WO2007015331A1 - Dispositif de filtrage d'onde élastique - Google Patents

Dispositif de filtrage d'onde élastique Download PDF

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Publication number
WO2007015331A1
WO2007015331A1 PCT/JP2006/310674 JP2006310674W WO2007015331A1 WO 2007015331 A1 WO2007015331 A1 WO 2007015331A1 JP 2006310674 W JP2006310674 W JP 2006310674W WO 2007015331 A1 WO2007015331 A1 WO 2007015331A1
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WIPO (PCT)
Prior art keywords
acoustic wave
filter device
wave filter
ground potential
surface acoustic
Prior art date
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Ceased
Application number
PCT/JP2006/310674
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English (en)
Japanese (ja)
Inventor
Kazumasa Haruta
Yasumasa Taniguchi
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Murata Manufacturing Co Ltd
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Murata Manufacturing Co Ltd
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Priority to JP2007529186A priority Critical patent/JP4626652B2/ja
Publication of WO2007015331A1 publication Critical patent/WO2007015331A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • H03H9/6406—Filters characterised by a particular frequency characteristic
    • H03H9/6409—SAW notch filters
    • 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
    • H03H9/05—Holders or supports
    • H03H9/0538—Constructional combinations of supports or holders with electromechanical or other electronic elements
    • H03H9/0542—Constructional combinations of supports or holders with electromechanical or other electronic elements consisting of a lateral arrangement

Definitions

  • the present invention relates to an acoustic wave filter device such as a surface acoustic wave filter device or a boundary acoustic wave filter device, and more specifically, a plurality of inductors are connected between an input end and an output end.
  • the present invention also relates to an elastic wave filter device in which a plurality of resonators are connected between a series arm connecting the input arm and the output arm and a ground potential.
  • Patent Document 1 a plurality of inductances connected in series between an input terminal and an output terminal are adjacent to each other between the input terminal and the ground potential and between the output terminal and the ground potential.
  • a band rejection filter is disclosed in which parallel arm resonators are respectively connected between a connection point between inductances and a ground potential.
  • FIG. 17 is a circuit diagram showing an example of the circuit configuration of this type of band rejection filter.
  • the band rejection filter 501 an inductance L 1 is connected between the input terminal IN and the output terminal OUT.
  • a parallel arm resonator P1 is connected between the input terminal IN and the ground potential.
  • a parallel arm resonator P2 is connected between the output terminal OUT and the ground potential.
  • the parallel arm resonators PI and P2 are each composed of a surface acoustic wave resonator formed by forming an IDT electrode on a piezoelectric substrate.
  • the resonance frequencies Fl and F2 of the parallel arm resonators P1 and P2 are substantially equal, and are located in the stop band.
  • Patent Document 1 Japanese Unexamined Patent Application Publication No. 2004-129238
  • the resonance frequencies Fl and F2 are positioned in the stopband so that the passage of signals in the stopband is blocked.
  • This band rejection filter 501 is formed by using a surface acoustic wave filter chip in which parallel arm resonators PI and P2 made of surface acoustic wave resonators are formed on one piezoelectric substrate.
  • the surface acoustic wave filter chip The group connected to the ground potential of the parallel arm resonators PI and P2 is connected to the GND land connected to the ground potential of the force knocker mounted on the knocker. . Therefore, a common inductance La shown in FIG. 17 is generated.
  • an inductance La is generated between the common connection portion formed by connecting one ends of the parallel arm resonators PI and P2 and the round potential.
  • the impedance becomes the magnitude of the resonance resistance and becomes smaller. For this reason, a voltage is generated in the inductance La due to a current flowing from the input terminal IN to the ground potential. A signal based on this voltage passes through the parallel arm resonator P2 and flows to the output terminal UT.
  • the resonance frequency of the parallel arm resonator P2 is substantially equal to the resonance frequency of the parallel arm resonator P1
  • the impedance of the parallel arm resonator P2 is low at the resonance frequency, so that a voltage is generated in the inductance La. The signal caused by this will flow to the output terminal OUT.
