JP4610584B2 - BANDPASS FILTER, RADIO COMMUNICATION MODULE AND RADIO COMMUNICATION DEVICE USING THE SAME - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a band-pass filter, a wireless communication module using the same, and a wireless communication device. The present invention relates to a module and a wireless communication device.

  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 JP 2004-180032 A

  However, the band-pass filters proposed in Non-Patent Document 1 and Patent Document 1 each have problems, and are not suitable for UWB band-pass filters.

  For example, the bandpass filter proposed in Non-Patent Document 1 has a problem that the passband width is too wide. In other words, UWB basically uses a frequency band of 3.1 GHz to 10.6 GHz, but the International Telecommunications Union wireless communication sector is about 3.1 to 4.7 GHz in a form avoiding 5.3 GHz used in IEEE802.11.a. There is a plan that divides the band into a low band that uses a band and a high band that uses a band of about 6 GHz to 10.6 GHz. In Japan, the low band is initially planned. . Therefore, since the filter used for this requires a passband width of about 40% in the specific band and attenuation at 5.3 GHz at the same time, it has a characteristic that the passband width exceeds 100% in the specific band. The band-pass filter proposed in Document 1 cannot be used because its pass bandwidth 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.

  Furthermore, bandpass filters for UWB Low Band require attenuation at 5.3 GHz used in IEEE802.11.a and 6 GHz to 10.6 GHz used in UWB High Band. In particular, it is necessary to ensure a sufficient amount of attenuation in the frequency region near the passband.

  The present invention has been devised in view of such problems in the prior art, and its purpose is to provide an appropriate passband width and a vicinity of the passband as a bandpass filter for UWB Low Band in UWB. An object of the present invention is to provide a bandpass filter having sufficient attenuation on the high frequency side, and 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 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 Are arranged side by side so that one end and the other end are alternated between one layer of the laminate, and each one end is grounded. A plurality of strip-shaped resonance electrodes that function as quarter-wave resonators connected to a potential and are electromagnetically coupled to each other, and are formed in an annular shape surrounding the plurality of resonance electrodes between the one layer; An annular ground electrode connected to the ground potential, to which the one end of the resonant electrode is connected, and an input stage of the plurality of resonant electrodes arranged between layers different from the one layer of the laminate. Half of resonant electrode The band-like input coupling electrode having an electric signal input point to which an electric signal from an external circuit is input is coupled with an electromagnetic field opposite to the above-described region, and a layer different from the one layer of the laminate. A band-like shape having an electric signal output point at which an electric signal is output to an external circuit while being coupled with an electromagnetic field opposite to a region of the plurality of resonance electrodes that is disposed over half of the resonance electrode of the output stage. The input coupling electrode has a resonance point in the input stage than the center in the length direction at the portion of the input coupling electrode facing the resonance electrode in the input stage. The output coupling electrode is located closer to the other end of the electrode, and the output coupling electrode has a resonance point of the output stage than the center in the length direction at the portion where the electrical signal output point faces the resonance electrode of the output stage. It is located on the side close to the other end of the pole, and at least one of the input coupling electrode or the output coupling electrode is one end portion on the opposite side of the electric signal input point or the electric signal output point in the length direction. Is extended so as to face the annular ground electrode beyond the one end of the opposed resonant electrode of the input stage or the resonant electrode of the output stage.

  The band-pass filter according to the present invention may have a configuration in which the at least one of the input coupling electrode and the output coupling electrode of the multilayer body has an interlayer located on the opposite side to the one layer. And an auxiliary earth electrode arranged to face the one end of at least one of the input coupling electrode and the output coupling electrode.

  Furthermore, the band-pass filter of the present invention is the above-described configuration, wherein at least one of the input coupling electrode and the output coupling electrode has an end of the opposing resonant electrode of the input stage or the resonant electrode of the output stage. It extends so as to face the annular ground electrode beyond the one end, and is bent along the annular ground electrode.

  Still further, in the bandpass filter of the present invention, in the above configuration, the one end of the input coupling electrode and the output coupling electrode is the one end of the resonance electrode of the input stage or the resonance electrode of the output stage facing each other. And is extended along the annular ground electrode so as to face the annular ground electrode, and the electrical lengths of the input coupling electrode and the output coupling electrode are different from each other. Is.

  Furthermore, in the bandpass filter of the present invention, in the configuration described above, the one end of the input coupling electrode and the output coupling electrode is the one end of the opposing resonance electrode of the input stage or the resonance electrode of the output stage. It is extended so that it may oppose the said cyclic | annular earth electrode, and it is bent so that it may mutually distance.

