JP5116653B2 - BANDPASS FILTER, RADIO COMMUNICATION MODULE AND RADIO COMMUNICATION DEVICE USING THE SAME - Google Patents

Description

  The present invention relates to a band-pass filter, a wireless communication module and a wireless communication device using the same, and more particularly, a band-pass filter having two pass bands that can be broadened and has a high degree of freedom in designing a pass band, and The present invention relates to a wireless communication module and a wireless communication device using the same.

In electronic devices such as communication devices, band-pass filters that pass only electrical signals of a specific frequency are used, particularly in a resonance system in which two resonators having the same resonance frequency are electromagnetically coupled. Bandpass filters that use even-mode resonance and odd-mode resonance to form passbands including even-mode resonance frequency and odd-mode resonance frequency are widely used. In such a bandpass filter, the difference between the even mode resonance frequency and the odd mode resonance frequency changes according to the strength of electromagnetic coupling between the two resonators, thereby determining the width of the passband. (For example, see Patent Document 1).
Japanese Patent Laid-Open No. 7-30303

  However, the above-described conventional band-pass filter has a limit in widening the band because the pass band is formed using two resonance peaks of even mode resonance and odd mode resonance. Also known is a bandpass filter in which a pass band is formed by using three resonance peaks in three resonance modes in a resonance system in which three resonators having the same resonance frequency are electromagnetically coupled. Such a bandpass filter can be further broadened, but it is difficult to arbitrarily set the frequencies of the three resonance peaks, and the degree of freedom in designing the passband is small.

  Further, in a dual mode communication device or the like, two band pass filters each having two communication bands as pass bands are used, which hinders miniaturization of the communication device.

  The present invention has been devised in view of such problems in the prior art, and an object of the present invention is to provide a band-pass filter having two pass bands that can be widened and has a high degree of freedom in designing the pass band. And providing a wireless communication module and a wireless communication device using the same.

  The band-pass filter of the present invention includes a laminated body in which a plurality of dielectric layers are laminated, a ground electrode disposed on at least one of an upper surface and a lower surface of the laminated body, and a first layer of the laminated body. Are arranged side by side so as to be electromagnetically coupled to each other, and each of the first to third resonance electrodes in the form of first to third resonators, each of which is grounded at one end thereof, and the second of the laminate. 4th and 5th resonance electrodes, which are arranged side by side so as to be electromagnetically coupled to each other between the layers, and constitute one of the fourth and fifth resonators with one end grounded, and the laminate A band-shaped first input / output coupling electrode disposed between the first and second layers and electromagnetically coupled to face the first and fourth resonance electrodes; and the laminated layer Between the first and second layers of the body The second input / output coupling electrode in the form of a strip that is electromagnetically coupled to face the second and fifth resonance electrodes, and the first input layer sandwiching the first layer of the laminate. The first and third resonance electrodes are disposed in an electromagnetic field through the layers disposed between the layer where the output coupling electrode is disposed and the layer located on the opposite side of the layer where the second input / output coupling electrode is disposed. A resonator coupling electrode to be coupled, wherein the resonance frequencies of the first and second resonators are set to be equal to each other and different from the resonance frequency of the third resonator; The resonance frequencies of the resonators are set equal to each other and different from the resonance frequencies of the first to third resonators, and a first passband is formed using the first to third resonators. And the fourth and fifth resonators It is intended to and forming a second pass band are.

  In the band-pass filter of the present invention, in the above configuration, the first to third resonance electrodes are arranged so that the grounded sides are staggered, and the band-pass filter is arranged with the resonator coupling electrode interposed therebetween. The electromagnetic coupling of the first and third resonant electrodes is mainly capacitive coupling, and the resonant frequency of the first and second resonators is set higher than the resonant frequency of the third resonator. It is characterized by being.

  A wireless communication module according to the present invention includes any one of the bandpass filters having the above-described configurations.

  A wireless communication device of the present invention includes an antenna, an RF unit including the bandpass filter of any of the above-described configurations connected to the antenna, and a baseband unit connected to the RF unit. To do.

  The band-pass filter according to the present invention includes first to third resonance electrodes that are disposed side by side and sequentially so as to be electromagnetically coupled to each other to form first to third resonators, and first and third resonances. And a resonator coupling electrode for electromagnetically coupling the electrodes, wherein the resonance frequencies of the first and second resonators are set to be equal to each other and different from the resonance frequency of the third resonator, The first passband is formed using three resonators.

