[go: up one dir, main page]

WO2011040332A1 - Dispositif de filtre à ondes acoustiques et filtre de dérivation équipé de celui-ci - Google Patents

Dispositif de filtre à ondes acoustiques et filtre de dérivation équipé de celui-ci Download PDF

Info

Publication number
WO2011040332A1
WO2011040332A1 PCT/JP2010/066556 JP2010066556W WO2011040332A1 WO 2011040332 A1 WO2011040332 A1 WO 2011040332A1 JP 2010066556 W JP2010066556 W JP 2010066556W WO 2011040332 A1 WO2011040332 A1 WO 2011040332A1
Authority
WO
WIPO (PCT)
Prior art keywords
resonator
wave filter
filter device
response
acoustic wave
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2010/066556
Other languages
English (en)
Japanese (ja)
Inventor
大輔 山本
真理 矢追
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Murata Manufacturing Co Ltd
Original Assignee
Murata Manufacturing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Murata Manufacturing Co Ltd filed Critical Murata Manufacturing Co Ltd
Priority to JP2011534220A priority Critical patent/JP5338912B2/ja
Publication of WO2011040332A1 publication Critical patent/WO2011040332A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; 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
    • H03H9/14538—Formation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/0023—Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns, or networks having balanced input and output
    • H03H9/0028—Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns, or networks having balanced input and output using surface acoustic wave devices
    • H03H9/0047—Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns, or networks having balanced input and output using surface acoustic wave devices having two acoustic tracks
    • H03H9/0066—Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns, or networks having balanced input and output using surface acoustic wave devices having two acoustic tracks being electrically parallel
    • H03H9/0071—Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns, or networks having balanced input and output using surface acoustic wave devices having two acoustic tracks being electrically parallel the balanced terminals being on the same side of the tracks
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; 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
    • H03H9/14544—Transducers of particular shape or position
    • H03H9/14573—Arrow type transducers