  Still further, the band-pass filter of the present invention has a region facing the annular ground electrode and a region facing the resonance electrode between layers different from the one layer of the multilayer body in each of the above configurations. An auxiliary resonance electrode disposed and connected to the other end side of the resonance electrode by a first through conductor penetrating the dielectric layer located between the resonance electrode and a region facing the resonance electrode; It is arranged corresponding to each of the plurality of resonance electrodes.

  Furthermore, the bandpass filter according to the present invention is connected to the resonance electrode of the input stage among the plurality of auxiliary resonance electrodes in a layer different from the one layer of the multilayer body and in a layer different from the one layer of the multilayer body in the above configuration. A region facing the auxiliary resonance electrode and a region facing the input coupling electrode are arranged, and the region facing the input coupling electrode penetrates the dielectric layer positioned between the input coupling electrode The 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 at the portion of the input coupling electrode facing the resonance electrode of the input stage by a second through conductor And a region facing the auxiliary resonant electrode connected to the output stage resonant electrode among the plurality of auxiliary resonant electrodes between a different layer from the one layer of the laminate and a different layer. A region facing the output coupling electrode, and the region facing the output coupling electrode is output by the third through conductor penetrating the dielectric layer located between the output coupling electrode and the output coupling electrode. And an auxiliary output coupling electrode connected to a side closer to the other end of the resonance electrode of the output stage than a center in a length direction at a portion of the coupling electrode facing the resonance electrode of the output stage. Is.

  A wireless communication module according to the present invention includes the band-pass filter according to the present invention having any one of the above-described configurations.

  A wireless communication device of the present invention includes an RF unit including the bandpass filter of the present invention having any one of the above-described configurations, a baseband unit connected to the RF unit, and an antenna connected to the RF unit. It is characterized by this.

  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 arranged in a layer different from the layer in which the plurality of resonance electrodes of the multilayer body are arranged, and the length of the resonance electrode in the input stage is increased. Electromagnetic field coupling is performed opposite to the region over half of the area, and the electric signal input point to which an electric signal from an external circuit is input is more in the input stage than the center in the length direction at the part facing the resonance electrode of the input stage. The output coupling electrode is located on the side close to the other end of the resonance electrode, and is arranged in a layer different from the layer in which the plurality of resonance electrodes of the multilayer body are arranged. Electromagnetic field coupling is performed opposite to more than half of the region, and the electrical signal output point at which the electrical signal is output to the external circuit is higher than the center in the length direction at the portion facing the resonance electrode of the output stage. Located on the side closer to the other end of the resonant electrode To have. With this configuration, the input coupling electrode and the resonance electrode of the input stage are strongly electromagnetically coupled by broadside coupling through the dielectric layer, and in addition to the case of the above-described resonant electrodes in order to couple to the interdigital type, Similarly, the coupling by the magnetic field and the coupling by the electric field are added to further strengthen the electromagnetic field coupling. Similarly, the output coupling electrode and the resonance electrode at the output stage are strongly electromagnetically coupled by broadside coupling through the dielectric layer, and are coupled to each other by an interdigital type, so that coupling by a magnetic field and coupling by an electric field are performed. Addition and electromagnetic field coupling further strongly. 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, it is formed in an annular shape surrounding the plurality of resonance electrodes between the layers where the plurality of resonance electrodes are arranged, and one end of the plurality of resonance electrodes is connected to the ground potential. Since the annular ground electrodes to be connected are arranged, there are electrodes to be connected to the ground potential on both sides of the length direction of the resonance electrodes, so that one end of each of the alternately arranged resonance electrodes is connected. It can be easily connected to ground potential.

  Furthermore, according to the band-pass filter of the present invention, at least one of the input coupling electrode and the output coupling electrode has an input stage in which one end on the opposite side to the electrical signal input point or electrical signal output point in the length direction is opposed. In addition to the effect of simply increasing the length, it is statically connected to the ground. Since the effect of forming the capacitance is added and the electrical length becomes very long, the resonant frequency when operating as a half-wave resonator is lowered. This makes it possible to form an attenuation pole due to half-wave resonance of at least one of the input coupling electrode and the output coupling electrode on the high frequency side near the pass band, and to increase the attenuation on the high frequency side near the pass band. can do.

