WO2017159834A1 - Élément de filtre haute fréquence, multiplexeur, émetteur et récepteur - Google Patents

Élément de filtre haute fréquence, multiplexeur, émetteur et récepteur Download PDF

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Publication number
WO2017159834A1
WO2017159834A1 PCT/JP2017/010814 JP2017010814W WO2017159834A1 WO 2017159834 A1 WO2017159834 A1 WO 2017159834A1 JP 2017010814 W JP2017010814 W JP 2017010814W WO 2017159834 A1 WO2017159834 A1 WO 2017159834A1
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Prior art keywords
frequency
band
transmission
filter
reception
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PCT/JP2017/010814
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English (en)
Japanese (ja)
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正人 荒木
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株式会社村田製作所
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Publication of WO2017159834A1 publication Critical patent/WO2017159834A1/fr

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/38—Impedance-matching networks
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/46—Networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source
    • 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
    • H03H9/46—Filters
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
    • H03H9/58—Multiple crystal filters
    • 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
    • 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 a high frequency filter element, a multiplexer, a transmission device, and a reception device.
  • Recent mobile phones are required to support a plurality of frequency bands and a plurality of wireless systems, so-called multiband and multimode, in one terminal.
  • a multiplexer for demultiplexing a high-frequency signal in accordance with a radio carrier frequency (band) is arranged immediately below one antenna.
  • a radio carrier frequency (band) is arranged immediately below one antenna.
  • band pass filters As the plurality of band pass filters constituting the multiplexer, an elastic wave filter characterized by low loss in the pass band and steepness in the vicinity of the pass band is used.
  • Patent Document 1 discloses a duplexer including a reception filter and a transmission filter composed of a ladder-type surface acoustic wave filter. More specifically, the transmission filter has a plurality of parallel arm resonators and a plurality of series arm resonators, and one of the plurality of parallel arm resonators has a higher resonance frequency than the plurality of series arm resonators. In addition, the parallel arm resonator has a lower capacitance than other parallel arm resonators. Thereby, the isolation characteristic in the reception frequency band is improved.
  • the duplexer described in Patent Document 1 can ensure low loss in the pass band, but only by optimizing the resonance frequency and capacitance of the parallel arm resonator, the frequency band of the other party (reception band) It is difficult to ensure a high attenuation throughout.
  • the present invention has been made to solve the above-described problem, and a high-frequency filter element, multiplexer, transmitter, and receiver that can achieve high attenuation outside the passband while ensuring low loss in the passband.
  • the purpose is to provide.
  • a high-frequency filter element includes a first terminal and a second terminal for inputting or outputting a high-frequency signal, and a high frequency in a first frequency band connected to the first terminal.
  • a first filter unit having a characteristic of selectively passing a signal; and a high-frequency signal connected between the second terminal and the first filter unit and having a second frequency band different from the first frequency band is selectively selected.
  • a second filter unit having a characteristic of attenuating the first filter unit, wherein the second filter unit includes a series resonator connected between the first filter unit and the second terminal, and the first filter unit.
  • a parallel resonator connected between a connection path to the second terminal and a reference terminal, and the anti-resonance frequency of the parallel resonator is arranged outside the band of the first frequency band,
  • the resonance frequency of the series resonator is
  • the antiresonance frequency of the series resonator and the resonance frequency of the parallel resonator are between the resonance frequency of the series resonator and the antiresonance frequency of the parallel resonator. It is arranged.
  • the high frequency filter element has a band blocking function for attenuating the high frequency signal in the second frequency band in addition to the first filter unit having a band pass function for allowing the high frequency signal in the first frequency band to pass.
  • a filter unit is provided.
  • the second filter unit has a pair of series resonators and parallel resonators, and from the low frequency side, (1) the resonance frequency of the series resonators, (2) the antiresonance frequency of the series resonators and the parallel resonators. They are arranged in the order of the resonance frequency of the resonator and (3) the anti-resonance frequency of the parallel resonator.
  • the antiresonance frequency of the parallel resonator is arranged outside the band of the first frequency band that is the pass band, the band between the resonance frequency of the series resonator and the antiresonance frequency of the parallel resonator is It is possible to use the second frequency band outside the one frequency band. Therefore, it is possible to achieve high attenuation outside the pass band while ensuring low loss of the pass band by the first filter unit.
  • the anti-resonance frequency of the series resonator and the resonance frequency of the parallel resonator may be arranged in the second frequency band.
  • the high frequency signal in the vicinity of the antiresonance frequency of the series resonator or the resonance frequency of the parallel resonator, which is arranged between the resonance frequency of the series resonator and the antiresonance frequency of the parallel resonator Since the impedance is high in the direction of propagation with the terminal, the passage is blocked. Therefore, it is possible to optimize the attenuation characteristic of the second frequency band that is outside the pass band.
  • an impedance matching circuit connected to the second terminal may be further provided.
  • the second filter unit has a band rejection function, and thus is externally connected to the second terminal. It is assumed that the impedance of the external circuit and the high frequency filter element do not match. On the other hand, by connecting an impedance matching circuit between the second terminal and the second filter unit, impedance matching between the high frequency filter element and the external circuit can be achieved, and a high frequency signal in the first frequency band can be obtained. Can be passed with lower loss.
  • each of the first filter unit and the second filter unit may be formed of an elastic wave resonator using SAW (Surface Acoustic Wave) or BAW (Bulk Acoustic Wave).
  • SAW Surface Acoustic Wave
  • BAW Bulk Acoustic Wave
  • first filter portion and the second filter portion may be formed on a single piezoelectric substrate.
  • first filter unit and the second filter unit may be integrated into one chip.
  • the multiplexer filters the high-frequency signal input from the transmission input terminal and outputs the high-frequency signal in the transmission band to the common terminal; and the input from the common terminal A reception-side filter circuit that filters a high-frequency signal and outputs a high-frequency signal in a reception band to a reception output terminal, wherein the transmission-side filter circuit includes the high-frequency filter element described above, and the transmission band Is the first frequency band, and the reception band is the second frequency band.
  • the multiplexer filters the high-frequency signal input from the transmission input terminal and outputs the high-frequency signal in the transmission band to the common terminal; and the input from the common terminal And a reception-side filter circuit that filters a high-frequency signal and outputs a high-frequency signal in a reception band to a reception output terminal, wherein the reception-side filter circuit includes the high-frequency filter element described above, and the transmission band Is the second frequency band, and the reception band is the first frequency band.
  • the second terminal may be the common terminal, and the impedance matching circuit may be connected between the common terminal and the second filter unit.
  • the impedance of the antenna element connected to the common terminal and the filter circuit may not match.