Definitions

  • the present invention relates to an elastic wave filter device, and more particularly, to an elastic wave filter device having a pass band and an attenuation band located on the high side of the pass band, and a duplexer including the same.
  • a duplexer using an elastic wave filter device as a band filter such as a reception filter or a transmission filter is known.
  • the bandpass filter that forms part of the duplexer is required to have a large attenuation outside the passband in order to achieve high isolation characteristics of the duplexer.
  • a band in which a transmission band and a reception band are very close is used.
  • an attenuation amount in an attenuation band on the high band side of the pass band Is strongly demanded.
  • Patent Document 1 describes a technique in which a series resonator is connected in series to a ladder filter.
  • Patent Document 1 when a series resonator is further connected in series to a ladder-type filter, the configuration of the filter device is complicated and the filter device is complicated because the series resonator must be provided separately. There was a problem of increasing the size.
  • the present invention has been made in view of such a point, and an object of the present invention is to provide an acoustic wave filter device having a pass band and an attenuation band located on the high frequency side of the pass band, and a duplexer including the same.
  • the object is to increase the attenuation in the attenuation band without increasing the size of the elastic wave filter device.
  • An elastic wave filter device includes an input terminal, an output terminal, a first resonator, and a second resonator.
  • the first resonator is provided between the input terminal and the output terminal.
  • the second resonator is connected between a connection point between the input terminal or the output terminal and the first resonator and the ground potential.
  • the first and second resonators form a pass band and an attenuation band on the high band side of the pass band.
  • the second resonator has a response other than the response contributing to the formation of the passband.
  • the value ((f Frh ⁇ f c ) / f c ) normalized by the center frequency is in the range of 0.073 to 0.250.
  • the response of the resonator means a response that appears on the impedance characteristics in detail.
  • a first resonator is provided so as to constitute a series arm resonator
  • the second resonator is:
  • a parallel arm resonator disposed on the parallel arm connected between the series arm and the ground potential is provided.
  • the elastic wave filter device is a ladder-type elastic wave filter device.
  • the first resonator constitutes a longitudinally coupled resonator type acoustic wave filter portion connected between the input terminal and the output terminal, and the second resonator Is connected between a connection point between the input terminal or the output terminal and the longitudinally coupled resonator type acoustic wave filter unit and the ground potential.
  • the elastic wave filter device is an elastic wave filter device having a longitudinally coupled resonator type elastic wave filter unit and a second resonator as a parallel trap.
  • each of the first and second resonators includes a piezoelectric substrate, a first dielectric layer formed on the piezoelectric substrate, a piezoelectric substrate, and a first dielectric.
  • each of the first and second resonators is formed on the first dielectric layer and has a higher sound velocity than the first dielectric layer.
  • the boundary acoustic wave resonator further includes two dielectric layers.
  • the first resonator is provided in the series arm connecting the input terminal and the output terminal so as to constitute the series arm resonator connected in series with each other.
  • the second resonator is provided so as to constitute a parallel arm resonator disposed in a parallel arm connected between the series arm and the ground potential, and the IDT electrode is formed of Al or Al.
  • the film thickness of the main conductive film normalized by the wavelength determined by the electrode finger pitch of the IDT electrode of the first resonator is 10% to It is in the range of 30%. According to this configuration, the attenuation amount of the attenuation band can be further increased.
  • the first arm is provided in the series arm connecting the input terminal and the output terminal so as to constitute the series arm resonator connected in series with each other.
  • the second resonator is provided so as to constitute a parallel arm resonator disposed in a parallel arm connected between the series arm and the ground potential, and the first dielectric layer is
  • the thickness of the first dielectric layer made of silicon oxide and normalized by the wavelength determined by the electrode finger pitch of the IDT electrode of the first resonator is in the range of 40% to 70%. According to this configuration, the attenuation amount of the attenuation band can be further increased.
  • the response other than the response contributing to the formation of the passband of the second resonator is a higher-order mode of the response contributing to the formation of the passband.
  • the response other than the response contributing to the formation of the passband of the second resonator is a response different in type from the response contributing to the formation of the passband. is there.
  • the duplexer according to the present invention includes the elastic wave filter according to the present invention.
  • the resonance frequency (f Frh) from the passband center frequency (f c) the value obtained by subtracting the normalized value of (f Frh -f c) at the center frequency of the passband of the response ((f Frh -f c) / f c ) is in the range of 0.073 to 0.250. Therefore, since a separate resonator for increasing the attenuation in the attenuation band is not required, the attenuation in the attenuation band can be increased without increasing the size of the elastic wave filter device. Therefore, high isolation characteristics can be realized by using the acoustic wave filter device of the present invention in a duplexer.
  • FIG. 1 is a schematic configuration diagram of a boundary acoustic wave filter device according to a first embodiment.
  • FIG. 2 is a schematic cross-sectional view of the acoustic wave resonator according to the first embodiment.