  • An object of the present invention is to provide a plurality of inductances connected in series between an input end and an output end in view of the current state of the prior art described above, and an elastic wave between the series arm and a ground potential. It is an elastic wave filter device having a circuit configuration in which a resonator is connected, and is to provide a band rejection type elastic wave filter device capable of reliably suppressing the passage of a signal in a trap band. .
  • an acoustic wave filter device having a trap band and a pass band positioned on the lower side of the trap band, and is connected in series between the input end and the output end.
  • a plurality of connected inductors at least one of the input terminal or output terminal, and a ground potential; a capacitive element that is capacitive in the trap band; and the input terminal or output terminal
  • the capacitive element is not connected between the ground potential and the first acoustic wave resonator that is connected to the ground potential, the connection point between the inductances that are adjacent to each other and the ground potential
  • a second elastic wave resonator connected between the second elastic wave resonator and the resonance frequency of the second elastic wave resonator is a frequency within the trap band !, Provided by elastic wave filter device It is.
  • a parallel resonance frequency of the capacitance of the capacitive element and the inductor having one end connected to the capacitive element is located in the trap band.
  • the capacitive element has a resonance frequency higher than a resonance frequency of the second acoustic wave resonator in the trap band and the pass band. This is a third acoustic wave resonator that is capacitive.
  • a piezoelectric substrate is further provided, and the second acoustic wave resonator is configured on the piezoelectric substrate.
  • the capacitive element is formed on the piezoelectric substrate.
  • the acoustic wave filter device further includes a package having one GND land, and all of the terminals connected to the ground potential of the capacitive element and the acoustic wave resonator are provided. Force Electrically connected to the GND land.
  • a plurality of terminals provided on the piezoelectric substrate are connected to the capacitive element and a ground potential of the acoustic wave resonator.
  • the plurality of electrodes are connected to the GND land of the knocker by bump bonding or wire bonding.
  • the electrode connected to the capacitive element and the ground potential of the acoustic wave resonator is provided on the piezoelectric substrate.
  • the one electrode is electrically connected to the GND land of the package.
  • a plurality of inductors are connected in series between the input end and the output end, and at least between the input end or the output end and the ground potential.
  • a capacitive element is connected to one side, and the capacitive element is connected between the input terminal or output terminal and the ground potential!
  • the first acoustic wave resonator is connected.
  • a second acoustic wave resonator is connected between a connection point between adjacent inductances and a ground potential.
  • the resonance frequency of the second acoustic wave resonator is The frequency is within the wrap band. Therefore, at the resonance frequency of the second elastic wave resonator, the impedance of the second elastic wave resonator becomes low, and a trap is formed.
  • the capacitive element Since the capacitive element is connected between the input terminal and the ground potential and between Z or the output terminal and the ground potential, current flows from the input terminal to the output terminal in the trap band. Therefore, it is difficult to flow through the portion connected to the ground potential. That is, it is possible to prevent the attenuation amount in the trap band from being deteriorated by the above-mentioned direct wave, which has been a problem in the conventional surface acoustic wave filter device. Therefore, it is possible to provide an elastic wave filter device having a sufficiently large attenuation in the trap band.
  • the attenuation in the trap band should be further increased. Can do.
  • the capacitive element is constituted by a third acoustic wave resonator that is capacitive in a trap band and a pass band in which the resonance frequency is higher than the resonance frequency of the second acoustic wave resonator
  • the third elastic wave resonator is capacitive in the trap band where the resonance frequency of the third elastic wave resonator is higher than the trap band
  • the direct wave is more effectively suppressed by the third elastic wave resonator and the attenuation in the trap band is reduced. Can be increased.
  • the third acoustic wave resonator can be formed by the same process as the second acoustic wave resonator, and the accuracy of the capacitance value can be increased. As a result, variations in trap attenuation can be reduced.
  • the second elastic wave resonator is formed in the elastic wave filter device of the present invention. It is possible to provide an elastic wave filter device in which main parts are integrated using an elastic wave filter chip having a piezoelectric substrate force.
  • the acoustic wave filter device can be further integrated by one acoustic wave filter chip using the piezoelectric substrate.