  • impedance matching between the antenna element and the filter circuit can be achieved by connecting the impedance matching circuit between the common terminal and the second filter unit, and a high-frequency signal in the first frequency band is It is possible to pass through with lower loss.
  • the second terminal may be the transmission input terminal or the reception output terminal, and the impedance matching circuit may be connected between the transmission input terminal or the reception output terminal and the second filter unit. Good.
  • the second filter unit is arranged on the transmission input terminal side or the reception output terminal side of the first filter unit and the second filter unit, an external circuit connected to the transmission input terminal or the reception output terminal And the impedance of the filter circuit are assumed not to match.
  • an impedance matching circuit is connected between the transmission input terminal or the reception output terminal and the second filter unit, so that impedance matching between the external circuit and the filter circuit can be achieved, and the first frequency band It is possible to pass the high-frequency signal with lower loss.
  • the multiplexer is a multiplexer including a first duplexer and a second duplexer, and the first duplexer performs first transmission by filtering a high-frequency signal input from a first transmission input terminal.
  • a first transmission-side filter circuit that outputs a high-frequency signal in a band to an antenna element via a common terminal; and the first transmission band by filtering a high-frequency signal input from the antenna element via the common terminal.
  • a first reception-side filter circuit that outputs a high-frequency signal in a first reception band different from the first reception output terminal to the first reception output terminal, wherein the second duplexer filters the high-frequency signal input from the second transmission input terminal
  • a high-frequency signal in a second transmission band different from the first transmission band and the first reception band is passed through the common terminal.
  • a second transmission-side filter circuit that outputs to the antenna element, and a high-frequency signal input from the antenna element via the common terminal to filter the first transmission band, the first reception band, and the second transmission 7.
  • a second reception side filter circuit that outputs a high-frequency signal in a second reception band different from the band to a second reception output terminal, wherein the first transmission side filter circuit is according to any one of claims 1 to 6.
  • the first transmission band may be the first frequency band
  • the second reception band may be the second frequency band.
  • the second loss is ensured while ensuring low loss in the first transmission band. It is possible to achieve high attenuation of the reception band and high isolation (cross isolation) between the duplexers.
  • the transmission device is a transmission device that transmits high-frequency signals in a plurality of transmission bands via an antenna element, and the transmission device receives a high-frequency signal input from a first transmission input terminal.
  • the first transmission side filter circuit that outputs the high-frequency signal in the first transmission band to the antenna element via the common terminal, and the high-frequency signal input from the second transmission input terminal to filter the first
  • a second transmission-side filter circuit that outputs a high-frequency signal in a second transmission band different from the transmission band to the antenna element via the common terminal, wherein the first transmission-side filter circuit comprises: 6.
  • the high-frequency filter element according to claim 6, wherein the first transmission band is the first frequency band, and the second transmission band is the second frequency band.
  • the first transmission side filter circuit includes the high-frequency filter element
  • the first transmission side filter circuit includes the high-frequency filter element
  • a receiving device is a receiving device that receives high-frequency signals in a plurality of reception bands via an antenna element, and the receiving device receives an input from the antenna element via a common terminal.
  • a first reception-side filter circuit that filters the received high-frequency signal and outputs a high-frequency signal in the first reception band to the first reception output terminal; and a high-frequency signal input from the antenna element via the common terminal
  • a second reception side filter circuit for outputting a high frequency signal in a second reception band different from the first reception band to a second reception output terminal, wherein the first reception side filter circuit comprises: The high frequency filter element according to any one of claims 1 to 4, wherein the first reception band is the first frequency band, and the second reception band is the second frequency band.
  • the first receiving side filter circuit when the first receiving side filter circuit includes the high frequency filter element, the first It is possible to achieve high attenuation in the second reception band and high isolation between the reception side filter circuits while ensuring low loss in the reception band.
  • high attenuation outside the pass band can be achieved while ensuring low loss in the pass band.
  • FIG. 1 is a circuit configuration diagram of a duplexer and peripheral circuits according to an embodiment.
  • FIG. 2 is a circuit configuration diagram of the transmission filter according to the embodiment.
  • FIG. 3 is a plan view and a cross-sectional view schematically showing the resonator of the surface acoustic wave filter according to the embodiment.
  • FIG. 4 is a circuit configuration diagram of a transmission filter according to a comparative example.
  • FIG. 5 is a graph showing the pass characteristic of the duplexer according to the comparative example and the impedance characteristic of each resonator.
  • FIG. 6 is a graph showing pass characteristics of the duplexer according to the embodiment and impedance characteristics of each resonator.
  • FIG. 1 is a circuit configuration diagram of a duplexer and peripheral circuits according to an embodiment.
  • FIG. 2 is a circuit configuration diagram of the transmission filter according to the embodiment.
  • FIG. 3 is a plan view and a cross-sectional view schematically showing the resonator of the surface
  • FIG. 7A is a graph comparing the pass characteristics of the duplexers according to the embodiment and the comparative example.
  • FIG. 7B is a graph comparing the isolation characteristics of the duplexers according to the embodiment and the comparative example.
  • FIG. 8A is a Smith chart of the transmission filter according to the embodiment before the matching circuit is added.
  • FIG. 8B is a Smith chart of the transmission filter according to the embodiment to which a matching circuit is added.
  • FIG. 9 is a circuit configuration diagram of a quadplexer and peripheral circuits according to a modification of the embodiment.
  • FIG. 10 is a circuit configuration diagram of a first transmission-side filter circuit according to a modification of the embodiment.
  • the duplexer 1 is a multiplexer in which a Band 8 transmission side filter circuit and a Band 8 reception side filter circuit are bundled at a common terminal.
  • FIG. 1 is a circuit configuration diagram of a duplexer 1 and peripheral circuits according to the embodiment.
  • the duplexer 1 includes a transmission filter 11, a reception filter 12, a matching circuit 13, a transmission input terminal 10, a reception output terminal 20, and a common terminal 30.
  • the transmission filter 11 and the matching circuit 13 constitute a high frequency filter element.
  • the duplexer 1, the antenna element 2, and the antenna matching circuit 3 constitute a front end circuit.
  • the antenna matching circuit 3 is a circuit that is connected to the antenna element 2 and the duplexer 1 and performs impedance matching between the antenna element 2 and the duplexer 1. As a result, the duplexer 1 can receive the received signal from the antenna element 2 with low loss and output the transmission signal to the antenna element 2 with low loss.
  • the antenna matching circuit 3 is composed of one or more high-frequency circuit components, and includes, for example, a chip-shaped inductor and a chip-shaped capacitor.
  • the antenna matching circuit 3 is not an essential component of the front end circuit.