  According to the bandpass filter of the present invention having such a configuration, the first and second resonators having the same resonance frequency adjacent to each other are electromagnetically coupled, so that two resonance peaks of the even mode and the odd mode are generated. Arise. In addition, the third resonator set at a different resonance frequency from the first and second resonators is directly electromagnetically coupled to the second resonator and electromagnetically coupled to the first resonator via the resonator coupling electrode. A third resonance peak is generated by the field coupling. Since the first passband can be formed using these three resonance peaks, a bandpass filter having a wide first passband can be obtained. In addition, since the frequencies of the three resonance peaks can be set arbitrarily, a bandpass filter having a high degree of freedom in designing the first passband can be obtained.

  In addition, according to the bandpass filter of the present invention, the fourth and fifth resonance electrodes constituting the fourth and fifth resonators, and the band-like shape that is electromagnetically coupled to face the first and fourth resonance electrodes. A first input / output coupling electrode and a band-like second input / output coupling electrode facing the second and fifth resonance electrodes and electromagnetically coupled to each other, and the resonance frequencies of the fourth and fifth resonators Are set to be equal to each other and different from the resonance frequencies of the first to third resonators, and form the second passband using the fourth and fifth resonators.

  According to the bandpass filter of the present invention having such a configuration, in addition to the first passband formed using the first to third resonators, the fourth and fifth resonators are used. Since the second passband is formed, a bandpass filter having two passbands can be obtained. The first input / output coupling electrode is electromagnetically coupled to face the first and fourth resonance electrodes, and the second input / output coupling electrode is electromagnetically coupled to face the second and fifth resonance electrodes. As a result, impedance matching between the two resonance systems forming the two pass bands and the input / output can be maintained well over a wide frequency band, so that a bandpass filter having two wide pass bands can be obtained. Is possible.

  According to the bandpass filter of the present invention, the first to third resonance electrodes are arranged so that the grounded sides are staggered, and the first and third resonance electrodes are interposed via the resonator coupling electrodes. The electromagnetic coupling of the resonant electrodes is mainly capacitive coupling. When the resonant frequency of the first and second resonators is set higher than the resonant frequency of the third resonator, The electromagnetic coupling between the third to third resonators is mainly capacitive coupling, and the electric signal transmitted directly from the first resonator to the second resonator and the third resonance from the first resonator. Since the phase inversion does not occur at the frequency between the three resonance peaks and the signal is transmitted to the second resonator through the resonator, the phase inversion occurs at the frequency outside the three resonance peaks. Pass including three resonance peaks in one passband No attenuation pole in the region, it is possible to obtain a band-pass filter having an excellent pass characteristics having three outer passband attenuation pole of the resonance peak.

  According to the wireless communication module of the present invention and the wireless communication device of the present invention, the bandpass filter of the present invention having the first passband and the second passband having a wide band is used for filtering the communication signal. Since attenuation of the communication signal passing through the filter can be reduced, a small and high-performance wireless communication module and wireless communication device can be obtained.

  Hereinafter, a bandpass filter of the present invention, a wireless communication module and a wireless communication device using the same will be described in detail with reference to the accompanying drawings.

(First example of embodiment)
FIG. 1 is an external perspective view schematically showing a first example of an embodiment of the bandpass filter of the present invention. FIG. 2 is a schematic exploded perspective view of the example of the bandpass filter shown in FIG. FIG. 3 is a plan view schematically showing upper and lower surfaces and layers of the example of the bandpass filter shown in FIG. FIG. 4 is a cross-sectional view taken along the line QQ ′ of the example of the bandpass filter shown in FIG.