  • a package having one GND land is further provided, and all the power of terminals connected to the ground potential of the capacitive element and the acoustic wave resonator are electrically connected to the GND land.
  • the elastic wave filter device can be downsized.
  • terminals connected to the ground potential of the capacitive element and the acoustic wave resonator are connected to a plurality of electrodes provided on the piezoelectric substrate, and the plurality of electrodes are connected by bump bonding or wire bonding.
  • a terminal connected to the GND potential of the capacitive element and the acoustic wave resonator is connected to one electrode provided on the piezoelectric substrate, and the one electrode is electrically connected to the GND land of the package. When connected to, it is possible to further reduce the amount of attenuation and variation in attenuation in the trap band.
  • FIG. 1 is a circuit diagram of a surface acoustic wave filter device according to a first embodiment of the present invention.
  • FIG. 2 is a diagram showing attenuation frequency characteristics of the surface acoustic wave filter device according to the first embodiment and impedance frequency characteristics of the respective acoustic wave resonators used in the filter device.
  • FIG. 3 is a schematic plan view of a piezoelectric substrate showing an electrode structure on the lower surface of the piezoelectric substrate of the surface acoustic wave filter chip used in the elastic wave filter device of the first embodiment.
  • FIG. 4 is a plan view of a package substrate used in the surface acoustic wave filter device of the first embodiment.
  • FIG. 5 (a) is a schematic block diagram showing the relationship between electrode lands provided in the package of the surface acoustic wave filter device of the first embodiment and external inductance;
  • FIG. 2 is a schematic front sectional view showing a main part of the surface acoustic wave filter device of the present embodiment.
  • FIG. 6 is a graph showing attenuation frequency characteristics of the first embodiment and a conventional equivalent surface acoustic wave filter device.
  • FIG. 7 is a schematic plan view showing an electrode structure of a surface acoustic wave resonator.
  • FIG. 8 shows a wiring pattern in a state where the surface acoustic wave device of the first embodiment is mounted.
  • FIG. 6 is a circuit diagram showing a circuit configuration including a parasitic inductance due to a loop or the like.
  • FIG. 9 is a circuit diagram including a parasitic inductance component due to a wiring pattern or the like of a surface acoustic wave filter device according to a modification of the present invention.
  • FIG. 10 is a schematic plan view showing the electrode structure provided on the lower surface of the piezoelectric substrate in order to explain a modification of the surface acoustic wave filter device of the first embodiment.
  • FIG. 11 is a schematic plan view of a package substrate for explaining electrode lands on the package substrate used in a modification of the surface acoustic wave filter device of the first embodiment.
  • FIG. 12 is a diagram showing attenuation frequency characteristics of the surface acoustic wave filter device of the first embodiment and the modification.
  • FIG. 13 is a schematic plan view illustrating a piezoelectric substrate used in a surface acoustic wave filter device according to a second embodiment of the present invention and an electrode structure formed on the lower surface of the piezoelectric substrate. is there.
  • FIG. 14 is a circuit diagram showing a circuit configuration of a surface acoustic wave filter device according to a second embodiment.
  • FIG. 15 is a plan view for explaining a modification of the surface acoustic wave device according to the first embodiment.
  • FIG. 16 is a schematic plan view showing a transparent electrode structure on the lower surface of a piezoelectric substrate used in a surface acoustic wave filter device according to still another modified example of the present invention.
  • FIG. 17 is a circuit diagram showing an example of a band rejection filter device using a conventional surface acoustic wave filter.
  • FIG. 1 is a circuit diagram of a surface acoustic wave filter device according to a first embodiment of the present invention.
  • inductances L11 to L13 are connected in series between the input terminal IN and the output terminal OUT.
  • a first acoustic wave resonator P11 is connected between the input terminal IN and the ground potential.
  • the second acoustic wave resonator P12 is connected between the connection point 2 between the adjacent inductances Lll and L12 and the ground potential.
  • another second elastic wave resonator P13 is connected between the connection point 3 between the inductances L12 and L13 and the ground potential.
  • a third acoustic wave resonator P14 as a capacitive element is connected between the output terminal OUT and the ground potential.