  • the transmission filter 11 receives a transmission signal generated by a high-frequency signal processing circuit (RFIC or the like) and amplified via a power amplifier via a transmission input terminal 10, and transmits a Band 8 transmission passband (first frequency). This is a band-pass filter that performs filtering by band) and outputs to the common terminal 30.
  • a matching circuit 13 is connected between the transmission input terminal 10 and the transmission filter 11.
  • the reception filter 12 is a band-pass filter that receives the reception signal input from the common terminal 30, filters the reception signal in the Band 8 reception pass band (second frequency band), and outputs the filtered signal to the reception output terminal 20.
  • the transmission filter 11 and the reception filter 12 are connected to a common terminal 30.
  • the matching circuit 13 is connected to the filter input terminal 14 and the transmission input terminal 10 of the transmission filter 11, and impedance matching is performed for impedance matching between the transmission circuit 11 and an external circuit such as a power amplifier connected to the transmission input terminal 10. Circuit. Thereby, the duplexer 1 can input a transmission signal from an external circuit with low loss.
  • the matching circuit 13 is composed of one or more high-frequency circuit components, and includes, for example, a chip-shaped inductor and a chip-shaped capacitor, or a wiring pattern formed on a substrate.
  • the matching circuit 13 may be connected between the common terminal 30 and the transmission filter 11.
  • the duplexer 1 having the simplest configuration as the multiplexer according to the present invention is described, but the multiplexer according to the present invention is not limited to the duplexer 1.
  • the multiplexer according to the present invention may be a multiplexer having at least a duplexer 1 configuration, a quadplexer, a pentaplexer, and a multiplexer having a higher number of bands.
  • the FDD (Frequency Division Duplex) system duplexer 1 is described as an example of the multiplexer according to the present invention, but the present invention is also applicable to a TDD (Time Division Duplex) system multiplexer.
  • TDD Time Division Duplex
  • the common terminal is connected to the antenna matching circuit 3
  • the first selection terminal is connected to the transmission filter 11, and the reception filter 12 is connected.
  • An SPDT (Single Pole Double Throw) type switch to which the second selection terminal is connected is arranged. By switching the switch, the transmission filter 11 or the reception filter 12 is exclusively connected to the antenna element 2. Even with this configuration, by having the configuration of the transmission filter 11 according to the present embodiment, it is possible to highly suppress the transmission signal from entering the reception filter 12 via the switch.
  • the transmission filter 11 is composed of a surface acoustic wave (SAW) filter. Thereby, the transmission filter 11 can be downsized.
  • SAW surface acoustic wave
  • FIG. 2 is a circuit configuration diagram of the transmission filter 11 according to the embodiment.
  • the transmission filter 11 has a configuration in which a first filter unit 11A and a second filter unit 11B are connected in cascade.
  • 11 A of 1st filter parts are connected to the common terminal 30 (1st terminal), are provided with the series resonators 101, 102, and 103, and the parallel resonators 151 and 152, and are a high frequency signal of a transmission band (1st frequency band). Is selectively passed.
  • the second filter unit 11B is connected to the transmission input terminal 10 (second terminal) via the filter input terminal 14 and the matching circuit 13, and includes a series resonator 104 and a parallel resonator 153, and a reception band different from the transmission band. It has a characteristic of selectively attenuating a high-frequency signal in the (second frequency band).
  • the series resonators 101 to 104 are connected in series with each other between the filter input terminal 14 and the common terminal 30.
  • the parallel resonators 151 to 153 are connected in parallel to each other between the connection points of the series resonators 101 to 104 and the reference terminal (ground).
  • the first filter unit 11A has a band pass function.
  • the second filter unit 11B has a band rejection function.
  • the transmission filter 11 constitutes a ladder-type bandpass filter as a whole by the cascade connection of the first filter unit 11A and the second filter unit 11B.
  • the first filter portion 11A may not have a configuration of a ladder-type surface acoustic wave element.
  • the circuit configuration of the first filter unit 11A may be, for example, a longitudinally coupled surface acoustic wave element or the like, or elastic using a BAW (Bulk Acoustic Wave), depending on the required specifications of the transmission filter 11. You may be comprised with the wave resonator. Furthermore, it may not have the structure of an acoustic wave element, and may have another filter structure.
  • the circuit configuration of the reception filter 12 is not particularly limited.
  • the reception filter 12 may be, for example, a ladder type surface acoustic wave element, a longitudinally coupled type surface acoustic wave element, or the like according to the required specifications.
  • the transmission filter 11 and the reception filter 12 can be formed on one piezoelectric substrate, and the size can be reduced. Can be realized.
  • the reception filter 12 may be constituted by an acoustic wave resonator using BAW, and may not have the configuration of an acoustic wave element, and may have another filter structure. Also good.
  • FIG. 3 is a plan view and a cross-sectional view schematically showing a resonator of the surface acoustic wave filter according to the embodiment.
  • a schematic plan view and a schematic cross-sectional view showing the structure of the series resonator 101 among the plurality of resonators constituting the transmission filter 11 are illustrated.
  • the series resonator shown in FIG. 3 is for explaining a typical structure of the plurality of resonators, and the number and length of electrode fingers constituting the electrode are limited to this. Not.
  • Each resonator of the transmission filter 11 includes a piezoelectric substrate 510 and comb-shaped IDT (InterDigital Transducer) electrodes 101a and 101b.
  • IDT InterDigital Transducer
  • the IDT electrode 101a includes a plurality of electrode fingers 110a that are parallel to each other and a bus bar electrode 111a that connects the plurality of electrode fingers 110a.
  • the IDT electrode 101b includes a plurality of electrode fingers 110b that are parallel to each other and a bus bar electrode 111b that connects the plurality of electrode fingers 110b.
  • the IDT electrode 54 constituted by the plurality of electrode fingers 110a and 110b and the bus bar electrodes 111a and 111b has a laminated structure of the adhesion layer 541 and the main electrode layer 542 as shown in the sectional view of FIG. ing.
  • the adhesion layer 541 is a layer for improving the adhesion between the piezoelectric substrate 510 and the main electrode layer 542, and, for example, Ti is used as the material.
  • the film thickness of the adhesion layer 541 is, for example, 12 nm.
  • the main electrode layer 542 is made of, for example, Al containing 1% Cu.
  • the film thickness of the main electrode layer 542 is, for example, 162 nm.
  • the protective layer 550 is formed so as to cover the IDT electrodes 101a and 101b.
  • the protective layer 550 is a layer for the purpose of protecting the main electrode layer 542 from the external environment, adjusting frequency temperature characteristics, and improving moisture resistance.
  • the protective layer 550 is a film mainly composed of silicon dioxide. .