  Still further, according to the bandpass filter of the present invention, the interlayer located on the opposite side of the interlayer where the plurality of resonant electrodes are disposed with respect to the interlayer where the input coupling electrode or the output coupling electrode of the multilayer body is disposed. Provided with an auxiliary earth electrode disposed so as to face at least one end of the input coupling electrode or the output coupling electrode, so that at least one end of the input coupling electrode or the output coupling electrode is connected to the ground. Since the capacitance formed between them can be further increased, it is possible to further increase the electrical length of at least one of the input coupling electrode and the output coupling electrode, and further lower the resonance frequency of 1/2 wavelength resonance. be able to. As a result, an attenuation pole due to 1/2 wavelength resonance of at least one of the input coupling electrode and the output coupling electrode is formed nearer the pass band on the high frequency side than the pass band, and the attenuation of the portion is increased. Can do.

  Furthermore, according to the band-pass filter of the present invention, at least one end of the input coupling electrode or the output coupling electrode is beyond the one end of the opposing input stage resonance electrode or output stage resonance electrode, and the annular ground Since it is extended so as to face the electrode and bent along the annular ground electrode, the size in the length direction of the resonance electrode of the band-pass filter can be reduced, so that a small band-pass filter is obtained. Can do.

  Still further, according to the bandpass filter of the present invention, one end of the input coupling electrode and the output coupling electrode is opposed to the annular ground electrode across one end of the opposing input stage resonance electrode or the output stage resonance electrode. The input coupling electrode and the output coupling electrode are different in electrical length from each other, so that both the input coupling electrode and the output coupling electrode have a half wavelength. The resonance frequency can be lowered, and the frequency of the half-wave resonance of the input coupling electrode and the output coupling electrode can be made different from each other. This makes it possible to form two attenuation poles due to half-wave resonance of the input coupling electrode and the output coupling electrode on the high frequency side near the pass band, which is sufficient in a wide frequency range on the high frequency side near the pass band. Attenuation can be ensured.

  Furthermore, according to the bandpass filter of the present invention, one end of the input coupling electrode and the output coupling electrode is opposed to the annular ground electrode across one end of the opposing input stage resonance electrode or the output stage resonance electrode. Since the electromagnetic coupling between one end portions of the input coupling electrode and the output coupling electrode can be reduced, the input coupling electrode and the output coupling electrode can be reduced. On the other hand, it is possible to prevent the attenuation amount outside the pass band from being reduced by electromagnetic coupling between the end portions.

  Still further, according to the bandpass 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. Since the electrostatic capacity is generated between the auxiliary resonant electrode and the annular ground electrode between the auxiliary resonant electrode and the annular ground electrode, the length of each resonant electrode can be shortened. The bandpass filter can be obtained.

  Furthermore, according to the band-pass 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 An auxiliary output coupling electrode connected to the output coupling electrode and having an area opposed to the auxiliary resonance electrode connected to the stage resonance electrode, the auxiliary connected to the input stage resonance electrode. Electromagnetic field coupling occurs between the resonant electrode and the auxiliary input coupling electrode, which is added to the electromagnetic coupling between the resonant electrode and the input coupling electrode of the input stage, and similarly connected to the resonant electrode of the output stage. An 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.

  Still further, according to the bandpass filter of the present invention, the auxiliary input coupling electrode is formed by the second through conductor in the input stage resonance electrode from the center in the length direction at the portion of the input coupling electrode facing the input stage resonance electrode. Similarly, the auxiliary output coupling electrode is connected to the side closer to the other end of the output terminal of the output coupling electrode by the third through conductor than the center in the length direction of the output coupling electrode facing the output stage resonance electrode. When connected to the other end of the circuit, an electric signal from the external circuit is input to the input coupling electrode via the auxiliary input coupling electrode, and the electric signal is transmitted from the output coupling electrode to the external circuit via the auxiliary output coupling electrode. Even in the case of output, the input coupling electrode and the input stage resonance electrode are coupled in an interdigital type, and the output coupling electrode and the output stage resonance electrode are coupled in an interdigital type. It can produce strong bonds which the coupling by coupling the electric field by the magnetic field is added.

  According to the wireless communication module of the present invention and the wireless communication device of the present invention, by using the band-pass filter of the present invention with a small loss of the signal passing over the entire communication band for filtering the transmission signal and the reception signal, Since the attenuation of the reception signal and the transmission signal passing through the band 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 wireless communication 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 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 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 XX ′ of FIG.

