JP4849959B2 - BANDPASS FILTER, HIGH FREQUENCY MODULE USING THE SAME, AND RADIO COMMUNICATION DEVICE USING THE SAME - Google Patents

Description

  The present invention relates to a bandpass filter, a high-frequency module using the same, and a wireless communication device using the same, and more particularly to a bandpass filter having a very wide passband that can be suitably used for UWB (Ultra Wide Band) and The present invention relates to a high-frequency module using the same and a wireless communication device using the same.

  In recent years, UWB has attracted attention as a new communication means. UWB realizes large-capacity data transfer using a wide frequency band over a short distance of about 10 m. For example, according to US FCC (Federal Communication Commission) regulations, a plan to use a frequency band of 3.1 to 10.6 GHz It has become. Thus, the feature of UWB is that it uses a very wide frequency band.

  In recent years, research on ultra-wideband filters that can be used for UWB has been actively conducted. For example, a bandpass filter that applies the principle of a directional coupler has a passband width of a specific bandwidth (bandwidth / center). There is a report that a broadband characteristic exceeding 100% is obtained in (frequency) (for example, see Non-Patent Document 1).

On the other hand, as a filter often used conventionally, there is known a band-pass filter configured by connecting a plurality of quarter-wavelength stripline resonators to each other (see, for example, Patent Document 1).
“Ultra-wideband bandpass filter using microstrip-CPW broadside coupling structure” Proceedings of the March 2005 IEICE General Conference C-2-114 p.147 Japanese Patent Laid-Open No. 2004-180032 (FIG. 1)

  However, each of the bandpass filters described above has problems, and is not suitable for a UWB bandpass filter.

  For example, the bandpass filter proposed in Non-Patent Document 1 has a problem that the passband width is too wide. That is, UWB finally uses a frequency band of 3.1 GHz to 10.6 GHz, but initially it is planned to use a frequency band of 3.1 GHz to 4.9 GHz, and the specific band is 45%. Therefore, the filter used for this is required to have a pass bandwidth of about 40% in a specific band. Moreover, it is necessary to consider the influence between W-LAN (802.11.a), and attenuation at 5.15 GHz is required. Therefore, the bandpass filter proposed in Non-Patent Document 1 having a characteristic such that the passband width exceeds 100% in the specific band cannot be used because the passband width is too wide.

  Further, the pass band width of a bandpass filter using a conventional quarter wavelength resonator is too narrow, and even if the pass band width of the band pass filter described in Patent Document 1 is intended to be wide, it is 10 It was less than%. Therefore, it cannot be used as a UWB band-pass filter that requires a wide pass bandwidth corresponding to 40% of the specific band.

  The present invention has been devised in view of such problems in the prior art, and an object thereof is a bandpass filter having an ultra-wideband and an appropriate passband as a UWB bandpass filter. Another object of the present invention is to provide a high-frequency module using the same and a radio communication device using them.

The band-pass filter of the present invention includes a laminated body in which a plurality of dielectric layers are laminated, a first ground electrode that is disposed on the lower surface of the laminated body and connected to a ground potential, and an upper surface of the laminated body And a second ground electrode connected to the ground potential and arranged side by side so as to be electromagnetically coupled to each other between one layer of the laminate, each having one end connected to the ground potential A plurality of strip-shaped resonance electrodes functioning as quarter-wave resonators, and electromagnetic coupling with an input-stage resonance electrode among the plurality of resonance electrodes disposed between layers different from the one layer of the multilayer body A strip-shaped input coupling electrode, and a strip-shaped output coupling electrode that is disposed between layers different from the one layer of the multilayer body and electromagnetically couples with a resonant electrode of an output stage among the plurality of resonant electrodes ; The plurality of common layers between one layer An annular ground electrode connected to the ground potential, formed in an annular shape surrounding the periphery of the electrode, and connected to the one end of the plurality of resonance electrodes; and the laminate corresponding to each of the plurality of resonance electrodes And a region opposite to the annular ground electrode and a region opposite to the resonance electrode between layers different from the one layer, and the region opposite to the resonance electrode is located between the resonance electrode and An auxiliary resonant electrode connected to the other end side of the resonant electrode by a first through conductor penetrating the dielectric layer, and a layer different from the one layer of the laminate and a different layer, A plurality of auxiliary resonance electrodes are arranged so as to have a region facing the auxiliary resonance electrode connected to the resonance electrode of the input stage and a region facing the input coupling electrode. The second region of the resonance electrode of the input stage is more than the center in the length direction of the input coupling electrode by the second through conductor penetrating through the dielectric layer located between the input coupling electrode and the second coupling conductor. An auxiliary input coupling electrode connected to a side close to the end, and an interlayer different from the one layer of the multilayer body and further different layers are connected to a resonance electrode of the output stage among the plurality of auxiliary resonance electrodes The dielectric layer is disposed so as to have a region facing the auxiliary resonance electrode and a region facing the output coupling electrode, and the region facing the output coupling electrode is located between the output coupling electrode and the dielectric layer. the third through conductor penetrating, e Bei and the other auxiliary output coupling connected to the side close to the end electrodes of the resonance electrode of the output stage than the center in the length direction of the output coupling electrode, said plurality of Each resonant electrode The one end and the other end are alternately arranged, and the input coupling electrode is arranged so as to face a region extending over half of the length direction of the resonance electrode of the input stage, and an external circuit The position to which the electric signal input from is supplied is closer to the other end of the resonance electrode of the input stage than the center in the length direction, and the output coupling electrode is connected to the resonance electrode of the output stage. The position where the electrical signal output to the external circuit is extracted is closer to the other end of the resonance electrode of the output stage than the center in the length direction. It is characterized by being side.

