JP4895982B2 - Filter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter device having large amount of attenuation in the outside of a broad passband. <P>SOLUTION: The filter device comprises: ground electrodes 2a/2a facing each other which sandwich a laminated 1 with dielectric layers 1a laminated; three or more but odd number of resonator electrodes 3a to 3c arranged in an interdigital shape; an input coupling electrode 4 and an output coupling electrode 5 electromagnetically coupled facing each other in a shape along the first and the last stage resonator electrodes 3a, 3c, and having an input point and an output point of an electrical signal at the opening end sides of the first and the last stage resonator electrodes 3a, 3c in plan view; and a coupling electrode 6 with its one end part electromagnetically coupled facing either the input coupling electrode 4 or the output coupling electrode 5, and with the other end part electromagnetically coupled facing the resonator electrode 3b without the input coupling electrode 4 or the output coupling electrode 5 with the one end part faced. The low loss filter device has the broad passband and has large amount of attenuation in the outside of the passband. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a filter device used in a wireless communication device such as a mobile phone, a wireless LAN (Local Area Network), a UWB (Ultra Wide Band), and other various communication devices, a wireless communication module using the filter device, and a wireless communication It relates to equipment.

  In recent years, wireless communication devices have been used in various applications such as mobile phones and wireless LANs, and the frequencies used in each wireless communication device are close to each other. In order to selectively pass only signals in the desired frequency band, and to prevent unwanted signals from being mixed in the signal band close to the low frequency side and high frequency side of the pass band so that high quality communication can be performed. A filter device having band pass characteristics having attenuation poles in the low frequency side and high frequency side attenuation bands of the pass frequency band is mounted.

  Along with the increase in information transmission capacity, wireless communication devices have secured the information transmission capacity by expanding the use bandwidth by increasing the frequency and bandwidth in the usable frequency band. Therefore, a filter device having a wide pass band and having an attenuation pole in the vicinity of the pass band (having a steep attenuation characteristic) has been demanded. In addition, a filter device in which a plurality of dielectrics and electrodes are stacked is employed in response to a demand for miniaturization and thinning of wireless communication devices.

As a conventional filter device, as shown in an exploded perspective view in FIG. 10, a plurality of dielectric sheets 11 a are laminated, joined, and integrated in a sintered chip 11. 13a and 13c and internal insertion output electrodes 14 and 15 are embedded, and a strip line type laminated dielectric in which a resonator outer conductor 12b and external input / output electrodes 14a and 15a are provided on the outer surface of the dielectric chip 11. In the body filter, the arrangement of the plurality of resonator inner conductors 13a and 13c is an interdigital type in which the short-circuited ends and the open ends of the resonator inner conductors 13a and 13c are alternated, and the adjacent resonator inner conductors 13a and 13c are arranged. One in which a short-circuit end connection pattern 16 that connects between the resonator outer conductors 12b and 12b in the vicinity of the short-circuit end is embedded is known (see, for example, Patent Document 1). According to this, by changing the position of the layer that forms the short-circuited end connection pattern 16 and the pattern shape such as the pattern width, an attenuation pole can be set at an arbitrary frequency near the passband and steep attenuation characteristics can be obtained. It can be done.
JP 11-88009 A

  In recent years, UWB, which has been attracting attention as a new communication means, realizes large-capacity data transfer using a wide frequency band over a short distance of about 10 m. For example, according to the provisions of the US FCC (Federal Communication Commission) It is planned to use a very wide frequency band of 3.1 to 10.6 GHz. And in Japan, avoiding the 5.15 GHz to 5.25 GHz used in the wireless LAN IEEE802.11.a, the low band using the band of about 3.4 GHz to 4.8 GHz and the band of about 7.25 GHz to 10.25 GHz are used. Standards divided into high bands are being drafted. For this reason, a low-band filter uses (passes) a wide band of about 3.4 GHz to 4.8 GHz, but attenuates at 5.15 GHz, which is only 0.35 GHz away, and attenuates very steeply. Characteristics are required.

  However, in the conventional filter device, only one attenuation pole can be generated on each of the low band side and the high band side from the pass band, and therefore, the filter apparatus attenuates steeply on both sides of a wide pass band such as a UWB low band. When the pole is formed, the attenuation characteristic has a jumping of the attenuation characteristic on the high frequency side and the low frequency side further than the attenuation pole. Therefore, the attenuation amount in the band used in the wireless LAN on the high frequency side of the pass band is not sufficient. There was a problem of interference with the wireless LAN.

  The present invention has been devised in view of the above-described problems, and an object of the present invention is to generate attenuation poles on a low frequency side and a high frequency side with respect to the pass band, and at a lower frequency than the pass band. It is an object of the present invention to provide a filter device that can sufficiently secure the attenuation on the high frequency side and the high frequency side, and can be used for, for example, UWB.

The filter device of the present invention is a plan view so that an electromagnetic field coupling is performed in a multilayer body in which a plurality of dielectric layers are laminated, a ground electrode disposed so as to be opposed to the multilayer body, and the multilayer body. The short-circuited end and the open end are alternately arranged side by side in an odd number of three or more resonator electrodes, and are formed between layers different from the dielectric layer in which the resonator electrodes are disposed in the stacked body. And an electric signal input point where an electric signal from an external circuit is input to the open end side of the first stage resonator electrode in a plan view while facing and electromagnetically coupling in a shape along the first stage resonator electrode And an electromagnetic coupling between the input coupling electrode and the dielectric layer disposed in a different layer from the dielectric layer in which the resonator electrode is disposed, facing each other in a shape along the resonator electrode in the final stage. And flat It has an output coupling electrode having an electrical signal output point an electrical signal is output to the open end of the resonator electrode of the final stage to the external circuit, the one and the other ends in view, the one end but the input coupling electrode or for the output coupling electrodes and the resonator electrodes of the first stage or the final stage is arranged on the opposite side, across the dielectric layer and the input coupling electrode or the output coupling electrode facing and electromagnetically coupled to the other end, said one end said resonance other than pre Symbol resonator electrodes of the first stage or the final stage the input coupling electrode or the output coupling electrodes that have opposing faces And a coupling electrode that opposes the electromagnetic coupling with the dielectric layer sandwiched therebetween, with the input coupling electrode and the output coupling electrode interposed therebetween .

  Further, in the filter device according to the aspect of the invention, in the above configuration, the connecting portion that connects the one end portion and the other end portion of the coupling electrode is more than the center in the length direction of the input coupling electrode or the output coupling electrode. It is arrange | positioned in the side away from the said electrical signal input point or the said electrical signal output point, It is characterized by the above-mentioned.

  The filter device according to the present invention is characterized in that, in the above-described configuration, the coupling electrode has two types, one that is electromagnetically coupled to the input coupling electrode and one that is coupled to the output coupling electrode. .

  Moreover, the filter device of the present invention includes an internal ground electrode formed so as to surround an odd number of the resonator electrodes in a plan view between the dielectric layers in which the resonator electrodes are arranged in each of the above configurations. It is characterized by this.

  In the filter device of the present invention, in each of the above configurations, the ground electrode is opposed to the ground electrode with the dielectric layer between the ground electrode and the resonator electrode, and the open ends of the plurality of resonator electrodes And a plurality of capacitor electrodes connected to each other.

  Further, the filter device of the present invention is characterized in that, in the above configuration, a part of the capacitive electrode is disposed so as to be electromagnetically coupled to face the internal ground electrode across the dielectric layer. Is.

  In the filter device of the present invention, in each of the above-described configurations, the capacitor electrode connected to the first-stage resonator electrode across the dielectric layer is electromagnetically coupled to be connected to the input coupling electrode. An auxiliary output coupling electrode connected to the output coupling electrode, coupled to the capacitive electrode connected to the resonator electrode at the final stage across the dielectric layer, and the auxiliary input coupling electrode connected to the output coupling electrode It is characterized by providing.

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

  A wireless communication device of the present invention includes an RF unit including the filter device 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.