  As shown in FIGS. 1 to 4, the bandpass filter of this example is connected to a laminated body 10 in which a plurality of dielectric layers 11 are laminated, and a ground potential disposed on the lower surface of the laminated body 10. The first ground electrode 21, the second ground electrode 22 disposed on the upper surface of the laminate 10 and connected to the ground potential, and the one end and the other end of the layer A in the layer A are staggered. Are arranged side by side, one end of which is connected to the ground potential and functions as a quarter wavelength resonator, and a plurality of strip-like resonance electrodes 30a, 30 which are electromagnetically coupled to each other, and a plurality of resonance electrodes 30a, 30b, A band-shaped input coupling electrode 40a having an electric signal input point 45a to which an electric signal from an external circuit is input, and is coupled to an electromagnetic field facing a region of 30c or more of the resonance electrode 30a in the input stage of 30c; b, 30c and a different layer from the layer A of the laminate 10 Electromagnetically opposed to the region of the plurality of resonance electrodes 30a, 30b, 30c that is disposed in B and is different from the layer A in the multilayer body 10 over half of the resonance electrode 30b in the output stage. A band-shaped output coupling electrode 40b having an electric signal output point 45b for outputting an electric signal to an external circuit while being field coupled, and an annular shape surrounding the plurality of resonance electrodes 30a, 30b, 30c between the layers A And an annular ground electrode 23 connected to the ground potential, to which one end of the plurality of resonance electrodes 30a, 30b, 30c is connected, and the input coupling electrode 40a has its electrical signal input point 45a is positioned closer to the other end of the resonance electrode 30a in the input stage than the center in the length direction at the portion facing the resonance electrode 30a in the input stage, and the output coupling electrode 40b has its electrical signal output point 45b. With the resonant electrode 30b of the output stage The output coupling electrode 40b is located closer to the other end of the resonance electrode 30b of the output stage than the center of the length direction in the direction portion, and the output coupling electrode 40b is one end portion opposite to the electric signal output point 45b in the length direction. Is extended so as to face the annular ground electrode 23 beyond one end of the resonance electrode 30b of the opposed output stage.

  In the band-pass filter of this example, the input terminal electrode 60a and the output terminal electrode 60b are disposed on the upper surface of the laminate 10 so as to be isolated from the second ground electrode 22. The input terminal electrode 60a is connected to the electric signal input point 45a of the input coupling electrode 40a by a fourth through conductor 53a that penetrates the dielectric layer 11, and the output terminal electrode 60b penetrates the dielectric layer 11. It is connected to the electrical signal output point 45b of the output coupling electrode 40b through the fifth through conductor 53b.

  In the bandpass filter of this example having such a configuration, an electric signal from an external circuit is input to the electric signal input point 45a of the input coupling electrode 40a via the input terminal electrode 60a and the fourth through conductor 53a. Then, the resonance electrode 30a of the input stage that is electromagnetically coupled to the input coupling electrode 40a is excited. The fifth through conductor 53b from the electric signal output point 45b of the output coupling electrode 40b electromagnetically coupled to the resonant electrode 30b of the output stage through the plurality of resonant electrodes 30a, 30b, 30c coupled to each other. An electrical signal is output to an external circuit via the output terminal electrode 60b. At this time, since a signal having a frequency at which the plurality of resonance electrodes 30a, 30b, and 30c resonate selectively passes, the filter functions as a band pass filter that allows a signal having a specific frequency to pass therethrough.

  The first ground electrode 21 is disposed on the entire lower surface of the multilayer body 10, and the second ground electrode 22 is disposed on almost the entire surface except for the periphery of the input terminal electrode 60a and the output terminal electrode 60b on the upper surface of the multilayer body 10. Both are connected to the ground potential and constitute a stripline resonator together with the resonance electrodes 30a, 30b, 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 electrical length is set to about ¼ of the wavelength at the center frequency of the bandpass filter.

  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.

  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, 30c are disposed so as to be opposed to the resonance electrode 30a in the input stage and to be electromagnetically coupled. And opposed to a region extending over half of the length direction of the resonance electrode 30a of the input stage. 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 input terminal electrode 60a by the fourth through conductor 53a, and the connection point between the input coupling electrode 40a and the fourth through conductor 53a is an electric signal input of the input coupling electrode 40a. It becomes point 45a. This electrical signal input point 45a is located at the end of the input coupling electrode 40a that is closer to the other end of the input stage resonance electrode 30a than the center in the length direction at the part facing the input stage resonance electrode 30a. The opposite end is an open end. An electric signal input from an external circuit is supplied from the electric signal input point 45a 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 electromagnetically coupled to an interlayer B different from the interlayer A where the resonance electrodes 30a, 30b, and 30c are disposed so as to face the resonance electrode 30b at the output stage as a whole. It is disposed and faces 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-shaped output coupling electrode 40b is connected to the output terminal electrode 60b by the fifth through conductor 53b, and the connection point between the output coupling electrode 40b and the fifth through conductor 53b is an electric signal output of the output coupling electrode 40b. It becomes point 45b. The electrical signal output point 45b is located at the end closer to the other end of the output stage resonance electrode 30b than the center in the length direction of the output coupling electrode 40b facing the output stage resonance electrode 30b. The opposite end is an open end. Then, an electric signal is output from the electric signal output point 45b of the output coupling electrode 40b to the external circuit via the fifth through conductor 53b and the output terminal electrode 60b. 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.