  • the materials forming the adhesion layer 541, the main electrode layer 542, and the protective layer 550 are not limited to the materials described above. Furthermore, the IDT electrode 54 does not have to have the above laminated structure.
  • the IDT electrode 54 may be made of, for example, a metal or alloy such as Ti, Al, Cu, Pt, Au, Ag, or Pd, or may be made of a plurality of laminates made of the above metal or alloy. May be. Further, the protective layer 550 may not be formed.
  • the piezoelectric substrate 510 is, for example, a lithium tantalate single crystal or ceramic cut at a predetermined cut angle, and is made of a single crystal or ceramic in which a surface acoustic wave propagates in a predetermined direction.
  • the wavelength of the surface acoustic wave resonator is defined by the repetition pitch ⁇ of the plurality of electrode fingers 110a and 110b constituting the IDT electrodes 101a and 101b shown in the middle of FIG.
  • the crossing width L of the IDT electrode is an electrode finger length where the electrode finger 110a of the IDT electrode 101a and the electrode finger 110b of the IDT electrode 101b overlap as shown in the upper part of FIG.
  • the logarithm is the number of electrode fingers 110a or 110b.
  • each surface acoustic wave filter constituting the transmission filter 11 is not limited to the structure described in FIG.
  • the IDT electrode 54 may not be a laminated structure of metal films but may be a single layer of metal films.
  • both the first filter unit 11A and the second filter unit 11B are formed of surface acoustic wave resonators
  • the first filter unit 11A and the second filter unit 11B are formed of a single piezoelectric substrate 510. It may be formed on the top. This accelerates the downsizing and the low profile of the transmission filter 11 and the duplexer 1.
  • first filter unit 11A and the second filter unit 11B are made into one chip regardless of the circuit configuration of the first filter unit 11A and the second filter unit 11B. Furthermore, the first filter unit 11A, the second filter unit 11B, and the matching circuit 13 may be integrated into one chip. This also promotes downsizing and low profile of the transmission filter 11 and the duplexer 1.
  • the pass characteristics of the duplexer 1 according to the present embodiment will be described in comparison with the pass characteristics of the duplexer according to the comparative example.
  • the circuit configuration and pass characteristic of the transmission filter 411 included in the duplexer according to the comparative example will be described.
  • FIG. 4 is a circuit configuration diagram of the transmission filter 411 according to the comparative example. As illustrated in FIG. 4, the transmission filter 411 includes series resonators 401, 402, 403, and 404 and parallel resonators 451, 452, and 453.
  • the series resonators 401 to 404 are connected in series with each other between the filter input terminal 14 and the common terminal 30.
  • the parallel resonators 451 to 453 are connected in parallel to each other between the connection points of the series resonators 401 to 404 and the reference terminal (ground).
  • the transmission filter 411 constitutes a ladder type band pass filter.
  • FIG. 5 is a graph showing the pass characteristic of the duplexer according to the comparative example and the impedance characteristic of each resonator. More specifically, the upper part of FIG. 5 shows the insertion loss of the duplexer according to the comparative example. The transmission characteristic of the transmission filter 411 between the transmission input terminal 10 and the common terminal 30 and the common terminal 30- The pass characteristics of the reception filter 12 between the reception output terminals 20 are simultaneously shown. The lower part of FIG. 5 shows impedance characteristics of the resonators of the transmission filter 411 included in the duplexer according to the comparative example.
  • the parallel resonators 451 to 453 have a resonance frequency frp and an anti-resonance frequency fap (> frp).
  • Each of the series resonators 401 to 404 has a resonance frequency frs and an anti-resonance frequency fas (> frs> frp).
  • the resonance frequencies of the parallel resonators 451 to 453 do not have to coincide with each other and may vary within a predetermined frequency range.
  • the antiresonance frequencies of the parallel resonators 451 to 453 may not coincide with each other, and may vary within a predetermined frequency range.
  • the resonance frequencies and antiresonance frequencies of the series resonators 401 to 404 do not have to coincide with each other and may vary within a predetermined frequency range.
  • the anti-resonance frequency fap of the parallel resonators 451 to 453 and the resonance frequency frs of the series resonators 401 to 404 are brought close to each other. That is, frp ⁇ frs ⁇ fap ⁇ fas is established.
  • frp ⁇ frs ⁇ fap ⁇ fas is established.
  • the vicinity of the resonance frequency frp where the impedances of the parallel resonators 451 to 453 approach zero becomes a low-frequency side stop band of the transmission band.
  • the impedance of the parallel resonators 451 to 453 increases near the antiresonance frequency fap, and the impedance of the series resonators 401 to 404 approaches 0 near the resonance frequency frs.
  • the signal path from the filter input terminal 14 to the common terminal 30 becomes a signal pass band.
  • the impedance of the series resonators 401 to 404 becomes high, and becomes a high frequency side blocking region of the transmission band.
  • the ladder-type surface acoustic wave filter has a resonance characteristic that is advantageous for ensuring low loss in the pass band and steepness at the low frequency end and high frequency end of the pass band, but outside the pass band. It is difficult to ensure high attenuation outside the passband because the insertion loss rebounds severely. In particular, it is easy to ensure high attenuation at a predetermined frequency point outside the pass band, but for example, it is difficult to ensure high attenuation in the entire reception band when the pass band is the transmission band. . As shown in the upper part of FIG. 5, in the pass characteristic of the transmission filter 411, the attenuation in the reception band cannot be secured.
  • the duplexer 1 according to the present embodiment, it is possible to ensure high attenuation in the reception band while ensuring low loss in the transmission band.
  • FIG. 6 is a graph showing the pass characteristic of the duplexer 1 and the impedance characteristic of each resonator according to the embodiment. More specifically, the upper part of FIG. 6 shows the insertion loss of the duplexer 1 according to the embodiment. The transmission characteristic of the transmission filter 11 between the transmission input terminal 10 and the common terminal 30 and the common terminal The pass characteristic of the reception filter 12 between 30 and the reception output terminal 20 is shown at the same time. 6 shows impedance characteristics of the resonators of the transmission filter 11 included in the duplexer 1 according to the embodiment.
  • the transmission filter 11 is connected to the common terminal 30 and connected to the transmission input terminal 10 via the matching circuit 13 and the first filter unit 11A having a characteristic of selectively allowing a high-frequency signal in the transmission band to pass therethrough. And a second filter unit 11B having a characteristic of selectively attenuating the high frequency signal.
  • the first filter unit 11A is composed of series resonators 101, 102, and 103 and parallel resonators 151 and 152, and has a band-pass function.
  • the parallel resonators 151 to 152 have a resonance frequency frp and an anti-resonance frequency fap (> frp).