RF module of the present invention is characterized by comprising a bandpass filter of the present invention the above Ki構 formed.

Wireless communication device of the present invention is characterized by using a high-frequency module of the present invention the band-pass filter or the structure of the present invention the above Ki構 formed.

  The band-pass filter of the present invention is arranged side by side so that a plurality of strip-shaped resonant electrodes whose one end is connected to the ground potential and function as a quarter-wave resonator are mutually electromagnetically coupled between one layer of the laminate. In addition, one end and the other end of each of the plurality of resonance electrodes are alternately arranged. Since one end and the other end of each of the plurality of resonance electrodes are alternately arranged, the plurality of resonance electrodes are coupled in an interdigital manner, so that the coupling by the magnetic field and the coupling by the electric field are added, and the comb line A stronger bond occurs compared to a type bond. As a result, it is suitable as a bandpass filter for UWB, in which the frequency interval between the resonance frequencies in each resonance mode far exceeds the range that could be realized by a filter using a conventional quarter wavelength resonator. It is reasonable to obtain a wide passband width of about 40% in a specific bandwidth.

  In addition, according to the band-pass filter of the present invention, the input coupling electrode is disposed so as to face a region extending over half of the length direction of the resonance electrode of the input stage, and is supplied from an external circuit. The position where the signal is supplied is closer to the other end of the resonance electrode of the input stage than the center in the length direction, and the output coupling electrode is a region extending over half of the length direction of the resonance electrode of the output stage. The position from which the electrical signal output to the external circuit is taken out is closer to the other end of the resonance electrode in the output stage than the center in the length direction. With this configuration, the input coupling electrode and the input stage resonance electrode are coupled in an interdigital manner, and similarly, the output coupling electrode and the output stage resonance electrode are coupled in an interdigital manner. In the same manner as above, the coupling by the magnetic field and the coupling by the electric field are added to produce a strong coupling. As a result, even at a wide passband far exceeding the range that could be realized by a filter using a conventional quarter wavelength resonator, insertion at a frequency located between the resonance frequencies of the respective resonance modes It is possible to obtain a bandpass filter having flat and low-loss pass characteristics over the entire wide passband with no significant increase in loss.

Further, according to the band-pass filter of the present invention, the annular ground electrode that is formed in an annular shape that surrounds the periphery of the plurality of resonance electrodes between one layer, and that is connected to the ground potential, with one end of the plurality of resonance electrodes connected. since there are arranged, to become the electrodes connected to both sides to the ground potential length direction of the resonance electrodes are present, one end of the staggered respective resonance electrodes easily ground potential Can be connected.

Furthermore, according to the band-pass filter of the present invention, the auxiliary resonant electrode that is disposed so as to have a region facing the annular ground electrode and is connected to the resonant electrode by the first through conductor is provided in each of the plurality of resonant electrodes. because it is arranged correspondingly, the electrostatic capacitance is generated therebetween in the opposing portion between each of the auxiliary resonance electrode and the annular ground electrode, it is possible to shorten the length of each of the resonance electrodes, a small The bandpass filter can be obtained.

Still further, according to the bandpass filter of the present invention, the auxiliary input coupling electrode connected to the input coupling electrode, arranged to have a region facing the auxiliary resonant electrode connected to the resonant electrode of the input stage, and the output It is arranged to have a region facing to the connected auxiliary resonance electrode to the resonance electrode of the stage, since it is a connected auxiliary output coupling electrode to the output coupling electrode, which is connected to the resonance electrode of the input stage Electromagnetic field coupling occurs between the auxiliary resonant electrode and the auxiliary input coupling electrode, which is added to the electromagnetic coupling between the input stage resonant electrode and the input coupling electrode, and is also connected to the output stage resonant electrode. Electromagnetic field coupling occurs between the auxiliary resonance electrode and the auxiliary output coupling electrode, and is added to the electromagnetic field coupling between the resonance electrode and the output coupling electrode in the output stage. As a result, the electromagnetic coupling between the input coupling electrode and the resonance electrode of the input stage and the electromagnetic coupling between the output coupling electrode and the resonance electrode of the output stage are further strengthened. However, a bandpass filter having a flatter and lower-loss pass characteristic over a wide passband, in which an increase in insertion loss at a frequency located between the resonance frequencies of the respective resonance modes is further reduced. Obtainable.

  The auxiliary input coupling electrode is connected to the side closer to the other end of the resonance electrode of the input stage than the center in the length direction of the input coupling electrode by the second through conductor, and similarly, the auxiliary output coupling electrode is connected to the third output coupling electrode. By connecting the output coupling electrode closer to the other end of the resonance electrode of the output stage than the center in the length direction of the output coupling electrode by the through conductor, an electric signal input from the outside is input to the input coupling electrode via the auxiliary input coupling electrode. Even when an electrical signal that is supplied to the output coupling electrode and output from the output coupling electrode is output to an external circuit via the auxiliary output coupling electrode, the input coupling electrode and the resonance electrode of the input stage are coupled in an interdigital manner, and output coupling is performed. The electrode and the resonant electrode at the output stage are coupled in an interdigital manner, and a strong coupling obtained by adding the coupling by the magnetic field and the coupling by the electric field can be generated.

  According to the high-frequency module of the present invention and the wireless communication device of the present invention, the band-pass filter of the present invention with a small loss of the signal passing over the entire communication band is used for filtering the transmission signal and the reception signal. Since the attenuation of the reception signal and the transmission signal passing through the pass filter is reduced, the reception sensitivity is improved, and the amplification degree of the transmission signal and the reception signal can be reduced, so that the power consumption in the amplifier circuit is reduced. Therefore, a high-performance high-frequency module and wireless communication device with high reception sensitivity and low power consumption can be obtained.