  Further, the output coupling electrode 40b is extended so that one end portion on the opposite side to the electric signal output point 45b in the length direction is opposed to the annular ground electrode 23 beyond one end of the opposed resonance electrode 30b of the output stage. Therefore, in addition to the effect of simply increasing the length, the effect of forming a capacitance with the ground is added and the electrical length becomes very long. The resonance frequency when operating as a resonator is lowered. As a result, an attenuation pole due to half-wave resonance of the output coupling electrode 40b can be formed on the high frequency side near the pass band, and the amount of attenuation on the high frequency side near the pass band can be increased.

  Furthermore, one end portion of the output coupling electrode 40b is extended so as to face one end of the opposing output stage resonance electrode 30b so as to face the annular ground electrode 23, and is bent along the annular ground electrode 23. Therefore, the size of the band pass filter in the length direction of the plurality of resonance electrodes 30a, 30b, 30c can be reduced compared with the case where the output coupling electrode 40b is not bent, and thus a small band pass filter can be obtained. Can do.

  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.

  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. A band-pass filter that has a flat and low-loss pass characteristic over the entire area and that has a sufficient attenuation on the high-frequency side near the pass band and can be suitably used as a UWB filter be able to.

(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 YY ′ 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 band-pass filter of the present example is opposed to one end of the output coupling electrode 40b in an interlayer C located opposite to the interlayer A with respect to the interlayer B where the output coupling electrode 40b of the multilayer body 10 is disposed. An auxiliary earth electrode 24 is provided.

  According to the bandpass filter of this example, a capacitance is formed between one end of the output coupling electrode 40b and the auxiliary earth electrode 24, and is formed between one end of the output coupling electrode 40b and the ground. Since the capacitance of the output coupling electrode 40b can be further increased, the electrical length of the output coupling electrode 40b can be further increased, and the frequency at which half-wave resonance occurs in the output coupling electrode 40b can be further reduced. . As a result, an attenuation pole due to half-wave resonance of the output coupling electrode 40b can be formed nearer the pass band on the high frequency side than the pass band, and the amount of attenuation in that portion can be increased.

  When the auxiliary earth electrode 24 is formed only in a region facing the annular earth electrode 23, the electrical characteristics due to the generation of unnecessary capacitance between the plurality of resonance electrodes 30a, 30b, 30c. Deterioration can be suppressed. Further, when the auxiliary earth electrode 24 is connected to the annular earth electrode 23 via the sixth through conductor 54 penetrating the laminated body 10, the auxiliary earth electrode 24 can be easily connected to the earth potential.

(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 the line ZZ ′ 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.

  In the band-pass filter of this example, one end of the input coupling electrode 40a and the output coupling electrode 40b is opposed to the annular ground electrode 23 beyond one end of the opposing input stage resonance electrode 30a or output stage resonance electrode 30b. It is extended so that it is bent away from each other.

  The band-pass filter of this example is arranged to have a region facing the annular ground electrode 23 and a region facing the resonant electrodes 30a, 30b, 30c in an interlayer B different from the interlayer A of the multilayer body 10, Resonant electrodes 30a, 30b, and 30c are formed by first through conductors 51a, 51b, and 51c penetrating through the dielectric layer 11 where the regions facing the resonant electrodes 30a, 30b, and 30c are located between the resonant electrodes 30a, 30b, and 30c. Auxiliary resonance electrodes 31a, 31b, 31c connected to the other end of each of the plurality of resonance electrodes 30a, 30b, 30c are arranged corresponding to each of the plurality of resonance electrodes 30a, 30b, 30c.

  Further, the band-pass filter of this example includes an auxiliary B connected to the input resonance electrode 30a among the auxiliary resonance electrodes 31a, 31b, and 31c in an interlayer B different from the interlayer A of the laminate 10 and an interlayer C different from the interlayer A. The region facing the resonance electrode 31a and the region facing the input coupling electrode 40a are arranged, and the region facing the input coupling electrode 40a penetrates the dielectric layer 11 positioned between the input coupling electrode 40a. The auxiliary input coupling electrode connected to the side closer to the other end of the resonance electrode 30a in the input stage than the center in the length direction at the portion of the input coupling electrode 40a facing the resonance electrode 30a in the input stage by the second through conductor 52a 41a and a region facing the auxiliary resonance electrode 31b connected to the output resonance electrode 30b among the plurality of auxiliary resonance electrodes 31a, 31b, 31c in an interlayer B different from the interlayer A of the laminate 10 and in an interlayer C different from the interlayer B And output coupling electrode 40 Of the output coupling electrode 40b by the 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. And an auxiliary output coupling electrode 41b connected to the side closer to the other end of the output stage resonance electrode 30b than the center in the length direction at the portion facing the output stage resonance electrode 30b.