  • the surface acoustic wave filter device 1 is a band-pass filter having a trap band and a pass band positioned on the lower side of the trap band.
  • the resonance frequencies of the first and second parallel arm resonators PI and P2 are equalized.
  • the resonance frequency of the first elastic wave resonator P11 is equal to the resonance frequency of the two second elastic wave resonators P12 and P13.
  • the resonant frequency of the third acoustic wave resonator P14 as a capacitive element is set higher than the resonant frequency of the second acoustic wave resonators P12 and P13, and the third acoustic wave resonator P14 has a trap band and The passband is considered to be capacitive.
  • the solid line A shows the attenuation-frequency characteristic of the surface acoustic wave filter device 1.
  • the broken line B, the solid line C, and the two-dot chain line D indicate the impedance frequency characteristics of the acoustic wave resonators Pl1, P12, and P13, respectively, while the one-dot chain line E indicates the impedance of the third acoustic wave resonator P14. Shows frequency characteristics.
  • the surface acoustic wave filter device 1 has a trap band in the vicinity of 830 to 845 MHz and a pass band of 800 MHz or less.
  • the resonance frequencies of the first and second acoustic wave resonators P11 to P13 are located in the trap band.
  • the third elastic wave resonator P14 The frequency is higher than the trap band and in the vicinity of 1000. 5 MHz, and it is considered to be capacitive in the pass band and trap band.
  • the portions connected to the ground potential of the acoustic wave resonators P 11 to P 14 are commonly connected, and the common connection point 4 is a round-down point. It will be connected to the potential. Then, as will be described later, specifically, the acoustic wave resonators P11 to P14 are mounted on the piezoelectric substrate force S package. In this case, an inductance La is generated due to the mounting structure.
  • a voltage is generated in the inductance La in the resonance frequency of the first and second parallel arm resonators PI and P2, that is, in the rejection band. Passes through the second parallel arm resonator P2 with low signal force impedance based on, and is applied to the output terminal OUT. In other words, a direct wave was generated, and the deterioration of attenuation in the stopband was a problem.
  • an inductance La is generated between the common connection point 4 and the ground potential, and the impedance of the acoustic wave resonator P11 is reduced in the trap band. A voltage is applied and a signal is generated.
  • the impedance of the third elastic wave resonator P14 is about 50 times larger than the impedance at the resonance frequency in the trap band. That is, since the third elastic wave resonator P14 is capacitive in the pass band, the signal generated in the inductance La is difficult to flow to the output terminal OUT.
  • the acoustic wave resonator P14 is connected in parallel to the inductance L13 that not only exhibits capacitance in the trap band, but forms a parallel resonance circuit. Therefore, when the parallel resonance frequency of the parallel resonance circuit is within the trap band of the surface acoustic wave filter device 1, the impedance in the trap band can be increased, and accordingly, the inductance La and the output terminal OUT can be increased. Can further increase the impedance of the Thus, the influence of the direct wave can be more effectively suppressed.
  • FIG. 3 is a schematic plan view showing the surface acoustic wave filter chip 11 used in the surface acoustic wave filter device 1 of the present embodiment.
  • the surface acoustic wave filter chip 11 has a rectangular piezoelectric substrate 12.
  • the piezoelectric substrate 12 is shown in a schematic plan view, but here, the electrodes formed on the lower surface of the piezoelectric substrate 12 are shown in perspective. This is because the piezoelectric substrate 12 is mounted on the package substrate 14 shown in FIG. 4 with the orientation shown in the figure, thereby constituting the main part of the surface acoustic wave filter device 1 shown in a schematic cross-sectional view in FIG. By being done.
  • the first elastic wave resonator Pll As shown in FIG. 3, on the lower surface of the piezoelectric substrate 12, the first elastic wave resonator Pll, the two second elastic wave resonators P12 and P13, and the third elastic wave element as the capacitive element A wave resonator P14 is formed.
  • Such acoustic wave resonators P11 to P14 have IDT electrodes and reflectors arranged on both sides of the IDT electrode in the surface wave propagation direction. In FIG. 3, these electrodes are not specifically shown, and the portion where the IDT electrode and the pair of reflectors are arranged is schematically shown.