  As shown in FIGS. 1 to 4, the band-pass filter of this example includes a laminated body 10 in which a plurality of dielectric layers 11 are laminated, and a ground electrode disposed on almost the entire upper and lower surfaces of the laminated body 10. 21 and the first to third belt-shaped first to third resonators that are arranged side by side so as to be electromagnetically coupled to each other between the layers A of the laminated body 10 and that respectively constitute one of the first to third resonators. The resonance electrodes 31a, 31b, and 31c of the multilayer body 10 are arranged side by side so as to be electromagnetically coupled to each other between the layers B of the multilayer body 10, and one end is grounded to form the fourth and fifth resonators. The fourth and fifth resonance electrodes 31d and 31e are opposed to the first and fourth resonance electrodes 31a and 31d disposed in the interlayer C located between the interlayer A and the interlayer B of the multilayer body 10. A strip-shaped first input / output coupling electrode 40a for electromagnetic field coupling, and second and fifth resonance electrodes 31b A band-shaped second input / output coupling electrode 40b that is electromagnetically coupled to face 31e, and an interlayer D positioned on the opposite side of the interlayer C with the interlayer A of the laminate 10 interposed therebetween. And a resonator coupling electrode 43 for electromagnetically coupling the first and third resonance electrodes. Further, a first input / output terminal electrode 60a and a second input / output terminal electrode 60b are disposed on the upper surface of the laminate 10 with a space from the ground electrode 21, and the first input / output terminal electrode 60b and the second input / output terminal electrode 60b are respectively disposed through the through conductor 50. The input / output coupling electrode 40a and the second input / output coupling electrode 40b are connected. A first annular ground electrode 23 is disposed between the first and third resonance electrodes 31a, 31b, and 31c in the interlayer A of the multilayer body 10 so as to surround the first to third resonance electrodes 31a, 31b, and 31c. One ends of the electrodes 31a, 31b, and 31c are connected to each other. A second annular ground electrode 24 is disposed between the layers B of the laminate 10 so as to surround the fourth and fifth resonance electrodes 31d and 31e, and the fourth and fifth resonance electrodes 31d. , 31e are respectively connected to one end. The first to third resonance electrodes 31a, 31b, 31c are arranged so that their one ends are staggered, and the fourth and fifth resonance electrodes 31d, 31e are staggered at their one ends. It is arranged to be.

  Further, in the bandpass filter of this example, the resonator coupling electrode 43 has one end connected to the other end of the third resonance electrode 31c through the through conductor 50, and the third resonance electrode 31c and the through-hole filter 43 pass through. A third resonator is formed together with the conductor 50. Further, the other end of the resonator coupling electrode 43 is opposed to the other end of the first resonance electrode 31a through the dielectric layer 11, and the first resonance electrode 31a is mainly capacitively coupled to the electromagnetic field. is doing. The resonance frequencies of the first and second resonators are set to be equal to each other and higher than the resonance frequency of the third resonator, and the resonance frequencies of the fourth and fifth resonators are equal to each other. Further, the resonance frequency is set to be higher than the resonance frequency of the first to third resonators.

  Further, in the band-pass filter of this example, the first input / output point 45a where an electric signal is input to or output from the first input / output coupling electrode 40a is more than the center of the portion facing the first resonance electrode 31a. It is on the side closer to the other end of the first resonance electrode 31a, and is closer to the other end of the fourth resonance electrode 31d than the center of the portion facing the fourth resonance electrode 31d. In addition, the second input / output point 45b at which an electric signal is input to or output from the second input / output coupling electrode 40b is located on the other side of the second resonance electrode 31b rather than the center of the portion facing the second resonance electrode 31b. It is on the side close to the end and is closer to the other end of the fifth resonance electrode 31e than the center of the portion facing the fifth resonance electrode 31e.

  According to the band-pass filter of this example having such a configuration, for example, an electric signal from an external circuit is input to the first input / output coupling electrode 40a via the first input / output terminal electrode 60a and the through conductor 50. Then, the first resonance electrode 31a electromagnetically coupled to the first input / output coupling electrode 40a is excited, and the second resonance electrode 31b electromagnetically coupled to the first resonance electrode 31a resonates. Further, when the first resonance electrode 31a resonates, the third resonance electrode 31c electromagnetically coupled to the first resonance electrode 31a via the resonator coupling electrode 43 also resonates, and the energy thereof is the third resonance electrode 31c. Is transmitted to the second resonance electrode 31b which is electromagnetically coupled. An electric signal is transmitted to the second resonance electrode 31b through these two routes, and the through conductor 50 and the second input / output terminal electrode 60b are connected from the second input / output coupling electrode 40b electromagnetically coupled to the second resonance electrode 31b. An electrical signal is output to an external circuit via the. As a result, a first pass band is formed. In addition, the fourth resonance electrode 31d electromagnetically coupled to the first input / output coupling electrode 40a is excited, and the fifth resonance electrode 31e electromagnetically coupled to the first resonance electrode 31e resonates. An electric signal is output from the second input / output coupling electrode 40b that is electromagnetically coupled to the external circuit via the through conductor 50 and the second input / output terminal electrode 60b. As a result, a second pass band is formed. In this way, the band pass filter of this example can function as a band pass filter having two pass bands.