  • FIG. 3 is a schematic cross-sectional view in which a part of the acoustic wave resonator according to the first embodiment is enlarged.
  • FIG. 4 is a schematic plan view for explaining the electrode structure of the acoustic wave resonator according to the first embodiment.
  • FIG. 5 is a graph showing filter characteristics of the boundary acoustic wave filter device according to the first embodiment and impedance characteristics of the parallel arm resonator and the series arm resonator.
  • FIG. 6 is a graph showing the relationship between the attenuation in (f Frh -f c) / f c and 1880MHz in the first embodiment.
  • FIG. 7 is a schematic configuration diagram of the duplexer according to the first embodiment.
  • FIG. 8 is a schematic configuration diagram of a reception filter of the duplexer in the first embodiment.
  • FIG. 9 is a graph showing impedance characteristics of the parallel arm resonator at various second main conductive film thicknesses.
  • FIG. 10 is a graph showing filter characteristics of the boundary acoustic wave filter device at various thicknesses of the second main conductive film.
  • FIG. 11 is an enlarged graph of a part of the graph shown in FIG. FIG.
  • FIG. 12 is a graph showing the isolation characteristics of the duplexer at various thicknesses of the second main conductive film.
  • FIG. 13 is a graph showing impedance characteristics of the second resonator at various thicknesses of the first dielectric layer.
  • FIG. 14 is a graph showing filter characteristics of the boundary acoustic wave filter device at various thicknesses of the first dielectric layer.
  • FIG. 15 is an enlarged graph of a part of the graph shown in FIG.
  • FIG. 16 is a graph showing the isolation characteristics of the duplexer at various thicknesses of the first dielectric layer.
  • FIG. 17 is a schematic configuration diagram of an acoustic wave resonator according to the second embodiment.
  • FIG. 1 is a schematic configuration diagram of a boundary acoustic wave filter device according to this embodiment.
  • the boundary acoustic wave filter device 1 shown in FIG. 1 is a ladder-type boundary acoustic wave filter device 1.
  • the boundary acoustic wave filter device 1 includes an input terminal 11 and an output terminal 12. Between the input terminal 11 and the output terminal 12, series arm resonators S11, S12, S21 to S23, S31, and S32 are provided as first resonators. Specifically, the input terminal 11 and the output terminal 12 are connected by a series arm 13.
  • the first to third series arm resonators S 1 to S 3 are connected to each other in series at the series arm 13.
  • the first series arm resonator S1 is composed of two series arm resonators S11 and S12 connected in series with each other.
  • the second series arm resonator S2 includes three series arm resonators S21 to S23 connected in series with each other.
  • the third series arm resonator S3 includes two series arm resonators S31 and S32 connected in series with each other.
  • the first parallel arm 14a is connected between the connection point 13a between the first series arm resonator S1 and the second series arm resonator S2 and the ground electrode 15a.
  • the first parallel arm 14a is provided with a first parallel arm resonator P1.
  • the first parallel arm resonator P1 is composed of two parallel arm resonators P11 and P12 connected in series with each other.
  • a first inductor L1 is provided between the first parallel arm resonator P1 and the ground electrode 15a.
  • the second parallel arm 14b is connected between the connection point 13b between the second series arm resonator S2 and the third series arm resonator S3 and the ground electrode 15b.
  • the second parallel arm 14b is provided with a second parallel arm resonator P2.
  • the second parallel arm resonator P2 includes two parallel arm resonators P21 and P22 connected in series.
  • a third parallel arm 14c is connected between the connection point 13c between the third series arm resonator S3 and the output terminal 12 and the ground electrode 15b.
  • the third parallel arm 14c is provided with a third parallel arm resonator P3.
  • the third parallel arm resonator P3 includes two parallel arm resonators P31 and P32 connected in series with each other.
  • a second inductor L2 is provided between the connection point between the second parallel arm resonator P2 and the third series arm resonator S3 and the ground electrode 15b.
  • the series arm resonators S11, S12, S21 to S23, S31, and S32 may be collectively referred to as the series arm resonator S.
  • the parallel arm resonators P11, P12, P21, P22, P31, and P32 may be collectively referred to as a parallel arm resonator P.
  • the series arm resonator S and the parallel arm resonator P may be collectively referred to as “resonator 29”.
  • the boundary acoustic wave filter device 1 is a filter device using a boundary acoustic wave
  • the resonator 29 is a boundary acoustic wave resonator.
  • the resonator 29 is a so-called three-medium type boundary acoustic wave resonator. More specifically, as shown in FIGS. 2 to 4, the resonator 29 includes a piezoelectric substrate 20 and first and second dielectric layers 21 and 22.
  • the piezoelectric substrate 20 is not particularly limited as long as the substrate expressing a piezoelectric effect, for example, can be constituted by a substrate such as LiTaO 3 substrate or a LiNbO 3 substrate.
  • the first dielectric layer 21 is formed on the piezoelectric substrate 20.
  • An IDT electrode 30 and first and second grating reflectors 33 and 34 are formed at the boundary between the first dielectric layer 21 and the piezoelectric substrate 20.
  • a second dielectric layer 22 is formed on the surface of the first dielectric layer 21 opposite to the piezoelectric substrate 20.
  • the elastic wave excited in the IDT electrode 30 is confined in the first dielectric layer 21, 1 propagates through the dielectric layer 21.
  • the material of the first and second dielectric layers 21 and 22 is not particularly limited as long as the sound speed of the second dielectric layer 22 is higher than the sound speed of the first dielectric layer 21.
  • the first dielectric layer 21 can be formed of silicon oxide such as SiO 2
  • the second dielectric layer 22 can be formed of silicon nitride such as SiN.
  • the IDT electrode 30 and the first and second grating reflectors 33 and 34 have the same film configuration.