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

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

  The band-pass filter of this example has a laminated body 10 in which a plurality of dielectric layers 11 are laminated, a first ground electrode 21 arranged on the lower surface of the laminated body 10, and an upper surface of the laminated body 10. The second ground electrode 22, the strip-shaped resonance electrodes 30 a, 30 b, 30 c arranged side by side between the layers A of the laminate 10, and the resonance electrode 30 a, 30 b, 30 c are surrounded by the layers A of the laminate 10. An annular ground electrode 23 formed in an annular shape and connected to one end of the resonant electrodes 30a, 30b, 30c, and a strip-shaped electrode disposed in a different layer B of the laminate 10 so as to face the resonant electrode 30a of the input stage. An input coupling electrode 40a, a strip-shaped output coupling electrode 40b disposed so as to face the output-stage resonance electrode 30b in an interlayer B of the laminate 10, and an annular ground electrode 23 in an interlayer B of the laminate 10 The first through conductors 51a and 51b that are arranged so as to penetrate the dielectric layer 11 , 51c are connected to the resonant electrodes 30a, 30b, 30c, respectively, and the dielectric layer 11 is arranged in a further different layer C of the laminate 10 so as to face the auxiliary resonant electrode 31a. The auxiliary input coupling electrode 41a connected to the resonance electrode 30a of the input stage by the second through conductor 52a penetrating through the dielectric layer, and the dielectric layer disposed in the interlayer C of the laminated body 10 so as to face the auxiliary resonance electrode 31b. The auxiliary output coupling electrode 41b connected to the resonance electrode 30b of the output stage by the third through conductor 52b that penetrates 11 and the fourth through conductor 53a that is disposed on the upper surface of the multilayer body 10 and penetrates the dielectric layer 11 The input terminal electrode 60a connected to the auxiliary input coupling electrode 41a by the same, and the output connected to the auxiliary output coupling electrode 41b by the fifth through conductor 53b which is also disposed on the upper surface of the laminate 10 and penetrates the dielectric layer 11. It consists of terminal electrode 60b It is made.

  The first ground electrode 21 is disposed on the entire lower surface of the laminate 10 and the second ground electrode 22 is disposed on substantially the entire surface of the upper surface of the laminate 10 except for the periphery of the input terminal electrode 60a and the output terminal electrode 60b. Both are connected to the ground potential to form a stripline resonator together with the resonance electrodes 30a, 30b and 30c.

  The strip-shaped resonance electrodes 30a, 30b, and 30c constitute a stripline resonator together with the first ground electrode 21 and the second ground electrode 22, and one end thereof is connected to the annular ground electrode 23 so as to be at the ground potential. By being connected, it functions as a quarter wavelength resonator. Each length is shorter than ¼ of the wavelength at the center frequency of the band-pass filter in consideration of the effect of capacitance generated between the auxiliary resonant electrodes 31a, 31b, 31c and the annular ground electrode 23. Is set. For example, when the center frequency is 4 GHz and the relative dielectric constant of the dielectric layer 11 is about 10, the length is set to about 2 to 6 mm.

  The resonance electrodes 30a, 30b, and 30c are arranged side by side in the interlayer A of the multilayer body 10 and edge-coupled to each other. If the distance between the resonant electrodes 30a, 30b, and 30c is smaller, stronger coupling is obtained. However, if the distance is reduced, manufacturing becomes difficult. For example, the distance is set to about 0.05 to 0.5 mm. Furthermore, the resonance electrodes 30a, 30b, and 30c are alternately arranged at their one end and the other end, and are coupled to each other in an interdigital manner. Compared to the case of connecting to a line type, the connection is stronger. In this way, the resonant electrodes 30a, 30b, and 30c are edge-coupled to each other and coupled in an interdigital manner, so that the frequency interval between the resonant frequencies in the respective resonant modes can be reduced by using a conventional quarter wavelength resonator. It is reasonable to obtain a wide passband width of about 40% in a specific band suitable as a bandpass filter for UWB, far exceeding the range that could be realized with the used filter.

  If the resonant electrodes 30a, 30b, and 30c are coupled in an interdigital manner and broadside coupled to each other, the coupling becomes too strong, and in order to achieve a pass bandwidth of about 40% in the specific band. Has been found to be undesirable.

  The annular ground electrode 23 is formed in an annular shape surrounding the resonance electrodes 30a, 30b, and 30c in the interlayer A of the laminate 10, and is connected to one end of the resonance electrodes 30a, 30b, and 30c. And it has a function which connects one end of resonance electrode 30a, 30b, 30c to earth potential by being connected to earth potential. Even when a band pass filter is formed in a part of the module substrate due to the presence of the annular ground electrode 23, one end of the resonance electrodes 30a, 30b, 30c arranged in an interdigital manner can be easily formed. Can be connected to a ground electrode. Further, since the annular ground electrode 23 surrounds the resonance electrodes 30a, 30b, and 30c in an annular shape, leakage of electromagnetic waves generated from the resonance electrodes 30a, 30b, and 30c to the periphery can be reduced. This effect is particularly useful in preventing adverse effects on other areas of the module substrate when a bandpass filter is formed in a partial area of the module substrate. Further, the capacitance generated between the annular ground electrode 23 and the auxiliary resonance electrodes 31a, 31b, 31c reduces the length of the resonance electrodes 30a, 30b, 30c, and has a function of realizing a small bandpass filter. .