  Further, according to the band-pass filter of this example, two adjacent resonance peaks of the even mode and the odd mode are generated by the electromagnetic coupling between the first and second resonators having the same resonance frequency. A third resonator having a resonance frequency lower than that of the first and second resonators is directly electromagnetically coupled to the second resonator, and the first resonator is connected via the resonator coupling electrode 43. And a third resonance peak is generated by electromagnetic coupling. Since the first passband can be formed using these three resonance peaks, a bandpass filter having a wide first passband can be obtained. In addition, since the frequencies of the three resonance peaks can be set arbitrarily, a bandpass filter having a high degree of freedom in designing the first passband can be obtained.

  Furthermore, according to the bandpass filter of this example, the grounded sides of the first to third resonance electrodes 31a, 31b, 31c are arranged alternately and electromagnetically coupled to the interdigital type. Both the electromagnetic coupling between the first resonance electrode 31a and the second resonance electrode 31b and the electromagnetic coupling between the second resonance electrode 31b and the third resonance electrode 31c are mainly capacitive coupling. Since the first resonance electrode 31a and the third resonance electrode 31c are electromagnetically coupled mainly via the resonator coupling electrode 43, the electromagnetic field coupling between the first to third resonators is performed. Are all mainly capacitive couplings. In addition, since the resonance frequency of the first and second resonators is set higher than the resonance frequency of the third resonator, it is directly transmitted from the first resonator to the second resonator. Between the electrical signal and the signal transmitted from the first resonator through the third resonator to the second resonator, phase inversion does not occur at the frequency between the three resonance peaks. Since phase inversion occurs at a frequency outside the peak, there is no attenuation pole in the first passband including the three resonance peaks, and excellent pass characteristics having an attenuation pole outside the passband outside the three resonance peaks Can be obtained.

(Second example of embodiment)
FIG. 5 is an exploded perspective view schematically showing a second example of the embodiment of the bandpass filter of the present invention. Note that in this example, only differences from the first example described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

  As shown in FIG. 5, the band-pass filter of this example has a sixth resonance electrode 31f on the opposite side of the fifth resonance electrode 31e with the fourth resonance electrode 31d interposed between the layers B of the multilayer body 10. Is arranged. The sixth resonance electrode 31f has one end connected to the second annular ground electrode 24 and grounded. In addition, a second resonator coupling electrode 44 is disposed in an interlayer E located on the opposite side of the interlayer C with the interlayer B of the multilayer body 10 interposed therebetween, and one end of the second resonator coupling electrode 44 is interposed through the through conductor 50. The sixth resonance electrode 31f is connected to the other end of the sixth resonance electrode 31f, and constitutes a sixth resonator together with the sixth resonance electrode 31f and the through conductor 50. The other end of the second resonator coupling electrode 44 is opposed to the other end of the fifth resonance electrode 31e with the dielectric layer 11 in between, and is mainly capacitive capacitive electromagnetic waves with the fifth resonance electrode 31e. Has a field connection. The resonance frequency of the sixth resonator is set to be higher than the resonance frequencies of the first to third resonators and lower than the resonance frequencies of the fourth and fifth resonators. The fourth through sixth resonators form the second passband.

  According to the band-pass filter of this example having such a configuration, the fourth and fifth resonators are electromagnetically coupled to generate two resonance peaks of an even mode and an odd mode. The sixth resonator is directly electromagnetically coupled to the fourth resonator and electromagnetically coupled to the fifth resonator via the second resonator coupling electrode 44, whereby the third resonance peak is obtained. Arise. Since the second passband can be formed using these three resonance peaks, a bandpass filter having a wideband second passband can be obtained. In addition, since the frequencies of the three resonance peaks can be set arbitrarily, a bandpass filter having a high degree of freedom in designing the second passband can be obtained.

