first comparative example.
  • FIG. 7 is a circuit diagram of an acoustic wave filter device according to the second embodiment of the present invention.
  • FIG. 8 is a schematic plan view for explaining the electrode structure on the piezoelectric substrate used in the elastic wave filter device according to the second embodiment of the present invention.
  • FIG. 9 is a schematic plan view for explaining a package substrate used in the acoustic wave filter device according to the second embodiment of the present invention.
  • FIG. 10 is a schematic plan view for explaining the electrode structure on the lower surface of the package substrate used in the acoustic wave filter device according to the second embodiment of the present invention.
  • FIG. 11 is a diagram showing the isolation characteristics of the elastic wave filter device of the second embodiment of the present invention and the elastic wave filter device of the second comparative example.
  • FIG. 12 is a circuit diagram of an acoustic wave filter device according to the third embodiment of the present invention.
  • FIG. 13 is a schematic plan view showing an electrode structure on a piezoelectric substrate used in the third embodiment of the present invention.
  • FIG. 14 is a diagram illustrating the isolation characteristics of the elastic wave filter devices of the second embodiment, the third embodiment, and the second comparative example of the present invention.
  • FIG. 15 is a circuit diagram of an acoustic wave filter device according to a fourth embodiment of the present invention.
  • FIG. 16 is a schematic plan view showing an electrode structure on a piezoelectric substrate used in the fourth embodiment of the present invention.
  • FIG. 1 is a circuit diagram of an elastic wave filter device according to a first embodiment of the present invention.
  • FIG. 2 is a front sectional view of the acoustic wave filter device according to the first embodiment of the present invention.
  • the elastic wave filter device 1 is a duplexer used for a mobile phone.
  • the acoustic wave filter device 1 is commonly connected to a common terminal 2.
  • the common terminal 2 is a terminal connected to the antenna.
  • a first filter 5 as a reception filter is connected between the common terminal 2 and the reception terminal 3.
  • a second filter 6 serving as a transmission filter is connected between the common terminal 2 and the transmission terminal 4.
  • Each of the first and second filters 5 and 6 is a band-pass filter.
  • the reception band that is the pass band of the first filter 5 is defined as a first pass band.
  • a transmission band that is a pass band of the second filter 6 is defined as a second pass band.
  • the second pass band is located on the lower band side than the first pass band.
  • the first filter 5 has a longitudinally coupled resonator type elastic wave filter 11.
  • the longitudinally coupled resonator type acoustic wave filter 11 is a 5IDT type longitudinally coupled resonator type acoustic wave filter.
  • a longitudinally coupled resonator type acoustic wave filter having a 3IDT type or an IDT exceeding 5 may be used.
  • series arm resonators S1 and S2 and a parallel arm resonator P1 are provided between the longitudinally coupled resonator type acoustic wave filter 11 and the common terminal 2.
  • the series arm resonators S1 and S2 and the parallel arm resonator P1 are each formed of a 1-port elastic wave resonator.
  • a ladder type filter having series arm resonators S 1 and S 2 and a parallel arm resonator P 1 is connected to the longitudinally coupled resonator type elastic wave filter 11.
  • a pass band is formed by the longitudinally coupled resonator type elastic wave filter 11, and the attenuation characteristics of the pass band are adjusted by a ladder type filter.
  • the second filter 6 has series arm resonators S11 to S15 in order from the transmission terminal 4 side.
  • Parallel arm resonators P11 to P14 are connected between the series arm and the ground potential. All of the series arm resonators S11 to S15 and the parallel arm resonators P11 to P14 are formed of a 1-port type acoustic wave resonator.
  • the second filter 6 is a ladder type filter.
  • the circuit configuration of the second filter 6 is not limited to the ladder type, and may be configured by various band-pass filters such as those using a longitudinally coupled resonator type acoustic wave filter.
  • the impedance adjustment inductor L1 is connected between the common terminal 2 and the ground potential.
  • the feature of the acoustic wave filter device 1 is that an inductor L2 for adjusting the position of the attenuation pole is connected between the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11 and the ground terminal 12. There is. Thereby, the isolation in the pass band, that is, the transmission band of the second filter 6 can be improved. This will be described in detail later.
  • the part surrounded by the alternate long and short dash line T is the part configured in the acoustic wave filter chip.
  • a portion outside the one-dot chain line T and surrounded by the two-dot chain line U is formed in the package substrate. This will be described with reference to FIGS.
  • an acoustic wave filter chip 14 is mounted on the package substrate 13.
  • a mold resin 15 is provided so as to surround the acoustic wave filter chip 14.
  • electrode lands serving as the reception terminal 3 and the transmission terminal 4 are formed.
  • An electrode land that becomes the ground terminal 12 is also formed.
  • the acoustic wave filter chip 14 has a piezoelectric substrate 16.
  • An electrode structure for forming the first filter 5 and the second filter 6 is formed on the lower surface of the piezoelectric substrate 16.
  • FIG. 3 is a plan view schematically showing an electrode structure on the lower surface of the piezoelectric substrate 16 used in the present embodiment.
  • the electrode lands 2 a, 3 a, 4 a are provided on the lower surface of the piezoelectric substrate 16.
  • the portions where the electrode lands 2a, 3a, 4a are provided are denoted by the same reference numerals in FIG.
  • a longitudinally coupled resonator type acoustic wave filter 11, series arm resonators S1 and S2, and a parallel arm resonator P1 are provided on a line connecting the electrode land 2a and the electrode land 3a.
  • IDTs connected to the ground terminal 12 of the longitudinally coupled resonator type acoustic wave filter 11 are commonly connected by wiring and reach the electrode land 12a.
  • the electrode land 12 a is located at the center of the edge on the short side of the piezoelectric substrate 16.
  • FIG. 4 is a schematic plan view for explaining the electrode structure of the upper surface and the intermediate layer of the package substrate.
  • the solid line indicates the electrode structure on the upper surface
  • the broken line indicates the electrode structure of the second layer, which is the intermediate layer on the upper surface side
  • the alternate long and short dash line indicates the electrode structure of the third layer, which is the intermediate layer on the lower surface side.
  • FIG. 5 is a plan view schematically showing the electrode structure on the lower surface of the package substrate 13.
  • the electrode land 21 is a portion connected to the electrode land 2a of the acoustic wave filter chip 14 and is finally connected to the antenna.
  • the electrode land 22 is a portion connected to the electrode land 3 a of the acoustic wave filter chip 14.
  • the electrode land 23 is a portion connected to the electrode land 4 a of the acoustic wave filter chip 14.
  • the electrode land 24 is a part electrically connected to the electrode land 12a shown in FIGS.
  • An inductor L2 is provided on the upper surface of the package substrate 13 by wiring as a conductor pattern so as to be connected to the electrode land 24. The other end of the inductor L2 is connected to the electrode land 23.
  • the electrode land 25 and the electrode lands 26 to 28 are electrically connected to the electrode land as the ground terminal 12 provided on the lower surface of the package substrate 13. Further, as shown in FIG. 5, the reception terminal 3, the transmission terminal 4, and the common terminal 2 are configured as electrode lands provided on the lower surface of the package substrate 13.
  • the acoustic wave filter device 1 is characterized in that in order to adjust the frequency position of the attenuation pole, the inductor L2 is connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11, and the ground terminal. 12 is connected to the terminal 12. Thereby, the isolation characteristics in the pass band of the second filter can be improved.
  • the solid line in FIG. 6 shows the isolation characteristics of the elastic wave filter device of the first embodiment.
  • a broken line indicates the isolation characteristic of the elastic wave filter device of the first comparative example.
  • the elastic wave filter device of the first comparative example is configured in the same manner as the elastic wave filter device of the first embodiment, except that the inductor L2 is not provided.
  • the first pass band of the first filter 5 is 2110 MHz to 2170 MHz.
  • the second pass band of the second filter 6 is 1920 MHz to 1980 MHz.
  • the design parameters of the elastic wave filter device 1 of the above embodiment are as follows.