  • FIG. 3 shows the film configuration of the IDT electrode 30 as a representative.
  • the IDT electrode 30 and the first and second grating reflectors 33 and 34 include first to third main conductive films 30a to 30c. Then, between the first to third main conductive films 30a to 30c, between the first main conductive film 30a and the piezoelectric substrate 20, and between the third main conductive film 30c and the first dielectric layer 21.
  • Adhesive films 30d to 30f or a protective film 30g are provided in each of the gaps.
  • a first main conductive film 30a made of Pt is formed on the piezoelectric substrate 20 via an adhesion film 30d made of NiCr.
  • a second main conductive film 30b made of AlCu is formed via an adhesion film 30e made of Ti.
  • a third main conductive film 30c made of Pt is formed on the second main conductive film 30b via an adhesion film 30f made of Ti.
  • a protective film 30g made of Ti is formed between the third main conductive film 30c and the first dielectric layer 21.
  • the main conductive film in the present invention refers to a film containing a relatively high conductive material such as Pt, Al, or Cu, and a relatively thick film.
  • the IDT electrode 30 includes first and second comb electrodes 31 and 32 that are inserted into each other.
  • Each of the first and second comb electrodes 31 and 32 includes bus bars 31a and 32a, electrode fingers 31b and 32b extending from the bus bars 31a and 32a, and dummy electrodes 31c and 32c.
  • the IDT electrode 30 is so-called cross width weighted, and is configured such that the region surrounded by the envelopes l1 and l2 passing through the tips of the electrode fingers 31b and 32b is substantially rhombus.
  • the IDT electrode is not particularly limited, and may be a regular IDT electrode or an IDT electrode to which weighting other than cross width weighting is applied.
  • the first and second grating reflectors 33 and 34 are disposed on both sides of the IDT electrode 30 in the elastic wave propagation direction.
  • FIG. 5 is a graph showing the filter characteristics of the boundary acoustic wave filter device according to this embodiment and the impedance characteristics of the parallel arm resonator and the series arm resonator.
  • the solid line indicates the filter characteristic of the boundary acoustic wave filter device
  • the one-dot broken line indicates the impedance characteristic of the series arm resonator
  • the two-dot broken line indicates the impedance characteristic of the parallel arm resonator.
  • the resonance point and antiresonance point of the main response Rs1 of the series arm resonator S are higher than the resonance point and antiresonance point of the main response Rp1 of the parallel arm resonator P, respectively. Is located.
  • the resonance frequency of the main response Rs1 of the series arm resonator S and the antiresonance frequency of the main response Rp1 of the parallel arm resonator P are set to be approximately equal.
  • the boundary acoustic wave filter device 1 of this embodiment is used as a transmission filter.
  • Attenuation bands are formed on the low band side and high band side of the pass band.
  • the attenuation band located on the lower side of the pass band is mainly formed by the resonance point of the main response Rp1 of the parallel arm resonator P.
  • the attenuation band located on the high frequency side of the pass band is mainly formed by the antiresonance point of the main response Rs1 of the series arm resonator S.
  • the impedance value of the parallel arm resonator P in the attenuation band also contributes to the attenuation band located on the high band side of the pass band. The smaller the impedance value of the parallel arm resonator P in the attenuation band, the more in the attenuation band. The amount of attenuation increases.
  • the parallel arm resonator P and the series arm resonator S which are boundary acoustic wave resonators are used, in addition to the main responses Rp1 and Rs1 that contribute to the formation of the passband and the attenuation bands on both sides of the passband.
  • the main responses Rp1 and Rs1 are one of the response by the SH wave and the response by the Stoneley wave, the response by the other boundary acoustic wave exists.
  • the parallel arm resonator P and the series arm resonator S are designed so that the response is located sufficiently away from the main responses Rp1 and Rs1 so that the filter characteristics are not adversely affected.
  • (f Frh -f c) / f c is, when in the range of 0.073 to 0.250, the attenuation band which is located on the high frequency side of the pass band It can be seen that the effect of increasing the attenuation at is great.
  • (f Frh -f c) / f c is, when in the range of 0.073 ⁇ 0.250, 39.5dB attenuation in the attenuation band located on the higher frequency side of the pass band This can be done.
  • the electrode film thickness needs to be 200 nm or more.
  • (f Frh -f c) / f c has a value of 0.250 or less. This also, it is understood that it is preferable to 0.250 for the upper limit of (f Frh -f c) / f c.
  • (f Frh -f c) / f c is, when it becomes 0.250 or less, i.e., when the resonance frequency of the response Rp2 approached somewhat above the passband, located at the higher-frequency side of the pass band.
  • the reason why the attenuation in the attenuation band increases is not clear, but is considered to be due to the following reason. That is, when the response Rp2 is positioned sufficiently higher than the main response Rp1, the effect of the response Rp2 on the attenuation band on the high frequency side of the pass band formed by the main response Rp1 There is nothing.
  • the resonance point of the response Rp2 having a small impedance value shifts to the low frequency side and is affected by this, and the high frequency side of the antiresonance point of the main response Rp1 Impedance value at. For this reason, it is considered that the attenuation amount of the attenuation band located on the high frequency side of the pass band becomes large.
  • (f Frh -f c) / f c is, when it becomes 0.073 or less, i.e., the attenuation in the attenuation band of a band higher than the passband when the resonance frequency of the response Rp2 too close to the pass band
  • the resonance point of the response Rp2 having a small impedance value approaches the attenuation band