  The strip-shaped input coupling electrode 40a is disposed in an interlayer B different from the interlayer A in which the resonance electrodes 30a, 30b, and 30c are disposed so as to face the resonance electrode 30a of the input stage as a whole. It is opposed to a region extending over half the length of the resonance electrode 30a. Therefore, the input coupling electrode 40a and the input stage resonance electrode 30a are broadside coupled, and are strongly coupled as compared to the edge coupling. The strip-shaped input coupling electrode 40a is connected to the auxiliary input coupling electrode 41a by the second through conductor 52a, and the connection point 71a between the input coupling electrode 40a and the second through conductor 52a is the length of the input coupling electrode 40a. It is located at the end closer to the other end of the input stage resonance electrode 30a than the center in the vertical direction, and the opposite end is an open end. An electrical signal input from an external circuit is supplied from the connection point 71a to the input coupling electrode 40a. As a result, the input coupling electrode 40a and the input stage resonance electrode 30a are coupled in an interdigital manner, and the coupling due to the magnetic field and the coupling due to the electric field are added and coupled in the combline type or simply capacitively coupled. The bond is stronger than in the case. Thus, the input coupling electrode 40a is broad-side coupled to the input stage resonance electrode 30a and is interdigitally coupled to the entire input coupling electrode 40a. Are connected.

  Similarly, the strip-shaped output coupling electrode 40b is disposed in an interlayer B different from the interlayer A in which the resonance electrodes 30a, 30b, and 30c are disposed so that the entire band faces the resonance electrode 30b in the output stage. It is opposed to a region extending over half of the length direction of the resonance electrode 30b of the output stage. Therefore, the output coupling electrode 40b and the output stage resonance electrode 30b are broadside coupled, and are strongly coupled as compared to the edge coupling. The strip-like output coupling electrode 40b is connected to the auxiliary output coupling electrode 41b by the third through conductor 52b, and the connection point 71b between the output coupling electrode 40b and the third through conductor 52b is the length of the output coupling electrode 40b. It is positioned at the end closer to the other end of the resonance electrode 30b of the output stage than the center in the vertical direction, and the opposite end is an open end. An electric signal input from an external circuit is supplied from the connection point 71b to the output coupling electrode 40b. As a result, the output coupling electrode 40b and the output stage resonance electrode 30b are coupled in an interdigital manner, and the coupling due to the magnetic field and the coupling due to the electric field are added to form a combline coupling or simply capacitive coupling. The bond is stronger than in the case. In this way, the output coupling electrode 40b is broadside coupled to the output stage resonance electrode 30b and is interdigitally coupled to the entire output coupling electrode 40b. Are connected.

  Thus, the input coupling electrode 40a and the input stage resonance electrode 30a are very strongly coupled, and the output coupling electrode 40b and the output stage resonance electrode 30b are very strongly coupled. Even in a wide passband far exceeding the region that could be realized with a filter using a resonator, the insertion loss at frequencies located between the resonance frequencies of the respective resonance modes does not increase significantly. A bandpass filter having flat and low-loss pass characteristics over the entire wide passband can be obtained.

  The input coupling electrode 40a and the output coupling electrode 40b are preferably set to have the same dimensions as the input stage resonance electrode 30a and the output stage resonance electrode 30b. If the distance between the input coupling electrode 40a and the input stage resonance electrode 30a and the distance between the output coupling electrode 40b and the output stage resonance electrode 30b are reduced, the coupling becomes stronger but the manufacturing becomes difficult. It is set to about 0.5 mm.

  The auxiliary resonant electrodes 31a, 31b, 31c are arranged in the layer B of the laminate 10 so as to have a region facing the resonant electrodes 30a, 30b, 30c and a region facing the annular ground electrode 23, respectively. , 30b, 30c, the other end of the resonance electrodes 30a, 30b, 30c is formed by the first through conductors 51a, 51b, 51c penetrating the dielectric layer 11 located between the resonance electrodes 30a, 30b, 30c. Connected to the side. Capacitance is generated between the ring-shaped ground electrode 23 and the ring-shaped ground electrode 23, so that the length of the resonant electrodes 30a, 30b, 30c can be shortened. A filter can be obtained.

  The auxiliary resonance electrodes 31a, 31b, 31c are connected to the other ends of the resonance electrodes 30a, 30b, 30c, respectively, and extend from the other ends to the opposite side of the resonance electrodes 30a, 30b, 30c. Therefore, as described in detail later, a joined body of the input stage resonant electrode 30a and the auxiliary resonant electrode 31a connected thereto, an input coupled electrode 40a and a joined body of the auxiliary input coupled electrode 41a connected thereto, The coupling between the resonance electrode 30b in the output stage and the auxiliary resonance electrode 31b connected to the output electrode 30b and the output coupling electrode 40b And the joint of the auxiliary output coupling electrode 41b connected thereto are broad-side coupled as a whole, and are very strongly coupled by coupling to the interdigital type. Is possible.

The area of the facing portion between the auxiliary resonant electrodes 31a, 31b, 31c and the annular ground electrode 23 is set to, for example, about 0.01 to ³ mm ² in consideration of the required size and the obtained capacitance. A smaller capacitance between the auxiliary resonant electrodes 31a, 31b, 31c and the annular ground electrode 23 can cause a larger capacitance, but it is difficult to manufacture. For example, it is set to about 0.01 to 0.5 mm. Is done.