  According to the band-pass filter of this example, one end of both the input coupling electrode 40a and the output coupling electrode 40b exceeds the one end of the opposing input stage resonance electrode 30a or output stage resonance electrode 30b, and is annularly grounded. Since the electrical length of both the input coupling electrode 40a and the output coupling electrode 40b is increased because it is extended so as to oppose the electrode 23, the 1/2 wavelength resonance of both the input coupling electrode 40a and the output coupling electrode 40b. The resonance frequency when operating as a vessel is lowered. As a result, it is possible to form both an attenuation pole due to 1/2 wavelength resonance of the input coupling electrode 40a and an attenuation pole due to 1/2 wavelength resonance of the output coupling electrode 40b on the high frequency side near the passband. The attenuation amount on the high frequency side in the vicinity can be further increased.

  Further, according to the bandpass filter of this example, the one end of the input coupling electrode 40a and the output coupling electrode 40b are bent away from each other, so that the one end of the input coupling electrode 40a and the output coupling electrode 40b are bent. Since it is possible to prevent an increase in coupling due to the electromagnetic field between the one end portion of the first and second end portions, it is possible to prevent the deterioration of the attenuation outside the passband.

  Furthermore, according to the bandpass filter of the present example, the input coupling electrode 40a is disposed in the interlayer C located on the opposite side of the interlayer A from the interlayer B where the input coupling electrode 40a and the output coupling electrode 40b of the multilayer body 10 are arranged. And an auxiliary earth electrode 24 disposed so as to face one end of the output coupling electrode 40b, and therefore between the one end of the input coupling electrode 40a and the output coupling electrode 40b and the auxiliary earth electrode 24. Since the capacitance is formed and the capacitance formed between one end of the input coupling electrode 40a and the output coupling electrode 40b and the ground can be further increased, the input coupling electrode 40a and the output coupling electrode The electrical length of 40b can be further increased, and the frequency at which half-wave resonance of the input coupling electrode 40a and the output coupling electrode 40b occurs can be further reduced. As a result, attenuation poles due to half-wave resonance of the input coupling electrode 40a and the output coupling electrode 40b are formed nearer to the pass band on the high frequency side than the pass band, and the attenuation amount of the portion can be increased. it can.

  Furthermore, according to the bandpass filter of this example, the electrical length of the input coupling electrode 40a is equal to the electrical length of the output coupling electrode 40b, and therefore an attenuation pole due to the 1/2 wavelength resonance of the input coupling electrode 40a is generated. Since the frequency and the frequency at which the attenuation pole due to the half-wave resonance of the output coupling electrode 40b is generated coincide with each other, the two attenuation poles become one. Compared to the case where the two attenuation poles are formed at different frequencies. Thus, the amount of attenuation at the frequency where the attenuation pole is formed can be increased. This makes it possible to ensure a large attenuation at a specific frequency.

  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, thereby reducing the length of the resonance electrodes 30a, 30b, 30c. 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 seventh through conductor 55a. 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. In the band-pass filter of this example, an electric signal from an external circuit is input to the input coupling electrode 40a via the input terminal electrode 60a, the seventh through conductor 55a, the auxiliary input coupling electrode 41a, and the second through conductor 52a. Since the signal is input, a connection point between the input coupling electrode 40a and the second through conductor 52a is an electric signal input point 45a of 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 end of the auxiliary output coupling electrode 41b in the length direction opposite to the side connected to the third through conductor 52b is an output terminal electrode 60b disposed on the upper surface of the multilayer body 10 by the eighth through conductor 55b. 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. In the band pass filter of this example, an electrical signal is output from the output coupling electrode 40b to the external circuit via the third through conductor 52b, the auxiliary output coupling electrode 41b, the eighth through conductor 55b, and the output terminal electrode 60b. Therefore, the connection point between the output coupling electrode 40b and the third through conductor 52b is the electrical signal output point 45b of 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.

  According to the bandpass filter of this example, it is possible to obtain a bandpass filter that is smaller and capable of widening the band compared to the bandpass filter of the example of the embodiment described above.