  • the narrow pitch portion is a portion where the electrode finger pitch is smaller than that of the main portion.
  • a narrow pitch part is provided in the part of the adjacent side in adjacent IDT. Accordingly, in the second to fourth IDTs, narrow pitch portions are provided on both sides of the main portion.
  • the inductance value of the attenuation pole position adjusting inductor L2 was set to 0.4 nH.
  • the isolation characteristic is higher in the band of 1920 MHz to 1980 MHz, which is the second pass band of the second filter 6. It can be seen that it can be greatly improved. This is because an attenuation pole is formed by the capacitive component between the comb electrodes of the longitudinally coupled resonator type elastic wave filter 11 and the inductor L2, thereby improving the isolation in the second passband. It is thought that it is planned. Meanwhile, the capacitance between the comb electrodes in the longitudinally coupled resonator type acoustic wave filter 11 needs to be adjusted as a parameter for forming the first passband.
  • the isolation characteristic it cannot be positively used as a parameter for improving the isolation of the second passband of the second filter 6.
  • the isolation in the second passband can be effectively improved.
  • the inductor L2 is provided in the package substrate 13 by wiring. Therefore, the inductor L2 can be easily formed.
  • the inductor L2 when providing the inductor L2 in the package substrate 13, you may provide the part which functions as an inductance element in the arbitrary positions in the package substrate 13 not only in the conductor pattern by routing of wiring.
  • the inductor L2 is provided in the package substrate 13, an inductor having a desired inductance value can be easily provided.
  • FIG. 7 is a circuit diagram of an elastic wave filter device according to a second embodiment of the present invention.
  • FIG. 8 is a schematic plan view for explaining an electrode structure on a piezoelectric substrate used in the acoustic wave filter device of the second embodiment.
  • FIG. 9 is a schematic plan view showing the electrode structure of the upper surface, the second layer, and the third layer of the package substrate used in the second embodiment.
  • FIG. 10 is a schematic plan view for explaining the electrode structure on the lower surface of the package substrate used in the second embodiment.
  • the inductor L2 is provided in the elastic wave filter chip indicated by the alternate long and short dash line T.
  • the circuit of the elastic wave filter apparatus 31 is the same as the circuit of the elastic wave filter apparatus 1 shown in FIG.
  • an inductor L2 is formed on the lower surface of the piezoelectric substrate 16 with a coiled conductor pattern.
  • the inductor L2 is provided on the bottom surface of the piezoelectric substrate 16 so as to be electrically connected to a portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11.
  • the electrode structure on the bottom surface of the piezoelectric substrate 16 is the same as that of the elastic wave filter device 1 of the first embodiment.
  • the inductor L ⁇ b> 2 shown in FIG. 4 is not provided on the upper surface of the package substrate 13.
  • Other configurations of the package substrate 13 are the same as those of the package substrate 13 in the first embodiment.
  • the inductor L2 may be provided on the piezoelectric substrate 16 of the acoustic wave filter chip 14 instead of the package substrate 13 side.
  • the coiled conductor pattern for the inductor L2 can be formed by the thin film formation method simultaneously with the electrode structure such as the IDT shown in FIG. Therefore, the inductor L2 can be formed with high accuracy. Therefore, in the acoustic wave filter device 31, variation in characteristics can be reduced.
  • FIG. 11 shows the isolation characteristics of the second embodiment and the isolation characteristics of the second comparative example.
  • the solid line in FIG. 11 shows the isolation characteristic of the second embodiment, and the broken line shows the isolation characteristic of the second comparative example.
  • the inductor L2 is formed by a coiled conductor pattern provided on the piezoelectric substrate 16, and the inductance value is 0.6 nH.
  • the second comparative example is the same as the second embodiment except that the inductor L2 is not provided.
  • the design parameters of the first and second filters 5 and 6 are the same as those in the first embodiment.
  • the isolation characteristics in the second pass band can be effectively improved as compared with the second comparative example.
  • FIG. 12 is a circuit diagram of an acoustic wave filter device 41 according to the third embodiment of the present invention
  • FIG. 13 is a schematic plan view showing an electrode structure on the piezoelectric substrate used in the present embodiment. is there.
  • an inductor L2 is connected to a portion of the longitudinally coupled resonator type acoustic wave filter 11 that is connected to the ground potential.
  • the inductor L2 is connected by a wiring 43 to a wiring 42 connected to the ground potential of the parallel arm resonator P1.
  • the inductor L2 is connected between the ground terminal 12 connected to the ground potential of the acoustic wave filter device 41 and the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11.
  • the inductor L2 is provided in the acoustic wave filter chip as in the second embodiment. That is, as shown in FIG.
  • FIG. 14 is a diagram illustrating isolation characteristics of the elastic wave filter devices of the second embodiment, the third embodiment, and the second comparative example.
  • the solid line shows the result of the third embodiment
  • the alternate long and short dash line shows the result of the second embodiment
  • the broken line shows the result of the second comparative example.
  • the third embodiment can effectively improve the isolation characteristics in the second passband as compared with the second comparative example, as in the second embodiment.
  • the inductor L2 is commonly connected to the ground potential side end of the parallel arm resonator P1 and connected to the ground terminal 12 with respect to the ground terminal 12 connected to the ground potential of the acoustic wave filter device 41. Also good. That is, the end of the inductor L2 on the ground potential side is not necessarily connected to the ground terminal 12 alone.
  • FIG. 15 is a circuit diagram of an acoustic wave filter device according to a fourth embodiment of the present invention
  • FIG. 16 is a schematic plan view showing an electrode structure on a piezoelectric substrate used in the fourth embodiment. It is.
  • the inductor L2 is provided on the piezoelectric substrate 16 of the acoustic wave filter chip 14.
  • the parallel arm resonator P ⁇ b> 1 is provided between the longitudinally coupled resonator type elastic wave filter 11 and the receiving terminal 3.
  • the parallel arm resonator P ⁇ b> 1 may be provided between the longitudinally coupled resonator type acoustic wave filter 11 and the receiving terminal 3.
  • the end of the inductor L2 on the ground potential side is connected to the wiring 52 connected to the ground potential of the parallel arm resonator P1 on the piezoelectric substrate 16.
  • the number and arrangement of the series arm resonators and the parallel arm resonators connected to the longitudinally coupled resonator type acoustic wave filter 11 are not particularly limited.
  • the end on the ground potential side of the parallel arm resonator P1 and the end on the ground potential side of the inductor L2 are commonly connected and electrically connected to the ground terminal 12.
  • the first filter 5 having a relatively high passband includes a longitudinally coupled resonator type elastic wave filter and at least one of a series arm resonator and a parallel arm resonator.
  • the circuit configuration of the first filter 5 is not particularly limited.
  • the second filter 6 is not particularly limited with respect to the circuit configuration and the elements to be used as long as the second filter 6 has a second pass band that is lower than the first filter 5.
  • the duplexer has been described as an example.
  • the present invention is also applicable to a CA (CARRIER AGGREGATION) filter device in which three or more band-pass filters are bundled on one end side. Can do.

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

Abstract

Provided is an acoustic wave filter device having improved isolation characteristics. In an acoustic wave filter device 1, a first filter 5 which has a first passband and includes a vertically coupled resonator-type acoustic wave filter 11 and at least one of series-arm resonators S1, S2 and a parallel-arm resonator P1, and a second filter 6 which has a second passband located in a frequency region lower than the first passband are commonly connected at one end side thereof. An inductor L2 is provided between a ground terminal 12 and a part of the vertically coupled resonator-type acoustic wave filter 11 that is to be connected to a ground potential.

Description

弾性波フィルタ装置Elastic wave filter device
　本発明は、通過帯域が異なる第１及び第２のフィルタを有する、弾性波フィルタ装置に関する。 The present invention relates to an elastic wave filter device having first and second filters having different passbands.