  The auxiliary input coupling electrode 41a has a band shape, and is a region facing the auxiliary resonance electrode 31a connected to the resonance electrode 30a in the input stage, in an interlayer C different from the interlayer B where the input coupling electrode 40a and the output coupling electrode 40b are arranged. And a second through conductor 52a penetrating through the dielectric layer 11 located between the input coupling electrode 40a and the region facing the input coupling electrode 40a. Are connected to the input coupling electrode 40a. As a result, the auxiliary input coupling electrode 41a connected to the input coupling electrode 40a and the auxiliary resonance electrode 31a connected to the input stage resonance electrode 30a are broadside coupled, and this coupling is connected to the input coupling electrode 40a and the input stage resonance electrode 30a. Since it is added to the coupling with the resonance electrode 30a, the coupling is stronger as a whole.

  Further, an input terminal electrode 60a in which the end of the auxiliary input coupling electrode 41a opposite to the side connected to the second through conductor 52a in the length direction is arranged on the upper surface of the multilayer body 10 by the fourth through conductor 53a. Therefore, the joined body of the input stage resonant electrode 30a and the auxiliary resonant electrode 31a connected thereto, and the joined body of the input coupled electrode 40a and the auxiliary input coupled electrode 41a connected thereto are totally formed. Therefore, it is a strong coupling in which the coupling by the magnetic field and the coupling by the electric field are added. Therefore, stronger coupling can be realized in the length direction of the auxiliary input coupling electrode 41a than in the case where the auxiliary input coupling electrode 41a is connected to the input terminal electrode 60a on the same side as the side connected to the input coupling electrode 40a.

  The auxiliary output coupling electrode 41b has a belt-like shape, and is a region facing the auxiliary resonance electrode 31b connected to the resonance electrode 30b at the output stage, in an interlayer C different from the layer B where the input coupling electrode 40a and the output coupling electrode 40b are arranged. And a third through conductor 52b penetrating through the dielectric layer 11 located between the output coupling electrode 40b and the region facing the output coupling electrode 40b. Is connected to the output coupling electrode 40b. As a result, the auxiliary output coupling electrode 41b connected to the output coupling electrode 40b and the auxiliary resonance electrode 31b connected to the output stage resonance electrode 30b are broadside coupled, and this coupling is connected to the output coupling electrode 40b and the output stage resonance electrode 30b. Since it is added to the coupling with the resonant electrode 30b, the coupling is stronger as a whole.

  Further, an output terminal electrode 60b in which the end of the auxiliary output coupling electrode 41b opposite to the side connected to the third through conductor 52b in the length direction is arranged on the upper surface of the multilayer body 10 by the fifth through conductor 53b. Therefore, the output stage resonance electrode 30b and the joined body of the auxiliary resonance electrode 31b connected thereto, and the output coupling electrode 40b and the joined body of the auxiliary output coupling electrode 41b connected thereto are totally formed. Therefore, it is a strong coupling in which the coupling by the magnetic field and the coupling by the electric field are added. Therefore, stronger coupling can be realized in the length direction of the auxiliary output coupling electrode 41b than in the case where the auxiliary output coupling electrode 41b is connected to the output terminal electrode 60b on the same side as the side connected to the output coupling electrode 40b.

  As described above, the joint of the input stage resonance electrode 30a and the auxiliary resonance electrode 31a connected thereto, and the input coupling electrode 40a and the joint of the auxiliary input coupling electrode 41a connected thereto are broad-side coupled. In addition, the coupling is very strong by coupling to the interdigital type, and similarly, a joined body of the resonance electrode 30b of the output stage and the auxiliary resonance electrode 31b connected thereto, and the output coupling electrode 40b and the auxiliary connected thereto Since the joint of the output coupling electrode 41b is broad-side coupled as a whole and is very strongly coupled by interdigital coupling, the resonance frequency of each resonance mode can be achieved even in a very wide pass band. The insertion loss increase at frequencies located between is further reduced, and the flatter and lower loss pass characteristics across the wide passband. Can be obtained.

  Note that the widths of the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b are set to be approximately the same as the input coupling electrode 40a and the output coupling electrode 40b, for example, and the lengths of the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b are For example, it is set slightly longer than the length of the auxiliary resonant electrodes 31a and 31b. The smaller distances between the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b and the auxiliary resonant electrodes 31a and 31b are desirable in terms of causing strong coupling, but are difficult to manufacture. For example, 0.01 to 0.5 mm Set to degree.

  Thus, according to the band-pass filter of this example, a very wide passband of 40% in a ratio band far exceeding the range that could be realized by a filter using a conventional quarter wavelength resonator. It is possible to obtain a high-performance band-pass filter that can be suitably used as a UWB filter and has a flat and low-loss pass characteristic over the entire area.

(Second example of embodiment)
FIG. 5 is an external perspective view schematically showing another example of the embodiment of the band-pass filter of the present invention. 6 is a schematic exploded perspective view of the bandpass filter shown in FIG. FIG. 7 is a plan view schematically showing the upper and lower surfaces and layers of the bandpass filter shown in FIG. 8 is a cross-sectional view taken along line AA ′ of 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.

  The characteristic part of the band-pass filter of this example is opposite to the layer B where the auxiliary resonance electrodes 31a, 31b and 31c are arranged with respect to the layer A where the resonance electrodes 30a, 30b and 30c and the annular ground electrode 23 are arranged. In the interlayer D located on the side, a region facing the resonance electrodes 30a, 30b, 30c and a region facing the annular ground electrode 23 are arranged, and the region facing the resonance electrodes 30a, 30b, 30c Second auxiliary resonance electrode connected to the other end side of the resonance electrodes 30a, 30b, 30c by sixth through conductors 54a, 54b, 54c passing through the dielectric layer 11 positioned between 30a, 30b, 30c 32a, 32b, and 32c are arranged.