According to the filter device of the present invention, an input coupling electrode having an electric signal input point on the open end side of the first-stage resonator electrode in a plan view is opposed and electromagnetically coupled in a shape along the first-stage resonator electrode. And an electric field output point at which an electric signal is output to an external circuit on the open end side of the final stage resonator electrode in a plan view. Since the output coupling electrode is provided, the coupling between the input coupling electrode and the first stage resonator electrode and the coupling between the output coupling electrode and the last stage resonator electrode are interdigital type on the broad side via a dielectric layer. Therefore, the coupling by the magnetic field and the coupling by the electric field can be added, and the electromagnetic coupling can be further strengthened, far exceeding the range that can be realized by the filter using the conventional quarter wavelength resonator. Wide communication Even bands, can be obtained without insertion loss is greatly increased, a filter apparatus having a low-loss pass characteristic flat over the entire wide pass band. Also has a one and the other ends, one end, disposed on the opposite side to the resonator electrodes of the first stage or the final stage for the input coupling electrode or the output coupling electrodes, input coupling face each other across the electrode or the output coupling electrode and the dielectric layer have been electromagnetically coupled and the other end, one end resonator of the first stage or the final stage input coupling electrode or the output coupling electrodes that have opposing faces Since the dielectric layer is sandwiched between the resonator electrodes other than the resonator electrodes and the coupling electrodes are electromagnetically coupled to face each other without interposing the input coupling electrode and the output coupling electrode, the input coupling electrode and the output coupling electrode are provided. Phase difference of 180 ° between the signals transmitted through the resonator electrodes arranged side by side and the signals transmitted through the coupling electrodes and a part of the plurality of resonator electrodes. Since they cancel each other, the high frequency side of the passband and Attenuation pole is formed on the frequency side attenuation of the high frequency side and the low frequency side of the pass band is increased. As a result, it is possible to obtain a filter device having a wide pass band, a large amount of attenuation on the high frequency side and a low frequency side, low loss, and excellent attenuation characteristics.

  Further, according to the filter device of the present invention, the connecting portion that connects the one end portion and the other end portion of the coupling electrode has an electric signal input point or electric signal from the center in the length direction of the input coupling electrode or the output coupling electrode. When arranged on the side away from the output point, on the high-frequency side of the pass band, the side closer to the pass band (lower than the attenuation pole generated when each of the input coupling electrode and the output coupling electrode resonates at half wavelength) An attenuation pole is generated on the frequency side. As a result, the attenuation on the high frequency side of the pass band becomes larger and steeper, and the filter device has a particularly excellent attenuation characteristic on the high frequency side of the pass band.

  Further, according to the filter device of the present invention, when there are two coupling electrodes, one that is electromagnetically coupled to the input coupling electrode and one that is coupled to the output coupling electrode, adjustment of the frequency at which the attenuation pole is formed by the coupling electrode Therefore, it is not necessary to extremely increase the size of the coupling electrode or extremely reduce the thickness of the dielectric layer, and the filter device can be easily formed.

  According to the filter device of the present invention, when the internal ground electrode formed so as to surround the odd number of resonator electrodes in plan view is provided between the dielectric layers where the resonator electrodes are disposed, By surrounding the periphery of the resonator electrode, leakage of electromagnetic waves generated from the resonator electrode to the periphery can be reduced. This effect is particularly useful in preventing adverse effects on other areas of the module substrate when the filter device of the present invention is formed in a partial area of the module substrate. In addition, since the internal ground electrode has electrodes connected to the ground potential on both sides in the length direction of the resonator electrode, the short-circuit ends of the resonator electrodes arranged alternately can be easily short-circuited. be able to.

  In addition, according to the filter device of the present invention, a plurality of dielectric electrodes sandwiched between the ground electrode and the resonator electrode are opposed to the ground electrode and are electrically connected to the open ends of the plurality of resonator electrodes, respectively. When the capacitive electrode is provided, the distance between the capacitive electrode and the ground electrode is shorter than the distance between the resonator electrode and the ground electrode, and thereby the coupling between the resonator electrode and the ground electrode becomes stronger and resonance occurs. Since the capacitive coupling of the resonator electrodes is strengthened, the length of each resonator electrode can be shortened, and a smaller filter device can be provided.

  Further, according to the filter device of the present invention, when a part of the capacitive electrode is disposed so as to face the internal ground electrode with the dielectric layer interposed therebetween, the internal ground electrode is disposed between the same dielectric layer as the resonator electrode. It is formed between the same dielectric layers, and when the capacitor electrode is opposed to the internal ground electrode so as to be electromagnetically coupled, the wiring length of a through conductor or the like for electrical connection between the resonator electrode and the capacitor electrode is shortened. Therefore, an unnecessary inductance due to this wiring can be reduced, and a filter device having excellent filter characteristics without secondary resonance due to the inductance of the wiring between the electrodes can be obtained.

  Further, according to the filter device of the present invention, the auxiliary input coupling electrode connected to the input coupling electrode is electromagnetically coupled opposite to the capacitor electrode connected to the first-stage resonator electrode across the dielectric layer, and When the dielectric layer is sandwiched between the capacitive electrode connected to the final-stage resonator electrode and electromagnetically coupled opposite to the capacitor electrode and connected to the output-coupled electrode, the auxiliary output-coupled electrode is connected to the first-stage resonator electrode. The electromagnetic coupling between the capacitive electrode connected to the input coupling electrode and the auxiliary input coupling electrode connected to the input coupling electrode is added to the electromagnetic coupling between the first-stage resonator electrode and the input coupling electrode. Electromagnetic field coupling between the capacitive electrode connected to the resonator electrode and the auxiliary output coupling electrode connected to the output coupling electrode is added to the electromagnetic field coupling between the final stage resonator electrode and the output coupling electrode. Between the input coupling electrode and the first-stage resonator electrode. EM coupling, and the coupling between the output coupling electrode and the final-stage resonator electrode is further strengthened, and the increase in insertion loss is further reduced even with a very wide pass bandwidth. It is possible to obtain a filter device that has a flatter and lower-loss pass characteristic over the entire band. This effect is that when the capacitor electrode is formed and the resonator electrode is shortened, the area where the input coupling electrode and the first stage resonator electrode overlap, and the area where the output coupling electrode and the last stage resonator electrode overlap, are reduced. Since the electromagnetic coupling between them becomes small, it is particularly useful in such a case, and a small and high-performance filter device can be obtained.

  According to the wireless communication module of the present invention and the wireless communication device of the present invention, the filter device of the present invention, which has a small loss of signals passing over the entire communication band, is used for filtering the transmission signal and the reception signal. Since the attenuation of the reception signal and the transmission signal passing through the apparatus 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.

  The filter device of the present invention will be described in detail below. 1 to 3 are exploded perspective views showing examples of embodiments of the filter device of the present invention. 1 to 3, 1a is a dielectric layer, 1 is a laminate formed by laminating a plurality of dielectric layers 1a, 2 is a ground electrode, 2a is an internal ground electrode, 3a to 3e are resonator electrodes, and 3a is a resonator electrode. The first-stage resonator electrode, 3c is the last-stage resonator electrode, 4 is the input coupling electrode, 5 is the output coupling electrode, 4a is the input terminal electrode, 5a is the output terminal electrode, and 6 is the coupling electrode. Moreover, the broken line has shown that there exists a through-conductor which penetrates the dielectric material layer 1a for electrically connecting the conductor layers located above and below the dielectric material layer 1a. In the following drawings, similar parts are denoted by the same reference numerals.

  In the example shown in FIGS. 1 to 3, in the filter device of the present invention, the input terminal electrode 4a is connected to the input terminal electrode 4a formed on the outer surface of the laminate 1 from the external circuit. The signal is transmitted from the electric signal input point to the input coupling electrode 4, and is mainly transmitted to the first-stage resonator electrode 3 a electromagnetically coupled to the input coupling electrode 4, and further to the final-stage resonator electrode 3 c by electromagnetic coupling. This is transmitted to the output terminal electrode 5a via the output coupling electrode 5 electromagnetically coupled to the resonator electrode 3c and functions as a filter.