  • the series resonators 101 to 103 each have a resonance frequency frs and an anti-resonance frequency fas (> frs> frp). Note that the resonance frequencies of the parallel resonators 151 and 152 do not have to coincide with each other and may vary within a predetermined frequency range. Further, the antiresonance frequencies of the parallel resonators 151 and 152 may not coincide with each other, and may vary within a predetermined frequency range. Further, the resonance frequencies and the anti-resonance frequencies of the series resonators 101 to 103 do not have to coincide with each other and may vary within a predetermined frequency range.
  • the anti-resonance frequency fap of the parallel resonators 151 and 152 and the resonance frequency frs of the series resonators 101 to 103 are brought close to each other. That is, frp ⁇ frs ⁇ fap ⁇ fas is established.
  • frp ⁇ frs ⁇ fap ⁇ fas is established.
  • the vicinity of the resonance frequency frp where the impedance of the parallel resonators 151 and 152 approaches 0 becomes a low-frequency side stop band of the transmission band.
  • the impedances of the parallel resonators 151 and 152 increase near the anti-resonance frequency fap, and the impedances of the series resonators 101 to 103 approach 0 near the resonance frequency frs.
  • the signal path from the transmission input terminal 10 to the common terminal 30 becomes a signal pass band.
  • the impedance of the series resonators 101 to 103 becomes high, which becomes a high-frequency side blocking area of the transmission band.
  • the second filter unit 11B includes a series resonator 104 connected between the first filter unit 11A and the transmission input terminal 10, and a connection path from the first filter unit 11A to the transmission input terminal 10 and the reference terminal. And a parallel resonator 153 connected to each other, and has a band rejection function. More specifically, as shown in the lower part of FIG. 6, the antiresonance frequency fap3 of the parallel resonator 153 is arranged outside the transmission band.
  • the resonance frequency frs4 of the series resonator 104 is lower than the antiresonance frequency fap3 of the parallel resonator 153, and the antiresonance frequency fas4 and parallel resonance of the series resonator 104 are between the resonance frequency frs4 and the antiresonance frequency fap3.
  • the resonance frequency frp3 of the child 153 is arranged. Further, the antiresonance frequency fas4 and the resonance frequency frp3 are substantially the same. That is, frs4 ⁇ fas4 ⁇ frp3 ⁇ fap3 is established in the second filter unit 11B. As a result, as shown in FIG.
  • the vicinity of the resonance frequency frs4 in which the impedance of the series resonator 104 approaches 0 becomes a high-frequency side passband of the transmission band. Further, when the frequency is increased, the impedance of the series resonator 104 increases near the antiresonance frequency fas4, and the impedance of the parallel resonator 153 approaches 0 near the resonance frequency frp3. As a result, in the vicinity of the anti-resonance frequency fas4 to the resonance frequency frp3, a signal blocking region is provided in the signal path from the transmission input terminal 10 to the common terminal 30.
  • the impedance of the parallel resonator 153 becomes high and falls outside the reception band. That is, a high frequency signal between the resonance frequency frs4 of the series resonator 104 and the anti-resonance frequency fap3 of the parallel resonator 153 can be prevented from propagating from the transmission input terminal 10 to the common terminal 30.
  • the anti-resonance frequency fap3 of the parallel resonator 153 is arranged outside the band of the transmission band, a band between the resonance frequency frs4 of the series resonator 104 and the anti-resonance frequency fap3 of the parallel resonator 153 is It is possible to use the reception band outside the transmission band. Therefore, it is possible to achieve high attenuation of the reception band while ensuring low loss of the transmission band by the first filter unit 11A.
  • the antiresonance frequency fas4 of the series resonator 104 and the resonance frequency frp3 of the parallel resonator 153 are preferably arranged in the reception band.
  • the high-frequency signal having the anti-resonance frequency fas4 or the resonance frequency frp3 that has a high impedance in the propagation direction from the transmission input terminal 10 to the common terminal 30 is highly blocked. Therefore, it is possible to optimize the attenuation characteristic of the reception band outside the pass band.
  • the anti-resonance frequency fas4 and the resonance frequency frp3 being arranged in the reception band are not limited to the anti-resonance frequency fas4 and the resonance frequency frp3 being arranged in the reception band.
  • the anti-resonance frequency fas4 and the resonance frequency frp3 may be arranged in a low frequency region or a high frequency region close to the reception band. It is possible to ensure high attenuation over the entire reception band.
  • the antiresonance frequency fas4 of the series resonator 104 and the resonance frequency frp3 of the parallel resonator 153 may be adjusted.
  • the antiresonance frequency fas4 of the series resonator 104 may be shifted to the low frequency side
  • the resonance frequency frp3 of the parallel resonator 153 may be shifted to the high frequency side.
  • FIG. 7A is a graph comparing pass characteristics of the duplexers according to the embodiment and the comparative example.
  • the insertion loss in the pass band of the duplexer 1 according to the present embodiment is substantially equal to the insertion loss in the pass band of the duplexer according to the comparative example.
  • the reception band attenuation characteristic of the transmission filter 11 according to the present embodiment is improved by 10 dB or more compared to the reception band attenuation characteristic of the transmission filter 411 according to the comparative example. I understand.
  • FIG. 7B is a graph comparing the isolation characteristics of the duplexers according to the embodiment and the comparative example. As shown in FIG. 7B, the isolation between the transmission filter 11 and the reception filter 12 of the duplexer 1 according to the present embodiment also includes the transmission filter 411 and the reception filter 12 of the duplexer according to the comparative example. It can be seen that there is an improvement of 10 dB or more compared to the isolation between the two.
  • the transmission filter 11 includes the second filter unit 11B having a band rejection function, so that the impedance between the external circuit connected to the transmission input terminal 10 and the transmission filter 11 is low. Inconsistencies are assumed.
  • the duplexer 1 according to the present embodiment includes a matching circuit 13 connected to the transmission input terminal 10 as a transmission-side filter circuit. Hereinafter, the effect of the matching circuit 13 will be described with reference to FIGS. 8A and 8B.
  • FIG. 8A is a Smith chart of the transmission filter 11 according to the embodiment before the matching circuit 13 is added.
  • the left side of the figure shows the configuration of the front-end circuit including the duplexer 1 according to the present embodiment.
  • the right side of the figure shows the complex when the transmission filter 11 is viewed from the filter input terminal 14.
  • a Smith chart representing impedance is shown.
  • the matching circuit 13 is not disposed between the transmission input terminal 10 and the second filter unit 11B.
  • FIG. 8B is a Smith chart of the transmission filter 11 according to the embodiment to which the matching circuit 13 is added.
