JP5132236B2 - BANDPASS FILTER, RADIO COMMUNICATION MODULE AND RADIO COMMUNICATION DEVICE USING THE SAME - Google Patents

Description

  The present invention relates to a band-pass filter, a wireless communication module and a wireless communication device using the same, and has attenuation poles in the vicinity of both sides of a very wide passband that can be suitably used for, for example, UWB (Ultra Wide Band). The present invention relates to a band-pass filter capable of operating input / output, a high-frequency module using the same, and a wireless communication device using them.

  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 Japan and ITU-R, a low band that uses a band of about 3.1 to 4.7 GHz and a high band that uses a band of about 6 GHz to 10.6 GHz, avoiding the 5.3 GHz used in IEEE802.11.a. Standards divided into “high band” have been drafted, and the filter for low band is required to have a characteristic of sharply attenuating at 2.5 GHz and 5.3 GHz.

  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).

Also, a plurality of resonator internal conductors (¼ wavelength stripline resonators) arranged in an interdigital manner so that the short-circuited end and the open end are staggered are provided, and each resonator internal conductor is provided. A multilayer dielectric filter having a configuration in which a short-circuit end connection pattern that connects between outer resonator conductors in the vicinity of a short-circuit end of an adjacent resonator inner conductor is embedded in a layer different from the layer is known (for example, Patent Documents). 2).
“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 JP 11-88009 A

  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 about 3.1 GHz to 4.7 GHz, and the specific band is about 40%. Therefore, the filter used for this is required to have a pass bandwidth of about 40% in a specific band. In addition, it is necessary to consider the influence with W-LAN (IEEE 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 bandpass filter for UWB requiring a wide pass bandwidth corresponding to about 40% in the specific band.

  Furthermore, in the bandpass filter described in Patent Document 2, since only one attenuation pole can be generated on either the low band side or the high band side of the pass band, 2.5 GHz in the vicinity of both sides of the pass band. However, it was not usable as a low band filter for UWB that needs to be attenuated sharply at 5.3 GHz.

  Furthermore, in the RF section of wireless communication equipment such as UWB, balanced parts and unbalanced parts are mixed, and balanced-unbalanced conversion parts such as baluns are used for their connection. Therefore, a band-pass filter is required to have a balanced-unbalanced conversion function.

  The present invention has been devised in view of such problems in the prior art, and its purpose is to provide a very wide passband that can be suitably used, for example, as a UWB Low Band bandpass filter. An object of the present invention is to provide a band-pass filter having a balance-unbalance conversion function having attenuation poles on both sides, a high-frequency module and a radio communication device using the same.

  The bandpass filter of the present invention includes a laminated body in which a plurality of dielectric layers are laminated, a first ground electrode disposed on a lower surface of the laminated body, a second ground electrode disposed on an upper surface, Band-like input / output stage 1/2 wavelength resonant electrode and middle stage 1/2 wavelength resonant electrode arranged parallel to each other between the first layers of the laminate, and the input / output stage 1/2 wavelength resonant electrode and the middle stage 1 / An electromagnetic field is formed between the first layer between the two-wavelength resonance electrodes and opposite one end-side region of the input / output stage half-wavelength resonance electrode and one end-side region of the middle-stage half-wavelength resonance electrode. The ends near the one end of the input / output stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength resonant electrode are ground ends, and the opposite end is an open end. A first middle-stage quarter-wavelength resonant electrode in a band shape and the input-output stage half-wavelength The other end side region of the input / output stage 1/2 wavelength resonant electrode and the other end side region of the middle stage 1/2 wavelength resonant electrode between the first layer between the vibrating electrode and the middle stage 1/2 wavelength resonant electrode Arranged so that they are opposed to each other and electromagnetically coupled to each other, the end of the input / output stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength resonant electrode close to the other end is a ground end, and the opposite side A band-shaped second middle-quarter wavelength resonant electrode having an open end and the first middle-stage quarter-wavelength resonant electrode sandwiching the middle-stage half-wavelength resonant electrode between the first layers Opposite to the one end side region of the middle stage half-wavelength resonance electrode and disposed so as to be electromagnetically coupled to each other, and an end closer to the one end of the middle stage half-wavelength resonance electrode The first input / output stage ¼ wave in the form of a belt whose part is the ground end and whose opposite end is the open end The other end side region of the intermediate half-wavelength resonance electrode on the opposite side of the second intermediate-stage quarter-wavelength resonance electrode across the resonance electrode and the middle-stage half-wavelength resonance electrode between the first layers Is arranged so as to be opposed to each other and electromagnetically coupled to each other, and the end of the middle half-wavelength resonant electrode close to the other end is a ground end, and the opposite end is an open end The second input / output stage quarter-wavelength resonant electrode and the second input / output stage quarter-wavelength resonant electrode opposite to the first input-output stage quarter-wavelength resonant electrode A strip-shaped first coupling electrode disposed so as to be field-coupled, and a strip-shaped disposed so as to be electromagnetically coupled between the second layer so as to face the second input / output stage quarter-wave resonance electrode Between the second coupling electrode and the second layer and the one end region of the input / output stage half-wavelength resonant electrode. And a third band-like coupling electrode arranged to be electromagnetically coupled to each other, and to be electromagnetically coupled between the second layer and the other end side region of the input / output stage half-wavelength resonant electrode. A fourth coupling electrode in the form of a band disposed on the third layer, and a third layer located on the opposite side of the second layer across the first layer of the stacked body, with one end at the first layer The input / output stage 1/4 wavelength resonant electrode is grounded in the vicinity of the grounding end, and has an area to be electromagnetically coupled facing the grounding end side of the first input / output stage 1/4 wavelength resonant electrode. And the other end is grounded in the vicinity of the ground end side of the second input / output stage ¼ wavelength resonant electrode and is opposed to the ground end side of the second input / output stage ¼ wavelength resonant electrode. And the one end side region of the input / output stage ½ wavelength resonant electrode at the center. And a resonance electrode coupling conductor having a region that is electromagnetically coupled to the other end side from the center of the one end side region and from the center of the other end side region to the one end side in the other end side region. An unbalanced signal is input / output between the input / output stage half-wavelength resonant electrode and an external circuit, and is a band-pass filter between the first coupling electrode, the second coupling electrode, and the external circuit. The first input / output point at which one of the differential signals is input to or output from the first coupling electrode is the first input / output stage ¼ wavelength resonance. A second input / output point that is located opposite to the open end side from the center of the electrode and that receives or outputs the other of the differential signals at the second coupling electrode is the second input / output stage 1. / 4 above the center of the 4-wavelength resonant electrode It is characterized in that the allyl position opposed to the side.