(Fourth example of embodiment)
FIG. 13 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 the present invention having such a configuration, a transmission signal and a reception are received using the band-pass filter 821 of the present invention in which the loss of a signal passing through the entire communication band is small. Since the signal is filtered, the attenuation of the transmission signal and the reception signal passing through the bandpass filter 821 can be reduced over the entire communication band, so that the reception sensitivity is improved and the transmission signal and the reception signal are reduced. Since the amplification degree can be reduced, power consumption in the amplifier circuit is reduced. Therefore, a 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 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 apparatus, and fired at a peak temperature of about 800 ° C. 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 band-pass filter of the third example of the above-described embodiment, an example in which the electrical lengths of the input coupling electrode 40a and the output coupling electrode 40b are equal is shown, but the electrical lengths of the input coupling electrode 40a and the output coupling electrode 40b are shown. May be different from each other. By making the electrical lengths of the input coupling electrode 40a and the output coupling electrode 40b different from each other, the frequency at which the attenuation pole due to the 1/2 wavelength resonance of the input coupling electrode 40a is generated and the attenuation pole due to the 1/2 wavelength resonance of the output coupling electrode 40b. Since both the frequency at which the signal is generated can be reduced and made different from each other, the attenuation pole due to the 1/2 wavelength resonance of the input coupling electrode 40a and the 1/2 wavelength resonance of the output coupling electrode 40b are arranged on the high frequency side near the passband. Two attenuation poles with the attenuation pole can be generated. Thereby, a large amount of attenuation can be ensured over a wide frequency range on the high frequency side near the pass band.

  In the example of the embodiment described above, 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 output terminal electrode 60b are not necessarily required, and a wiring conductor from an external circuit in the module substrate may be directly connected to input coupling electrode 40a and output coupling electrode 40b. In this case, the connection point between the input coupling electrode 40a and the output coupling electrode 40b and the wiring conductor becomes the electrical signal input point 45a of the input coupling electrode 40a and the electrical signal output point 45b of the output coupling electrode 40b.

  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, an example in which a band-pass filter is configured by electromagnetically coupling the three resonance electrodes 30a, 30b, and 30c has been described, but 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 is shown. For example, the dielectric layer 11 may be further disposed below the first ground electrode 21, or the dielectric layer 11 may be further disposed on the second ground electrode 22.

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

  The bandpass filter of the first example of the embodiment having the first structure shown in FIGS. 1 to 4 and the bandpass of the second example of the embodiment having the second structure shown in FIGS. As a filter and a comparative example, the electric characteristics of the bandpass filter having the third structure in which the shape of the output coupling electrode 40b is the same as that of the input coupling electrode 40a in the bandpass filter of the first example of the embodiment are finite elements. Calculated by simulation using the method. The calculation conditions were such that the dielectric constant of the dielectric layer 11 was 9.4. The resonant electrodes 30a, 30b, and 30c were 0.4 mm wide and 5.55 mm long, and the spacing between adjacent resonant electrodes was 0.095 mm. The input terminal electrode 60a and the output terminal electrode 60b were square with sides of 0.3 mm. The input coupling electrode 40a has a width of 0.3 mm and a length of 5.5 mm, the output coupling electrode 40b has a width of 0.3 mm, the length in the first structure and the second structure is 6.55 mm, and the length in the third structure is 5.55 mm. did. The auxiliary earth electrode 24 in the second structure has a width of 0.7 mm and a length of 0.9 mm. The thickness of the entire bandpass filter was 0.61 mm, and the interlayer A was positioned in the center in the thickness direction. The intervals between the interlayer A and the interlayer B and between the interlayer B and the interlayer C were 0.08 mm, respectively.

  FIG. 14 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) of the bandpass filter. According to the graph shown in FIG. 14, a frequency of 3.2 GHz to 4.7 GHz corresponding to about 40% in a specific band, which is much wider than a region realized by a filter using a conventional quarter wavelength resonator. A low loss characteristic with little attenuation over the entire range is obtained in all the bandpass filters of the first to third structures. In the band-pass filter of the third structure, the attenuation pole due to 1/2 resonance of the input coupling electrode 40a and the output coupling electrode 40b is formed in the vicinity of 8.5 GHz, whereas in the band-pass filter of the first structure, the output is The attenuation pole due to 1/2 resonance of the coupling electrode 40b has moved to around 7.5 GHz. In the bandpass filter of the second structure, the attenuation pole due to 1/2 resonance of the output coupling electrode 40b has moved to around 7 GHz. Thus, according to the band-pass filter of the present invention, it is possible to form attenuation poles due to 1/2 wavelength resonance of the input coupling electrode 40a and the output coupling electrode 40b at an arbitrary frequency higher than the pass band. Thus, it can be seen that the distribution of attenuation on the higher frequency side than the passband can be controlled. According to the bandpass filter of the present invention, excellent pass characteristics that are flat and low loss over the entire wide passband and sufficient attenuation on the high frequency side near the passband are obtained. The effectiveness of 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 sectional view taken along line X-X ′ in 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 sectional view taken along line Y-Y ′ 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 sectional view taken along line Z-Z ′ of FIG. 9. 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 band pass filter of this invention and a comparative example.