As shown in the example shown in FIG. 1, the filter device of the present invention includes a laminated body 1 in which a plurality of dielectric layers 1 a are laminated, and a ground electrode 2 disposed so as to face the laminated body 1. 2 and three or more odd-numbered resonator electrodes 3a to 3c in which the short-circuited ends and the open ends are alternately arranged in a plan view so as to be electromagnetically coupled in the stacked body 1, and in the stacked body 1 Are formed in a layer different from the layer of the dielectric layer 1a where the resonator electrodes 3a to 3c are disposed, opposed to each other in a shape along the resonator electrode 3a of the first stage, and coupled to the first stage in plan view. An input coupling electrode 4 having an electric signal input point to which an electric signal is input from an external circuit on the open end side of the resonator electrode 3a, and a dielectric layer 1a in which the resonator electrodes 3a to 3c are arranged in the stacked body 1. It is formed between different layers than between 1a and An output coupling electrode having an electric signal output point at which an electric signal is output to an external circuit on the open end side of the resonator electrode 3c at the final stage in plan view, while facing and electromagnetically coupling in a shape along the resonator electrode 3c 5, has a one end and the other end, one end, the resonator electrodes 3a of the first stage or the final stage for the input coupling electrode 4 or the output coupling electrode 5 is disposed on the opposite side of the 3c opposite it has been electromagnetically coupled and the other end, the resonator electrodes 3a of the first stage or the last stage is an input coupling electrode 4 or the output coupling electrode 5 that are opposite end faces, the resonator electrodes other than 3c A dielectric layer 1a is sandwiched between 3b and a coupling electrode 6 that is opposed to the electromagnetic coupling without any input coupling electrode and output coupling electrodes 3a and 3c interposed therebetween is provided.

  According to the filter device of the present invention, because of such a configuration, the coupling between the input coupling electrode 4 and the first-stage resonator electrode 3a and the coupling between the output coupling electrode 5 and the last-stage resonator electrode 3c are as follows. Since it is coupled to the broad side via the dielectric layer 1a in an interdigital manner, the coupling by the magnetic field and the coupling by the electric field can be added to achieve stronger electromagnetic coupling, and a conventional quarter wavelength resonator is used. A filter that has a flat and low-loss pass characteristic over the entire wide passband, with no significant increase in insertion loss, even in a wide passband that far exceeds the range that could be achieved with a special filter. A device can be obtained. In addition, a signal transmitted between the input coupling electrode 4 and the output coupling electrode 5 via the side-by-side resonator electrodes 3a to 3c, and the coupling electrode 6 and the plurality of resonator electrodes via the portions 3b and 3c. A phase difference of 180 ° is generated between the signal and the transmitted signal and cancel each other, so that attenuation poles are formed on the high-frequency side and low-frequency side of the passband, and the attenuation on the high-frequency side and low-frequency side of the passband Becomes larger. As a result, it is possible to obtain a filter device having a wide pass band, a large amount of attenuation on the high frequency side and a low frequency side, low loss, and excellent attenuation characteristics.

  4 (a) to 4 (e) are plan views seen through the insulating layer 1a in which the coupling electrode 6 in the example shown in FIG. There is shown an example in which the coupling electrode 6 and the input coupling electrode 4 and the output coupling electrode 5 formed on the insulating layer 1a therebelow are overlapped. 4A to 4E, 4c is an electric signal input point, 5c is an electric signal output point, 6a is one end portion of the coupling electrode 6, 6b is a connection portion of the coupling electrode 6, and 6c is the other portion of the coupling electrode 6. It is an end.

  In the filter device of the present invention, in the configuration described above, the connection portion 6b that connects the one end portion 6a and the other end portion 6c of the coupling electrode 6 has an input coupling as shown in the example shown in FIGS. It is preferable that the electrode 4 or the output coupling electrode 5 is disposed on the side farther from the electric signal input point 4c or the electric signal output point 5c than the center in the length direction. In this way, on the high frequency side of the pass band, the attenuation pole is closer to the pass band (lower frequency side) than the attenuation pole generated when each of the input coupling electrode 4 and the output coupling electrode 5 resonates at half wavelength. Will occur. As a result, the attenuation on the high frequency side of the pass band becomes larger and steeper, and the filter device has a particularly excellent attenuation characteristic on the high frequency side of the pass band.

  Further, in the filter device of the present invention, as in the example shown in FIG. 2, in the above configuration, the coupling electrode 6 includes an electromagnetic coupling to the input coupling electrode 4 and an electromagnetic coupling to the output coupling electrode 5. Two are preferred. This facilitates the adjustment of the frequency at which the attenuation pole is formed by the coupling electrode 6. Therefore, it is necessary to extremely increase the size of the coupling electrode 6 or extremely thin the dielectric layer 1a. Therefore, the filter device can be easily formed.

  Further, as in the example shown in FIGS. 2 and 3, the filter device of the present invention has an odd number of pieces in a plan view between the dielectric layers 1 a and 1 a in which the resonator electrodes 3 a to 3 e are arranged. It is preferable to include an internal ground electrode 2a formed so as to surround the resonator electrodes 3a to 3e. As described above, the internal ground electrode 2a surrounds the periphery of the resonator electrodes 3a to 3e, whereby leakage of electromagnetic waves generated from the resonator electrodes 3a to 3e to the periphery can be reduced. This effect is particularly useful in preventing adverse effects on other areas of the module substrate when the filter device is formed in a partial area of the module substrate. Further, since the internal ground electrode 2a has electrodes connected to the ground potential on both sides in the length direction of the resonator electrodes 3a to 3e, each of the resonator electrodes 3a to 3e arranged alternately is arranged. One end can be easily short-circuited.

  5 and FIG. 6 are exploded perspective views similar to FIG. 1. In FIGS. 5 and 6, 4b is an auxiliary input coupling electrode, 5b is an auxiliary output coupling electrode, and 7a to 7c are capacitive electrodes.

  Further, in the filter device of the present invention, the ground electrode 2 is sandwiched between the ground electrode 2 and the resonator electrodes 3a to 3c with the dielectric layer 1a sandwiched between the ground electrode 2 and the resonator electrodes 3a to 3c, as in the examples shown in FIGS. It is preferable to have a plurality of capacitive electrodes 7a to 7c connected to the open ends of the plurality of resonator electrodes 3a to 3c, respectively. With such a configuration, the distance between the capacitive electrodes 7a to 7c and the ground electrode 2 is shorter than the distance between the resonator electrodes 3a to 3c and the ground electrode 2, whereby the resonator electrodes 3a to 3c and the ground electrode 2 are separated. And the capacitive coupling of the resonator electrodes 3a to 3c is strengthened, so that the length of each of the resonator electrodes 3a to 3c can be shortened, and a more compact filter device is provided. Can do.

  Further, in the filter device of the present invention, in the configuration described above, as in the example shown in FIG. 6, a part of the capacitive electrodes 7a to 7c is opposed to the internal ground electrode 2a with the dielectric layer 1a interposed therebetween and is electromagnetically coupled. It is preferable that they are arranged as described above. Thus, the internal ground electrode 2a is formed between the same dielectric layers 1a and 1a as the dielectric layers 1a and 1a on which the resonator electrodes 3a to 3c are formed, and the capacitive electrodes 7a to 7c are internally grounded. When facing the electrode 2a so as to be coupled, the capacitance electrodes 7a to 7c are electrically connected to the resonator electrodes 3a to 3c and the capacitor electrodes 7a to 7c as compared to the case where the capacitor electrodes 7a to 7c are opposed to only the ground electrode 2. Since the wiring length of the through conductor or the like for performing the general connection can be shortened, unnecessary inductance due to this wiring can be reduced, and a filter device having excellent filter characteristics free from secondary resonance due to this inductance. be able to. Further, even if the wiring lengths of through conductors and the like for electrical connection between the resonator electrodes 3a to 3c and the capacitive electrodes 7a to 7c are the same, the static electricity between the capacitive electrodes 7a to 7c and the internal ground electrode 2a is not limited. Since the capacitance is added, the capacitance between the open ends of the resonator electrodes 3a to 3c and the ground potential is further increased, and the length of the resonator electrodes 3a to 3c can be shortened. A filter device can be obtained.