　下記の特許文献１には、携帯電話機などで用いられるデュプレクサが開示されている。このデュプレクサでは、送信フィルタ及び受信フィルタが、それぞれ、弾性波フィルタからなる。送信フィルタの通過帯域に比べ、受信フィルタの通過帯域が高い。この受信フィルタは、縦結合共振子型弾性波フィルタと、ラダー型フィルタとを接続した回路を有する。 The following Patent Document 1 discloses a duplexer used in a mobile phone or the like. In this duplexer, each of the transmission filter and the reception filter includes an elastic wave filter. The pass band of the reception filter is higher than the pass band of the transmission filter. This reception filter has a circuit in which a longitudinally coupled resonator type acoustic wave filter and a ladder type filter are connected.
特開２００７－１８９７４７号公報JP 2007-189747 A
　特許文献１に記載のデュプレクサのように、縦結合共振子型弾性波フィルタとラダー型フィルタとを接続した回路を有する受信フィルタでは、アイソレーション特性の調整が難しく、送信フィルタの通過帯域において、十分なアイソレーション特性が確保できないという問題があった。 In a reception filter having a circuit in which a longitudinally coupled resonator type acoustic wave filter and a ladder type filter are connected like the duplexer described in Patent Document 1, it is difficult to adjust the isolation characteristics, and the transmission filter has a sufficient pass band. There has been a problem that it is not possible to ensure a good isolation characteristic.
　本発明の目的は、アイソレーション特性が改善された弾性波フィルタ装置を提供することにある。 An object of the present invention is to provide an elastic wave filter device with improved isolation characteristics.
　本発明に係る弾性波フィルタ装置は、第１の通過帯域を有し、縦結合共振子型弾性波フィルタと、直列腕共振子及び並列腕共振子の内の少なくとも一方とを有する第１のフィルタと、前記第１のフィルタの前記第１の通過帯域よりも低域側に位置している第２の通過帯域を有する、第２のフィルタと、前記第１のフィルタの一端と、前記第２のフィルタの一端とが共通接続されており、グラウンド電位に接続されるグラウンド端子と、前記縦結合共振子型弾性波フィルタのグラウンド電位に接続される部分と、前記グラウンド端子との間に設けられているインダクタと、をさらに備える。 An elastic wave filter device according to the present invention has a first passband, and includes a longitudinally coupled resonator type elastic wave filter and at least one of a series arm resonator and a parallel arm resonator. A second filter having a second passband located on a lower frequency side than the first passband of the first filter, one end of the first filter, and the second One end of the filter is commonly connected, and is provided between the ground terminal connected to the ground potential, the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter, and the ground terminal. And an inductor.
　本発明に係る弾性波フィルタ装置のある特定の局面では、前記第１のフィルタが、前記縦結合共振子型弾性波フィルタと、前記直列腕共振子及び並列腕共振子を有するラダー型フィルタとを含む。 In a specific aspect of the elastic wave filter device according to the present invention, the first filter includes the longitudinally coupled resonator type elastic wave filter, and a ladder type filter having the series arm resonator and the parallel arm resonator. Including.
　本発明に係る弾性波フィルタ装置の他の特定の局面では、前記第１及び第２のフィルタが、１つの弾性波フィルタチップに構成されている。この場合には、弾性波フィルタ装置の小型化を図ることができる。 In another specific aspect of the elastic wave filter device according to the present invention, the first and second filters are configured as one elastic wave filter chip. In this case, the acoustic wave filter device can be downsized.
　本発明に係る弾性波フィルタ装置のさらに他の特定の局面では、前記インダクタが、前記弾性波フィルタチップに設けられている。この場合には、薄膜形成法などにより、インダクタを高精度に形成することができる。従って、特性のばらつきの低減を図ることができる。 In still another specific aspect of the elastic wave filter device according to the present invention, the inductor is provided in the elastic wave filter chip. In this case, the inductor can be formed with high accuracy by a thin film forming method or the like. Accordingly, variation in characteristics can be reduced.
　本発明に係る弾性波フィルタ装置のさらに他の特定の局面では、前記弾性波フィルタチップが圧電基板を有し、前記インダクタが前記圧電基板上に設けられている。この場合には、薄膜形成法などにより、インダクタを高精度に形成することができ、特性のばらつきの低減を効果的に図ることができる。 In still another specific aspect of the acoustic wave filter device according to the present invention, the acoustic wave filter chip has a piezoelectric substrate, and the inductor is provided on the piezoelectric substrate. In this case, the inductor can be formed with high accuracy by a thin film formation method or the like, and the variation in characteristics can be effectively reduced.
　本発明に係る弾性波フィルタ装置のさらに他の特定の局面では、前記弾性波フィルタチップが搭載されているパッケージ基板をさらに備え、前記パッケージ基板に前記グラウンド端子及び前記インダクタが設けられている。この場合には、パッケージ基板内に、所望のインダクタンス値のインダクタを容易に形成することができる。 In another specific aspect of the acoustic wave filter device according to the present invention, the acoustic wave filter device further includes a package substrate on which the acoustic wave filter chip is mounted, and the ground terminal and the inductor are provided on the package substrate. In this case, an inductor having a desired inductance value can be easily formed in the package substrate.
　本発明に係る弾性波フィルタ装置のさらに他の特定の局面では、前記並列腕共振子が、前記縦結合共振子型弾性波フィルタの前記共通接続されている一端側とは反対側に接続されており、前記並列腕共振子のグラウンド電位側の端部と、前記縦結合共振子型弾性波フィルタのグラウンド電位に接続される部分との間に前記インダクタが接続されている。この場合には、グラウンド電位と接続される端子の数を減らすことができる。 In still another specific aspect of the acoustic wave filter device according to the present invention, the parallel arm resonator is connected to a side opposite to the commonly connected one end side of the longitudinally coupled resonator type acoustic wave filter. The inductor is connected between the end of the parallel arm resonator on the ground potential side and the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter. In this case, the number of terminals connected to the ground potential can be reduced.
　本発明に係る弾性波フィルタ装置によれば、第２の通過帯域におけるアイソレーション特性を改善することができる。 According to the elastic wave filter device of the present invention, it is possible to improve the isolation characteristics in the second pass band.