  In the bandpass filter of the present invention, in the above configuration, the third coupling electrode and the fourth coupling electrode are integrated, and the one end side region of the input / output stage 1/2 wavelength resonant electrode and the It is a composite coupling electrode that opposes the other end side region and electromagnetically couples, and an unbalanced signal is input / output between the composite coupling electrode and an external circuit instead of the input / output stage 1/2 wavelength resonance electrode. It is characterized by that.

  Furthermore, the band-pass filter according to the present invention is divided into two parts, with the resonance electrode coupling conductor facing the central portion in the length direction of the input / output stage 1/2 wavelength resonance electrode as a boundary in each of the above configurations. Each of the divided ends is grounded.

  Furthermore, the band-pass filter of the present invention is the above-described configuration, wherein the input / output stage ½ wavelength resonant electrode, the middle stage ½ wavelength resonant electrode, and the first stage are disposed between the first layers of the multilayer body. Surrounding the middle ¼ wavelength resonant electrode, the second middle ¼ wavelength resonant electrode, the first input / output ¼ wavelength resonant electrode and the second input / output ¼ wavelength resonant electrode An annular ground electrode is formed, and the first middle-stage quarter-wave resonance electrode, the second middle-stage quarter-wave resonance electrode, the first input / output stage quarter-wave resonance electrode, and the second The ground ends of the input / output stage ¼ wavelength resonant electrodes are connected to the annular ground electrode.

  Furthermore, the band-pass filter according to the present invention, in each of the above configurations, includes a first through-conductor between the first interlayer of the multilayer body and a layer located on the same side as the second layer. The first resonance auxiliary electrode connected to the open end side of the output stage 1/4 wavelength resonant electrode and the open end side of the second input / output stage 1/4 wavelength resonant electrode connected by a through conductor A second resonance auxiliary electrode is disposed, and the first through fourth resonance auxiliary electrodes of the multilayer body, the first layer, and a layer different from the second layer are penetrated. A first coupling auxiliary electrode connected to the first input / output point of the first coupling electrode by a conductor and disposed so as to have a region facing the first resonance auxiliary electrode, and the first coupling auxiliary electrode by a through conductor The second input / output of the two coupling electrodes And a second coupling auxiliary electrode disposed so as to have a region facing the second resonance auxiliary electrode, via the first coupling auxiliary electrode and the second coupling auxiliary electrode The differential signal is input / output between the first coupling electrode and the second coupling electrode and an external circuit.

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

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

  The band-pass filter of the present invention includes a laminate in which a plurality of dielectric layers are laminated, a first ground electrode disposed on the lower surface of the laminate, a second ground electrode disposed on the upper surface, and a laminate. Band-like input / output stage 1/2 wavelength resonant electrode and middle stage 1/2 wavelength resonant electrode, input / output stage 1/2 wavelength resonant electrode and middle stage 1/2 wavelength resonant electrode arranged in parallel with each other between the first layers Between the first layer between the first and second input / output half-wave resonance electrodes and the one-end side region of the intermediate and half-wave resonance electrodes, so as to be electromagnetically coupled to each other. The end portion of the input / output stage half-wavelength resonance electrode and the middle stage half-wavelength resonance electrode close to one end is a ground end, and the opposite end is an open end. 4 wavelength resonant electrode, input / output stage 1/2 wavelength resonant electrode and middle stage 1/2 wavelength resonant electrode Between the first layer and the other end side region of the input / output stage ½ wavelength resonant electrode and the other end side region of the intermediate stage ½ wavelength resonant electrode so as to be electromagnetically coupled to each other. The band-like second middle-stage 1/4 wavelength whose end near the other end of the stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength resonant electrode is the ground end and whose opposite end is the open end. The resonance electrode and the first half-wavelength resonance electrode on the opposite side of the first half-wavelength resonance electrode across the first interlayer are opposed to one end side region of the middle-half wavelength resonance electrode. The first input / output stage in the form of a band in which the end near the one end of the middle-stage half-wavelength resonant electrode is a ground end and the opposite end is an open end. Opposite to the second middle-quarter wavelength resonant electrode with the quarter-wave resonant electrode and the middle half-wavelength resonant electrode between the first layers Are arranged so as to be electromagnetically coupled to each other in opposition to the other end side region of the intermediate half-wavelength resonance electrode, and the end portion on the side close to the other end of the intermediate half-wavelength resonance electrode is a grounding end, A band-shaped second input / output stage quarter-wavelength resonance electrode having an open end on the opposite side. With such a configuration, operation input / output becomes possible, and the first input / output stage ¼ wavelength resonant electrode and the second input / output stage ¼ wavelength resonant electrode and the middle stage 1 / The two-wavelength resonant electrodes are electromagnetically coupled to each other in an interdigital manner, and the middle half-wavelength resonant electrode, the first middle-stage quarter-wavelength resonant electrode, and the second middle-stage quarter-wavelength resonant electrode are interdigitally connected to each other. Electromagnetically coupled to the mold, and the first middle stage 1/4 wavelength resonant electrode and the second middle stage 1/4 wavelength resonant electrode and the input / output stage 1/2 wavelength resonant electrode are electromagnetically coupled to each other in an interdigital manner. Adjacent resonant electrodes are all electromagnetically coupled in an interdigital manner. As a result, the coupling by the electric field and the coupling by the magnetic field are added to produce a stronger coupling compared with the case of coupling to the comb line type. It can be made moderate to obtain a very wide pass bandwidth of about 40% in a specific band, far exceeding the range that can be realized by a filter using a quarter wavelength resonator.