  Further, as in the example shown in FIG. 6, the filter device according to the present invention has an electromagnetic field coupling facing the capacitor electrode 7a connected to the first-stage resonator electrode 3a with the dielectric layer 1a interposed therebetween, as in the example shown in FIG. The auxiliary input coupling electrode 4b connected to the input coupling electrode 4 and the capacitive electrode 7c connected to the resonator electrode 3c at the final stage across the dielectric layer 1a are electromagnetically coupled to face the output coupling electrode 5 It is preferable that the auxiliary output coupling electrode 5b connected to is provided. In this case, the electromagnetic coupling between the capacitive electrode 7a connected to the first-stage resonator electrode 3a and the auxiliary input coupling electrode 4b connected to the input coupling electrode 4 causes the first-stage resonator electrode 3a and the input to be input. It is added to the electromagnetic field coupling with the coupling electrode 4. Similarly, the electromagnetic field coupling between the capacitive coupling 7c connected to the final stage resonator electrode 3c and the auxiliary output coupling electrode 5b connected to the output coupling electrode 5 results in the output coupling between the final stage resonator electrode 3c and the output coupling electrode 5b. This is added to the electromagnetic field coupling with the electrode 5. As a result, the electromagnetic coupling between the input coupling electrode 4 and the first-stage resonator electrode 3a and the electromagnetic coupling between the output coupling electrode 5 and the last-stage resonator electrode 3c are further strengthened. Even with the passband width, it is possible to obtain a filter device having a flatter and lower-loss pass characteristic over the entire wide passband, in which the increase in insertion loss is further reduced. This effect is obtained by forming the capacitive electrodes 7a to 7c and shortening the resonator electrodes 3a to 3c, the area where the input coupling electrode 4 and the first-stage resonator electrode 3a overlap, and the output coupling electrode 5 and the last-stage resonator. Since the area where the electrode 3c overlaps is reduced and the electromagnetic coupling between them is reduced, it is particularly useful in such a case, and a small and high-performance filter device can be obtained.

  The ground electrodes 2 and 2 are arranged on the upper and lower surfaces of the multilayer body 1 on which the dielectric layers 1a are laminated, on almost the entire surface excluding the periphery of the input terminal electrode 4a and the output terminal electrode 5a, and are connected to the ground potential. ing.

  The resonator electrodes 3a to 3e may be aligned side by side in a plan view so as to be electromagnetically coupled to each other in the multilayer body 1. Usually, for example, as shown in FIG. 1, three resonator electrodes 3a to 3c are arranged between one dielectric layer 1a and 1a, but the resonator electrodes 3a and 3c are arranged as one dielectric layer 1a and 1a. The resonator electrode 3b may be disposed between the other dielectric layers 1a and 1a with one dielectric layer 1a interposed therebetween. This arrangement is preferable because there is no short circuit between adjacent resonator electrodes and the formation thereof is facilitated. However, the number of dielectric layers 1a is increased and the thickness of the filter device is increased.

  Further, the resonator electrodes 3a to 3e are arranged in a so-called interdigital type in which the short-circuited end and the open end are alternately arranged, and thereby the coupling of the resonator electrodes 3a to 3e as compared with the comb-line type arrangement. Is a strong bond. For this reason, since it is not necessary to reduce the pattern width of the resonator electrodes 3a to 3e to increase the magnetic field, the electrical resistance of the resonator electrodes 3a to 3e is reduced by increasing the pattern width of the resonator electrodes 3a to 3e. The Q value (quality factor) indicating the sharpness of the sharp resonance of the resonator can be increased. As a result, it is possible to obtain a filter device having a flat and low-loss pass characteristic over the entire wide passband, in which insertion loss does not increase greatly even in a wide passband.

  A smaller gap between the resonator electrodes 3a to 3e is preferable because strong coupling can be obtained and a pass band can be easily widened. For example, it is set to about 0.05 to 0.5 mm. In order to arrange the electrodes side by side and electromagnetically couple each other, it is preferable that the resonator electrodes 3a to 3e have an elongated strip shape.

  In the filter device of the present invention, the number of the resonator electrodes 3a to 3e is an odd number. If the number is an even number, the resonator electrodes 3a to 3e arranged side by side between the input coupling electrode 4 and the output coupling electrode 5 are arranged. Since the phase change is different compared to the case where the number of the resonator electrodes 3a to 3e whose signals are transmitted through 3e are arranged side by side is odd, there is no change in the attenuation characteristic due to the coupling electrode 6 as described above. Because.

  Further, in the examples shown in FIGS. 1, 2, 5, and 6, the filter device is formed by the three resonator electrodes 3a to 3c. In order to obtain a filter device having excellent attenuation characteristics, the filter device may be constituted by five resonator electrodes 3a to 3e as in the example shown in FIG. However, if the number of resonator electrodes is too large, the loss in the passband increases and the filter device increases in size. Therefore, the number of resonator electrodes is often about 5 or less in practice. In UWB low-band applications, three are preferable from the balance of loss and attenuation characteristics.

  The resonator electrodes 3a to 3e constitute a stripline resonator together with the upper and lower ground electrodes 2 and 2, and the short-circuited end is connected to the upper and lower ground electrodes 2 and 2 to be connected to the ground potential. Functions as a / 4 wavelength resonator. Connection of the resonator electrodes 3a to 3e and the upper and lower ground electrodes 2 and 2 is performed between the resonator electrodes 3a to 1a between the dielectric layers 1a and 1a in which the resonator electrodes 3a to 3c are formed, as in the example shown in FIG. A conductor layer for connecting the short-circuit ends of 3c is provided, and the conductor layer is connected to the through conductor (not shown), or the conductor layer is extended to the end of the dielectric layer 1a to form a dielectric layer. What is necessary is just to connect by the end surface conductor (not shown) formed in the end surface (side surface of the laminated body 1) of 1a. When the conductor layer for connecting the short-circuit ends of the resonator electrodes 3a to 3e is not provided, each of the resonator electrodes 3a to 3e may be connected to the ground electrodes 2 and 2 by a through conductor, The short-circuit ends of the electrodes 3a to 3e may be extended to the end of the dielectric layer 1a and connected to the ground electrodes 2 and 2 by an end surface conductor formed on the end surface of the dielectric layer 1a (side surface of the multilayer body 1). When connected by an end face conductor, the end face conductor can function as a shield layer that reduces leakage of electromagnetic waves generated from the resonator electrodes 3a to 3e to the surroundings. It is preferable to arrange the electrode conductors 3a to 3e in a double or more manner around the electrodes 3a to 3e and arrange the through conductors with no gaps as much as possible when viewed from the side because the function of the shield becomes more remarkable. When the conductor layer for connecting the short-circuit ends of the resonator electrodes 3 a to 3 c is provided as in the example shown in FIG. 1, the short-circuit ends of the resonator electrodes 3 a to 3 c are connected to the ground electrodes 2 and 2. Since it becomes easy, it is preferable.

  The internal ground electrode 2a is an annular one composed of a conductor layer for connecting the short-circuit ends of the resonator electrodes 3a to 3e described above, and a conductor layer formed on both sides of the array of the resonator electrodes 3a to 3e. is there. The distance between the internal ground electrode 2a and the resonator electrodes 3a to 3e affects the magnetic field generated by the resonator electrodes 3a to 3e so that the Q value of the filter device decreases and the loss of the pass band does not increase. It is sufficient that there is a distance through which the magnetic flux by the resonator electrodes 3 a to 3 e can pass, and it is preferable that the distance is larger than the distance between the resonator electrodes 3 a to 3 e and the ground electrode 2.