図１は、本発明の第１の実施形態に係る弾性波フィルタ装置の回路図である。FIG. 1 is a circuit diagram of an elastic wave filter device according to a first embodiment of the present invention. 図２は、本発明の第１の実施形態に係る弾性波フィルタ装置の正面断面図である。FIG. 2 is a front sectional view of the acoustic wave filter device according to the first embodiment of the present invention. 図３は、本発明の第１の実施形態で用いられている圧電基板の下面の電極構造を模式的に示す平面図である。FIG. 3 is a plan view schematically showing the electrode structure on the lower surface of the piezoelectric substrate used in the first embodiment of the present invention. 図４は、本発明の第１の実施形態に係る弾性波フィルタ装置のパッケージ基板を説明するための模式的平面図である。FIG. 4 is a schematic plan view for explaining the package substrate of the acoustic wave filter device according to the first embodiment of the present invention. 図５は、本発明の第１の実施形態の弾性波フィルタ装置で用いられているパッケージ基板の下面の電極構造を示す模式的平面図である。FIG. 5 is a schematic plan view showing an electrode structure on the lower surface of the package substrate used in the acoustic wave filter device according to the first embodiment of the present invention. 図６は、本発明の第１の実施形態の弾性波フィルタ装置及び第１の比較例の弾性波フィルタ装置のアイソレーション特性を示す図である。FIG. 6 is a diagram showing the isolation characteristics of the elastic wave filter device of the first embodiment of the present invention and the elastic wave filter device of the first comparative example. 図７は、本発明の第２の実施形態に係る弾性波フィルタ装置の回路図である。FIG. 7 is a circuit diagram of an acoustic wave filter device according to the second embodiment of the present invention. 図８は、本発明の第２の実施形態に係る弾性波フィルタ装置において用いられている、圧電基板上の電極構造を説明するための模式的平面図である。FIG. 8 is a schematic plan view for explaining the electrode structure on the piezoelectric substrate used in the elastic wave filter device according to the second embodiment of the present invention. 図９は、本発明の第２の実施形態に係る弾性波フィルタ装置で用いられているパッケージ基板を説明するための模式的平面図である。FIG. 9 is a schematic plan view for explaining a package substrate used in the acoustic wave filter device according to the second embodiment of the present invention. 図１０は、本発明の第２の実施形態に係る弾性波フィルタ装置で用いられているパッケージ基板の下面の電極構造を説明するための模式的平面図である。FIG. 10 is a schematic plan view for explaining the electrode structure on the lower surface of the package substrate used in the acoustic wave filter device according to the second embodiment of the present invention. 図１１は、本発明の第２の実施形態の弾性波フィルタ装置及び第２の比較例の弾性波フィルタ装置のアイソレーション特性を示す図である。FIG. 11 is a diagram showing the isolation characteristics of the elastic wave filter device of the second embodiment of the present invention and the elastic wave filter device of the second comparative example. 図１２は、本発明の第３の実施形態に係る弾性波フィルタ装置の回路図である。FIG. 12 is a circuit diagram of an acoustic wave filter device according to the third embodiment of the present invention. 図１３は、本発明の第３の実施形態で用いられている圧電基板上の電極構造を示す模式的平面図である。FIG. 13 is a schematic plan view showing an electrode structure on a piezoelectric substrate used in the third embodiment of the present invention. 図１４は、本発明の第２の実施形態、第３の実施形態及び第２の比較例の弾性波フィルタ装置のアイソレーション特性を示す図である。FIG. 14 is a diagram illustrating the isolation characteristics of the elastic wave filter devices of the second embodiment, the third embodiment, and the second comparative example of the present invention. 図１５は、本発明の第４の実施形態に係る弾性波フィルタ装置の回路図である。FIG. 15 is a circuit diagram of an acoustic wave filter device according to a fourth embodiment of the present invention. 図１６は、本発明の第４の実施形態で用いられている圧電基板上の電極構造を示す模式的平面図である。FIG. 16 is a schematic plan view showing an electrode structure on a piezoelectric substrate used in the fourth embodiment of the present invention.
　以下、図面を参照しつつ、本発明の具体的な実施形態を説明することにより、本発明を明らかにする。 Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.
　なお、本明細書に記載の各実施形態は、例示的なものであり、異なる実施形態間において、構成の部分的な置換または組み合わせが可能であることを指摘しておく。 It should be pointed out that each embodiment described in this specification is an example, and a partial replacement or combination of configurations is possible between different embodiments.
　図１は、本発明の第１の実施形態に係る弾性波フィルタ装置の回路図である。図２は、本発明の第１の実施形態に係る弾性波フィルタ装置の正面断面図である。 FIG. 1 is a circuit diagram of an elastic wave filter device according to a first embodiment of the present invention. FIG. 2 is a front sectional view of the acoustic wave filter device according to the first embodiment of the present invention.
　弾性波フィルタ装置１は、携帯電話機に用いられるデュプレクサである。弾性波フィルタ装置１は、共通端子２に共通接続されている。共通端子２は、アンテナに接続される端子である。共通端子２と受信端子３との間に受信フィルタとしての第１のフィルタ５が接続されている。共通端子２と送信端子４との間に、送信フィルタとしての第２のフィルタ６が接続されている。第１，第２のフィルタ５，６は、いずれも、帯域通過型フィルタである。第１のフィルタ５の通過帯域である受信帯域を、第１の通過帯域とする。第２のフィルタ６の通過帯域である送信帯域を、第２の通過帯域とする。第１の通過帯域よりも第２の通過帯域が低域側に位置している。 The elastic wave filter device 1 is a duplexer used for a mobile phone. The acoustic wave filter device 1 is commonly connected to a common terminal 2. The common terminal 2 is a terminal connected to the antenna. A first filter 5 as a reception filter is connected between the common terminal 2 and the reception terminal 3. A second filter 6 serving as a transmission filter is connected between the common terminal 2 and the transmission terminal 4. Each of the first and second filters 5 and 6 is a band-pass filter. The reception band that is the pass band of the first filter 5 is defined as a first pass band. A transmission band that is a pass band of the second filter 6 is defined as a second pass band. The second pass band is located on the lower band side than the first pass band.
　第１のフィルタ５は、縦結合共振子型弾性波フィルタ１１を有する。縦結合共振子型弾性波フィルタ１１は、５ＩＤＴ型の縦結合共振子型弾性波フィルタである。もっとも、３ＩＤＴ型や５を超えるＩＤＴを有する縦結合共振子型弾性波フィルタを用いてもよい。 The first filter 5 has a longitudinally coupled resonator type elastic wave filter 11. The longitudinally coupled resonator type acoustic wave filter 11 is a 5IDT type longitudinally coupled resonator type acoustic wave filter. However, a longitudinally coupled resonator type acoustic wave filter having a 3IDT type or an IDT exceeding 5 may be used.
　縦結合共振子型弾性波フィルタ１１と、共通端子２との間に、直列腕共振子Ｓ１，Ｓ２及び並列腕共振子Ｐ１が設けられている。直列腕共振子Ｓ１，Ｓ２及び並列腕共振子Ｐ１は、１ポート型弾性波共振子からなる。本実施形態では、直列腕共振子Ｓ１，Ｓ２及び並列腕共振子Ｐ１を有するラダー型フィルタが、縦結合共振子型弾性波フィルタ１１に接続されている。縦結合共振子型弾性波フィルタ１１により、通過帯域が形成され、さらにラダー型フィルタにより、この通過帯域の減衰特性が調整されている。 Between the longitudinally coupled resonator type acoustic wave filter 11 and the common terminal 2, series arm resonators S1 and S2 and a parallel arm resonator P1 are provided. The series arm resonators S1 and S2 and the parallel arm resonator P1 are each formed of a 1-port elastic wave resonator. In the present embodiment, a ladder type filter having series arm resonators S 1 and S 2 and a parallel arm resonator P 1 is connected to the longitudinally coupled resonator type elastic wave filter 11. A pass band is formed by the longitudinally coupled resonator type elastic wave filter 11, and the attenuation characteristics of the pass band are adjusted by a ladder type filter.
　他方、第２のフィルタ６は、送信端子４側から順に、直列腕共振子Ｓ１１～Ｓ１５を有する。そして、並列腕共振子Ｐ１１～Ｐ１４が、直列腕とグラウンド電位との間に接続されている。直列腕共振子Ｓ１１～Ｓ１５及び並列腕共振子Ｐ１１～Ｐ１４は、いずれも、１ポート型弾性波共振子からなる。第２のフィルタ６は、ラダー型フィルタである。本発明において、第２のフィルタ６の回路構成はラダー型に限定されず、縦結合共振子型弾性波フィルタを用いたものなど、様々な帯域通過型フィルタにより構成され得る。 On the other hand, the second filter 6 has series arm resonators S11 to S15 in order from the transmission terminal 4 side. Parallel arm resonators P11 to P14 are connected between the series arm and the ground potential. All of the series arm resonators S11 to S15 and the parallel arm resonators P11 to P14 are formed of a 1-port type acoustic wave resonator. The second filter 6 is a ladder type filter. In the present invention, the circuit configuration of the second filter 6 is not limited to the ladder type, and may be configured by various band-pass filters such as those using a longitudinally coupled resonator type acoustic wave filter.
　共通端子２とグラウンド電位との間に、インピーダンス調整用インダクタＬ１が接続されている。 The impedance adjustment inductor L1 is connected between the common terminal 2 and the ground potential.
　弾性波フィルタ装置１の特徴は、縦結合共振子型弾性波フィルタ１１のグラウンド電位に接続される部分と、グラウンド端子１２との間に、減衰極の位置調整用のインダクタＬ２が接続されていることにある。それによって、第２のフィルタ６の通過帯域すなわち送信帯域におけるアイソレーションを改善することができる。これを後程、詳細に説明する。 The feature of the acoustic wave filter device 1 is that an inductor L2 for adjusting the position of the attenuation pole is connected between the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11 and the ground terminal 12. There is. Thereby, the isolation in the pass band, that is, the transmission band of the second filter 6 can be improved. This will be described in detail later.