  In addition, the band-pass filter of the present invention is disposed so as to be electromagnetically coupled to the second layer different from the first layer of the multilayer body so as to face the first input / output stage quarter-wavelength resonance electrode. A strip-shaped first coupling electrode, and a strip-shaped second coupling electrode disposed between the second layers so as to be electromagnetically coupled to face the second input / output stage quarter-wave resonance electrode; A band-like third coupling electrode disposed so as to be electromagnetically coupled to one end side region of the input / output stage ½ wavelength resonant electrode between the second layers and the input / output stage 1 between the second layers. / 2 band-like fourth coupling electrode arranged so as to oppose the other end side region of the two-wavelength resonance electrode and to be electromagnetically coupled. An unbalanced signal is input / output between them, and a differential signal is input / output between the first and second coupling electrodes and the external circuit. In addition, the first input / output point where one of the differential signals is input to or output from the first coupling electrode is opposed to the open end side of the center of the first input / output stage quarter wavelength resonant electrode. And the second input / output point where the other differential signal is input or output at the second coupling electrode is opposed to the open end side of the center of the second input / output stage quarter-wavelength resonance electrode. There is. Since it has such a configuration, the first coupling electrode and the second coupling electrode, the first input / output stage ¼ wavelength resonance electrode, and the second input / output stage ¼ wavelength resonance electrode, Broadside coupling and interdigital coupling. Because it is broadside coupling, it becomes stronger compared to edge coupling, and since it is interdigitally coupled, the coupling by magnetic field and coupling by electric field are added together as in the case of the resonance electrodes described above, resulting in strong coupling Therefore, there is a very strong coupling between the first coupling electrode and the second coupling electrode and the first input / output stage ¼ wavelength resonant electrode and the second input / output stage ¼ wavelength resonant electrode. Arise. 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.

  The band-pass filter of the present invention is disposed between the third layers located on the opposite side of the second layer across the first layer of the multilayer body, and has one end at the first input / output stage 1/4. There is a region which is grounded in the vicinity of the grounding end of the wavelength resonant electrode and is electromagnetically coupled to the grounding end side of the first input / output stage quarter wavelength resonant electrode, and the other end is the second input / output. A region that is grounded in the vicinity of the ground end side of the stage 1/4 wavelength resonant electrode and has an electromagnetic field coupling facing the ground end side of the second input / output stage 1/4 wavelength resonant electrode; A region that is electromagnetically coupled opposite to the other end side from the center of the one end side region in the one end side region of the input / output stage 1/2 wavelength resonance electrode and from the center of the other end side region in the other end side region. And a resonance electrode coupling conductor. Since it has such a configuration, the first input / output stage 1/4 wavelength resonant electrode, the one end region of the middle stage 1/2 wavelength resonant electrode, the first middle stage 1/4 wavelength resonant electrode, and the input / output A filter circuit constituted by four resonant electrodes in one end region of the stage 1/2 wavelength resonant electrode, the second input / output stage 1/4 wavelength resonant electrode, the other end region of the middle half wavelength resonant electrode, In both of the two filter circuits connected in parallel to each other, the filter circuit is composed of a four-stage resonance electrode in the other end region of the middle-stage quarter-wavelength resonance electrode 2 and the input / output-stage half-wavelength resonance electrode. Inductive coupling occurs between the foremost resonance electrode and the last resonance electrode of the filter circuit including four stages of resonance electrodes by the resonance electrode coupling conductor. In each filter circuit, adjacent resonant electrodes are coupled in an interdigital manner, and are strongly coupled with the addition of coupling by a magnetic field and coupling by an electric field, but as a whole, capacitive coupling is achieved. ing. For this reason, the signal transmitted by the inductive coupling via the resonant electrode coupling conductor between the first-stage resonance electrode and the last-stage resonance electrode of the filter circuit composed of four-stage resonance electrodes and the adjacent resonance A phase difference of 180 ° is generated between the signals transmitted by capacitive coupling between the electrodes, and a phenomenon of canceling each other can be caused. Since this phenomenon can occur near both sides of the passband of the bandpass filter, an attenuation pole that hardly transmits a signal near both sides of the passband can be formed in the pass characteristics of the bandpass filter.

  Further, according to the bandpass filter of the present invention, the input / output stage ½ wavelength resonance electrode, the middle stage ½ wavelength resonance electrode, the first middle stage ¼ wavelength resonance electrode, between the first layers of the multilayer body, An annular ground electrode is formed so as to surround the second middle stage 1/4 wavelength resonant electrode, the first input / output stage 1/4 wavelength resonant electrode, and the second input / output stage 1/4 wavelength resonant electrode, The ground ends of the middle stage 1/4 wavelength resonant electrode, the second middle stage 1/4 wavelength resonant electrode, the first input / output stage 1/4 wavelength resonant electrode, and the second input / output stage 1/4 wavelength resonant electrode are respectively When connected to the annular ground electrode, the first middle stage 1/4 wavelength resonant electrode, the second middle stage 1/4 wavelength resonant electrode, the first input / output stage quarter wavelength resonant electrode, and the second input / output Each of the stage 1/4 wavelength resonant electrodes can be easily grounded.

  Furthermore, the band-pass filter of the present invention is configured such that the first input / output stage quarter-wavelength resonance electrode is opened by a through conductor between layers located on the same side as the second layer with respect to the first layer of the multilayer body. A first resonance auxiliary electrode connected to the end side and a second resonance auxiliary electrode connected to the open end side of the second input / output stage quarter-wave resonance electrode by a through conductor; and Connected to the first input / output point of the first coupling electrode by a through conductor between the layer where the first or second resonance auxiliary electrode of the multilayer body is disposed, the first layer, and a layer different from the second layer, A first coupling auxiliary electrode arranged so as to have a region facing the first resonance auxiliary electrode, and a second input / output point of the second coupling electrode connected by a through conductor, Second coupling aid arranged to have opposing regions And a differential signal is input / output between the first coupling electrode and the second coupling electrode and an external circuit via the first coupling auxiliary electrode and the second coupling auxiliary electrode. Also good. When having such a configuration, the first coupling auxiliary electrode, the second coupling auxiliary electrode, the first resonance auxiliary electrode, and the second resonance auxiliary electrode are coupled by the electromagnetic field to the first coupling electrode and the second coupling auxiliary electrode. Are added to the coupling between the first coupling electrode and the first input / output stage ¼ wavelength resonant electrode and the second input / output stage ¼ wavelength resonant electrode by the electromagnetic field. As a result, the electromagnetic coupling between the first coupling electrode and the second coupling electrode, the first input / output stage ¼ wavelength resonant electrode, and the second input / output stage ¼ wavelength resonant electrode is further enhanced. Even with very wide passbands, the increase in insertion loss at frequencies located between the resonant frequencies of the respective resonant modes is further reduced, flatter and lower loss across the wide passband A bandpass filter having excellent pass characteristics can be obtained.