  Furthermore, according to the bandpass filter of this example, the grounded sides of the fourth to sixth resonance electrodes 31d, 31e, 31f are arranged alternately and electromagnetically coupled to the interdigital type. The electromagnetic coupling between the fourth resonance electrode 31d and the fifth resonance electrode 31e and the electromagnetic coupling between the fourth resonance electrode 31d and the sixth resonance electrode 31f are both mainly capacitive coupling. Since the fifth resonance electrode 31e and the sixth resonance electrode 31f are mainly capacitively coupled via the second resonator coupling electrode 44, the fourth to sixth resonators are connected. All electromagnetic field coupling is mainly capacitive coupling. In addition, since the resonance frequencies of the fourth and fifth resonators are set higher than the resonance frequency of the sixth resonator, they are directly transmitted from the fourth resonator to the fifth resonator. Between the electrical signal and the signal transmitted from the fourth resonator via the sixth resonator to the fifth resonator, phase inversion does not occur at the frequency between the three resonance peaks. Since phase inversion occurs at a frequency outside the peak, there is no attenuation pole in the second passband including the three resonance peaks, and excellent pass characteristics having an attenuation pole outside the passband outside the three resonance peaks Can be obtained.

(Third example of embodiment)
FIG. 6 is an external perspective view schematically showing a third example of the embodiment of the bandpass filter of the present invention. FIG. 7 is a schematic exploded perspective view of the example of the bandpass filter shown in FIG. FIG. 8 is a plan view schematically showing the upper and lower surfaces and the layers of the example of the bandpass filter shown in FIG. Note that in this example, only differences from the first example described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

  In the bandpass filter of this example, as shown in FIGS. 6 to 8, the first input / output terminal electrode 60 a and the second input / output terminal electrode 60 b are separately arranged on the two opposing side surfaces of the multilayer body 10. The ground terminal electrode 60c connected to the ground electrode 21 is disposed on the other two side surfaces of the laminate 10. Then, instead of the first annular ground electrode 23, an inner layer ground electrode 23a to which one end of the first resonance electrode 31a and the third resonance electrode 31c is connected and one end of the second resonance electrode 31b are connected. An inner layer ground electrode 23b is disposed between the first layers, and the inner layer ground electrode 23a and the inner layer ground electrode 23b are connected to a ground terminal electrode 60c disposed on the side surface of the laminate 10.

  In the bandpass filter of this example, the first input / output coupling electrode 40a includes the first portion 41a disposed in the interlayer C located between the interlayer A and the interlayer B of the multilayer body 10, and the interlayer C. And the second portion 42a disposed in the interlayer F located between the interlayer B and the interlayer B. Each of the first portion 41a and the second portion 42a is connected to the first input / output terminal electrode 60a disposed on the side surface of the multilayer body 10, and the other end is located between the first portion 41a and the second portion 42a. Are connected to each other by through conductors 50 penetrating through the dielectric layer 11. Similarly, the second input / output coupling electrode 40b is separated into two layers of a first portion 41b disposed in the interlayer C of the stacked body 10 and a second portion 42b disposed in the interlayer F. Yes. Each of the first portion 41b and the second portion 42b has one end connected to the second input / output terminal electrode 60b disposed on the side surface of the stacked body 10, and the other end is located between the two. Are connected to each other by through conductors 50 penetrating through the dielectric layer 11.

  Further, in the band pass filter of this example, the second annular ground electrode 24 is not provided, and one end of the fourth resonance electrode 31d is connected to the ground terminal electrode 60c disposed on the side surface of the multilayer body 10. In addition, one end of the fifth resonance electrode 31e is connected to the inner layer ground electrode 23b through a through conductor 50 penetrating the dielectric layer 11. The other end of the first resonance electrode 31a is connected to one end of the resonator coupling electrode 43 disposed between the layers D through the through conductor 50, and the other end of the resonator coupling electrode 43 is positioned between the other ends. A capacitive electromagnetic field coupling is mainly performed so as to face the other end of the third resonance electrode 31c through the dielectric layer 11 to be coupled. Further, an inner layer ground electrode 22a connected to the ground terminal electrode 60c is disposed in an interlayer H located on the opposite side of the interlayer A with the interlayer D interposed therebetween. The interlayer J located between the interlayer H and the lower surface of the multilayer body 10 includes an inner layer ground electrode 22a disposed in the interlayer H, and a ground electrode 21 and a dielectric layer 11 disposed on the lower surface of the multilayer body 10. A first capacitor electrode 35a is disposed opposite to the first capacitor electrode 35a. The first capacitor electrode 35a is connected to the resonator coupling electrode 43 through the through conductor 50, and constitutes a first resonator together with the resonator coupling electrode 43 and the first resonance electrode 31a.