　ところで、図１において、一点鎖線Ｔで囲まれた部分は、弾性波フィルタチップに構成されている部分である。そして、一点鎖線Ｔよりも外側であって、二点鎖線Ｕに囲まれた部分は、パッケージ基板内に構成されている。これを、図２～図５を参照して説明する。 By the way, in FIG. 1, the part surrounded by the alternate long and short dash line T is the part configured in the acoustic wave filter chip. A portion outside the one-dot chain line T and surrounded by the two-dot chain line U is formed in the package substrate. This will be described with reference to FIGS.
　図２に示すように、パッケージ基板１３上に、弾性波フィルタチップ１４が実装されている。弾性波フィルタチップ１４を囲むように、モールド樹脂１５が設けられている。パッケージ基板１３の下面には、受信端子３及び送信端子４となる電極ランドが形成されている。また、グラウンド端子１２となる電極ランドも形成されている。上記弾性波フィルタチップ１４は、圧電基板１６を有する。圧電基板１６の下面には、第１のフィルタ５及び第２のフィルタ６を構成するための電極構造が形成されている。図３は、本実施形態で用いられている圧電基板１６の下面の電極構造を模式的に示す平面図である。図３に示すように、電極ランド２ａ，３ａ，４ａが、圧電基板１６の下面に設けられている。この電極ランド２ａ，３ａ，４ａが設けられている部分を、図１において、同じ参照番号を用いて示すこととする。 As shown in FIG. 2, an acoustic wave filter chip 14 is mounted on the package substrate 13. A mold resin 15 is provided so as to surround the acoustic wave filter chip 14. On the lower surface of the package substrate 13, electrode lands serving as the reception terminal 3 and the transmission terminal 4 are formed. An electrode land that becomes the ground terminal 12 is also formed. The acoustic wave filter chip 14 has a piezoelectric substrate 16. An electrode structure for forming the first filter 5 and the second filter 6 is formed on the lower surface of the piezoelectric substrate 16. FIG. 3 is a plan view schematically showing an electrode structure on the lower surface of the piezoelectric substrate 16 used in the present embodiment. As shown in FIG. 3, the electrode lands 2 a, 3 a, 4 a are provided on the lower surface of the piezoelectric substrate 16. The portions where the electrode lands 2a, 3a, 4a are provided are denoted by the same reference numerals in FIG.
　図３に示すように、電極ランド２ａと、電極ランド３ａとを結ぶ線路に、縦結合共振子型弾性波フィルタ１１、直列腕共振子Ｓ１，Ｓ２及び並列腕共振子Ｐ１が設けられている。図１において、縦結合共振子型弾性波フィルタ１１のグラウンド端子１２に接続されるＩＤＴは、配線により共通接続され、電極ランド１２ａに至っている。この電極ランド１２ａは、図３に示すように、圧電基板１６の短辺側の端縁中央に位置している。 As shown in FIG. 3, a longitudinally coupled resonator type acoustic wave filter 11, series arm resonators S1 and S2, and a parallel arm resonator P1 are provided on a line connecting the electrode land 2a and the electrode land 3a. In FIG. 1, IDTs connected to the ground terminal 12 of the longitudinally coupled resonator type acoustic wave filter 11 are commonly connected by wiring and reach the electrode land 12a. As shown in FIG. 3, the electrode land 12 a is located at the center of the edge on the short side of the piezoelectric substrate 16.
　図２に戻り、パッケージ基板１３は、上面、中間層及び下面に、それぞれ電極構造を有する。図４は、パッケージ基板の上面及び中間層の電極構造を説明するための模式的平面図である。図４において、実線は上面の電極構造を、破線は上面側の中間層である第２層の電極構造を、一点鎖線は、下面側の中間層である第３層の電極構造を示す。図５は、パッケージ基板１３の下面の電極構造を模式的に示す平面図である。 Referring back to FIG. 2, the package substrate 13 has electrode structures on the upper surface, the intermediate layer, and the lower surface. FIG. 4 is a schematic plan view for explaining the electrode structure of the upper surface and the intermediate layer of the package substrate. In FIG. 4, the solid line indicates the electrode structure on the upper surface, the broken line indicates the electrode structure of the second layer, which is the intermediate layer on the upper surface side, and the alternate long and short dash line indicates the electrode structure of the third layer, which is the intermediate layer on the lower surface side. FIG. 5 is a plan view schematically showing the electrode structure on the lower surface of the package substrate 13.
　電極ランド２１は、弾性波フィルタチップ１４の電極ランド２ａに接続される部分であり、最終的にアンテナに接続される部分である。また、電極ランド２２は、弾性波フィルタチップ１４の電極ランド３ａに接続される部分である。電極ランド２３は、弾性波フィルタチップ１４の電極ランド４ａに接続される部分である。電極ランド２４は、図１及び図３に示した電極ランド１２ａに電気的に接続される部分である。この電極ランド２４に接続されるように、パッケージ基板１３の上面において、導体パターンとしての配線により、インダクタＬ２が設けられている。このインダクタＬ２の他端は電極ランド２３に接続されている。電極ランド２５と、電極ランド２６～２８とが、パッケージ基板１３の下面に設けられているグラウンド端子１２としての電極ランドに電気的に接続されている。また、図５に示すように、受信端子３、送信端子４、共通端子２が、パッケージ基板１３の下面に設けられた電極ランドとして構成されている。 The electrode land 21 is a portion connected to the electrode land 2a of the acoustic wave filter chip 14 and is finally connected to the antenna. The electrode land 22 is a portion connected to the electrode land 3 a of the acoustic wave filter chip 14. The electrode land 23 is a portion connected to the electrode land 4 a of the acoustic wave filter chip 14. The electrode land 24 is a part electrically connected to the electrode land 12a shown in FIGS. An inductor L2 is provided on the upper surface of the package substrate 13 by wiring as a conductor pattern so as to be connected to the electrode land 24. The other end of the inductor L2 is connected to the electrode land 23. The electrode land 25 and the electrode lands 26 to 28 are electrically connected to the electrode land as the ground terminal 12 provided on the lower surface of the package substrate 13. Further, as shown in FIG. 5, the reception terminal 3, the transmission terminal 4, and the common terminal 2 are configured as electrode lands provided on the lower surface of the package substrate 13.
　前述したように、弾性波フィルタ装置１の特徴は、減衰極の周波数位置を調整するために、インダクタＬ２が、縦結合共振子型弾性波フィルタ１１のグラウンド電位に接続される部分と、グラウンド端子１２との間に接続されていることにある。それによって、第２のフィルタの通過帯域におけるアイソレーション特性を改善することができる。これを、図６を参照して説明する。図６の実線は、第１の実施形態の弾性波フィルタ装置のアイソレーション特性を示す。破線は、第１の比較例の弾性波フィルタ装置のアイソレーション特性を示す。第１の比較例の弾性波フィルタ装置は、上記インダクタＬ２を有しないことを除いては、第１の実施形態の弾性波フィルタ装置と同様に構成されている。 As described above, the acoustic wave filter device 1 is characterized in that in order to adjust the frequency position of the attenuation pole, the inductor L2 is connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11, and the ground terminal. 12 is connected to the terminal 12. Thereby, the isolation characteristics in the pass band of the second filter can be improved. This will be described with reference to FIG. The solid line in FIG. 6 shows the isolation characteristics of the elastic wave filter device of the first embodiment. A broken line indicates the isolation characteristic of the elastic wave filter device of the first comparative example. The elastic wave filter device of the first comparative example is configured in the same manner as the elastic wave filter device of the first embodiment, except that the inductor L2 is not provided.