  • FIG. 7 schematically shows the electrode structures of the IDT electrode and the reflector constituting the acoustic wave resonator.
  • the IDT electrode 15 has a plurality of electrode fingers that are interleaved with each other.
  • Reflectors 16 and 17 are disposed on both sides of the IDT electrode 15.
  • the first acoustic wave resonator P 11 is connected to the electrode land 12 a on the input terminal side by a wiring pattern.
  • a bump 13a is bonded to the lower surface of the electrode land 12a.
  • the bump 13a is provided for electrical connection to an electrode land on the package substrate 14 to be described later.
  • each of the acoustic wave resonators Pl 1 and P 12 is commonly connected, and is electrically connected to the electrode land 12 b by a wiring pattern.
  • the electrode land 12b is an electrode land connected to the ground potential, and the bump 13b is also bonded to the lower surface of the electrode land 12b.
  • the end of the neutral wave resonator P12 opposite to the side connected to the electrode land 12b is connected to the electrode land 12c by a wiring pattern.
  • a bump 13c is bonded to the lower surface of the electrode land 12c.
  • One end of the surface acoustic wave resonator P13 is connected to the ground potential. It is connected to the pole land 12d, and the bump 13d is joined to the lower surface of the electrode land 12d.
  • the other end of the acoustic wave resonator P13 is electrically connected to the electrode land 12e by a wiring pattern.
  • a bump 13e is connected to the lower surface of the electrode land 12e.
  • one end of the third acoustic wave resonator P14 is connected to the electrode land 12d by a wiring pattern, and the other end is connected to the electrode land 12f by a wiring pattern.
  • the electrode land 12f is an electrode land connected to the output terminal, and a bump 13f is connected to the lower surface of the electrode land 12f.
  • electrode lands 14 a to 14 e are formed on the package substrate 14.
  • the electrode land 14a is connected to the input terminal, and the electrode land 14e is connected to the output terminal.
  • the electrode land 14d is the only electrode land connected to the ground.
  • Each of the electrode land 14b and 14c constitutes a terminal connected to an inductance (not shown).
  • the inductances L11 to L13 shown in FIG. 1 are constituted by chip-type inductance components different from the surface acoustic wave filter chip 11 and the package substrate 14.
  • an inductance L11 is electrically connected between the electrode lands 14a and 14b of the package substrate 14
  • an inductance L12 is electrically connected between the electrode lands 14b and 14c
  • an inductance L13 is electrically connected between the electrode lands 14c and 14e. Connected to.
  • the surface acoustic wave filter device 1 of the above embodiment can have a sufficient amount of attenuation in the passband as compared with the conventional filter device 1 having the circuit configuration shown in FIG. A description will be given based on a typical experimental example.
  • acoustic wave resonators P11 to P14 surface acoustic wave resonators having the circuit constants shown in Table 1 below were used.
  • fr indicates the resonance frequency of the surface acoustic wave resonator.
  • the acoustic wave resonator has an equivalent circuit in which a series inductance Ll, a series capacitance C1, a series resistance R1, and a parallel capacitance CO, which are connected in series with each other, are connected in parallel.
  • CO is the parallel capacitance in the equivalent circuit of the acoustic wave resonator
  • C1 is the series capacitance in the equivalent circuit
  • L1 is the series inductance in the equivalent circuit
  • R1 is the series resistance in the equivalent circuit.
  • the inductance value of the inductance LI 1 is 13 nH
  • the inductance value of the inductance L 12 is 16 nH
  • the inductance value of the inductance L 13 is 13 nH.
  • the resonance frequency characteristic of the surface acoustic wave filter device 1 configured as described above is shown by a solid line in FIG.
  • it was configured to be equivalent to the surface acoustic wave filter device of the above embodiment except that the acoustic wave resonators P1 to P4 having the equivalent circuit constants shown in Table 1 were used.
  • a band-stop filter device was created and the attenuation-frequency characteristics were measured.
  • Figure 6 shows the attenuation frequency characteristics of the conventional filter device in broken lines.
  • the surface acoustic wave filter device of the above embodiment can ensure a large attenuation in the vicinity of 840 MHz, which is the stop band.