  • the left side of the figure shows the configuration of the front end circuit including the duplexer 1 according to the present embodiment, and the right side of the figure shows the complex when the transmission filter 11 is viewed from the transmission input terminal 10.
  • a Smith chart representing impedance is shown.
  • the matching circuit 13 is arranged between the transmission input terminal 10 and the second filter unit 11B.
  • the matching circuit 13 includes, for example, an inductor 131 and a capacitor 132.
  • the inductor 131 is connected to the transmission input terminal 10 and the filter input terminal 14.
  • the capacitor 132 is connected to the transmission input terminal 10 and the reference terminal.
  • the transmission band impedance of the transmission filter 11 in the case where the matching circuit 13 is not added indicates capacitance.
  • an inductor 131 having a predetermined inductance value (15 nH) is connected in series between the second filter unit 11B and the transmission input terminal 10, and a predetermined capacitance value (2.0 pF) is obtained.
  • a capacitor 132 having the same is connected in parallel.
  • the transmission band impedance of the transmission filter 11 is shifted to the characteristic impedance (near the center), so that the insertion loss in the transmission band of the transmission filter 11 is not deteriorated. Furthermore, the impedance of the reception band is higher in FIG. 8B to which the matching circuit 13 is added, so that the attenuation in the reception band can be improved. That is, by connecting the matching circuit 13 between the transmission input terminal 10 and the second filter unit 11B, impedance matching between the transmission filter 11 and the external circuit can be achieved, and a high-frequency signal in the transmission band is It is possible to pass through with lower loss.
  • the matching circuit 13 is added between the second filter unit 11B and the transmission input terminal 10, but the matching circuit 13 is not an essential component.
  • the matching circuit 13 may be appropriately arranged according to the required specifications of the duplexer 1.
  • the second filter unit 11B is disposed between the first filter unit 11A and the filter input terminal 14.
  • the second filter unit 11B includes the common terminal 30 and the first filter unit. It may be arranged between 11A.
  • impedance matching between the antenna element 2 and the transmission filter 11 can be achieved by connecting and arranging the matching circuit 13 between the common terminal 30 and the second filter unit 11B.
  • the high-frequency filter element including the transmission filter 11 and the matching circuit 13 is connected to the common terminal 30 and has a first filter unit 11A having a band-pass function for passing a high-frequency signal in the transmission band.
  • a second filter unit 11B connected between the transmission input terminal 10 and the first filter unit 11A and having a band rejection function for attenuating a high-frequency signal in the reception band.
  • the second filter unit 11B includes a series resonator 104 and a parallel resonator 153, the antiresonance frequency fap3 of the parallel resonator 153 is arranged outside the transmission band, and the resonance frequency frs4 of the series resonator 104 is parallel.
  • the anti-resonance frequency fap3 of the series resonator 104 and the resonance frequency frp3 of the parallel resonator 153 are arranged between the resonance frequency frs4 and the anti-resonance frequency fap3. Further, the high frequency filter element includes a matching circuit 13 connected to the transmission input terminal 10.
  • the quadplexer 4 is a multiplexer in which a Band1 transmission filter circuit and a Band1 reception filter circuit, a Band3 transmission filter circuit, and a Band3 reception filter circuit are bundled at a common terminal. .
  • FIG. 9 is a circuit configuration diagram of the quadplexer 4 and peripheral circuits according to a modification of the embodiment.
  • the quadplexer 4 includes transmission filters 16 (first transmission filter circuit) and 26 (second transmission filter circuit), reception filter 17 (first reception filter circuit), and 27 (second reception side filter circuit), matching circuit 23, transmission input terminal 41 (first transmission input terminal) and 51 (second transmission input terminal), reception output terminal 42 (first reception output terminal), and 52 (second reception output terminal) and a common terminal 30.
  • the transmission filter 16 and the matching circuit 23 constitute a high frequency filter element.
  • the transmission filter 16, the reception filter 17, and the matching circuit 23 constitute a duplexer 1A (first duplexer).
  • the transmission filter 26 and the reception filter 27 constitute a duplexer 1B (second duplexer).
  • the duplexers 1A and 1B, the antenna element 2, and the antenna matching circuit 3 constitute a front end circuit.
  • the antenna matching circuit 3 is connected to the antenna element 2 and the duplexers 1A and 1B, and performs impedance matching between the antenna element 2 and the duplexer 1A, and impedance matching between the antenna element 2 and the duplexer 1B. Thereby, the duplexers 1A and 1B can receive the received signal from the antenna element 2 with low loss and output the transmission signal to the antenna element 2 with low loss.
  • the antenna matching circuit 3 is composed of one or more high-frequency circuit components, and includes, for example, a chip-shaped inductor and a chip-shaped capacitor.
  • the antenna matching circuit 3 is not an essential component of the front end circuit.
  • the transmission filter 16 inputs a transmission signal generated by a high-frequency signal processing circuit (RFIC or the like) and amplified via a power amplifier via a transmission input terminal 41, and transmits a first transmission band (first) of Band3.
  • This is a band-pass filter that performs filtering in the frequency band and outputs to the common terminal 30.
  • a matching circuit 23 is connected between the transmission input terminal 41 and the transmission filter 16.
  • the reception filter 17 is a band-pass filter that receives the reception signal input from the common terminal 30, filters the first reception band of Band 3, and outputs the filtered signal to the reception output terminal 42.
  • the transmission filter 26 inputs a transmission signal generated by a high-frequency signal processing circuit (RFIC or the like) and amplified via a power amplifier via the transmission input terminal 51, and filters it in the second transmission band of Band1. This is a band-pass filter that outputs to the common terminal 30.
  • RFIC high-frequency signal processing circuit
  • the reception filter 27 is a band-pass filter that receives the reception signal input from the common terminal 30, filters it in the second reception band (second frequency band) of Band 1 and outputs it to the reception output terminal 52.
  • the transmission filters 16 and 26 and the reception filters 17 and 27 are connected to the common terminal 30.
  • the matching circuit 23 is connected to the filter input terminal 24 and the transmission input terminal 41 of the transmission filter 16, and impedance matching is performed for impedance matching between the transmission circuit 16 and an external circuit such as a power amplifier connected to the transmission input terminal 41. Circuit. As a result, the duplexer 1A can input a transmission signal with low loss from an external circuit.
  • the matching circuit 23 is composed of one or more high-frequency circuit components, and includes, for example, a chip-shaped inductor and a chip-shaped capacitor, or a wiring pattern formed on a substrate. The matching circuit 23 may be connected between the common terminal 30 and the transmission filter 16.
  • the quadplexer 4 is cited as the multiplexer according to the present invention.
  • the multiplexer according to the present invention is not limited to the quadplexer 4, and is a triplexer, a pentaplexer, and the like.