  Since the input coupling electrode 4 and the output coupling electrode 5 are electromagnetically coupled to the first-stage resonator electrode 3a and the final-stage resonator electrode 3c, respectively, the first-stage resonator electrode 3a and the final-stage resonator electrode 3 respectively. It is the shape along 3c. As described above, the resonator electrodes 3a to 3e are preferably formed in an elongated band shape, and therefore, the shapes of the input coupling electrode 4 and the output coupling electrode 5 are also preferably formed in an elongated band shape.

  In the example shown in FIGS. 1, 3 and 5, the input coupling electrode 4 and the output coupling electrode 5 are both the same dielectric layer on the upper side with the dielectric layer 1a interposed between the resonator electrodes 3a to 3e. Although arranged between 1a and 1a, as in the example shown in FIGS. 2 and 6, the dielectric layers 1a are disposed between the upper and lower dielectric layers 1a and 1a with respect to the resonators 3a to 3e. May be.

  Further, regarding the arrangement of the input coupling electrode 4 and the output coupling electrode 5 in plan view, the input coupling electrode 4 and the output coupling electrode 5 are internally grounded as in the examples shown in FIGS. 4A and 4D. If they overlap with the electrode 2a in plan view, unnecessary stray capacitance generated between them will increase, so the examples shown in FIGS. 4B, 4C, and 4E As described above, the input coupling electrode 4 and the output coupling electrode 5 are preferably arranged so as not to overlap the internal ground electrode 2a in plan view.

  The input coupling electrode 4 and the output coupling electrode 5 are connected to the input terminal electrode 4a and the output terminal electrode 5a formed on the outer surface of the multilayer body 1, respectively. In the examples shown in FIGS. 1 to 6, the input terminal electrode 4 a and the output terminal electrode 5 a formed on the upper surface and the lower surface of the multilayer body 1 are connected by through conductors, but the end surface conductor formed on the side surface of the multilayer body 1. You may connect by. Further, the input terminal electrode 4 a and the output terminal electrode 5 a formed on the side surface of the multilayer body 1 may be connected by a conductor layer drawn from the input coupling electrode 4 and the output coupling electrode 5. In order to suppress the generation of unnecessary stray capacitance, it is preferable to connect the input terminal electrode 4a and the output terminal electrode 5a formed on the upper and lower surfaces of the multilayer body 1 with through conductors.

  The coupling electrode 6 includes one end 6a that is electromagnetically coupled to the input coupling electrode 4 or the output coupling electrode 5, and a resonator that is not opposed to the input coupling electrode 4 or the output coupling electrode 5 that is opposed to the one end 6a. The shape is constituted by the other end portion 6c that is electromagnetically coupled to face the electrode 3b, and a connection portion 6b that connects them. In the example shown in FIG. 1, the one end 6a, the other end 6c, and the connecting portion of the coupling electrode 6 are formed between the same insulating layers 1a and 1a. However, as in the example shown in FIG. 6, one end 6a and the other end 6c may be formed between different insulating layers 1a and 1a and connected by connecting portions such as through conductors. When the one end portion 6a and the other end portion 6c are formed between the same insulating layers 1a and 1a, the entire coupling electrode 6 can be formed simultaneously by printing or the like, which is easy to form. When the part 6a and the other end part 6c are formed between different insulating layers 1a and 1a, the distance between the one end part 6a or the other end part 6c and the facing electrode can be changed, and the amount of coupling between them Can be adjusted.

  The one end 6a and the other end 6c of the coupling electrode 6 have a shape along the input coupling electrode 4 or the output coupling electrode 5 and the resonator electrode 3b facing each other, for example, a rectangular shape as in the example shown in FIG. What is necessary is just to adjust the width | variety, length, etc. according to the required amount of coupling | bonding.

  The connecting portion 6b that connects the one end portion 6a having the shape along the input coupling electrode 4 or the output coupling electrode 5 and the other end portion 6c having the shape along the resonator electrode 3b has a resistance as short as possible. Since it is preferable that the component is small, it may have a rectangular shape extending in a direction perpendicular to the length direction of the input coupling electrode 4 and the output coupling electrode 5 or the resonator electrode 3b in plan view.

  The shape of the coupling electrode 6 is such that one end 6a and the other end 6c are arranged in parallel and shifted in the length direction as in the example shown in FIGS. 4 (a) and 4 (b). One end 6a and the other end 6c are arranged in parallel and connected to each other, as in the crank shape connected at the connecting portion 6b or the example shown in FIGS. 4C and 4D. The U-shaped (U-shaped) connected at the portion 6b and the one end 6a and the other end 6c are arranged in parallel as in the example shown in FIG. There is no particular limitation such as an H-type connected by the connecting portion 6b.

  As described above, the connecting portion 6b of the coupling electrode 6 is disposed on the side farther from the electrical signal input point 4c or the electrical signal output point 5c than the center of the input coupling electrode 4 or the output coupling electrode 5 in the length direction. It is preferable that 4 (a) to 4 (e), the alternate long and short dash line indicates the length direction of the input coupling electrode 4 facing one end 6a, as indicated by symbols in FIGS. 4 (a) to 4 (e). The connecting portion 6b is disposed on the side farther from the electric signal input point 4c than the center line. By doing so, an attenuation pole due to the coupling electrode 6 can be generated at a position closer to the pass band on the higher frequency side than the pass band, and thus is particularly suitable for a filter device that requires a steeper attenuation characteristic. Thus, the center in the length direction of the input coupling electrode 4 or the output coupling electrode 5 indicated by the center line is independent of the length or position of the input coupling electrode 4 or the output coupling electrode 5. 5 in the middle of the length direction.

  In the example shown in FIG. 1, the coupling electrode 6 has one end 6a facing the input coupling electrode 4 and the other end 6c facing the two-stage resonator electrode 3b, but the one end 6a is the output coupling electrode. 5, and the input coupling electrode 4 and the output coupling electrode 5 may be placed up and down with the dielectric layer 1 a sandwiched between the resonators 3 a to 3 c as in the examples shown in FIGS. 2 and 6. When arranged between the separate dielectric layers 1a and 1a, the other end 6c of the coupling electrode 6 may be opposed to the resonator electrode 3c at the final stage. Similarly, when the five-stage resonator electrodes 3a to 3e are provided as in the example shown in FIG. 3, when the one end portion 6a is opposed to the input coupling electrode 4, the other end portion 6c has two stages. You may couple | bond with any of the resonance electrodes 3b-3e of the last stage. However, as the resonance electrodes 3b to 3e opposed to the other end 6c become farther from the first-stage resonator electrode 3a, the coupling electrode 6 and the plurality of resonator electrodes 3b are interposed between the input coupling electrode 4 and the output coupling electrode 5. The signal transmitted through a part of ˜3e increases and the signal transmitted through the side-by-side resonator electrodes 3a-3e decreases, so that the attenuation characteristic on the higher frequency side than the pass band tends to be lowered. is there. Therefore, the other end portion 6c of the coupling electrode 6 is located closer to the first-stage resonator electrode 3a or the last-stage resonator electrode 3c opposed to the input coupling electrode 4 or the output coupling electrode 5 opposed to the one-end portion 6a. , 3e.

  The other end 6c of the coupling electrode 6 may be opposed to a plurality of resonator electrodes 3a to 3e as long as the input coupling electrode 4 or the output coupling electrode 5 is not opposed to the one end 6a. However, as described above, the resonator electrodes 3a to 3e that are further away from the first-stage resonator electrode 3a or the last-stage resonator electrode 3c that the input coupling electrode 4 or the output coupling electrode 5 that the one end 6a faces are opposed to each other. Since it is affected by the electromagnetic field coupling facing each other, it becomes meaningless.