  Furthermore, in the band pass filter of this example, the inner layer ground electrode 22b connected to the ground terminal electrode 60c is disposed in the interlayer H of the multilayer body 10, and the inner layer ground disposed in the interlayer H is disposed in the interlayer J. A second capacitor electrode 35b is disposed opposite to the electrode 22b and the ground electrode 21 disposed on the lower surface of the multilayer body 10 with the dielectric layer 11 therebetween. The second capacitor electrode 35b is connected to the other end of the second resonance electrode 31b via the through conductor 50 and the connection electrode 36 disposed between the layers D, and the through conductor 50, the connection electrode 36, and the second electrode. A second resonator is configured together with the resonance electrode 31b.

  Furthermore, in the band-pass filter of this example, the inner layer ground electrode 22c connected to the ground terminal electrode 60c is disposed in the layer E located between the layer B and the upper surface of the multilayer body 10. Further, in the interlayer G located between the interlayer E and the upper surface of the multilayer body 10, the inner layer ground electrode 22c disposed in the interlayer E, the ground electrode 21 disposed on the upper surface of the multilayer body, and the dielectric layer 11 are interposed. Opposing third capacitor electrode 35c is arranged. The third capacitor electrode 35c is connected to the other end of the third resonance electrode 31c through the through conductor 50, and constitutes a third resonator together with the through conductor 50 and the third resonance electrode 31c. .

  According to the bandpass filter of this example having such a configuration, the first input / output coupling electrode 40a and the second input / output coupling electrode 40b are separated into two layers. The first and second resonance electrodes 31a and 31b and the fourth and fifth resonance electrodes 31d and 31e and the first input / output coupling electrode 40a and the second input / output coupling electrode 40b are maintained at the same distance. The distance between the resonance electrodes 31a and 31b and the fourth and fifth resonance electrodes 31d and 31e can be increased. As a result, the electromagnetic coupling between the first and second resonance electrodes 31a and 31b and the fourth and fifth resonance electrodes 31d and 31e and the first input / output coupling electrode 40a and the second input / output coupling electrode 40b is achieved. Therefore, even when the first and second passbands are wide, it is possible to obtain a bandpass filter having a flat passband in which the input / output impedance is well matched over the entire passband. it can.

  Further, according to the band-pass filter of this example, due to the capacitance generated between the first capacitor electrode 35a and the inner layer ground electrode 22a and the ground electrode 21, and the inductance of the resonator coupling electrode 43 and the through conductor 50, The length of the first resonance electrode 31a can be shortened. Further, the second resonant electrode is caused by the capacitance generated between the second capacitive electrode 35b and the inner layer ground electrode 22b and the ground electrode 21 and the inductance of the second capacitive electrode 35b, the connection electrode 36 and the through conductor 50. The length of 31b can be shortened. Further, the length of the third resonance electrode 31c is determined by the capacitance generated between the third resonance electrode 31c, the inner layer ground electrode 22c and the ground electrode 21, and the inductance of the third capacitance electrode 35c and the through conductor 50. Can be shortened. Therefore, a small bandpass filter can be obtained.

(Fourth example of embodiment)
FIG. 9 is a block diagram showing a configuration example of the wireless communication module 80 and the wireless communication device 85 using the bandpass filter of the present invention.

  The wireless communication module 80 of the present invention includes, for example, a baseband unit 81 that processes baseband signals, and an RF unit 82 that is connected to the baseband unit 81 and processes RF signals after modulation and before demodulation of the baseband signals. And. The RF unit 82 includes the bandpass filter 821 of the present invention described above, and an RF signal obtained by modulating the baseband signal or a signal other than the communication band in the received RF signal is attenuated by the bandpass filter 821. Yes. Specifically, a baseband IC 811 is disposed in the baseband unit 81, and an RF IC 822 is disposed between the bandpass filter 821 and the baseband unit 81 in the RF unit 82. Note that another circuit may be interposed between these circuits. Then, by connecting the antenna 84 to the bandpass filter 821 of the wireless communication module 80, the wireless communication device 85 of the present invention that transmits and receives RF signals is configured.