　本実施形態では、第１のフィルタ５の第１の通過帯域は、２１１０ＭＨｚ～２１７０ＭＨｚである。第２のフィルタ６の第２の通過帯域は、１９２０ＭＨｚ～１９８０ＭＨｚである。 In the present embodiment, the first pass band of the first filter 5 is 2110 MHz to 2170 MHz. The second pass band of the second filter 6 is 1920 MHz to 1980 MHz.
　上記実施形態の弾性波フィルタ装置１の設計パラメータは以下の通りとした。 The design parameters of the elastic wave filter device 1 of the above embodiment are as follows.
　（第１のフィルタ５の設計パラメータ）
　縦結合共振子型弾性波フィルタ１１の設計パラメータは以下の通りとした。 (Design parameters of the first filter 5)
The design parameters of the longitudinally coupled resonator type acoustic wave filter 11 were as follows.
　表１では、一方のリフレクタから、他方のリフレクタにかけての各構造の波長及びＩＤＴの本数が示されている。狭ピッチ部とは、電極指ピッチがメイン部よりも小さい部分である。狭ピッチ部は、隣り合うＩＤＴにおいて、隣り合っている側の部分に設けられている。従って、第２～第４ＩＤＴでは、メイン部の両側に狭ピッチ部が設けられている。 Table 1 shows the wavelength of each structure and the number of IDTs from one reflector to the other reflector. The narrow pitch portion is a portion where the electrode finger pitch is smaller than that of the main portion. A narrow pitch part is provided in the part of the adjacent side in adjacent IDT. Accordingly, in the second to fourth IDTs, narrow pitch portions are provided on both sides of the main portion.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　直列腕共振子Ｓ１，Ｓ２及び並列腕共振子Ｐ１の設計パラメータは以下の通りとした。 The design parameters of the series arm resonators S1 and S2 and the parallel arm resonator P1 were as follows.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　減衰極の位置調整用インダクタＬ２のインダクタンス値＝０．４ｎＨとした。 The inductance value of the attenuation pole position adjusting inductor L2 was set to 0.4 nH.
　図６から明らかなように、第１の比較例に比べて、第１の実施形態によれば、第２のフィルタ６の第２の通過帯域である、１９２０ＭＨｚ～１９８０ＭＨｚの帯域において、アイソレーション特性を大幅に改善し得ることがわかる。これは、縦結合共振子型弾性波フィルタ１１のくし歯電極間の容量成分と、上記インダクタＬ２によって、減衰極が形成されており、それによって、上記第２の通過帯域におけるアイソレーションの改善が図られていると考えられる。ところで、上記縦結合共振子型弾性波フィルタ１１におけるくし歯電極間の容量は、第１の通過帯域を形成するためのパラメータとして調整される必要がある。そのため、アイソレーション特性において、第２のフィルタ６の第２の通過帯域のアイソレーションを改善するパラメータとしては積極的には用いることができない。これに対して、本実施形態では、上記インダクタＬ２を調整することにより、前述したように、第２の通過帯域におけるアイソレーションを効果的に改善することができる。しかも、本実施形態では、パッケージ基板１３において上記インダクタＬ２を配線の引き回しにより設けている。従って、インダクタＬ２を容易に形成することができる。 As is clear from FIG. 6, according to the first embodiment, compared with the first comparative example, the isolation characteristic is higher in the band of 1920 MHz to 1980 MHz, which is the second pass band of the second filter 6. It can be seen that it can be greatly improved. This is because an attenuation pole is formed by the capacitive component between the comb electrodes of the longitudinally coupled resonator type elastic wave filter 11 and the inductor L2, thereby improving the isolation in the second passband. It is thought that it is planned. Meanwhile, the capacitance between the comb electrodes in the longitudinally coupled resonator type acoustic wave filter 11 needs to be adjusted as a parameter for forming the first passband. Therefore, in the isolation characteristic, it cannot be positively used as a parameter for improving the isolation of the second passband of the second filter 6. On the other hand, in this embodiment, by adjusting the inductor L2, as described above, the isolation in the second passband can be effectively improved. In addition, in the present embodiment, the inductor L2 is provided in the package substrate 13 by wiring. Therefore, the inductor L2 can be easily formed.
　なお、パッケージ基板１３にインダクタＬ２を設ける場合、配線の引き回しによる導体パターンに限らず、インダクタンス素子として機能する部分をパッケージ基板１３内の任意の位置に設けてもよい。パッケージ基板１３内において、インダクタＬ２を設ける場合、所望とするインダクタンス値のインダクタを容易に設けることができる。 In addition, when providing the inductor L2 in the package substrate 13, you may provide the part which functions as an inductance element in the arbitrary positions in the package substrate 13 not only in the conductor pattern by routing of wiring. When the inductor L2 is provided in the package substrate 13, an inductor having a desired inductance value can be easily provided.
　図７は、本発明の第２の実施形態に係る弾性波フィルタ装置の回路図である。図８は、第２の実施形態の弾性波フィルタ装置で用いられている圧電基板上の電極構造を説明するための模式的平面図である。図９は、第２の実施形態で用いられているパッケージ基板の上面、第２層及び第３層の電極構造を示す模式的平面図である。図１０は、第２の実施形態で用いられているパッケージ基板の下面の電極構造を説明するための模式的平面図である。 FIG. 7 is a circuit diagram of an elastic wave filter device according to a second embodiment of the present invention. FIG. 8 is a schematic plan view for explaining an electrode structure on a piezoelectric substrate used in the acoustic wave filter device of the second embodiment. FIG. 9 is a schematic plan view showing the electrode structure of the upper surface, the second layer, and the third layer of the package substrate used in the second embodiment. FIG. 10 is a schematic plan view for explaining the electrode structure on the lower surface of the package substrate used in the second embodiment.
　図７に示すように、第２の実施形態では、インダクタＬ２が、一点鎖線Ｔで示す弾性波フィルタチップ内に設けられている。その他の構成については、弾性波フィルタ装置３１の回路は、図１に示した弾性波フィルタ装置１の回路と同様である。 As shown in FIG. 7, in the second embodiment, the inductor L2 is provided in the elastic wave filter chip indicated by the alternate long and short dash line T. About the other structure, the circuit of the elastic wave filter apparatus 31 is the same as the circuit of the elastic wave filter apparatus 1 shown in FIG.
　図８に示すように、圧電基板１６の下面において、コイル状の導体パターンによりインダクタＬ２が形成されている。このインダクタＬ２は、縦結合共振子型弾性波フィルタ１１のグラウンド電位に接続される部分に電気的に接続されるように、圧電基板１６の底面に設けられている。その他の構成は、圧電基板１６の底面の電極構造は、第１の実施形態の弾性波フィルタ装置１の場合と同様である。 As shown in FIG. 8, an inductor L2 is formed on the lower surface of the piezoelectric substrate 16 with a coiled conductor pattern. The inductor L2 is provided on the bottom surface of the piezoelectric substrate 16 so as to be electrically connected to a portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11. In other configurations, the electrode structure on the bottom surface of the piezoelectric substrate 16 is the same as that of the elastic wave filter device 1 of the first embodiment.
　他方、図９に示すように、パッケージ基板１３の上面においては、図４に示したインダクタＬ２は設けられていない。パッケージ基板１３のその他の構成は、第１の実施形態におけるパッケージ基板１３と同様である。 On the other hand, as shown in FIG. 9, the inductor L <b> 2 shown in FIG. 4 is not provided on the upper surface of the package substrate 13. Other configurations of the package substrate 13 are the same as those of the package substrate 13 in the first embodiment.
　上記のように、インダクタＬ２は、パッケージ基板１３側ではなく、弾性波フィルタチップ１４の圧電基板１６上に設けられてもよい。この場合、図８に示すＩＤＴなどの電極構造と同時に、薄膜形成法により、インダクタＬ２用のコイル状の導体パターンを形成することができる。従って、インダクタＬ２を高精度に形成することができる。よって、弾性波フィルタ装置３１では、特性のばらつきを小さくすることができる。 As described above, the inductor L2 may be provided on the piezoelectric substrate 16 of the acoustic wave filter chip 14 instead of the package substrate 13 side. In this case, the coiled conductor pattern for the inductor L2 can be formed by the thin film formation method simultaneously with the electrode structure such as the IDT shown in FIG. Therefore, the inductor L2 can be formed with high accuracy. Therefore, in the acoustic wave filter device 31, variation in characteristics can be reduced.