  • the anti-resonance point having a large impedance value also approaches the attenuation band. For this reason, it is considered that the effect of the antiresonance point reducing the attenuation amount of the attenuation band is greater than the effect of the resonance point increasing the attenuation amount of the attenuation band.
  • the range of 0.073 ⁇ (f Frh ⁇ f c ) / f c ⁇ 0.250 is 0.05 ⁇ (f Frh ⁇ f h ) / f It can be converted to h ⁇ 0.212.
  • the boundary acoustic wave filter device 1 of the present embodiment is useful for, for example, a duplexer because the amount of attenuation in the attenuation band on the high frequency side of the pass band is large.
  • it is useful as a transmission filter for a duplexer in which a transmission band (1710 to 1785 MHz) and a reception band (1805 to 1880 MHz) are close to each other.
  • FIG. 7 is a schematic diagram of a duplexer 3 including the boundary acoustic wave filter device 1 as a transmission filter. As shown in FIG. 7, the duplexer 3 includes the antenna terminal Ant. And transmission side signal terminals Tx and reception side signal terminals Rx1 and Rx2. Only one transmission-side signal terminal Tx is provided, which is an unbalanced signal terminal. On the other hand, two receiving side signal terminals Rx1 and Rx2 are provided, which are balanced signal terminals.
  • Antenna terminal Ant The boundary acoustic wave filter device 1 as a transmission filter is connected between the transmission side signal terminal Tx and the transmission side signal terminal Tx.
  • the antenna terminal Ant On the other hand, the antenna terminal Ant.
  • a reception filter 2 is provided. Transmission filter 1 and reception filter 2 and antenna terminal Ant.
  • An inductor L3 is connected between the connection point and the ground potential.
  • FIG. 8 is a schematic configuration diagram of the reception filter 2.
  • the reception filter 2 shown in FIG. 8 is a longitudinally coupled resonator type acoustic wave filter device. As shown in FIG. 8, an unbalanced signal terminal 41 and a pair of balanced signal terminals 42a and 42b are provided.
  • the unbalanced signal terminal 41 is the antenna terminal plan Ant. It is connected to the.
  • the balanced signal terminals 42a and 42b are connected to the receiving signal terminals Rx1 and Rx2 shown in FIG.
  • a first boundary acoustic wave filter unit 44a is connected between the unbalanced signal terminal 41 and the first balanced signal terminal 42a.
  • a second boundary acoustic wave filter unit 44b is connected between the unbalanced signal terminal 41 and the second balanced signal terminal 42b.
  • a boundary acoustic wave resonator 43 is connected between the unbalanced signal terminal 41 and the first and second boundary acoustic wave filter units 44a and 44b.
  • the boundary acoustic wave resonators 45a and 45b are connected between the first and second boundary acoustic wave filter units 44a and 44b and the balanced signal terminals 42a and 42b, respectively.
  • the duplexer 3 is a duplexer in which a transmission band (1710 to 1785 MHz) and a reception band (1805 to 1880 MHz) are close to each other. For this reason, the duplexer 3 is strongly required to have a large amount of attenuation in the high-side attenuation band of the pass band (transmission band) of the boundary acoustic wave filter device 1 constituting the transmission filter.
  • the duplexer 3 including the boundary acoustic wave filter device 1 of the present embodiment as a transmission filter has a good isolation characteristic between the transmission side signal terminal Tx and the reception side signal terminals Rx1 and Rx2.
  • the method for controlling the frequency difference between the center frequency of the passband and the resonance frequency of the response Rp2 that is, a method of controlling the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2.
  • the method for controlling the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2 is not particularly limited.
  • the film thickness of the main conductive films 30a to 30c constituting the IDT electrode 30 is changed. Can be controlled.
  • FIG. 9 is a graph showing impedance characteristics of the parallel arm resonator P when the film thickness of the second main conductive film 30b is variously changed in the boundary acoustic wave filter device 1 of the present embodiment having the following design parameters. It is.
  • the impedance characteristic when the wavelength is determined.
  • the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2 can be controlled by changing the film thickness of at least one of the main conductive films 30a to 30c. Specifically, it can be seen that by increasing the film thickness of the main conductive films 30a to 30c, the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2 can be reduced.
  • FIGS. 10 and 11 As shown in FIGS. 10 and 11, as the film thickness of the second main conductive film 30b increases and the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2 decreases, FIG. It can be seen that the amount of attenuation in the circled attenuation band increases.
  • the attenuation amount in the high-side attenuation band of the pass band is increased, and the isolation characteristics between the transmission-side signal terminal Tx and the reception-side signal terminals Rx1 and Rx2 are improved.
  • the wavelength normalized film thickness of the main conductive film made of Al or an alloy containing Al as a main component is preferably in the range of 10% to 30%.
  • Adhesion film 30d 10 nm
  • first main conductive film 30a 36 nm
  • adhesion film 30e 10 nm
  • adhesion film 30f 10 nm
  • third main Conductive film 30c 22 nm
  • protective film 30g 10 nm
  • Piezoelectric substrate 20 25 ° YX LiNbO 3 substrate Thickness of the piezoelectric substrate 20: 500 ⁇ m
  • the frequency difference between the center frequency of the passband and the resonance frequency of the response Rp2 that is, the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2
  • 6 is a graph showing impedance characteristics of the parallel arm resonator P when the thickness of the first dielectric layer 21 is variously changed in the boundary acoustic wave filter device 1 having the above design parameters.
  • the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2 can be controlled by changing the thickness of the first dielectric layer 21. Specifically, it can be seen that by increasing the thickness of the first dielectric layer 21, the frequency difference between the anti-resonance frequency of the main response Rp1 and the resonance frequency of the response Rp2 can be reduced.