As a result, the capacitance between the second auxiliary resonance electrodes 32a, 32b, 32c and the annular earth electrode 23 is added to the capacitance between the auxiliary resonance electrodes 31a, 31b, 31c and the annular earth electrode 23. As a result, the capacitance between the open ends of the resonance electrodes 30a, 30b, and 30c and the ground potential is further increased, and the length of the resonance electrodes 30a, 30b, and 30c can be further shortened. The bandpass filter can be obtained. Further, when the capacitance between the open ends of the resonance electrodes 30a, 30b, and 30c and the ground potential is not increased, as compared with the bandpass filter of the first example of the embodiment of the present invention described above, Since the planar shapes of the auxiliary resonance electrodes 31a, 31b, 31c and the second auxiliary resonance electrodes 32a, 32b, 32c can be reduced, a smaller bandpass filter can be obtained in this case as well. The area of the facing portion between the second auxiliary resonance electrodes 32a, 32b, 32c and the annular ground electrode 23 is set to, for example, about 0.01 to ³ mm ² in consideration of the necessary size and the obtained capacitance. A smaller capacitance between the second auxiliary resonance electrodes 32a, 32b, and 32c and the annular ground electrode 23 can cause a larger capacitance, but it is difficult to manufacture. For example, 0.01 to 0.5 mm Set to degree.

  Thus, according to the bandpass filter of this example, a smaller bandpass filter can be obtained as compared with the bandpass filter of the first example of the embodiment of the present invention described above.

(Third example of embodiment)
FIG. 9 is an external perspective view schematically showing still another example of the embodiment of the band-pass filter of the present invention. FIG. 10 is a schematic exploded perspective view of the bandpass filter shown in FIG. FIG. 11 is a plan view schematically showing upper and lower surfaces and layers of the bandpass filter shown in FIG. 12 is a cross-sectional view taken along line AA ′ of FIG. In this example, only points different from the above-described example will be described, and the same components will be denoted by the same reference numerals and redundant description will be omitted.

A characteristic part of the bandpass filter of this example is that the input coupling electrode 40a, the output coupling electrode 40b, and the auxiliary resonance electrodes 31a and 31b are arranged with respect to the interlayer C where the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b are arranged. , 31c are arranged on the side E of the laminate 10 located on the opposite side of the layer B,
A first input coupling enhancement electrode 81a, part of which is opposed to the auxiliary input coupling electrode 41a, and a first output coupling enhancement electrode 81b, part of which is opposed to the auxiliary output coupling electrode 41b, are arranged, It is located on the opposite side to the interlayer C where the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b are arranged with respect to the interlayer E where the first input coupling enhancing electrode 81a and the first output coupling enhancing electrode 81b are arranged. A second auxiliary input coupling electrode 42a, part of which is opposed to the first input coupling enhancement electrode 81a, and a part of which is opposed to the first output coupling enhancement electrode 81b, are disposed between the layers F of the laminate 10. The auxiliary output coupling electrode 42b of the second auxiliary input coupling electrode 42a and the second auxiliary input coupling electrode 42a and the interlayer F where the second auxiliary output coupling electrode 42b is disposed are connected to the first input coupling enhancement electrode 81a, The interlayer E in which the first output coupling reinforcing electrode 81b is disposed A second input coupling enhancement electrode 82a partly facing the second auxiliary input coupling electrode 42a and a part of the second auxiliary output coupling electrode partly facing the second auxiliary input coupling electrode 42a. The second output coupling enhancement electrode 82b facing 42b is arranged.

  The second auxiliary input coupling electrode 42a is connected to a fourth through conductor 53a that connects the auxiliary input coupling electrode 41a and the input terminal electrode 60a, and the second auxiliary output coupling electrode 42b is connected to the auxiliary output. The coupling electrode 41b is connected to a fifth through conductor 53b that connects the output terminal electrode 60b. The first input coupling enhancing electrode 81a and the second input coupling enhancing electrode 82a are connected by the seventh through conductor 55a to the auxiliary resonant electrode 31a connected to the resonant electrode 30a in the input stage. The output coupling enhancing electrode 81b and the second output coupling enhancing electrode 82b are connected to the auxiliary resonant electrode 31b connected to the resonant electrode 30b at the output stage by an eighth through conductor 55b.

  According to the bandpass filter of this example having such a configuration, the first input coupling enhancement electrode 81a and the second input coupling enhancement electrode 82a, the auxiliary input coupling electrode 41a, and the second auxiliary input coupling electrode 42a The coupling is added to the coupling of the input coupling electrode 40a and the auxiliary input coupling electrode 41a with the resonant electrode 30a of the input stage and the auxiliary resonant electrode 31a connected thereto, thereby obtaining a stronger coupling. Similarly, the coupling between the first output coupling enhancement electrode 81b and the second output coupling enhancement electrode 82b and the auxiliary output coupling electrode 41b and the second auxiliary output coupling electrode 42b is the output coupling electrode 40b and the auxiliary output coupling electrode 41b. And the output resonance electrode 30b and the auxiliary resonance electrode 31b connected to the output resonance electrode 30b are combined into stronger coupling. This further reduces the increase in insertion loss at frequencies located between the resonant frequencies of the respective resonant modes, even at very wide passband widths, and is flatter over the entire very wide passband. A band-pass filter having a lower loss pass characteristic can be obtained.

(Fourth example of embodiment)
FIG. 13 is a block diagram showing a configuration example of a high-frequency module 80 using the bandpass filter of the present invention and a radio communication device 85 using the same.

  The high-frequency module 80 of the present invention includes a MAC (Medium Access Control) IC 81 that performs medium access control, and a PHY (physical layer) IC 82 that transmits and receives a multi-band OFDM (Orthogonal Frequency Division Multiplexing) signal, The wireless communication device 85 of the present invention is configured by connecting the antenna 84 to the band pass filter 83. When the transmission signal output from the PHY IC 82 passes through the band-pass filter 83, the signal having a frequency other than the communication band is attenuated and transmitted from the antenna 84. Further, when the received signal received by the antenna 84 passes through the band pass filter 83, a signal of a frequency other than the communication band is attenuated and input to the PHY IC.