  • the surface acoustic wave filter chip 11 is configured using the piezoelectric substrate 12, and the bumps 13a to 13f are applied to the electrode lands 14a to 14e on the package substrate 14. It was mounted by bump bonding. (See Fig. 5 (b))
  • FIG. 8 is a circuit diagram for explaining a circuit configuration when the surface acoustic wave filter device 1 and the print according to the embodiment are mounted on a circuit board or the like.
  • first and second acoustic wave resonators Pl 1 and P 12 are commonly connected to the electrode land 12 b, they are commonly connected to the electrode land 12 b and on the package substrate 14.
  • An inductance Lb due to the wiring pattern is generated in the portion connected to the electrode land 14d.
  • the acoustic wave resonators P13 and P14 are commonly connected, and are connected to the electrode land 14d by a wiring pattern. Pulling by this wiring pattern Even if it is turned, a parasitic inductance Lc is generated.
  • an inductance Ld occurs in the portion of the package substrate 14 where the electrode land 14d is connected to the ground. Furthermore, a parasitic inductance component Le is also generated due to the mounting structure when the surface acoustic wave filter device 1 consisting of these parasitic inductances Lb to Ld, which is composed only of the inductance La in FIG. 1, is mounted on a printed circuit board or the like.
  • the inductance Le is connected in series to the parasitic inductance La shown in FIG.
  • the bumps 13 b and 13 d that is, the surface acoustic wave filter chip 11 is formed on the electrode land 14 d connected to one ground potential, and thus the piezoelectric Since all the terminals connected to the ground potential are connected to the substrate 12, the parasitic inductance L d due to the knock substrate 14 becomes one. Therefore, the variation of the parasitic inductance due to the package substrate 14 can be reduced.
  • the inductances L 11 to L 13 and the acoustic wave resonators P 11 to P 14 are the same as those of the surface acoustic wave filter device 1 of the above embodiment.
  • the electrode structure shown in FIG. 10 is formed on the lower surface of the piezoelectric substrate 22 to form the acoustic wave resonators PI 1 to PI P14 is configured.
  • the IDT electrode waves of the respective acoustic wave resonators P11 to P14 are schematically shown, but reflectors are arranged on both sides of the IDT electrode as in the above embodiment.
  • Electrode lands 24a to 24h are formed on the package substrate 24 shown in FIG. This Here, the electrode land 24a is an electrode land connected to the input terminal, and the electrode land 24c is an electrode land connected to the output terminal.
  • the electrode land on the package substrate 24 that is electrically connected to the portion connected to the ground potential of the acoustic wave resonators P11 to P14 is divided into two electrode lands 24f and 24g.
  • An inductance L11 is electrically connected between the electrode lands 24a and 24e of the package substrate 24, an inductance L12 is electrically connected between the electrode lands 24e and 24h, and an inductance L13 is electrically connected between the electrode lands 24h and 24c.
  • the parasitic inductance due to the package substrate is reduced by the inductance as shown in FIG. It occurs in both Ldl and Ld2. Therefore, since the parasitic inductance Ld shown in FIG. 8 is divided into inductances Ldl and Ld2 as shown in FIG. 9 as described above, due to variations in the inductance Ldl and Ld2 due to the wiring portion of the package substrate, etc. However, there is a possibility that the attenuation in the trap band is deteriorated.
  • FIG. 12 is a diagram showing attenuation-frequency characteristics of the surface acoustic wave filter device 1 according to the embodiment and the surface acoustic wave filter device according to the modification.
  • the solid line in FIG. 12 shows the result of the above embodiment, and the broken line shows the result of the above modification.
  • the amount of attenuation in the trap band can be increased as compared with the surface acoustic wave filter device of the above modification.
  • the attenuation amount of the trap band is sufficiently increased according to the present invention as compared with the conventional band rejection filter device shown in FIG. That is, the propagation of the direct wave described above is effectively suppressed, and a sufficient attenuation is ensured in the trap band.