  • the filter characteristics of the boundary acoustic wave filter device 1 of the present embodiment at various thicknesses of the first dielectric layer 21 are shown in FIGS. Further, the isolation characteristics between the transmission side signal terminal Tx and the reception side signal terminals Rx1 and Rx2 in the duplexer 3 using the boundary acoustic wave filter device 1 of the present embodiment in various thicknesses of the first dielectric layer 21. Is shown in FIG.
  • the isolation characteristics between the terminal Tx and the reception-side signal terminals Rx1 and Rx2 are good.
  • the isolation characteristic does not change so much
  • the thickness of the first dielectric layer 21 made of SiO 2 is 70% or less. It is preferable.
  • the elastic wave filter device is a ladder type filter device.
  • the elastic wave filter device of the present invention is not limited to a ladder type filter device.
  • the acoustic wave filter device of the present invention includes a first resonator that contributes to formation of a pass band between an input terminal and an output terminal, and a signal transmission path between the input terminal and the output terminal.
  • the second resonator is provided between the ground potential and the ground potential, there is no particular limitation.
  • the antiresonance frequency of the second resonator is located in the passband. This is because the amount of attenuation in the attenuation band located on the high frequency side of the pass band depends on the low impedance in the attenuation band of the second resonator.
  • the present invention which can reduce the impedance in the attenuation band of the second resonator, is suitable for the entire acoustic wave filter device in which the second resonator is provided between them.
  • the acoustic wave filter device may be a longitudinally coupled resonator type acoustic wave filter having parallel traps as shown in FIG.
  • the boundary acoustic wave filter device 5 of this embodiment includes an input terminal 11 that is an unbalanced signal terminal, and first and second output terminals 12a and 12b that are balanced signal terminals. . Between the input terminal 11 and the first and second output terminals 12a and 12b, longitudinally coupled resonator type acoustic wave filter sections 50a and 50b are connected.
  • the longitudinally coupled resonator type acoustic wave filter unit 50a is connected between the input terminal 11 and the first output terminal 12a.
  • the longitudinally coupled resonator type acoustic wave filter unit 50a includes first to third IDT electrodes 51a to 53a and first to third IDT electrodes 51a to 53a arranged along the propagation direction of the boundary acoustic wave.
  • the region is provided with first and second grating reflectors 54a and 55a disposed on both sides in the boundary acoustic wave propagation direction.
  • One side of each of the first and third IDT electrodes 51a and 53a is connected to the input terminal 11 via the boundary acoustic wave resonator 56, and the other side is connected to the ground potential.
  • One side of the second IDT electrode 52a is connected to the ground potential, and the other side is connected to the first output terminal 12a.
  • the longitudinally coupled resonator type acoustic wave filter unit 50b is connected between the input terminal 11 and the second output terminal 12b.
  • the longitudinally coupled resonator type acoustic wave filter unit 50b includes first to third IDT electrodes 51b to 53b and first to third IDT electrodes 51b to 53b arranged along the propagation direction of the boundary acoustic wave.
  • the region is provided with first and second grating reflectors 54b and 55b arranged on both sides in the boundary acoustic wave propagation direction.
  • One side of each of the first and third IDT electrodes 51b and 53b is connected to the input terminal 11 via the boundary acoustic wave resonator 56, and the other side is connected to the ground potential.
  • One side of the second IDT electrode 52b is connected to the ground potential, and the other side is connected to the second output terminal 12b.
  • a parallel trap 60a as a second resonator is connected between a connection point between the longitudinally coupled resonator type acoustic wave filter unit 50a and the first output terminal 12a and the ground potential.
  • a parallel trap 60b as a second resonator is connected between the connection point between the longitudinally coupled resonator type acoustic wave filter unit 50b and the second output terminal 12b and the ground potential.
  • the amount of attenuation in the attenuation band located on the high frequency side of the pass band is increased by the parallel traps 60a and 60b.
  • c ) is a value ((f Frh ⁇ f c ) / f c ) normalized by the center frequency of the pass band is in the range of 0.073 to 0.250.
  • the amount of attenuation in the attenuation band located on the side is increased.
  • the boundary acoustic wave filter device using the boundary acoustic wave and the duplexer including the boundary acoustic wave filter device have been described.
  • the boundary acoustic wave filter device according to the present invention includes the boundary acoustic wave. It is not limited to what uses.
  • at least one of the first and second resonators may be a surface acoustic wave resonator. That is, the boundary acoustic wave filter device according to the present invention may be a surface acoustic wave filter device.
  • a duplexer is used as an example of a duplexer.
  • the duplexer may be, for example, a triplexer.
  • ground electrode 20 piezoelectric substrate 21 ... first dielectric layer 22 ... second dielectric Body layer 29 ... resonator 30 ... IDT electrode 30a ... first main conductive film 30b ... second main conductive film 30c ... third main conductive films 30d to 30f ... adhesion film 30g ... protective films 31, 32 ... comb teeth Electrode 31a, 32a ... bus bar 31 32b ... electrode fingers 31c, 32c ... dummy electrodes 33, 34 ... second grating reflector 41 ... unbalanced signal terminal 42a ... first balanced signal terminal 42b ... second balanced signal terminal 43 ... boundary acoustic wave resonator 44a ... first boundary acoustic wave filter unit 44b ...