  According to the high-frequency module 80 and the radio communication device 85 of the present invention, the bandpass filter of the present invention with a small loss of a signal passing over the entire communication band is used for filtering the transmission signal and the reception signal. Since the attenuation of the reception signal and the transmission signal passing through the filter is reduced, the reception sensitivity is improved, and the amplification degree of the transmission signal and the reception signal can be reduced, so that the power consumption in the amplifier circuit is reduced. Therefore, a high-performance high-frequency module 80 and a 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, 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 form a slurry, and a ceramic green sheet is formed by a doctor blade method. Next, a through hole to be a through conductor is formed in the obtained ceramic green sheet using a punching machine or the like, and a through conductor is formed by filling a conductor paste such as Ag, Ag-Pd, Au, Cu or the like. Next, the various electrodes described above are formed on the ceramic green sheet using a printing method. Next, these are laminated, pressure-bonded using a hot press device, and fired at 800 to 1050 ° C.

(Modification)
The present invention is not limited to the first to fourth examples of the embodiment described above, and various modifications and improvements can be made without departing from the gist of the present invention.

For example, in the example of the above-described embodiment, an example in which the input terminal electrode 60a and the output terminal electrode 60b are provided is shown. However, when a band-pass filter is formed in one region in the module substrate, the input terminal electrode 60a and the output terminal electrode 60b always necessary have.

  Furthermore, in the example of the above-described embodiment, an example in which the input coupling electrode 40a, the output coupling electrode 40b, and the auxiliary resonance electrodes 31a, 31b, and 31c are arranged in the same layer B of the stacked body 10 is shown. The coupling electrode 40a, the output coupling electrode 40b, and the auxiliary resonance electrodes 31a, 31b, 31c may be arranged between different layers of the multilayer body 10, and the input coupling electrode 40a and the output coupling electrode 40b are laminated body 10. The auxiliary resonant electrodes 31a, 31b, 31c may be arranged between different layers of the multilayer body 10.

  Furthermore, in the example of the above-described embodiment, the example in which the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b are arranged in the same layer C of the stacked body 10 is shown. However, the auxiliary input coupling electrode 41a and the auxiliary output are arranged. The coupling electrode 41b may be disposed between different layers of the stacked body 10.

  Furthermore, in the example of the above-described embodiment, the example in which the band-pass filter is configured by electromagnetically coupling the three resonance electrodes 30a, 30b, and 30c has been shown. However, for example, two or four or more resonances A band pass filter may be configured by electromagnetically coupling the electrodes. It can be selected depending on the required electrical properties and the allowable geometry.

  Furthermore, in the example of the embodiment described above, the example in which the first ground electrode 21 is disposed on the lower surface of the multilayer body 10 and the second ground electrode 22 is disposed on the upper surface of the multilayer body 10 has been shown. For example, a dielectric layer may be further disposed below the first ground electrode 21, and a dielectric layer may be further disposed on the second ground electrode 22.

  Furthermore, in the example of the above-described embodiment, an example of the high frequency module 80 configured by the MAC IC 81 that performs medium access control, the PHY IC 82 connected thereto, and the band pass filter 83 connected thereto. Although shown, a one-chip IC in which the MAC IC 81 and the PHY IC 82 are integrated may be used. Further, for example, the radio communication device 85 may be configured by configuring a high-frequency module only by the PHY IC 82 and the band pass filter 83 connected thereto, and connecting the MAC IC 81 and the antenna 84 thereto.

  Furthermore, although the band pass filter used for UWB has been described above as an example, it goes without saying that the band pass filter of the present invention is effective in other applications that require a wide band.

  Next, specific examples of the electronic component of the present invention will be described.

Electrical characteristics of the bandpass filter having the structure shown in FIGS. 1 to 5 were calculated by simulation using a finite element method. The calculation conditions were as follows: the relative dielectric constant of the dielectric layer 11 was 9.4, the dielectric loss tangent of the dielectric layer 11 was 0.0005, and the electrical conductivity of various electrodes was 3.0 × 10 ⁷ S / m. In terms of shape dimensions, the resonance electrodes 30a, 30b, and 30c have a width of 0.4 mm and a length of 2.9 mm, and the interval between adjacent resonance electrodes is 0.13 mm. The input coupling electrode 40a and the output coupling electrode 40b have a width of 0.3 mm and a length of 2.5 mm, and the auxiliary input coupling electrode 41a and the auxiliary output coupling electrode 41b have a width of 0.3 mm and a length of 1.45 mm. The auxiliary resonant electrodes 31a, 31b, 31c are arranged in a rectangular shape with a width of 0.45 mm and a length of 0.8 mm arranged at a distance of 0.3 mm from the other end of the resonant electrodes 30a, 30b, 30c, and then the resonant electrodes 30a, 30b, 30c A rectangular shape having a width of 0.2 mm and a length of 0.4 mm was joined. The input terminal electrode 60a and the output terminal electrode 60b were square with sides of 0.3 mm, and the distance from the second ground electrode 22 was 0.2 mm. The outer shape of the first earth electrode 21, the second earth electrode 22, and the annular earth electrode 23 was 3 mm wide and 5 mm long, and the opening of the annular earth electrode 23 was 2.4 mm wide and 3 mm long. The overall shape of the bandpass filter was 3 mm in width, 5 mm in length, and 0.91 mm in thickness, and the interlayer A was positioned in the center in the thickness direction. The distance between the interlayer A and the interlayer B and between the interlayer B and the interlayer C was 0.065 mm, respectively. The thickness of various electrodes was 0.01 mm, and the diameter of various through conductors was 0.1 mm.