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. Further, since the band-pass filter has a balance-unbalance conversion function, a balance-unbalance conversion component such as a balun is not necessary. Therefore, a small 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 exploded perspective view schematically showing an example of an embodiment of a bandpass filter of the present invention.

  The bandpass filter of this example includes a laminated body in which a plurality of dielectric layers 11 are laminated, a first ground electrode 21 disposed on the lower surface of the laminated body, and a second ground electrode 22 disposed on the upper surface. The band-like input / output stage ½ wavelength resonant electrode 30f and middle stage ½ wavelength resonant electrode 30c and the input / output stage ½ wavelength resonant electrode 30f and the middle stage disposed in parallel with each other between the first layers of the laminate. Between the first layer between the half-wavelength resonance electrodes 30c, the one-end region on the one end side from the center in the length direction of the input / output stage half-wavelength resonance electrode 30f and the middle half-wavelength resonance electrode 30c. Are arranged so as to be electromagnetically coupled to each other in opposition to one end side region on the one end side from the center in the length direction of the input / output stage 1/2 wavelength resonant electrode 30f and middle stage 1/2 wavelength resonant electrode 30c. The end near the one end is a grounding end, and the opposite end is an open end. Input / output stage 1/2 wavelength resonant electrode 30f between the first middle stage 1/4 wavelength resonant electrode 30d and the first layer between the input / output stage 1/2 wavelength resonant electrode 30f and the middle stage 1/2 wavelength resonant electrode 30c. Electromagnetic field coupling between the other end region on the other end side from the center in the length direction and the other end side region on the other end side from the center in the length direction of the middle half-wavelength resonant electrode 30c. The end of the input / output stage half-wavelength resonance electrode 30f and the middle stage half-wavelength resonance electrode 30c that is closer to the other end is the ground end, and the opposite end is the open end. The middle stage 1/2 on the opposite side of the first middle stage 1/4 wavelength resonance electrode 30d across the band-shaped second middle stage quarter wavelength resonance electrode 30e and the middle stage half wavelength resonance electrode 30c of the first interlayer. Arranged so as to oppose the one end side region of the wavelength resonant electrode 30c and to be electromagnetically coupled to each other. The first input / output stage quarter-wavelength resonant electrode 30a in the form of a band whose end near the one end of the pole 30c is the ground end and the other end is the open end, and the middle stage of the first layer The second half-wavelength resonance electrode 30c is sandwiched between the second half-wavelength resonance electrode 30e and opposite to the other end side region of the middle-half-wavelength resonance electrode 30c so as to be electromagnetically coupled to each other. The band-like second input / output stage quarter-wavelength resonance electrode is disposed and has an end on the side close to the other end of the middle-stage half-wavelength resonance electrode 30c as a grounding end and an end on the opposite side as an open end. 30b and a first band-like coupling disposed so as to be electromagnetically coupled to the second interlayer different from the first interlayer of the laminate so as to face the first input / output stage quarter-wave resonance electrode 30a A strip-shaped second coupling disposed so as to be electromagnetically coupled between the electrode 40a and the second input / output stage ¼ wavelength resonant electrode 30b between the second layers. An electrode 40b, a band-like third coupling electrode 40c disposed between the second layers so as to be electromagnetically coupled to face one end side region of the input / output stage half-wavelength resonant electrode 30f, A band-shaped fourth coupling electrode 40d disposed so as to be electromagnetically coupled opposite to the other end side region of the input / output stage half-wavelength resonance electrode 30f between the layer and the first layer of the multilayer body. The first input / output stage is arranged between a third layer located on the opposite side of the second interlayer, and has one end grounded in the vicinity of the ground end of the first input / output stage quarter-wavelength resonance electrode 30a. There is a region that is electromagnetically coupled facing the ground end side of the quarter-wave resonance electrode 30a, and the other end is grounded near the ground end side of the second input / output stage quarter-wave resonance electrode 30b. In addition, the second input / output stage ¼ wavelength resonance electrode 30b has a region facing the ground end side and electromagnetically coupled, and an input / output at the center. A region that is electromagnetically coupled facing the other end side from the center of the one end side region in the one end side region of the step 1/2 wavelength resonance electrode 30f and the one end side from the center of the other end side region in the other end side region. And a resonance electrode coupling conductor 32 having the same.

  In addition, the bandpass filter of this example includes an input / output stage ½ wavelength resonant electrode 30f, a middle stage ½ wavelength resonant electrode 30c, and a first middle stage ¼ wavelength resonant electrode 30d between the first layers of the laminate. The annular ground electrode 23 is formed so as to surround the second middle stage 1/4 wavelength resonance electrode 30e, the first input / output stage 1/4 wavelength resonance electrode 30a, and the second input / output stage 1/4 wavelength resonance electrode 30b. The first middle stage 1/4 wavelength resonant electrode 30d, the second middle stage 1/4 wavelength resonant electrode 30e, the first input / output stage quarter wavelength resonant electrode 30a and the second input / output stage quarter wavelength Each ground end of the resonance electrode 30 b is connected to the annular ground electrode 23. One end of the resonance electrode coupling conductor 32 is connected to the first ground electrode 21 and the annular ground electrode 23 through the through conductor 50 in the vicinity of the ground end of the first input / output stage quarter-wave resonance electrode 30a. The other end is connected to the first ground electrode 21 and the annular ground electrode 23 through the through conductor 50 in the vicinity of the ground end side of the second input / output stage ¼ wavelength resonance electrode 30b.

  Further, in the band-pass filter of this example, the first input / output terminal electrode 60a and the second input / output terminal electrode 60b are connected to the first coupling electrode 40a and the second coupling electrode 40b through the through conductor 50, respectively. In addition, the third input / output terminal electrode 60c and the fourth input / output terminal electrode 60d are connected to the third coupling electrode 40c and the fourth coupling electrode 40d through the through conductor 50, respectively. A differential signal is transmitted between the first coupling electrode 40a and the second coupling electrode 40b and the external circuit via the first input / output terminal electrode 60a, the second input / output terminal electrode 60b, and the through conductor 50. In addition to being input / output, an unbalanced signal is input / output between the input / output stage half-wavelength resonant electrode 30f and an external circuit to function as a band-pass filter having a balanced-unbalanced conversion function.