Landscapes

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

Abstract

L'invention concerne un dispositif de filtre à ondes acoustiques possédant une bande passante et une bande atténuée située du côté des valeurs élevées de la bande passante, la valeur d'atténuation dans la bande atténuée étant accrue sans entraîner d'augmentation sensible des dimensions dudit dispositif de filtre à ondes acoustiques. L'invention concerne également un filtre de dérivation équipé de celui-ci. Le dispositif de filtre (1) à ondes acoustiques comprend : une borne d'entrée (11); une borne de sortie (12); un premier résonateur (S1) monté entre la borne d'entrée (11) et la borne de sortie (12); et un deuxième résonateur (P3) branché entre le potentiel de la masse et un noeud de connexion, le noeud de connexion étant situé entre la borne d'entrée (11) ou la borne de sortie (12) et le premier résonateur (S1). La valeur de la fréquence de résonance (fFrh) d'une réponse autre que la réponse contribuant à la formation de la bande passante du deuxième résonateur (P3), moins la fréquence centrale (fc) de la bande passante, avec une normalisation au moyen de la fréquence centrale de la bande passante, à savoir ((fFrh - fc) / fc), se situe entre 0,073 et 0,250.
PCT/JP2010/066556 2009-09-30 2010-09-24 Dispositif de filtre à ondes acoustiques et filtre de dérivation équipé de celui-ci Ceased WO2011040332A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2011534220A JP5338912B2 (ja) 2009-09-30 2010-09-24 弾性波フィルタ装置及びそれを備える分波器

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2009-226522 2009-09-30
JP2009226522 2009-09-30

Publications (1)

Publication Number Publication Date
WO2011040332A1 true WO2011040332A1 (fr) 2011-04-07

Family

ID=43826152

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2010/066556 Ceased WO2011040332A1 (fr) 2009-09-30 2010-09-24 Dispositif de filtre à ondes acoustiques et filtre de dérivation équipé de celui-ci

Country Status (2)

Country Link
JP (1) JP5338912B2 (fr)
WO (1) WO2011040332A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012169231A1 (fr) * 2011-06-09 2012-12-13 株式会社村田製作所 Dispositif de filtre à onde élastique
JP2013118584A (ja) * 2011-12-05 2013-06-13 Taiyo Yuden Co Ltd フィルタ及び分波器
JP2013225853A (ja) * 2012-04-19 2013-10-31 Triquint Semiconductor Inc 高結合で低損失な圧電境界波デバイスおよび関連する方法
CN109286384A (zh) * 2017-07-20 2019-01-29 株式会社村田制作所 多工器、高频前端电路以及通信装置
WO2019188864A1 (fr) * 2018-03-28 2019-10-03 株式会社村田製作所 Filtre à ondes élastiques, multiplexeur, circuit frontal haute fréquence et dispositif de communication
CN114301419A (zh) * 2020-10-05 2022-04-08 谐振公司 声矩阵滤波器和使用声矩阵滤波器的收音机
KR20220108977A (ko) * 2021-01-28 2022-08-04 (주)와이솔 탄성파 필터장치