  According to the wireless communication module 80 and the wireless communication device 85 of this example having such a configuration, 821 of the present invention having the first passband and the second passband which are widebands are used for filtering the transmission signal and the reception signal. As a result, the attenuation of the reception signal and transmission signal passing through the band-pass filter 821 is reduced, so that the reception sensitivity is improved, and the amplification degree of the transmission signal and reception signal can be reduced. Become. Also, the two passbands can be filtered with a single bandpass filter. Therefore, a small and high-performance wireless communication module 80 and wireless communication device 85 with high reception sensitivity and low power consumption can be obtained.

In the band-pass filter of the present invention, as the material of the dielectric layer 11, for example, a resin such as an epoxy resin or a ceramic such as a dielectric ceramic can be used. For example, a dielectric ceramic material such as BaTiO ₃ , Pb ₄ Fe ₂ Nb ₂ O ₁₂ , or TiO ₂ and a glass material such as B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , or ZnO, and 800 to 1200 ° C. Glass-ceramic materials that can be fired at relatively low temperatures are preferably used. The thickness of the dielectric layer 11 is set to about 0.01 to 0.1 mm, for example.

  Examples of the materials for the various electrodes and through conductors described above include conductive materials mainly composed of Ag alloys such as Ag, Ag-Pd, and Ag-Pt, Cu-based, W-based, Mo-based, and Pd-based conductive materials. Are preferably used. The thickness of various electrodes is set to 0.001 to 0.2 mm, for example.

  The bandpass filter of the present invention can be manufactured, for example, as follows. First, an appropriate organic solvent or the like is added to and mixed with the ceramic raw material powder to produce a slurry, and a ceramic green sheet is formed by a doctor blade method. Next, a through hole for forming a through conductor is formed on the obtained ceramic green sheet using a punching machine or the like, and a conductive paste containing a conductor such as Ag, Ag-Pd, Au, Cu is filled and the ceramic The same conductive paste as described above is applied to the surface of the green sheet using a printing method to produce a ceramic green sheet with a conductive paste. Next, these ceramic green sheets with a conductive paste are laminated, pressed using a hot press device, and fired at a peak temperature of about 800 ° C. to 1050 ° C.

  Next, a specific example of the bandpass filter of the present invention will be described.

  The electrical characteristics of the bandpass filter of the third example of the embodiment shown in FIGS. 6 to 8 were calculated by simulation using the finite element method.

  In this simulation, the first resonance electrode 31a has a rectangular shape with a width of 0.34 mm and a length of 1.6 mm. The second resonance electrode 31b has a rectangular shape with a width of 0.34 mm and a length of 1.9 mm. The third resonance electrode 31c has a rectangular shape with a width of 0.34 mm and a length of 2.0 mm. The first capacitor electrode 35a was rectangular with a width of 0.29 mm and a length of 0.7 mm. The second capacitor electrode 35b was rectangular with a width of 0.3 mm and a length of 1.0 mm. The third capacitor electrode 35c was rectangular with a width of 0.73 mm and a length of 0.63 mm. The fourth resonance electrode 31d has a rectangular shape with a width of 0.15 mm and a length of 1.5 mm. The fifth resonance electrode 31e has a rectangular shape with a width of 0.15 mm and a length of 1.55 mm. The first portion 41a of the first input / output coupling electrode 40a has a rectangular shape with a width of 0.09 mm and a length of 1.9 mm, and the second portion 42a has a rectangular shape with a width of 0.14 mm and a length of 1.9 mm. The first portion 41b of the second input / output coupling electrode 40b has a rectangular shape with a width of 0.09 mm and a length of 1.75 mm, and the second portion 42b has a rectangular shape with a width of 0.09 mm and a length of 1.75 mm. The entire bandpass filter was a rectangular parallelepiped having a width of 2.0 mm, a length of 2.5 mm, and a height of 0.9 mm, and the relative dielectric constant of the dielectric layer 11 was 18.7.