  In the band-pass filter of this example, the first input / output point 45a connected to the through conductor 50 in the first coupling electrode 40a and to which one of the differential signals is input or output is the first input / output stage 1. A second input / output point that is located opposite the open end side of the center of the / 4 wavelength resonant electrode 30a and is connected to the through conductor 50 in the second coupling electrode 40b and the other differential signal is input or output. 45b is located at a position facing the open end side of the center of the second input / output stage ¼ wavelength resonance electrode 30b.

  According to such a bandpass filter of this example, the first input / output stage ¼ wavelength resonance electrode 30a, the second input / output stage ¼ wavelength resonance electrode 30b, the middle stage ½ wavelength resonance electrode 30c, Are electromagnetically coupled to each other in an interdigital manner, and the middle half-wavelength resonance electrode 30c, the first middle-stage quarter-wavelength resonance electrode 30d, and the second middle-stage quarter-wavelength resonance electrode 30e are interdigital-type. The first middle stage 1/4 wavelength resonant electrode 30d and the second middle stage 1/4 wavelength resonant electrode 30e and the input / output stage 1/2 wavelength resonant electrode 30f are electromagnetically coupled to each other in an interdigital manner. Therefore, all the adjacent resonance electrodes are electromagnetically coupled to the interdigital type. As a result, the coupling by the electric field and the coupling by the magnetic field are added to produce a stronger coupling compared with the case of coupling to the comb line type. It can be made moderate to obtain a very wide pass bandwidth of about 40% in a specific band, far exceeding the range that can be realized by a filter using a quarter wavelength resonator.

  In addition, according to the bandpass filter of this example, the first coupling electrode 40a and the second coupling electrode 40b, the first input / output stage ¼ wavelength resonance electrode 30a, and the second input / output stage ¼ wavelength. The resonance electrode 30b is broadside-coupled and interdigitally coupled. Because it is broadside coupling, it becomes stronger compared to edge coupling, and since it is interdigitally coupled, the coupling by magnetic field and coupling by electric field are added together as in the case of the resonance electrodes described above, resulting in strong coupling Therefore, there is an emergency between the first coupling electrode 40a and the second coupling electrode 40b and the first input / output stage ¼ wavelength resonant electrode 30a and the second input / output stage ¼ wavelength resonant electrode 30b. A strong bond occurs. 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.

  Still further, according to the bandpass filter of this example, one end region of the first input / output stage 1/4 wavelength resonant electrode 30a and the middle stage 1/2 wavelength resonant electrode 30c, the first middle stage 1/4 wavelength resonant electrode. 30d and a filter circuit composed of four resonant electrodes in one end region of the input / output stage 1/2 wavelength resonant electrode 30f, as well as a second input / output stage 1/4 wavelength resonant electrode 30b, a middle stage 1/2 wavelength resonant electrode The other end region of 30c, the second middle stage 1/4 wavelength resonance electrode 30e and the input / output stage 1/2 wavelength resonance electrode 30f are connected in parallel to each other, comprising a filter circuit composed of the four stage resonance electrodes in the other end region. In both of the two filter circuits, an inductive coupling is generated by the resonance electrode coupling conductor 32 between the front-stage resonance electrode and the last-stage resonance electrode of the filter circuit including the four-stage resonance electrodes. In each filter circuit, adjacent resonant electrodes are coupled in an interdigital manner, and are strongly coupled with the addition of coupling by a magnetic field and coupling by an electric field, but as a whole, capacitive coupling is achieved. ing. For this reason, the signal transmitted by the inductive coupling via the resonant electrode coupling conductor 32 is adjacent between the first-stage resonance electrode and the last-stage resonance electrode of the filter circuit including the four-stage resonance electrodes. A phase difference of 180 ° is generated between signals transmitted by capacitive coupling between the resonance electrodes, and a phenomenon of canceling each other can be caused. Since this phenomenon can occur near both sides of the passband of the bandpass filter, an attenuation pole that hardly transmits a signal near both sides of the passband can be formed in the pass characteristics of the bandpass filter.

  Furthermore, according to the bandpass filter of this example, the input / output stage 1/2 wavelength resonant electrode 30f, the middle stage 1/2 wavelength resonant electrode 30c, and the first middle stage 1/4 wavelength are disposed between the first layers of the multilayer body. An annular ground electrode so as to surround the resonant electrode 30d, the second middle quarter wavelength resonant electrode 30e, the first input / output stage quarter wavelength resonant electrode 30a and the second input / output stage quarter wavelength resonant electrode 30b. 23, the first input / output stage ¼ wavelength resonance electrode 30a, the second input / output stage ¼ wavelength resonance electrode 30b, the first middle stage ¼ wavelength resonance electrode 30d and the first 2 can be easily grounded by connecting the ground end of each of the middle-stage quarter-wavelength resonance electrodes 30e to the annular ground electrode 23. In addition, by electromagnetically shielding the periphery of each resonance electrode, the influence of external electromagnetic noise can be reduced, and leakage of electromagnetic waves generated from each resonance electrode can be reduced. it can. 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.

(Second example of embodiment)
FIG. 2 is an exploded perspective view schematically showing another example of the embodiment of the bandpass filter of the present invention. Note that in this example, only differences from the first example described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

  The bandpass filter of this example includes a first resonance auxiliary electrode 31a connected to the open end side of the first input / output stage quarter-wave resonance electrode 30a by a through conductor 50 between the second layers of the multilayer body. The second resonance auxiliary electrode 31b connected to the open end side of the second input / output stage ¼ wavelength resonant electrode 30b by the through conductor 50 and the input / output stage 1/2 wavelength resonant electrode 30f by the through conductor 50 The third resonance auxiliary electrode 31c connected to one end side in the one end side region and the fourth end connected to the other end side in the other end side region of the input / output stage 1/2 wavelength resonance electrode 30f by the through conductor 50. The resonance auxiliary electrode 31d is arranged. The first resonance auxiliary electrode 31a, the second resonance auxiliary electrode 31b, the third resonance auxiliary electrode 31c, and the fourth resonance auxiliary electrode 31d are disposed so as to have regions facing the annular ground electrode 23, respectively. ing.