　第２の実施形態のアイソレーション特性及び第２の比較例のアイソレーション特性を図１１に示す。図１１の実線が第２の実施形態のアイソレーション特性を示し、破線が第２の比較例のアイソレーション特性を示す。 FIG. 11 shows the isolation characteristics of the second embodiment and the isolation characteristics of the second comparative example. The solid line in FIG. 11 shows the isolation characteristic of the second embodiment, and the broken line shows the isolation characteristic of the second comparative example.
　なお、第２の実施形態では、上記インダクタＬ２を、圧電基板１６上に設けられたコイル状の導体パターンにより形成し、そのインダクタンス値は０．６ｎＨとした。第２の比較例では、このインダクタＬ２を設けられていないことを除いては、第２の実施形態と同様とした。 In the second embodiment, the inductor L2 is formed by a coiled conductor pattern provided on the piezoelectric substrate 16, and the inductance value is 0.6 nH. The second comparative example is the same as the second embodiment except that the inductor L2 is not provided.
　第１，第２のフィルタ５，６の設計パラメータは第１の実施形態と同様とした。 The design parameters of the first and second filters 5 and 6 are the same as those in the first embodiment.
　図１１から明らかなように、第２の実施形態によれば、第２の比較例に比べ、第２の通過帯域におけるアイソレーション特性を効果的に改善し得ることがわかる。 As is apparent from FIG. 11, according to the second embodiment, it can be seen that the isolation characteristics in the second pass band can be effectively improved as compared with the second comparative example.
　図１２は、本発明の第３の実施形態に係る弾性波フィルタ装置４１の回路図であり、図１３は、本実施形態で用いられている圧電基板上の電極構造を示す模式的平面図である。 FIG. 12 is a circuit diagram of an acoustic wave filter device 41 according to the third embodiment of the present invention, and FIG. 13 is a schematic plan view showing an electrode structure on the piezoelectric substrate used in the present embodiment. is there.
　図１２に示すように、縦結合共振子型弾性波フィルタ１１のグラウンド電位に接続される部分に、インダクタＬ２が接続されている。インダクタＬ２は、並列腕共振子Ｐ１のグラウンド電位に接続される配線４２に、配線４３により接続されている。それによって、弾性波フィルタ装置４１のグラウンド電位に接続されるグラウンド端子１２と、縦結合共振子型弾性波フィルタ１１のグラウンド電位に接続される部分との間に、インダクタＬ２が接続されている。ここでは、インダクタＬ２は、第２の実施形態と同様に、弾性波フィルタチップ内に設けられている。すなわち、図１３に示すように、インダクタＬ２がコイル状の導体パターンにより、圧電基板１６の下面に設けられている。もっとも、このインダクタＬ２のグラウンド電位側の端部が、パッケージ基板内において、配線４２に電気的に接続されている。その他の構成は弾性波フィルタ装置４１は、第２の実施形態の弾性波フィルタ装置３１と同様である。図１４は、第２の実施形態、第３の実施形態及び第２の比較例の弾性波フィルタ装置のアイソレーション特性を示す図である。実線が第３の実施形態の結果を、一点鎖線が第２の実施形態の結果を、破線が第２の比較例の結果を示す。 As shown in FIG. 12, an inductor L2 is connected to a portion of the longitudinally coupled resonator type acoustic wave filter 11 that is connected to the ground potential. The inductor L2 is connected by a wiring 43 to a wiring 42 connected to the ground potential of the parallel arm resonator P1. Thereby, the inductor L2 is connected between the ground terminal 12 connected to the ground potential of the acoustic wave filter device 41 and the portion connected to the ground potential of the longitudinally coupled resonator type acoustic wave filter 11. Here, the inductor L2 is provided in the acoustic wave filter chip as in the second embodiment. That is, as shown in FIG. 13, the inductor L2 is provided on the lower surface of the piezoelectric substrate 16 by a coiled conductor pattern. However, the end on the ground potential side of the inductor L2 is electrically connected to the wiring 42 in the package substrate. Otherwise, the elastic wave filter device 41 is the same as the elastic wave filter device 31 of the second embodiment. FIG. 14 is a diagram illustrating isolation characteristics of the elastic wave filter devices of the second embodiment, the third embodiment, and the second comparative example. The solid line shows the result of the third embodiment, the alternate long and short dash line shows the result of the second embodiment, and the broken line shows the result of the second comparative example.
　図１４から明らかなように、第３の実施形態においても、第２の実施形態と同様に、第２の比較例に比べ、第２の通過帯域におけるアイソレーション特性を効果的に改善し得ることがわかる。このように、弾性波フィルタ装置４１のグラウンド電位に接続されるグラウンド端子１２に対し、インダクタＬ２が並列腕共振子Ｐ１のグラウンド電位側の端部と共通接続されて、グラウンド端子１２に接続されてもよい。すなわち、インダクタＬ２のグラウンド電位側の端部は、グラウンド端子１２に単独で接続される必要は必ずしもない。 As is apparent from FIG. 14, the third embodiment can effectively improve the isolation characteristics in the second passband as compared with the second comparative example, as in the second embodiment. I understand. As described above, the inductor L2 is commonly connected to the ground potential side end of the parallel arm resonator P1 and connected to the ground terminal 12 with respect to the ground terminal 12 connected to the ground potential of the acoustic wave filter device 41. Also good. That is, the end of the inductor L2 on the ground potential side is not necessarily connected to the ground terminal 12 alone.
　図１５は、本発明の第４の実施形態に係る弾性波フィルタ装置の回路図であり、図１６は、第４の実施形態で用いられている圧電基板上の電極構造を示す模式的平面図である。 FIG. 15 is a circuit diagram of an acoustic wave filter device according to a fourth embodiment of the present invention, and FIG. 16 is a schematic plan view showing an electrode structure on a piezoelectric substrate used in the fourth embodiment. It is.
　本実施形態においても、インダクタＬ２は、弾性波フィルタチップ１４の圧電基板１６上に設けられている。もっとも、第１のフィルタ５において、並列腕共振子Ｐ１が、縦結合共振子型弾性波フィルタ１１と、受信端子３との間に設けられている。このように、並列腕共振子Ｐ１は、縦結合共振子型弾性波フィルタ１１と受信端子３との間に設けられていてもよい。この場合、並列腕共振子Ｐ１のグラウンド電位に接続されている配線５２に、インダクタＬ２のグラウンド電位側の端部が圧電基板１６上において、接続されている。このように、縦結合共振子型弾性波フィルタ１１に接続されている直列腕共振子及び並列腕共振子の数及び配置の態様は、特に限定されるものではない。この場合には、並列腕共振子Ｐ１のグラウンド電位側の端部と、インダクタＬ２のグラウンド電位側の端部とが、共通接続され、グラウンド端子１２に電気的に接続されている。 Also in the present embodiment, the inductor L2 is provided on the piezoelectric substrate 16 of the acoustic wave filter chip 14. However, in the first filter 5, the parallel arm resonator P <b> 1 is provided between the longitudinally coupled resonator type elastic wave filter 11 and the receiving terminal 3. As described above, the parallel arm resonator P <b> 1 may be provided between the longitudinally coupled resonator type acoustic wave filter 11 and the receiving terminal 3. In this case, the end of the inductor L2 on the ground potential side is connected to the wiring 52 connected to the ground potential of the parallel arm resonator P1 on the piezoelectric substrate 16. As described above, the number and arrangement of the series arm resonators and the parallel arm resonators connected to the longitudinally coupled resonator type acoustic wave filter 11 are not particularly limited. In this case, the end on the ground potential side of the parallel arm resonator P1 and the end on the ground potential side of the inductor L2 are commonly connected and electrically connected to the ground terminal 12.