  FIG. 16 is a graph showing the simulation results, where the horizontal axis represents frequency and the vertical axis represents loss, and shows the transmission characteristic (S21) and the reflection characteristic (S11). According to the graph shown in FIG. 16, the pass characteristic (S21) is far wider than the area realized by the filter using the conventional quarter wavelength resonator, which is equivalent to 40% in the specific band. The loss is less than 1.5 dB in the frequency range of GHz to 4.7 GHz. In this way, excellent pass characteristics that are flat and have low loss over the entire wide passband were obtained, and the effectiveness of the present invention was confirmed.

It is an external appearance perspective view which shows typically an example of embodiment of the band pass filter of this invention. It is a typical exploded perspective view of the band pass filter shown in FIG. It is a top view which shows typically the upper and lower surfaces and interlayer of a band pass filter shown in FIG. FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. It is an external appearance perspective view which shows typically the other example of embodiment of the band pass filter of this invention. FIG. 6 is a schematic exploded perspective view of the bandpass filter shown in FIG. 5. It is a top view which shows typically the upper and lower surfaces and interlayer of a band pass filter shown in FIG. FIG. 6 is a cross-sectional view taken along line A-A ′ of FIG. 5. It is an external appearance perspective view which shows typically the further another example of embodiment of the band pass filter of this invention. FIG. 10 is a schematic exploded perspective view of the bandpass filter shown in FIG. 9. FIG. 10 is a plan view schematically showing upper and lower surfaces and layers of the bandpass filter shown in FIG. 9. FIG. 10 is a cross-sectional view taken along line A-A ′ of FIG. 9. It is a block diagram which shows the structural example of the high frequency module using the band pass filter of this invention, and a radio | wireless communication apparatus using the same. It is a figure which shows the simulation result of the electrical property of the band pass filter of this invention .

Explanation of symbols

10: Laminate
11: Dielectric layer
21: First ground electrode
22: Second ground electrode
23: Ring earth electrode
30a, 30b, 30c: Resonant electrode
31a, 31b, 31c: auxiliary resonant electrodes
40a: Input coupling electrode
40b: Output coupling electrode
41a: Auxiliary input coupling electrode
41b: Auxiliary output coupling electrode
51a, 51b, 51c: first through conductor
52a: second through conductor
52b: Third through conductor
80: High-frequency module
85: Wireless communication equipment

Claims (3)

A laminate in which a plurality of dielectric layers are laminated;
A first ground electrode disposed on the lower surface of the laminate and connected to a ground potential;
A second ground electrode disposed on the top surface of the laminate and connected to a ground potential;
A plurality of strip-shaped resonance electrodes which are arranged side by side so as to be electromagnetically coupled to each other between any one layer of the laminate, each having one end connected to a ground potential and functioning as a quarter wavelength resonator; ,
A band-shaped input coupling electrode that is electromagnetically coupled to the resonance electrode of the input stage among the plurality of resonance electrodes, disposed between layers different from the one layer of the laminate,
A band-shaped output coupling electrode that is disposed between different layers from the one layer of the laminate, and is electromagnetically coupled to an output stage resonance electrode among the plurality of resonance electrodes ;
An annular earth electrode connected to earth potential, formed in an annular shape surrounding the plurality of resonance electrodes between the one layer, and connected to the one end of the plurality of resonance electrodes;
Corresponding to each of the plurality of resonance electrodes, the multilayer body is disposed so as to have a region facing the annular ground electrode and a region facing the resonance electrode between layers different from the one layer of the laminate, An auxiliary resonant electrode connected to the other end side of the resonant electrode by a first through conductor penetrating the dielectric layer located between the resonant electrode and a region facing the resonant electrode;
A region facing the auxiliary resonance electrode connected to the resonance electrode of the input stage among the plurality of auxiliary resonance electrodes, between the different layer from the one layer of the stacked body and further different layers, and the input coupling electrode A region facing the input coupling electrode, and a region facing the input coupling electrode is formed by a second through conductor penetrating the dielectric layer located between the input coupling electrode and the input coupling electrode. An auxiliary input coupling electrode connected to the side closer to the other end of the resonance electrode of the input stage than the center in the length direction;
A region facing the auxiliary resonance electrode connected to the resonance electrode of the output stage among the plurality of auxiliary resonance electrodes, between the different layer from the one layer of the laminate and a different layer, and the output coupling electrode A region facing the output coupling electrode, and a region facing the output coupling electrode is formed by a third through conductor penetrating the dielectric layer located between the output coupling electrode and the output coupling electrode. e Bei and than the center in the length direction are connected to the side close to the other end of the resonance electrode of the output-stage auxiliary output coupling electrode,
The plurality of resonance electrodes are alternately arranged at the one end and the other end, and the input coupling electrode is opposed to a region extending over half the length direction of the resonance electrode of the input stage. And the position where the electric signal input from the external circuit is supplied is closer to the other end of the resonance electrode of the input stage than the center in the length direction,
The output coupling electrode is disposed so as to face a region extending over half the length direction of the resonance electrode of the output stage, and the position from which the electric signal output to the external circuit is taken out from the center in the length direction. The band-pass filter is characterized in that it is on the side closer to the other end of the resonance electrode of the output stage. A high-frequency module comprising the bandpass filter according to claim 1 . Wireless communication device characterized by using the high-frequency module according to the band-pass filter or claim 2 of claim 1.

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