  Further, the band pass filter of the present example is configured such that the first input / output point of the first coupling electrode 40a is provided by the through conductor 50 in the layer A located on the opposite side of the first layer across the second layer of the multilayer body. A first coupling auxiliary electrode 41a connected to 45a and disposed so as to have a region facing the first resonance auxiliary electrode 31a, and the second input / output point 45b of the second coupling electrode 40b by the through conductor 50 A second coupling auxiliary electrode 41b that is connected so as to have a region facing the second resonance auxiliary electrode 31b, and an input / output stage ½ wavelength resonance electrode in the third coupling electrode 40c by a through conductor 50 The third coupling auxiliary electrode 41c connected to the third input / output point 45c of 30f and arranged to have a region facing the third resonance auxiliary electrode 31c, and the fourth coupling electrode 40d by the through conductor 50 The fourth resonance auxiliary electrode 31d is connected to the fourth input / output point 45d. And a fourth coupling auxiliary electrode 41d arranged so as to have a region opposed to the first electrode.

  Further, in the bandpass filter of this example, the first input / output terminal electrode 60a and the second input / output terminal electrode 60b are respectively connected to the first coupling auxiliary electrode 41a and the second coupling auxiliary electrode 41b through the through conductor 50. The third input / output terminal electrode 60c and the fourth input / output terminal electrode 60d are connected to the third coupling auxiliary electrode 41c and the fourth coupling auxiliary electrode 41d through the through conductor 50, respectively. Yes. The first input / output terminal electrode 60a and the second input / output terminal electrode 60b and the first coupling auxiliary electrode 41a and the second coupling electrode 40a are connected between the first coupling electrode 40a and the second coupling electrode 40b and the external circuit. The differential signal is input / output via the coupling auxiliary electrode 41b and the through conductor 50, and an unbalanced signal is input / output between the input / output stage half-wavelength resonance electrode 30f and the external circuit. It functions as a bandpass filter with an unbalance conversion function.

  Note that the bandpass filter of this example is provided by a through conductor 50 disposed so as to face the second ground electrode 22 in an interlayer B located between the first interlayer of the multilayer body and the upper surface of the multilayer body. A resonance auxiliary electrode 31e and a resonance auxiliary electrode 31f connected to one end and the other end of the middle half-wave resonance electrode 30c, respectively, and a first middle quarter-wave resonance electrode 30d and a second middle stage by a through conductor 50. It further has a resonance auxiliary electrode 31g and a resonance auxiliary electrode 31h respectively connected to the open end side of the quarter wavelength resonance electrode 30e.

  According to the bandpass filter of this example, the first coupling auxiliary electrode 41a and the second coupling auxiliary electrode 41b are coupled to the first resonance auxiliary electrode 31a and the second resonance auxiliary electrode 31b by the electromagnetic field. This is added to the coupling of the first and second coupling electrodes 40a and 40b with the first input / output stage ¼ wavelength resonant electrode 30a and the second input / output stage ¼ wavelength resonant electrode 30b by the electromagnetic field. As a result, the first coupling electrode 40a and the second coupling electrode 40b are coupled to the first input / output stage ¼ wavelength resonance electrode 30a and the second input / output stage ¼ wavelength resonance electrode 30b by an electromagnetic field. Becomes even stronger, so even with very wide passbands, the increase in insertion loss at frequencies located between the resonant frequencies of the respective resonant modes is further reduced, flatter across the wide passband. Thus, it is possible to obtain a band-pass filter having a low-loss pass characteristic.

  Further, according to the bandpass filter of this example, the first resonance auxiliary electrode 31a, the second resonance auxiliary electrode 31b, the third resonance auxiliary electrode 31c, and the fourth resonance auxiliary electrode 31d are respectively formed into the annular ground electrode 23. The resonance auxiliary electrode 31e, the resonance auxiliary electrode 31f, the resonance auxiliary electrode 31g, and the resonance auxiliary electrode 31h are arranged so as to have a region opposite to the second ground electrode 22. Therefore, the length of the resonance electrode connected to each resonance auxiliary electrode is shortened by the capacitance generated between each resonance auxiliary electrode and the annular ground electrode 23 or the second ground electrode 22. Therefore, a smaller band pass filter can be obtained.

(Third example of embodiment)
FIG. 3 is an exploded perspective view schematically showing another example of the embodiment of the bandpass filter of the present invention. Note that in this example, only differences from the first example described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

  In the band pass filter of this example, the third coupling electrode 40c and the fourth coupling electrode 40d are integrated so as to face the one end side region and the other end side region of the input / output stage 1/2 wavelength resonance electrode 30f. The composite coupling electrode 40e is electromagnetically coupled, and an unbalanced signal is input / output between the composite coupling electrode 40e and an external circuit in place of the input / output half-wave resonant electrode 30f.

  The bandpass filter of this example having such a configuration is also a bandpass filter capable of operating input / output having attenuation poles in the vicinity of both sides of a very wide passband, like the bandpass filter of the first example described above. Function as.

  FIG. 4 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 that is connected to the baseband unit 81 and processes RF signals after modulation of the baseband signals and before demodulation. 82.

  The RF unit 82 includes the band-pass filter 821 of the present invention described above. The band-pass filter 821 attenuates signals other than the communication band in the RF signal obtained by modulating the baseband signal or the received RF signal. 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. Further, since the bandpass filter has a balanced-unbalanced conversion function, the bandpass filter 822 can be connected to the unbalanced type antenna 84 and the balanced output RF IC 822 without using a balanced-unbalanced conversion component such as a balun. It is possible to connect as it is through the network. Therefore, it is possible to obtain a small wireless communication module 80 and wireless communication device 85 with high reception sensitivity and low power consumption.

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. Further, the thickness of the dielectric layer 11 is set to about 0.01 to 0.4 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 0.03 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 third 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 one resonance electrode coupling conductor 32 is arranged is shown. However, the resonance electrode coupling conductor 32 is the center in the length direction of the input / output stage 1/2 wavelength resonance electrode 30f. It is divided into two parts with a part facing the part as a boundary, and each of the divided end parts may be grounded. The resonance electrode coupling conductor having such a structure also functions in exactly the same way as the resonance electrode coupling conductor 32 of the bandpass filter of the above-described embodiment.

  The second example of the embodiment described above shows an example in which the first to fourth resonance auxiliary electrodes 31a to 31d are arranged between the second layers in the same manner as the first to fourth coupling electrodes 40a to 40d. However, the first to fourth resonance auxiliary electrodes 31 a to 31 d and the first to fourth coupling electrodes 40 a to 40 d may be arranged between different layers of the multilayer body 10.