  • the present invention is also applied to a multiplexer having the above number of bands.
  • FIG. 10 is a circuit configuration diagram of the transmission filter 16 according to a modification of the embodiment. As shown in FIG. 10, the transmission filter 16 has a configuration in which a first filter unit 11A, a second filter unit 11B, and a third filter unit 11C are connected in cascade.
  • the first filter unit 11A is connected to the common terminal 30 (first terminal), includes series resonators 101, 102, and 103, and parallel resonators 151 and 152, and has a first transmission band (first frequency band) of Band3. ) To selectively pass high-frequency signals.
  • the third filter unit 11C is disposed between the first filter unit 11A and the filter input terminal 24, includes a series resonator 104 and a parallel resonator 153, and has a first reception band of Band3 different from the first transmission band. It has a characteristic of selectively attenuating a high frequency signal.
  • the second filter unit 11B is disposed between the first filter unit 11A and the filter input terminal 24, is connected to the transmission input terminal 41 (second terminal) via the matching circuit 23, and is in parallel resonance with the series resonator 105. And has a characteristic of selectively attenuating a high-frequency signal in a second reception band (second frequency band) of Band 1 different from the first transmission band and the first reception band.
  • the series resonators 101 to 105 are connected in series with each other between the filter input terminal 24 and the common terminal 30.
  • the parallel resonators 151 to 154 are connected in parallel to each other between the connection points of the series resonators 101 to 105 and the reference terminal (ground).
  • the first filter unit 11A has a band pass function.
  • the third filter unit 11C has a band rejection function of the first reception band of Band3.
  • the second filter unit 11B has a band rejection function of the second reception band of Band1.
  • the transmission filter 16 constitutes a ladder-type bandpass filter as a whole by the cascade connection of the first filter unit 11A, the third filter unit 11C, and the second filter unit 11B.
  • the first filter portion 11A may not have a configuration of a ladder-type surface acoustic wave element.
  • the circuit configuration of the first filter unit 11A may be, for example, a longitudinally coupled surface acoustic wave element or the like according to the required specifications of the transmission filter 16, or configured by an elastic wave resonator using BAW. May be. Furthermore, it may not have the structure of an acoustic wave element, and may have another filter structure.
  • the circuit configurations of the transmission filter 26 and the reception filters 17 and 27 are not particularly limited.
  • the transmission filter 26 and the reception filters 17 and 27 may be, for example, a ladder type surface acoustic wave element, a longitudinally coupled type surface acoustic wave element, or the like according to the required specifications.
  • the transmission filters 11 and 26 and the reception filters 17 and 27 are both composed of surface acoustic wave elements, they can be formed on a single piezoelectric substrate, and downsizing can be realized.
  • the transmission filter 26 and the reception filters 17 and 27 may be constituted by elastic wave resonators using BAW, and may not have an elastic wave element configuration. It may have a filter structure.
  • the third filter unit 11C corresponds to the second filter unit 11B in the duplexer 1 according to the embodiment, and the resonance impedance characteristics of the series resonator 104 and the parallel resonator 153 are the series shown in the lower stage of FIG. Impedance characteristics similar to those of the resonator 104 and the parallel resonator 153 are shown. That is, the antiresonance frequency of the parallel resonator 154 is arranged outside the first transmission band, the resonance frequency of the series resonator 104 is lower than the antiresonance frequency of the parallel resonator 153, and the resonance frequency of the series resonator 104.
  • the antiresonance frequency of the parallel resonator 153, the antiresonance frequency of the series resonator 104 and the resonance frequency of the parallel resonator 153 are arranged. Furthermore, the antiresonance frequency of the series resonator 104 and the resonance frequency of the parallel resonator 153 are arranged in the first reception band of Band3. Accordingly, it is possible to achieve high attenuation of the first reception band of the duplexer 1A while ensuring low loss of the first transmission band in the duplexer 1A. Further, it is possible to improve the isolation (IsoX in FIG. 9) between the transmission filter 16 and the reception filter 17 of the duplexer 1A.
  • the resonance impedance characteristics of the series resonator 105 and the parallel resonator 154 are the same as those of the series resonator 104 and the parallel resonator 153 shown in the lower part of FIG. Indicates. That is, the antiresonance frequency of the parallel resonator 154 is arranged outside the first transmission band, the resonance frequency of the series resonator 105 is lower than the antiresonance frequency of the parallel resonator 154, and the resonance frequency of the series resonator 105.
  • the anti-resonance frequency of the parallel resonator 154, the anti-resonance frequency of the series resonator 105 and the resonance frequency of the parallel resonator 154 are arranged. Furthermore, the antiresonance frequency of the series resonator 105 and the resonance frequency of the parallel resonator 154 are arranged in the second reception band (second frequency band) of Band1. According to this, since the transmission filter 16 of Band3 has the configuration of the second filter unit 11B, the second reception of the duplexer 1A is ensured while ensuring low loss of the first transmission band in the duplexer 1A. It becomes possible to achieve high attenuation of the band. Furthermore, cross-isolation (IsoY in FIG. 9) between the Band3 transmission filter 16 and the Band1 reception filter 27 can be improved.
  • the Band3 transmission filter 16 has a characteristic configuration, that is, a configuration example having the first filter unit 11A, the second filter unit 11B, and the third filter unit 11C.
  • the filter having the configuration may be the reception filters 17 and 27 or the transmission filter 26. Further, the third filter unit 11C may not be provided.
  • the high-frequency filter element and the multiplexer (duplexer) according to the present invention have been described with reference to the above embodiment, but the high-frequency filter element and the multiplexer according to the present invention are not limited to the above-described embodiment.
  • Examples and various devices incorporating the high-frequency filter element of the present disclosure are also included in the present invention.
  • the reception filter 12 may include the second filter unit.
  • the resonance frequency and antiresonance of the series resonator that constitutes the second filter unit when the reception filter 12 has the second filter unit, the resonance frequency and antiresonance of the series resonator that constitutes the second filter unit.
  • the frequency, and the resonance frequency and anti-resonance frequency of the parallel resonator constituting the second filter unit are arranged outside the low frequency band of the transmission band.
  • the high frequency filter element which concerns on this invention is a transmission apparatus which has several transmission bands which bear only transmission, and only reception
  • the present invention is also applied to a receiving apparatus having a plurality of receiving bands for carrying
  • a transmission device that transmits high-frequency signals in a plurality of transmission bands via an antenna element, the transmission device filtering a high-frequency signal input from a first transmission input terminal to generate a high-frequency signal in the first transmission band.