Explanation of symbols

10: Laminate
11: Dielectric layer
21: First ground electrode
22: Second ground electrode
23: Ring earth electrode
24: Auxiliary 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: Wireless communication module
85: Wireless communication equipment

Claims (9)

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;
The one end and the other end are arranged side by side between one layer of the laminate so that the one end is connected to the ground potential and functions as a quarter-wave resonator and electromagnetically mutually. A plurality of band-shaped resonant electrodes that are field coupled;
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;
The multi-layered resonance electrode is disposed between layers different from the one layer, and is electromagnetically coupled to a region extending over half of the resonance electrodes of the input stage among the plurality of resonance electrodes. A strip-shaped input coupling electrode having an electrical signal input point to which a signal is input; and
The electromagnetic wave coupling is opposed to a region extending over half of the resonance electrodes of the output stage among the plurality of resonance electrodes, which is disposed between layers different from the one layer of the laminate, and toward an external circuit. A band-pass filter comprising a strip-shaped output coupling electrode having an electrical signal output point from which an electrical signal is output,
The input coupling electrode is located closer to the other end of the resonance electrode of the input stage than the center in the length direction at the portion where the electrical signal input point faces the resonance electrode of the input stage.
The output coupling electrode is located closer to the other end of the output stage resonance electrode than the center in the length direction of the electrical signal output point facing the resonance electrode of the output stage,
At least one of the input coupling electrode or the output coupling electrode has a resonance electrode or the output stage of the input stage opposed to one end of the electrical signal input point or the electrical signal output point on the opposite side in the length direction. A band-pass filter extending beyond the one end of the resonance electrode so as to face the annular ground electrode.   At least one of the input coupling electrode and the output coupling electrode between layers on the opposite side of the one layer with respect to the layer where at least one of the input coupling electrode or the output coupling electrode of the laminate is disposed. The band pass filter according to claim 1, further comprising an auxiliary earth electrode disposed so as to face the one end. The one end portion of at least one of the input coupling electrode or the output coupling electrode is opposed to the annular ground electrode beyond the one end of the opposing resonance electrode of the input stage or the resonance electrode of the output stage. The band-pass filter according to claim 1 or 2, wherein the band-pass filter is extended and bent along the annular ground electrode. The one end of the input coupling electrode and the output coupling electrode is extended so as to face the annular ground electrode across the one end of the opposing resonance electrode of the input stage or the resonance electrode of the output stage. The band-pass filter according to claim 3, wherein the band-pass filter is bent along the annular ground electrode, and the input coupling electrode and the output coupling electrode have different electrical lengths. The one end of the input coupling electrode and the output coupling electrode is extended so as to face the annular ground electrode across the one end of the opposing resonance electrode of the input stage or the resonance electrode of the output stage. The band-pass filter according to claim 4, wherein the band-pass filter is bent so as to be away from each other.   The laminated 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, and the region facing the resonance electrode is connected to the resonance electrode. An auxiliary resonance electrode connected to the other end side of the resonance electrode by a first through conductor penetrating the dielectric layer positioned therebetween is disposed corresponding to each of the plurality of resonance electrodes. The bandpass filter according to any one of claims 1 to 5, wherein: A region of the plurality of auxiliary resonance electrodes facing the auxiliary resonance electrode connected to the resonance electrode of the input stage and the input coupling electrode between a layer different from the one layer of the laminate and a different layer. A region opposite to the input coupling electrode and 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 a side closer to the other end of the resonance electrode of the input stage than a center in a length direction in a portion facing the resonance electrode;
Of the plurality of auxiliary resonance electrodes, a region facing the auxiliary resonance electrode connected to the resonance electrode of the output stage and the output coupling electrode are opposed to a layer different from the one layer of the multilayer body and further different layers. A region opposite to the output coupling electrode and a third through conductor passing through the dielectric layer located between the output coupling electrode and the output coupling electrode. The band according to claim 6, further comprising: an auxiliary output coupling electrode connected to a side closer to the other end of the resonance electrode of the output stage than a center in a length direction at a portion facing the resonance electrode. Path filter.   A wireless communication module comprising the bandpass filter according to claim 1.   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. Wireless communication equipment.

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