  When there are two coupling electrodes 6 that are electromagnetically coupled to the input coupling electrode 4 and those that are coupled to the output coupling electrode 5, the input coupling electrode 4 and the output coupling are coupled as shown in FIGS. 2 and 6. It is preferable that the electrode 5 is disposed between the upper and lower dielectric layers 1a and 1a with the dielectric layer 1a interposed between the resonators 3a to 3c and the distance between the two coupling electrodes 6 and 6 is increased. As shown in FIG. 5, two coupling electrodes 6 and 6 are arranged between the same dielectric layers 1a and 1a with the dielectric layer 1a interposed between the three-stage resonator electrodes 3a to 3c. Then, the distance between the two coupling electrodes 6 and 6 is short, the two coupling electrodes 6 and 6 are electromagnetically coupled, and the signal input to the input coupling electrode 4 is output via the coupling electrode 6 to the output coupling electrode. This is because the attenuation characteristic on the higher frequency side than the pass band is reduced. For the same reason, if one end 6a and 6a of the two coupling electrodes 6 and 6 are connected to each other, for example, one other end 6c is shared by the two coupling electrodes 6 and 6, the coupling electrode 6 is obtained. It will not work.

  The capacitive electrodes 7a to 7c and the resonator electrodes 3a to 3e are preferably arranged so that the overlap in plan view is as small as possible. When the capacitive electrodes 7a to 7c and the resonator electrodes 3a to 3e overlap in plan view, the coupling between the resonator electrodes 3a to 3e and the ground electrode 2 or the internal ground electrode 2a is reduced by the overlapped area. For example, when the capacitive electrode 7a connected to the first-stage resonator electrode 3a and the other resonator electrodes 3b to 3e overlap in plan view, the first-stage resonator electrode 3a and the other resonator electrodes 3b to 3e This is because the amount of coupling changes. For this reason, the capacitive electrodes 7a to 7c are formed in an elongated shape such as a rectangle or an ellipse, and the open ends of the resonator electrodes 3a to 3e and one ends of the capacitive electrodes 7a to 7c are connected by through conductors. The other ends of the electrodes 7a to 7c may be oriented in the direction of extending the open ends of the resonator electrodes 3a to 3e. As in the examples shown in FIGS. 5 and 6, the width of the portion overlapping the resonator electrodes 3a to 3c of the capacitive electrodes 7a to 7c in plan view is narrow, and the width of the portion overlapping the ground electrode 2 and the internal ground electrode 2a is wide. For example, a convex shape is preferable because the above-described problems do not occur and even the short capacitive electrodes 7a to 7c can easily be coupled to the ground electrode 2 and the internal ground electrode 2a.

  Further, in the example shown in FIG. 5, the capacitive electrodes 7 a to 7 c are respectively provided only one below the resonator electrodes 3 a to 3 c with the dielectric layer 1 a interposed therebetween. In the example shown in FIG. One is provided above or below the resonator electrodes 3a to 3c with the dielectric layer 1a interposed therebetween, but only above the resonator electrodes 3a to 3c with the dielectric layer 1a interposed therebetween. Alternatively, one each may be provided above and below. When the capacitive electrodes 7a to 7c have the above-described convex shape, the capacitive electrodes 7a to 7a are divided into upper and lower parts with the dielectric layer 1a sandwiched with respect to the resonator electrodes 3a to 3c, as in the example shown in FIG. The arrangement of 7c is preferable because the width of the portion overlapping the ground electrode 2 and the internal ground electrode 2a can be increased.

  The auxiliary input coupling electrode 4b and the auxiliary output coupling electrode 5b are formed such that when the internal ground electrode 2a is formed and the capacitive electrodes 7a to 7c are mainly coupled to the internal ground electrode 2a, the capacitive electrodes 7a to 7c and the ground electrodes 2 and 2 are connected. What is necessary is just to form between. In the case where the internal ground electrode 2a is not formed or is mainly coupled to the ground electrode 2 even though the internal ground electrode 2a is formed, the capacitor electrode 7a is disposed at the position where the auxiliary input coupling electrode 4b in the example shown in FIG. 6 is disposed, for example. The auxiliary input coupling electrode 4b may be disposed on the open end side of the first-stage resonator electrode 3a of the input coupling electrode 4 and connected to the input coupling electrode 4 by a connection conductor layer. This connection conductor layer is prevented from being short-circuited with the through conductor connecting the capacitor electrode 7a and the first-stage resonator electrode 3a. The auxiliary output coupling electrode 5b may be similarly formed.

  The auxiliary input coupling electrode 4b and the auxiliary output coupling electrode 5b are similar to the opposing capacitive electrodes 7a and 7c and are made slightly smaller so that the auxiliary input coupling electrode 4b and the auxiliary output coupling electrode 5b are coupled to the capacitive coupling electrodes 7a and 7c. By arranging the auxiliary input coupling electrode 4b and the auxiliary output coupling electrode 5b between the ground electrode 2a and the capacitive coupling electrodes 7a and 7c, electromagnetic waves between the capacitive coupling electrodes 7a and 7c and the ground electrode 2 and the internal ground electrode 2a are provided. It is possible to prevent the field coupling from greatly decreasing.

  When the auxiliary input coupling electrode 4b and the auxiliary output coupling electrode 5b are arranged between the ground electrode 2 and the capacitive electrodes 7a and 7c as in the example shown in FIG. 6, the auxiliary input coupling electrode 4b and the capacitive electrode The electromagnetic field coupling between the auxiliary input coupling electrode 4b and the auxiliary output coupling electrode 5b and the ground electrodes 2 and 2 is relatively enhanced by strengthening the electromagnetic coupling between the auxiliary output coupling electrode 5b and the capacitive electrode 7c. Therefore, the dielectric between the auxiliary input coupling electrode 4b and the capacitive electrode 7a is larger than the thickness of the dielectric layer 1a between the auxiliary input coupling electrode 4b and the auxiliary input coupling electrode 4b and the ground electrodes 2 and 2. It is preferable to reduce the thickness of the dielectric layer 1a between the layer 1a and the auxiliary input coupling electrode 4b and the capacitive electrode 7a. In addition, since the electromagnetic coupling between the ground electrodes 2 and 2 and the capacitive electrodes 7a and 7c is weakened, the dielectric layer 1a between them is used to strengthen the electromagnetic coupling between the capacitive electrodes 7a and 7c and the internal ground electrode 2a. , 1a is preferably made thin so that this electromagnetic coupling is dominant.

As the dielectric layer 1a, for example, alumina, mullite, aluminum nitride, BaO—TiO ₂ series, CaO—TiO ₂ series, MgO—TiO ₂ series, ceramic materials such as glass ceramics, or tetrafluoroethylene resin (polytetra PTFE), tetrafluoroethylene-ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer resin; ETFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perfluteroalkyl vinyl ether) Fluorine resin such as copolymer resin (PFA), glass epoxy resin, and organic resin material such as polyimide are used. The shape and dimensions (thickness, width, length) of the dielectric layer 1a made of these materials are set according to the frequency used, the application, and the like. In the case of a ceramic material, low-temperature fired ceramics that can be fired simultaneously with a conductor material made of a low-resistance metal such as Au, Ag, or Cu that can transmit a higher frequency signal is preferable.

  Ground electrode 2, internal ground electrode 2a, resonator electrodes 3a-3e, input coupling electrode 4, output coupling electrode 5, input terminal electrode 4a, output terminal electrode 5a, auxiliary input coupling electrode 4b, auxiliary output coupling electrode 5b, coupling electrode 6, when the dielectric layer 1a is made of a ceramic material, the capacitor electrodes 7a to 7c are formed of a metallized layer containing a metal such as W, Mo, Mo—Mn, Au, Ag, or Cu as a main component. When the dielectric layer 1a is made of a resin material, a metal layer formed by a thick film printing method, various thin film forming methods, a plating method or a foil transfer method, or a plating layer on such a metal layer is formed. For example, Cu layer, Cr—Cu alloy layer, Cr—Cu alloy layer with Ni plating layer and Au plating layer deposited, TaN layer with Ni—Cr alloy layer and Au plating layer Examples thereof include those deposited, those obtained by depositing a Pt layer and an Au plating layer on a Ti layer, and those obtained by depositing a Pt layer and an Au plating layer on a Ni—Cr alloy layer. The thickness and width are set according to the frequency and application of the transmitted high-frequency signal.