  • a first transmission-side filter circuit that outputs to the antenna element via the common terminal, and a high-frequency signal in a second transmission band different from the first transmission band by filtering the high-frequency signal input from the second transmission input terminal, And a second transmission filter circuit that outputs to the antenna element via the common terminal.
  • the first transmission filter circuit includes the high-frequency filter element according to the above embodiment.
  • the receiving device receives high-frequency signals in a plurality of reception bands via an antenna element, and the receiving device filters high-frequency signals input from the antenna element via a common terminal to obtain a first reception band.
  • a first reception-side filter circuit that outputs a high-frequency signal to the first reception output terminal, and a high-frequency signal in a second reception band different from the first reception band by filtering the high-frequency signal input from the antenna element via the common terminal Is provided to the second reception output terminal.
  • the first reception-side filter circuit includes the high-frequency filter element according to the above embodiment.
  • the duplexer 1 according to the present invention is not limited to the Band8 duplexer as in the above embodiment, and the selection of the band is arbitrary. In the case of a multiplexer, the combination of bands is arbitrary.
  • the piezoelectric substrate 510 constituting the surface acoustic wave filter may have a laminated structure in which a high acoustic velocity support substrate, a low acoustic velocity film, and a piezoelectric film are laminated in this order.
  • the piezoelectric film is made of, for example, LiTaO 3 piezoelectric single crystal or piezoelectric ceramic.
  • the piezoelectric film has a thickness of 600 nm, for example.
  • the high sound velocity support substrate is a substrate that supports the low sound velocity film, the piezoelectric film, and the IDT electrode 54.
  • the high-sonic support substrate is a substrate in which the acoustic velocity of the bulk wave in the high-sonic support substrate is higher than that of the surface wave or boundary wave that propagates through the piezoelectric film. It functions in such a way that it is confined in the portion where the sonic film is laminated and does not leak below the high sonic support substrate.
  • the high sound speed support substrate is, for example, a silicon substrate, and has a thickness of, for example, 200 ⁇ m.
  • the low acoustic velocity film is a membrane in which the acoustic velocity of the bulk wave in the low acoustic velocity film is lower than the bulk wave propagating through the piezoelectric membrane, and is disposed between the piezoelectric membrane and the high acoustic velocity support substrate. Due to this structure and the property that energy is concentrated in a medium where acoustic waves are essentially low in sound velocity, leakage of surface acoustic wave energy to the outside of the IDT electrode is suppressed.
  • the low acoustic velocity film is, for example, a film mainly composed of silicon dioxide and has a thickness of, for example, 670 nm.
  • the Q value at the resonance frequency and the anti-resonance frequency can be significantly increased as compared with a structure in which the piezoelectric substrate 510 is used as a single layer. That is, since a surface acoustic wave resonator having a high Q value can be configured, a filter with a small insertion loss can be configured using the surface acoustic wave resonator.
  • the high sound velocity support substrate has a structure in which a support substrate and a high sound velocity film in which the velocity of the bulk wave propagating is higher than that of the surface wave and boundary wave propagating in the piezoelectric film are stacked. It may be.
  • the support substrate is a piezoelectric material such as sapphire, lithium tantalate, lithium niobate, crystal, alumina, magnesia, silicon nitride, aluminum nitride, silicon carbide, zirconia, cordierite, mullite, steatite, forsterite, etc.
  • Various ceramics, dielectrics such as glass, semiconductors such as silicon and gallium nitride, resin substrates, and the like can be used.
  • the high sound velocity film includes various materials such as aluminum nitride, aluminum oxide, silicon carbide, silicon nitride, silicon oxynitride, DLC film or diamond, a medium mainly composed of the above materials, and a medium mainly composed of a mixture of the above materials. High sound velocity material can be used.
  • the present invention is widely used in communication devices such as mobile phones as high-frequency filters, multiplexers, transmitters, and receivers that have low in-band loss and high out-of-band attenuation that can be applied to multiband and multimode frequency standards. it can.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

Cette invention concerne un filtre de transmission (11) doté d'une première partie de filtre (11A) connectée à une borne commune (30), un signal haute fréquence d'une bande de transmission passant à travers la première partie de filtre (11A), et une seconde partie de filtre (11B) connectée entre une borne d'entrée de transmission (10) et la première partie de filtre (11A), la seconde partie de filtre (11B) atténuant un signal haute fréquence d'une bande de réception. La seconde partie de filtre (11B) comprend un résonateur série (104) et un résonateur parallèle (153), la fréquence d'anti-résonance (fap3) du résonateur parallèle (153) étant à l'extérieur de la bande de transmission, la fréquence de résonance (frs4) du résonateur série (104) étant inférieure à la fréquence d'anti-résonance (fap3) du résonateur parallèle (153), et la fréquence d'anti-résonance (fa4) du résonateur série (104) ainsi que la fréquence de résonance (frp3) du résonateur parallèle (153) étant entre la fréquence de résonance (frs4) du résonateur série (104) et la fréquence d'anti-résonance (fap3) du résonateur parallèle (153).
PCT/JP2017/010814 2016-03-18 2017-03-16 Élément de filtre haute fréquence, multiplexeur, émetteur et récepteur WO2017159834A1 (fr)

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CN111527700A (zh) * 2017-12-25 2020-08-11 株式会社村田制作所 多工器
JPWO2019131501A1 (ja) * 2017-12-25 2020-08-06 株式会社村田製作所 マルチプレクサ
CN110365307B (zh) * 2018-03-26 2023-02-28 株式会社村田制作所 多工器
CN110365307A (zh) * 2018-03-26 2019-10-22 株式会社村田制作所 多工器
JPWO2019235490A1 (ja) * 2018-06-05 2021-02-12 株式会社村田製作所 マルチプレクサ
WO2019235490A1 (fr) * 2018-06-05 2019-12-12 株式会社村田製作所 Multiplexeur
US11929726B2 (en) 2018-06-05 2024-03-12 Murata Manufacturing Co., Ltd. Multiplexer
CN113196658A (zh) * 2018-12-20 2021-07-30 株式会社村田制作所 多工器
CN113196658B (zh) * 2018-12-20 2024-05-03 株式会社村田制作所 多工器
CN114144976A (zh) * 2019-07-03 2022-03-04 株式会社村田制作所 高频模块和通信装置
CN114051695A (zh) * 2019-07-03 2022-02-15 株式会社村田制作所 高频模块和通信装置
CN114051695B (zh) * 2019-07-03 2023-08-18 株式会社村田制作所 高频模块和通信装置
CN114144976B (zh) * 2019-07-03 2023-08-25 株式会社村田制作所 高频模块和通信装置
WO2022091582A1 (fr) * 2020-10-28 2022-05-05 株式会社村田製作所 Filtre à ondes élastiques

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