  FIG. 10 is a graph showing the simulation results, where the horizontal axis represents frequency and the vertical axis represents attenuation, and shows the pass characteristic (S21) and reflection characteristic (S11) of the bandpass filter. According to the graph shown in FIG. 10, there are provided two wide passbands, and three attenuation poles are formed on the lower frequency side than the first passband on the low frequency side. It can be seen that an excellent pass characteristic with sufficient attenuation on the low frequency side is obtained. The attenuation pole located at the frequency closest to the first passband is such that the first to third resonators are all capacitively coupled, the first and second resonators have the same resonance frequency, and the third resonator. The two attenuation poles on the lower frequency side are the first input / output coupling electrode 40a, the second input / output coupling electrode 40b, and the second one. 3 and the capacitive coupling between the first input / output coupling electrode 40a and the second input / output coupling electrode 40b. The effectiveness of the present invention was confirmed from the simulation results.

It is an external appearance perspective view which shows typically the 1st example of embodiment of the band pass filter of this invention. It is a typical exploded perspective view of the example of the band pass filter shown in FIG. It is a top view which shows typically the upper and lower surfaces and interlayer of an example of the band pass filter shown in FIG. FIG. 2 is a cross-sectional view taken along the line Q-Q ′ of the example of the bandpass filter illustrated in FIG. 1. It is a disassembled perspective view which shows typically the 2nd example of embodiment of the band pass filter of this invention. It is an external appearance perspective view which shows typically the 3rd example of embodiment of the band pass filter of this invention. FIG. 7 is a schematic exploded perspective view of the example of the bandpass filter shown in FIG. 6. It is a top view which shows typically the upper and lower surfaces and interlayer of the example of a band pass filter shown in FIG. It is a block diagram which shows the structural example of the radio | wireless communication module and radio | wireless communication apparatus using the band pass filter of this invention. It is a figure which shows the simulation result of the electrical property of the bandpass filter of the 3rd example of embodiment of this invention.

Explanation of symbols

10: Laminate
11: Dielectric layer
21: Ground electrode
31a: first resonance electrode
31b: second resonant electrode
31c: third resonant electrode
31d: fourth resonant electrode
31e: Fifth resonance electrode
40a: first input / output coupling electrode
40b: second input / output coupling electrode
43: Resonator coupling electrode
80: Wireless communication module
81: Baseband
82: RF section
84: Antenna
85: Wireless communication equipment

Claims (4)

A laminate in which a plurality of dielectric layers are laminated;
A ground electrode disposed on at least one of the upper surface and the lower surface of the laminate;
The first to third belt-shaped first to third resonators are arranged side by side so as to be electromagnetically coupled to each other between the first layers of the multilayer body, and each end thereof is grounded to form first to third resonators. A resonant electrode;
Band-like fourth and fifth resonances arranged side by side so as to be electromagnetically coupled to each other between the second layers of the multilayer body and having one end grounded to form fourth and fifth resonators, respectively. Electrodes,
A band-shaped first input / output coupling electrode which is disposed between the first and second layers of the laminate and is electromagnetically coupled to face the first and fourth resonance electrodes; ,
A band-shaped second input / output coupling electrode that is disposed between the first and second layers of the laminate and is electromagnetically coupled to face the second and fifth resonance electrodes; ,
Arranged between the layer in which the first input / output coupling electrode is disposed and the layer located on the opposite side of the layer in which the second input / output coupling electrode is disposed with the first layer of the laminate interposed therebetween And a resonator coupling electrode for electromagnetically coupling the first and third resonant electrodes via itself,
The resonance frequencies of the first and second resonators are set to be equal to each other and different from the resonance frequency of the third resonator,
The resonance frequencies of the fourth and fifth resonators are set to be equal to each other and different from the resonance frequencies of the first to third resonators,
A band-pass filter that forms a first passband using the first to third resonators and forms a second passband using the fourth and fifth resonators.   The first to third resonance electrodes are arranged so that the grounded sides are staggered, and electromagnetic coupling of the first and third resonance electrodes via the resonator coupling electrode is mainly performed. The resonance frequency of the first and second resonators is set to be higher than the resonance frequency of the third resonator. Bandpass filter.   A wireless communication module comprising the bandpass filter according to claim 1.   A radio communication device comprising: an RF unit including the bandpass filter according to claim 1; a baseband unit connected to the RF unit; and an antenna connected to the RF unit. .

Images