  • the electrode land connected to the ground potential of the piezoelectric substrate is one electrode land, and a surface acoustic wave filter chip is configured on the one electrode land. It is desirable that all terminals connected to the ground potential of the piezoelectric substrate are electrically connected.
  • FIG. 13 shows a piezoelectric substrate and a lower surface of the piezoelectric substrate constituting an inertial surface wave filter chip used in the surface acoustic wave filter device according to the second embodiment of the present invention.
  • FIG. 14 is a schematic plan view showing the electrodes formed in FIG. 14 in perspective, and FIG. 14 is a circuit diagram of the surface acoustic wave filter device according to the second embodiment.
  • the surface acoustic wave filter device of the second embodiment is configured in the same manner as the surface acoustic wave filter device 1 of the first embodiment, except that the configuration of the capacitive element is different. Therefore, the capacitive element portion will be described with reference to FIG. 13, and the description of the first embodiment will be used for the other portions.
  • the surface acoustic wave filter chip 31 is configured using a piezoelectric substrate 32.
  • a first surface acoustic wave resonator P11 and two second surface acoustic wave resonators P12 and P13 are formed on the lower surface of the piezoelectric substrate 32.
  • a capacitor C14 is formed instead of the third acoustic wave resonator P14 as the capacitive element of the first embodiment.
  • the capacitor C14 constitutes a capacitive element and has a pair of capacitive electrodes 33 and 34 facing each other.
  • the capacitive element in the present invention is not limited to the above-described third acoustic wave resonator P14, and may be constituted by various capacitor elements.
  • the capacitor electrodes 33 and 34 are formed so as to face the lower surface of the piezoelectric substrate 32 with a predetermined gap therebetween, but the capacitor C14 may be built in the piezoelectric substrate 22 or An external capacitor chip mounted on the piezoelectric substrate 32 may be used.
  • the capacitance electrodes 33 and 34 are formed on the lower surface of the piezoelectric substrate 32, the number of parts can be reduced and the size can be reduced.
  • the surface acoustic wave filter chip is bonded to the piezoelectric substrate by bump bonding.
  • the surface acoustic wave filter chip is bonded by bonding wires 42a to 42f. 43 may be electrically connected to the package substrate 44.
  • the surface acoustic wave filter chip 43 has a rectangular piezoelectric substrate 45, and the illustrated electrode structure is formed on the upper surface of the piezoelectric substrate 45.
  • the surface acoustic wave filter chip 43 is electrically connected to the electrode lands 44a to 44e formed on the upper surface of the package substrate 44 by bonding wires 42a to 42f.
  • the electrode land 44a is an electrode land connected to the input terminal, and the electrode land 44e is connected to the output terminal.
  • the electrode lands 44b and 44c are electrode lands as terminals to which external inductance is joined, and the electrode lands 44d are one electrode land connected to the ground potential.
  • the package substrate 44 is provided with the electrode land 44d connected to one ground potential, and all of the electrode lands 44d connected to the ground potential of the surface acoustic wave filter chip 43 are connected to the electrode land 44d. Are joined. Therefore, as in the case of the first embodiment described above, the amount of attenuation in the trap band can be made sufficiently large.
  • FIG. 16 is a schematic plan view of a surface acoustic wave filter chip for explaining a surface acoustic wave filter device of still another modified example of the first embodiment.
  • the surface acoustic wave filter chip 51 has a rectangular piezoelectric substrate 52.
  • the electrode structure provided on the lower surface of the piezoelectric substrate 52 is shown in a transparent manner.
  • the electrode structure has first to third elastic wave resonators P11 to P14.
  • all the terminals connected to the ground potential of the first to third acoustic wave resonators P11 to P14 are commonly connected on the piezoelectric substrate 52 and connected to one electrode land 53a.
  • the electrode land 53b is an electrode land connected to the input terminal
  • the electrode land 53c is a ground electrically connected to the output terminal
  • the electrode lands 53d and 53e are connected to an external inductance.
  • An electrode land as a terminal to be connected.
  • the electrode land connected to the round potential is shared, or the ground potential in the surface acoustic wave filter chip is used.
  • the surface acoustic wave filter device using the surface acoustic wave is shown as the surface acoustic wave filter device.