　なお、本発明の弾性波フィルタ装置では、通過帯域が相対的に高い第１のフィルタ５において、縦結合共振子型弾性波フィルタと、直列腕共振子及び並列腕共振子の少なくとも一方とを含む回路構成を有する限り、第１のフィルタ５の回路構成は特に限定されない。 In the elastic wave filter device of the present invention, the first filter 5 having a relatively high passband includes a longitudinally coupled resonator type elastic wave filter and at least one of a series arm resonator and a parallel arm resonator. As long as it has a circuit configuration, the circuit configuration of the first filter 5 is not particularly limited.
　また、第２のフィルタ６については、第１のフィルタ５よりも通過帯域が低い第２の通過帯域を有する限り、回路構成及び利用する素子について、特に限定されるものではない。また、上述してきた各実施形態では、デュプレクサを例にとり説明してきたが、本発明は３以上の帯域通過型フィルタが一端側で束ねられているＣＡ（ＣＡＲＲＩＥＲ　ＡＧＧＲＥＧＡＴＩＯＮ）用フィルタ装置にも適用することができる。 Further, the second filter 6 is not particularly limited with respect to the circuit configuration and the elements to be used as long as the second filter 6 has a second pass band that is lower than the first filter 5. In each of the embodiments described above, the duplexer has been described as an example. However, the present invention is also applicable to a CA (CARRIER AGGREGATION) filter device in which three or more band-pass filters are bundled on one end side. Can do.
１…弾性波フィルタ装置
２…共通端子
２ａ，３ａ，４ａ…電極ランド
３…受信端子
４…送信端子
５…第１のフィルタ
６…第２のフィルタ
１１…縦結合共振子型弾性波フィルタ
１２…グラウンド端子
１２ａ…電極ランド
１３…パッケージ基板
１４…弾性波フィルタチップ
１５…モールド樹脂
１６…圧電基板
２１～２８…電極ランド
３１，４１…弾性波フィルタ装置
４２，４３…配線
５２…配線
Ｌ１…インピーダンス調整用インダクタ
Ｌ２…インダクタ
Ｓ１，Ｓ２，Ｓ１１～Ｓ１５…直列腕共振子
Ｐ１，Ｐ１１～Ｐ１４…並列腕共振子 DESCRIPTION OF SYMBOLS 1 ... Elastic wave filter apparatus 2 ... Common terminal 2a, 3a, 4a ... Electrode land 3 ... Reception terminal 4 ... Transmission terminal 5 ... 1st filter 6 ... 2nd filter 11 ... Longitudinal coupled resonator type | mold elastic wave filter 12 ... Ground terminal 12a ... Electrode land 13 ... Package substrate 14 ... Elastic wave filter chip 15 ... Mold resin 16 ... Piezoelectric substrates 21-28 ... Electrode lands 31, 41 ... Elastic wave filter devices 42, 43 ... Wiring 52 ... Wiring L1 ... Impedance adjustment Inductor L2 ... inductors S1, S2, S11 to S15 ... series arm resonators P1, P11 to P14 ... parallel arm resonators

Claims (7)

  1. 　第１の通過帯域を有し、縦結合共振子型弾性波フィルタと、直列腕共振子及び並列腕共振子の内の少なくとも一方とを有する第１のフィルタと、
    　前記第１のフィルタの前記第１の通過帯域よりも低域側に位置している第２の通過帯域を有する、第２のフィルタと、
    　前記第１のフィルタの一端と、前記第２のフィルタの一端とが共通接続されており、
    　グラウンド電位に接続されるグラウンド端子と、
    　前記縦結合共振子型弾性波フィルタのグラウンド電位に接続される部分と、前記グラウンド端子との間に設けられているインダクタと、
    をさらに備える、弾性波フィルタ装置。     A first filter having a first passband and having a longitudinally coupled resonator type acoustic wave filter and at least one of a series arm resonator and a parallel arm resonator;
    A second filter having a second passband located on a lower frequency side than the first passband of the first filter;
    One end of the first filter and one end of the second filter are connected in common,
    A ground terminal connected to the ground potential;
    A portion connected to a ground potential of the longitudinally coupled resonator type acoustic wave filter and an inductor provided between the ground terminal;
    An elastic wave filter device further comprising:
  2. 　前記第１のフィルタが、前記縦結合共振子型弾性波フィルタと、前記直列腕共振子及び並列腕共振子を有するラダー型フィルタとを含む、請求項１に記載の弾性波フィルタ装置。 2. The elastic wave filter device according to claim 1, wherein the first filter includes the longitudinally coupled resonator type elastic wave filter and a ladder type filter having the series arm resonator and the parallel arm resonator.
  3. 　前記第１及び第２のフィルタが、１つの弾性波フィルタチップに構成されている、請求項１または２に記載の弾性波フィルタ装置。 The elastic wave filter device according to claim 1 or 2, wherein the first and second filters are configured in one elastic wave filter chip.
  4. 　前記インダクタが、前記弾性波フィルタチップに設けられている、請求項３に記載の弾性波フィルタ装置。 4. The acoustic wave filter device according to claim 3, wherein the inductor is provided in the acoustic wave filter chip.
  5. 　前記弾性波フィルタチップが圧電基板を有し、前記インダクタが前記圧電基板上に設けられている、請求項４に記載の弾性波フィルタ装置。 The elastic wave filter device according to claim 4, wherein the elastic wave filter chip has a piezoelectric substrate, and the inductor is provided on the piezoelectric substrate.
  6. 　前記弾性波フィルタチップが搭載されているパッケージ基板をさらに備え、前記パッケージ基板に前記グラウンド端子及び前記インダクタが設けられている、請求項３に記載の弾性波フィルタ装置。 4. The acoustic wave filter device according to claim 3, further comprising a package substrate on which the acoustic wave filter chip is mounted, wherein the package substrate is provided with the ground terminal and the inductor.
  7. 　前記並列腕共振子が、前記縦結合共振子型弾性波フィルタの前記共通接続されている一端側とは反対側に接続されており、前記並列腕共振子のグラウンド電位側の端部と、前記縦結合共振子型弾性波フィルタのグラウンド電位に接続される部分との間に前記インダクタが接続されている、請求項１～６のいずれか１項に記載の弾性波フィルタ装置。 The parallel arm resonator is connected to a side opposite to the commonly connected one end side of the longitudinally coupled resonator type acoustic wave filter, an end of the parallel arm resonator on the ground potential side, and The elastic wave filter device according to any one of claims 1 to 6, wherein the inductor is connected to a portion connected to a ground potential of a longitudinally coupled resonator type elastic wave filter.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170117873A1 (en) * 2015-10-26 2017-04-27 Murata Manufacturing Co., Ltd. Band pass filter and duplexer
CN110601676A (en) * 2018-05-23 2019-12-20 株式会社村田制作所 Multiplexer and communication device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008271230A (en) * 2007-04-20 2008-11-06 Fujitsu Ltd Antenna branch filter
WO2012169231A1 (en) * 2011-06-09 2012-12-13 株式会社村田製作所 Elastic wave filter device
WO2016013330A1 (en) * 2014-07-22 2016-01-28 株式会社村田製作所 Duplexer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008271230A (en) * 2007-04-20 2008-11-06 Fujitsu Ltd Antenna branch filter
WO2012169231A1 (en) * 2011-06-09 2012-12-13 株式会社村田製作所 Elastic wave filter device
WO2016013330A1 (en) * 2014-07-22 2016-01-28 株式会社村田製作所 Duplexer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170117873A1 (en) * 2015-10-26 2017-04-27 Murata Manufacturing Co., Ltd. Band pass filter and duplexer
US9998098B2 (en) * 2015-10-26 2018-06-12 Murata Manufacturing Co., Ltd. Band pass filter and duplexer
CN110601676A (en) * 2018-05-23 2019-12-20 株式会社村田制作所 Multiplexer and communication device
CN110601676B (en) * 2018-05-23 2023-07-14 株式会社村田制作所 Multiplexer and communication device

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