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006114930A1 (fr) * 2005-04-25 2006-11-02 Murata Manufacturing Co., Ltd. Dispositif a ondes acoustiques de bord
WO2006123585A1 (fr) * 2005-05-20 2006-11-23 Murata Manufacturing Co., Ltd. Dispositif a ondes limites elastiques
WO2007007476A1 (fr) * 2005-07-13 2007-01-18 Murata Manufacturing Co., Ltd. Filtre à onde acoustique d’interface
WO2009022410A1 (fr) * 2007-08-14 2009-02-19 Fujitsu Limited Dispositif d'onde d'interface élastique

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004140738A (ja) * 2002-10-21 2004-05-13 Toyo Commun Equip Co Ltd 弾性表面波フィルタ

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006114930A1 (fr) * 2005-04-25 2006-11-02 Murata Manufacturing Co., Ltd. Dispositif a ondes acoustiques de bord
WO2006123585A1 (fr) * 2005-05-20 2006-11-23 Murata Manufacturing Co., Ltd. Dispositif a ondes limites elastiques
WO2007007476A1 (fr) * 2005-07-13 2007-01-18 Murata Manufacturing Co., Ltd. Filtre à onde acoustique d’interface
WO2009022410A1 (fr) * 2007-08-14 2009-02-19 Fujitsu Limited Dispositif d'onde d'interface élastique

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012169231A1 (fr) * 2011-06-09 2012-12-13 株式会社村田製作所 Dispositif de filtre à onde élastique
JPWO2012169231A1 (ja) * 2011-06-09 2015-02-23 株式会社村田製作所 弾性波フィルタ装置
US9184728B2 (en) 2011-06-09 2015-11-10 Murata Manufacturing Co., Ltd. Elastic-wave filter device
JP2013118584A (ja) * 2011-12-05 2013-06-13 Taiyo Yuden Co Ltd フィルタ及び分波器
JP2013225853A (ja) * 2012-04-19 2013-10-31 Triquint Semiconductor Inc 高結合で低損失な圧電境界波デバイスおよび関連する方法
CN109286384A (zh) * 2017-07-20 2019-01-29 株式会社村田制作所 多工器、高频前端电路以及通信装置
CN109286384B (zh) * 2017-07-20 2022-06-10 株式会社村田制作所 多工器、高频前端电路以及通信装置
WO2019188864A1 (fr) * 2018-03-28 2019-10-03 株式会社村田製作所 Filtre à ondes élastiques, multiplexeur, circuit frontal haute fréquence et dispositif de communication
US11394368B2 (en) 2018-03-28 2022-07-19 Murata Manufacturing Co., Ltd. Acoustic wave filter, multiplexer, radio frequency front-end circuit, and communication device
CN114301419A (zh) * 2020-10-05 2022-04-08 谐振公司 声矩阵滤波器和使用声矩阵滤波器的收音机
KR20220108977A (ko) * 2021-01-28 2022-08-04 (주)와이솔 탄성파 필터장치
KR102579221B1 (ko) 2021-01-28 2023-09-15 (주)와이솔 탄성파 필터장치

Also Published As

Publication number Publication date
JP5338912B2 (ja) 2013-11-13
JPWO2011040332A1 (ja) 2013-02-28

Similar Documents

Publication Publication Date Title
JP6479086B2 (ja) ラダー型弾性波フィルタと、これを用いたアンテナ共用器
US11496116B2 (en) Acoustic wave filter device, multiplexer and composite filter device
JP5182459B2 (ja) ラダー型弾性波フィルタ及びこれを用いたアンテナ共用器
JP4894911B2 (ja) 弾性境界波フィルタ
JP4917396B2 (ja) フィルタおよび分波器
JP5338912B2 (ja) 弾性波フィルタ装置及びそれを備える分波器
WO2016013659A1 (fr) Filtre passe-bande et module de filtre
CN102652395A (zh) 天线共用器
JP2019068309A (ja) 弾性波デバイス、フィルタおよびマルチプレクサ
JP5810113B2 (ja) 弾性波共振器とこれを用いた弾性波フィルタおよびアンテナ共用器
JP5083469B2 (ja) 弾性表面波装置
CN102197593B (zh) 弹性波滤波装置
JP4407696B2 (ja) 弾性表面波装置
CN101218743B (zh) 声波滤波器装置
US20090201105A1 (en) Acoustic wave device
JPWO2005036743A1 (ja) 弾性境界波装置
JP2010263296A (ja) 弾性境界波装置
JP4548305B2 (ja) 二重モード弾性表面波フィルタ
HK1232346B (zh) 梯型弹性波滤波器和天线共用器
HK1200608B (en) Ladder-type elastic wave filter and antenna duplexer using same
HK1207482B (en) Ladder-type elastic wave filter and antenna duplexer using same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10820449

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2011534220

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10820449

Country of ref document: EP

Kind code of ref document: A1