  • the present invention uses the boundary acoustic wave.
  • the present invention can also be provided for the boundary acoustic wave filter device.
  • the capacitive element is disposed on the output side, but it may be disposed on the input side or on both input and output sides.

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

Abstract

La présente invention concerne un dispositif de filtrage d'onde élastique d'un type interdisant la bande, formé par l'utilisation d'un élément de filtrage d'onde élastique et ayant une bande de piégeage et une bande de passage. La quantité d'atténuation dans la bande de piégeage est suffisamment large. Une pluralité d'inductances est reliée entre un terminal d'entrée et un terminal de sortie. Un élément de capacitance est relié entre la borne d'entrée ou la borne de sortie et le potentiel à la masse. Le dispositif de filtrage d'onde élastique (1) comprend un premier résonateur élastique connecté lorsque l'élément de capacitance n'est pas connecté entre la borne d'entrée ou la borne de sortie et le potentiel à la masse et un second résonateur élastique connecté entre les points de raccordement entre les inductances adjacentes et le potentiel à la masse. La fréquence de résonance du second résonateur élastique est une fréquence dans la bande de piégeage.
PCT/JP2006/310674 2005-08-02 2006-05-29 Dispositif de filtrage d'onde élastique Ceased WO2007015331A1 (fr)

Priority Applications (1)

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JP2007529186A JP4626652B2 (ja) 2005-08-02 2006-05-29 弾性波フィルタ装置

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JPWO2007094139A1 (ja) * 2006-02-13 2009-07-02 株式会社村田製作所 Ｓａｗフィルタ装置
WO2011108289A1 (fr) * 2010-03-01 2011-09-09 株式会社村田製作所 Dispositif de filtre à ondes acoustiques
US9935612B2 (en) 2015-06-09 2018-04-03 Taiyo Yuden Co., Ltd. Ladder-type filter, duplexer, and module
WO2022227347A1 (fr) * 2021-04-26 2022-11-03 安徽安努奇科技有限公司 Filtre coupe-bande et filtre coupe-bande multifréquence
US12040780B2 (en) 2021-04-26 2024-07-16 Anhui Anuki Technologies Co., Ltd. Band-stop filter and multi-frequency band-stop filter

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JPH06236815A (ja) * 1992-09-14 1994-08-23 Hitachi Ltd 高周波回路装置および無線機
JP2000101388A (ja) * 1998-09-22 2000-04-07 Oki Electric Ind Co Ltd 弾性表面波フィルタパッケージ
WO2000030252A1 (fr) * 1998-11-13 2000-05-25 Matsushita Electric Industrial Co., Ltd. Filtre d'ondes acoustiques de surface
JP2004129238A (ja) * 2002-09-10 2004-04-22 Matsushita Electric Ind Co Ltd 帯域阻止型フィルタ、フィルタ装置、アンテナ共用器、通信機器

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2007094139A1 (ja) * 2006-02-13 2009-07-02 株式会社村田製作所 Ｓａｗフィルタ装置
JP4640502B2 (ja) * 2006-02-13 2011-03-02 株式会社村田製作所 Ｓａｗフィルタ装置
WO2011108289A1 (fr) * 2010-03-01 2011-09-09 株式会社村田製作所 Dispositif de filtre à ondes acoustiques
JP4835814B2 (ja) * 2010-03-01 2011-12-14 株式会社村田製作所 弾性波フィルタ装置
US8410869B2 (en) 2010-03-01 2013-04-02 Murata Manufacturing Co., Ltd. Elastic-wave filter device having a band-pass filter and a band-reject filter
US9935612B2 (en) 2015-06-09 2018-04-03 Taiyo Yuden Co., Ltd. Ladder-type filter, duplexer, and module
WO2022227347A1 (fr) * 2021-04-26 2022-11-03 安徽安努奇科技有限公司 Filtre coupe-bande et filtre coupe-bande multifréquence
US12040780B2 (en) 2021-04-26 2024-07-16 Anhui Anuki Technologies Co., Ltd. Band-stop filter and multi-frequency band-stop filter

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JP4626652B2 (ja) 2011-02-09

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