  Furthermore, although the example in which the first to fourth resonance auxiliary electrodes 31a to 31d are arranged so as to have a region facing the annular ground electrode 23 is shown, the first to fourth resonance auxiliary electrodes 31a to 31d are the first ones. You may arrange | position so that the 1st ground electrode 21 or the 2nd ground electrode 22 may be opposed.

  Furthermore, in the example of the above-described embodiment, the example in which the first ground electrode 21 is disposed on the lower surface of the multilayer body and the second ground electrode 22 is disposed on the upper surface of the multilayer body 10 has been described. Further, the dielectric layer 11 may be further disposed under the first ground electrode 21, and the dielectric layer 11 may be further disposed on the second ground electrode 22.

  Furthermore, the band-pass filter used for UWB has been described above as an example, but 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 electrical characteristics of the bandpass filter of the present invention having the structure shown in FIG. 2 were calculated by simulation using the 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. The shape dimensions of the first and second input / output stage quarter wavelength resonant electrodes 30a and 30b and the first and second middle quarter wavelength resonant electrodes 30d and 30e are 0.4 mm wide and long. Is 2.9 mm, the input / output stage 1/2 wavelength resonant electrode 30f and the middle stage 1/2 wavelength resonant electrode 30c have a width of 0.4 mm and a length of 5.8 mm, and the spacing between adjacent resonant electrodes is 0.13 mm. did. The first to fourth coupling electrodes 40a, 40b, 40c, and 40d have a width of 0.3 mm and a length of 2.5 mm, and the first to fourth coupling auxiliary electrodes 41a, 41b, 41c, and 41d have a width. Was 0.3 mm and the length was 1.4 mm. The first to fourth resonance auxiliary electrodes 31a, 31b, 31c, and 31d were formed by joining a rectangle having a width of 0.55 mm and a length of 0.6 mm and a rectangle having a width of 0.2 mm and a length of 0.7 mm. The resonance auxiliary electrodes 31e, 31f, 31g, and 31h are rectangular shapes having a width of 0.65 mm and a length of 0.7 mm. The outer shapes of the first and second ground electrodes 21 and 22 and the annular ground electrode 23 were 4.6 mm wide and 7.1 mm long, and the opening of the annular ground electrode 23 was 2.9 mm wide and 6 mm long. The resonance electrode coupling conductor 32 for forming the attenuation pole has a width of 0.2 mm and a length of a region where the first and second input / output stage quarter-wave resonance electrodes 30a and 30b are opposed to each other and are electromagnetically coupled. A rectangular shape with a width of 1.7 mm and a rectangular shape with a width of 0.2 mm and a length of 3.2 mm in an electromagnetic field coupling facing the input / output stage half-wavelength resonance electrode 30f, a connecting portion having a width of 0.1 mm It was set as the shape joined by. The overall shape of the bandpass filter was 4.6 mm in width, 7.1 mm in length and 0.91 mm in thickness, and the first layer was positioned in the center in the thickness direction. The distance between adjacent layers in the first to third layers and the layer A was 0.065 mm, and the distance between the layer B and the upper surface of the laminate was also 0.065 mm. The thickness of various electrodes was 0.01 mm, and the diameter of various through conductors was 0.1 mm.

  FIG. 5 is a graph showing the simulation results, and FIG. 6 is a simulation result of electrical characteristics of a comparative band-pass filter having a structure in which the resonant electrode coupling conductor 32 is removed from the band-pass filter of the present invention shown in FIG. It is a graph which shows. In each graph, the horizontal axis represents frequency, and the vertical axis represents attenuation, and shows the pass characteristic (S21) and reflection characteristic (S11) of the bandpass filter. According to the graph shown in FIG. 5, the bandpass filter according to the present invention is much wider than the area realized by the filter using the conventional quarter wavelength resonator, and has a specific band of 40% to 50%. A low-loss characteristic is obtained over the entire very wide passband. Further, when compared with the electrical characteristics of the band-pass filter of the comparative example shown in FIG. 6, it can be seen that the attenuation in the vicinity of both sides of the pass band is greatly increased by the formation of attenuation poles in the vicinity of both sides of the pass band. . From this result, it can be seen that according to the present invention, a bandpass filter having a balanced-unbalanced conversion function having attenuation poles on both sides of a very wide passband can be obtained, and the effectiveness of the present invention has been confirmed. .

It is a disassembled perspective view which shows typically an example of embodiment of the band pass filter of this invention. It is a disassembled perspective view which shows typically the other example of embodiment of the band pass filter of this invention. It is a disassembled perspective view which shows typically the further another example of embodiment of the band pass filter of this invention. 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. It is a figure which shows the simulation result of the electrical property of the band pass filter of a comparative example.

Explanation of symbols

11: Dielectric layer
21: First ground electrode
22: Second ground electrode
23: Annular ground electrode
30a: 1st input / output stage 1/4 resonant electrode
30b: Second input / output stage 1/4 resonant electrode
30c: Middle stage 1/2 wavelength resonant electrode
30d: 1st middle stage 1/4 wavelength resonant electrode
30e: Second middle-stage quarter-wave resonant electrode
30f: input / output stage 1/2 wavelength resonant electrode
31a: first resonance auxiliary electrode
31b: second resonance auxiliary electrode
31c: third resonance auxiliary electrode
31d: Fourth resonance auxiliary electrode
32: Resonant electrode coupling conductor
40a: first coupling electrode
40b: second coupling electrode
40c: third coupling electrode
40d: fourth coupling electrode
40e: Composite coupling electrode
41a: first coupling auxiliary electrode
41b: second coupling auxiliary electrode
41c: third coupling auxiliary electrode
41d: fourth coupling auxiliary electrode
45a: First input / output point
45b: Second input / output point
45c: Third input / output point
45d: Fourth input / output point
50: Through conductor
80: Wireless communication module
81: Baseband
82: RF section
84: Antenna
85: Wireless communication equipment

Claims (7)