  Ground electrode 2, internal ground electrode 2a, resonator electrodes 3a-3e, input coupling electrode 4, output coupling electrode 5, input terminal electrode 4a, output terminal electrode 5a, auxiliary input coupling electrode 4b, auxiliary output coupling electrode 5b, coupling electrode 6, formation of the capacitance electrodes 7a to 7c may be performed by a conventionally known method. For example, when the dielectric layer 1a is made of glass ceramics, first, glass ceramic green sheets to be the dielectric layers 1a are prepared, and a conductive paste such as Ag is formed on the green sheets by a screen printing method in a predetermined shape. Grounded electrode 2, internal ground electrode 2a, resonator electrodes 3a-3e, input coupling electrode 4, output coupling electrode 5, input terminal electrode 4a, output terminal electrode 5a, auxiliary input coupling electrode 4b, auxiliary output coupling electrode 5b, the coupling electrode 6, and the electrode patterns of the capacitive electrodes 7a to 7c are formed. Next, a green body with these electrode patterns formed thereon is stacked and pressure-bonded, for example, to produce a laminate, and this laminate is formed by firing at 850 to 1000 ° C. Thereafter, a plating film such as Ni plating or Au plating is formed on the conductor layer exposed on the outer surface. If the dielectric layer 1a is made of an organic resin material, for example, the ground electrode 2, the internal ground electrode 2a, the resonator electrodes 3a to 3e, the input coupling electrode 4, the output coupling electrode 5, and the input terminal electrode on the organic resin sheet 4a, the output terminal electrode 5a, the auxiliary input coupling electrode 4b, the auxiliary output coupling electrode 5b, the coupling electrode 6, the Cu foil processed into each electrode pattern shape of the capacitive electrodes 7a to 7c, and the organic resin to which the Cu foil is transferred It is formed by laminating sheets and bonding them with an adhesive.

  The connection conductor that connects the ground electrode 2 and the short-circuit ends of the resonator electrodes 3a to 3e is formed on the through conductor formed in the dielectric layer 1a located between them, or on the end face of the dielectric layer 1a. By forming it in the form of an end face conductor, the degree of freedom in designing the filter device formed inside the laminated dielectric layers 1a is improved, and a more compact and high-performance filter device can be obtained.

  When the dielectric layer 1a is made of ceramics such as glass ceramics, the through conductors and side conductors serving as connection conductors are, for example, the ground electrode 2 and the internal ground electrode 2a in the above-described manufacturing method. , Resonator electrodes 3a to 3e, input coupling electrode 4, output coupling electrode 5, input terminal electrode 4a, output terminal electrode 5a, auxiliary input coupling electrode 4b, auxiliary output coupling electrode 5b, coupling electrode 6, and capacitive electrodes 7a to 7c. Before forming each electrode pattern, it can be formed by filling a similar conductive paste into a through-hole formed in advance in a green sheet by die processing or laser processing by a printing method or the like. The end face conductor is formed by, for example, forming a green sheet laminate in which the short-circuit ends of the electrode patterns of the resonator electrodes 3a to 3e are exposed on the end face, and then printing the same conductor paste on the side surface of the green sheet laminate. Can be formed. Further, the end face conductor is formed so that a through hole having a width about the width of the resonator electrodes 3a to 3e is formed in the green sheet, and a short-circuit end of the electrode pattern of the resonator electrodes 3a to 3e is in contact with the through hole. Thereafter, the conductive paste can be printed on the inner surface of the through hole before or after the green sheet is laminated, or can be formed by filling the through hole and cutting at the portion of the through hole. Similarly, when the dielectric layer 1a is made of a resin-based material, an organic resin sheet is used instead of the green sheet, and a through conductor is formed in the through hole by printing or plating a conductor paste, or a side conductor is formed by a thin film method or the like. May be formed. In order to expose the short-circuit ends of the electrode patterns of the resonator electrodes 3a to 3e on the side surfaces of the laminate, the short-circuit ends of the electrode patterns of the resonator electrodes 3a to 3e are located at the end of the green sheet (or organic resin sheet). Or after laminating green sheets (organic resin sheets) on which the electrode patterns of the resonator electrodes 3a to 3e are formed, the short circuit ends of the electrode patterns of the resonator electrodes 3a to 3e are laminated so as to be exposed on the side surfaces. Just cut your body.

  In order to obtain desired filter characteristics with such a filter device, the thickness of the dielectric layer 1a, the length and width of the resonator electrodes 3a to 3e, the distance between the resonators, the input coupling electrode 4 and the output coupling electrode 5 The length and width, the length and width of the one end portion 6a and the other end portion 6c of the coupling electrode 6, and the coupling position to each electrode may be adjusted so as to obtain desired attenuation characteristics.

Specifically, a filter device as a bandpass filter having a center frequency of 3.9 GHz as used in the UWB low-band standard has a form as shown in FIG. 1, for example, as a dielectric layer 1a. Glass ceramics having a relative dielectric constant of 9.2 are used, and ground electrode 2, internal ground electrode 2a, resonator electrodes 3a to 3c, input coupling electrode 4, output coupling electrode 5, input terminal electrode 4a, output terminal electrode 5a, coupling electrode 6 It can be obtained by using Ag metallization for the through conductor. Glass ceramics having a relative dielectric constant of 9.2 include, for example, 50% by mass of crystallized glass mainly composed of PbO, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , ZnO and alkaline earth metal oxide as glass components. And what consists of 50 mass% of alumina as a filler component may be used.

  At this time, the thickness of the dielectric layer 1a is 140 μm, 80 μm, 80 μm, and 300 μm in order from the top. The ground electrodes 2 and 2 have a size of 6.9 mm × 3.3 mm, and two openings of 0.5 mm × 0.5 mm for arranging the input terminal electrode 4a and the output terminal electrode 5a are provided. The internal ground electrode 2a has an outer dimension of 6.9 mm × 3.3 mm and an inner dimension (opening dimension) of 5.9 mm × 2.9 mm. In this opening, resonator electrodes 3a, 3b and 3c having dimensions of 5.75 mm × 0.4 mm are aligned side by side at intervals of 0.095 mm and 0.095 mm, and each short-circuited end is connected to the internal ground electrode 2a to open each opening. The gap between the end and the internal ground electrode 2a is 0.15 mm, and the distance between the resonator electrodes 3a and 3c and the internal ground electrode 2a is 0.755 mm. The internal ground electrode 2a and the ground electrodes 2 and 2 on the upper and lower surfaces of the laminate 1 are connected by through conductors having a diameter of 0.1 mm arranged on the outer periphery. The input coupling electrode 4 has a dimension of 5.65 mm × 0.3 mm, and is arranged so that the center of the first-stage resonator electrode 3 a and the center of the width direction are aligned and overlaps with the open end side in a range of 5.65 mm × 0.3 mm in plan view. To do. Similarly, the output coupling electrode 7 has a dimension of 5.65 mm × 0.3 mm, and is aligned with the center of the final stage resonator electrode 3 c in the width direction and overlaps with the open end side in a range of 5.65 mm × 0.3 mm in plan view. Arrange as follows. The input terminal electrode 4a has a size of 0.2 mm × 0.2 mm, the center of the first-stage resonator electrode 3a is aligned with the center in the width direction in the center of the opening of the ground electrode 2, and 0.2 mm in plan view of the open end side. It arrange | positions so that it may overlap in the range of * 0.2mm, and it connects with the edge part by the side of the open end of the resonator electrode 3a of the first stage of the input coupling electrode 4 with the through conductor of diameter 0.1mm. Similarly, the output terminal electrode 5a has a size of 0.2 mm × 0.2 mm, and is aligned with the center in the width direction of the resonator electrode 3c at the final stage in the center of the opening provided in the ground electrode 2, and the open end side thereof. They are arranged so as to overlap in a range of 0.2 mm × 0.2 mm in plan view, and are connected to the end of the output coupling electrode 5 on the open end side of the final-stage resonator electrode 3 c by a through conductor having a diameter of 0.1 mm. The coupling electrode 6 has both one end 6a and the other end 6c having dimensions of 1.55 mm × 0.2 mm. The first stage resonator electrode 3a and the second stage resonator electrode 3b are respectively aligned with the center in the width direction so that the first stage is the same. The resonator electrode 3a and the two-stage resonator electrode 3b are arranged so as to overlap with each other in a range of 1.55 mm × 0.2 mm in a plan view at positions of 2.325 mm and 3.175 mm from the open ends of the resonator electrode 3b. A crank type in which each end portion is connected by a connecting portion 6b having a line width of 0.1 mm at a position away from the end side by 2.325 mm.