A laminate in which a plurality of dielectric layers are laminated;
A first ground electrode disposed on the lower surface of the laminate and a second ground electrode disposed on the upper surface;
A band-like input / output stage 1/2 wavelength resonant electrode and a middle stage 1/2 wavelength resonant electrode arranged in parallel with each other between the first layers of the laminate;
One end side region of the input / output stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength between the first layer between the input / output stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength resonant electrode An end on the side close to one end of the input / output stage half-wavelength resonance electrode and the middle stage half-wavelength resonance electrode, arranged so as to be electromagnetically coupled to each other so as to face one end side region of the resonance electrode Is a grounded end, and a first middle-stage quarter-wavelength resonant electrode in the form of a strip whose opposite end is an open end;
The other end side region of the input / output stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength are disposed between the first layer between the input / output stage 1/2 wavelength resonant electrode and the middle stage 1/2 wavelength resonant electrode. An end on the side close to the other end of the input / output stage ½ wavelength resonant electrode and the intermediate stage ½ wavelength resonant electrode, disposed opposite the other end side region of the resonant electrode and electromagnetically coupled to each other Is a grounding end, and a strip-shaped second middle-quarter-wavelength resonant electrode whose opposite end is an open end;
Opposing to the one end side region of the intermediate half-wavelength resonant electrode on the opposite side of the first middle-half wavelength resonant electrode across the middle half-wavelength resonant electrode between the first layers. A first band-shaped first electrode disposed so as to be electromagnetically coupled to each other, the end of the middle half-wavelength resonant electrode close to the one end being a ground end, and the opposite end being an open end. An input / output stage 1/4 wavelength resonant electrode;
Opposite the second intermediate-stage quarter-wavelength resonance electrode across the middle-stage half-wavelength resonance electrode between the first layers, facing the other end side region of the intermediate-stage half-wavelength resonance electrode. A second band-shaped second electrode disposed so as to be electromagnetically coupled to each other, the end of the middle half-wavelength resonant electrode near the other end being a ground end, and the opposite end being an open end. An input / output stage 1/4 wavelength resonant electrode;
A strip-shaped first coupling electrode disposed so as to be electromagnetically coupled opposite to the first input / output stage quarter-wave resonance electrode between a second layer different from the first layer of the laminate. When,
A band-shaped second coupling electrode disposed between the second layers so as to be electromagnetically coupled opposite the second input / output stage ¼ wavelength resonant electrode;
A band-like third coupling electrode disposed between the second layers so as to be electromagnetically coupled opposite the one end side region of the input / output stage half-wavelength resonant electrode;
A strip-shaped fourth coupling electrode disposed between the second layers so as to be electromagnetically coupled to face the other end side region of the input / output stage half-wavelength resonant electrode;
The laminated body is disposed between a third layer located opposite to the second layer across the first layer, and one end is the ground of the first input / output stage quarter wavelength resonant electrode. The second input / output stage 1 has a region grounded in the vicinity of the end and electromagnetically coupled to the grounded end side of the first input / output stage quarter-wavelength resonant electrode. A region that is grounded in the vicinity of the ground end side of the / 4 wavelength resonant electrode and that is electromagnetically coupled to the ground end side of the second input / output stage quarter wavelength resonant electrode; The input / output stage ½ wavelength resonant electrode is located on the other end side from the center of the one end side region in the one end side region and on the one end side from the center of the other end side region in the other end side region. A band pass filter comprising a resonant electrode coupling conductor having a region for electromagnetic field coupling facing each other A filter,
An unbalanced signal is input / output between the input / output stage 1/2 wavelength resonant electrode and the external circuit, and a differential signal is input between the first coupling electrode and the second coupling electrode and the external circuit. Output,
A first input / output point at which one of the differential signals is input to or output from the first coupling electrode is opposed to the open end side of the center of the first input / output stage quarter-wavelength resonance electrode. In position
A second input / output point at which the other of the differential signals is input to or output from the second coupling electrode is opposed to the open end side from the center of the second input / output stage quarter-wavelength resonance electrode. A bandpass filter characterized by being in position.   Composite coupling in which the third coupling electrode and the fourth coupling electrode are integrated and electromagnetically coupled opposite the one end side region and the other end side region of the input / output stage half-wavelength resonance electrode 2. The band according to claim 1, wherein an unbalanced signal is input / output between the composite coupling electrode and an external circuit instead of the input / output stage ½ wavelength resonant electrode. Path filter.   The resonant electrode coupling conductor is divided into two with a portion facing the central portion in the length direction of the input / output stage ½ wavelength resonant electrode as a boundary, and each of the divided ends is grounded. The band-pass filter according to claim 1 or 2, wherein   Between the first layer of the laminate, the input / output stage 1/2 wavelength resonant electrode, the middle stage 1/2 wavelength resonant electrode, the first middle stage 1/4 wavelength resonant electrode, the second middle stage 1 / An annular ground electrode is formed to surround the four-wavelength resonant electrode, the first input / output stage quarter-wavelength resonant electrode, and the second input-output stage quarter-wavelength resonant electrode, and the first middle stage 1 / Ground ends of the four-wavelength resonant electrode, the second middle-stage quarter-wavelength resonant electrode, the first input / output stage quarter-wavelength resonant electrode, and the second input-output stage quarter-wavelength resonant electrode, The band-pass filter according to any one of claims 1 to 3, wherein the band-pass filter is connected to the annular ground electrode. Between the layers located on the same side as the second layer with respect to the first layer of the laminate,
A first resonance auxiliary electrode connected to the open end side of the first input / output stage quarter-wave resonance electrode by a through conductor;
A second resonance auxiliary electrode connected to the open end side of the second input / output stage ¼ wavelength resonance electrode by a through conductor; and
Between the layers where the first to fourth resonance auxiliary electrodes of the laminate are disposed, and between the first layer and a layer different from the second layer,
A first coupling auxiliary electrode connected to the first input / output point of the first coupling electrode by a through conductor and arranged to have a region facing the first resonance auxiliary electrode;
A second coupling auxiliary electrode connected to the second input / output point of the second coupling electrode by a through conductor and arranged to have a region facing the second resonance auxiliary electrode;
The differential signal is input / output between the first coupling electrode and the second coupling electrode and an external circuit via the first coupling auxiliary electrode and the second coupling auxiliary electrode. The band-pass filter according to any one of claims 1 to 4.   A wireless communication module comprising the bandpass filter according to any one of claims 1 to 5.   An antenna, an RF unit including the bandpass filter according to any one of claims 1 to 5 connected to the antenna, and a baseband unit connected to the RF unit. Wireless communication equipment.

Images