  The filter characteristics of the filter device (Example 1) of the present invention in such an example are as shown by a solid characteristic curve in the diagram of FIG. Further, the filter characteristics obtained in the filter device (comparative example) not having only the coupling electrode 6 with respect to the filter properties of the filter device of the present invention in such an example are shown by a broken-line characteristic curve in FIG. It will be something. In the diagram shown in FIG. 7, the vertical axis represents insertion loss (unit: dB), and the horizontal axis represents frequency (unit: GHz).

  Further, with respect to the filter device of the first embodiment, the one end 6a and the other end 6c of the coupling electrode 6 are set to 3.225 mm and 2.275 mm from the open ends of the first-stage resonator electrode 3a and the two-stage resonator electrode 3b. The filter of another example (Example 2) of the filter device of the present invention, which is the same except that the connection part 6b is arranged at a position and arranged at a position away from the open end of the first-stage resonator electrode 3a by 3.225 mm. The characteristics are as shown by a dotted characteristic curve in the diagram of FIG. In the diagram of FIG. 8, the solid characteristic curve indicates the filter characteristic of the first embodiment, as in FIG. Whereas the connecting portion 6b of the filter device of the first embodiment is located closer to the electrical signal input point 4c than the center in the length direction of the input coupling electrode 4, the connecting portion 6b of the filter device of the second embodiment is It is located on the side away from the electric signal input point 4c from the center of the input coupling electrode 4 in the length direction.

  From the filter characteristics shown in FIG. 7 and FIG. 8, in any filter device, it is much wider than the region realized by the filter using the conventional quarter wavelength resonator, and is about 40% in the specific band. It can be seen that low-loss characteristics are obtained over the entire very wide passband. Note that the attenuation pole of 6.6 GHz is generated when the first-stage resonance electrode 3 a and the last-stage resonance electrode 3 c are arranged close to each other, so that they are naturally weakly inductively coupled. Is considered to be caused by the half-wave resonance of each of the input coupling electrode 4 and the output coupling electrode 5. Compared with the comparative example, in the filter device of the present invention of Example 1, two in total, one on the lower frequency side (0.5 GHz) than the passband and one on the higher frequency side (9.3 GHz) than the passband. An attenuation pole is further formed, which increases the attenuation in the stop band. Further, in the filter device of the present invention of the second embodiment, as in the first embodiment, one attenuation pole is provided on the lower frequency side (0.5 GHz) than the pass band, and the above 6.6 is provided on the higher frequency side than the pass band. One attenuation pole is formed at 7.5 GHz between the attenuation pole of GHZ and the attenuation pole of 8.3 GHz, and as a result, the attenuation amount in the stop band is large and the attenuation is steeper.

  From the above, the filter device of the present invention is provided with the input coupling electrode 4 and the output coupling electrode 5 to obtain excellent pass characteristics that are flat and low loss over the entire wide passband. By providing the coupling electrode 6, it has been confirmed that the high frequency side and low frequency side attenuation amount is larger than the pass band.

  FIG. 9 is a block diagram showing a configuration example of a wireless communication module and a wireless communication device using the filter device of the present invention. In FIG. 9, 20 is a wireless communication module, 21 is a baseband unit, 21a is a baseband IC, 22 is an RF unit, 22a is a filter device, 22b is an RF-IC, 23 is an antenna, and 24 is a wireless communication device.

  The wireless communication module 20 of the present invention includes, for example, a baseband unit 21 that processes baseband signals, and an RF unit 22 that is connected to the baseband unit 21 and processes RF signals after modulation of the baseband signals and before demodulation. And.

  The RF unit 22 includes the above-described filter device 22a of the present invention, and an RF signal obtained by modulating a baseband signal or a signal other than the communication band in the received RF signal is attenuated by the filter device 22a.

  Specifically, a baseband IC 21 a is arranged in the baseband unit 21, and an RF-IC 22 b is arranged in the RF unit 22 between the filter device 22 a and the baseband unit 21. Note that another circuit may be interposed between these circuits.

  Then, by connecting the antenna 23 to the filter device 22a of the wireless communication module 20, the wireless communication device 24 of the present invention that transmits and receives RF signals is configured.

  According to the wireless communication module 20 and the wireless communication device 24 of the present invention having such a configuration, a transmission signal and a received signal are transmitted using the filter device 22a of the present invention with a small loss of a signal passing over the entire communication band. Therefore, the attenuation of the transmission signal and the reception signal passing through the filter device 22a over the entire communication band can be reduced, so that the reception sensitivity is improved and the amplification degree of the transmission signal and the reception signal is increased. Therefore, power consumption in the amplifier circuit is reduced. Therefore, it is possible to obtain the high-performance wireless communication module 20 and the wireless communication device 24 with high reception sensitivity and low power consumption.

It is a disassembled perspective view which shows typically an example of embodiment of the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment of the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment of the filter apparatus of this invention. (A)-(e) is a top view which shows an example of embodiment of the filter apparatus of this invention, respectively. It is a disassembled perspective view which shows typically an example of embodiment of the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment of the filter apparatus of this invention. It is a figure which shows the simulation result of the transmission characteristic of the filter apparatus shown in FIG. It is a figure which shows the simulation result of the transmission characteristic of the filter apparatus shown in FIG. It is a block diagram which shows the structural example of the communication apparatus module and radio | wireless communication apparatus using the filter apparatus of this invention. It is a disassembled perspective view which shows the conventional filter apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated body 1a ... Dielectric layer 2 ... Ground electrode 2a ... Internal ground electrode 3a-3e ... Resonator electrode 4 ... Input coupling electrode 5 ... Output coupling electrode 4a ... Input terminal electrode 5a ... Output terminal electrode 4b ... Auxiliary input coupling electrode 5b ... Auxiliary output coupling electrode 4c ... Electric signal input point 5c ... Electric signal output point 6 ... Coupling Electrode 6a ... One end 6b ... Connection 6c ... Other end 7a-7c ... Capacitance electrode
20 ... Wireless communication module
21 ... Baseband part
22 ... RF section
23 ・ ・ ・ Antenna
24 ... Wireless communication equipment

Claims (9)

A laminate in which a plurality of dielectric layers are laminated;
A ground electrode disposed so as to face each other with the laminate interposed therebetween;
Three or more odd-numbered resonator electrodes in which short-circuit ends and open ends are alternately arranged side by side in a plan view so as to be electromagnetically coupled in the stacked body;
The multilayer body is formed between layers different from the dielectric layer in which the resonator electrode is disposed, and is opposed to the electromagnetic field in a shape along the first-stage resonator electrode, and the first-stage in the plan view. An input coupling electrode having an electric signal input point to which an electric signal from an external circuit is input to the open end side of the resonator electrode;
The multilayer body is formed between layers different from the dielectric layer where the resonator electrode is disposed, and is opposed to the electromagnetic field in a shape along the resonator electrode in the final stage, and in the plan view, the final stage. An output coupling electrode having an electrical signal output point at which an electrical signal is output to an external circuit on the open end side of the resonator electrode;
Has one end and the other end, said one end, disposed on the opposite side to the resonator electrodes of the first stage or the final stage for the input coupling electrode or the output coupling electrodes, the input coupling electrode or on opposite sides of the dielectric layer and the output coupling electrode is electromagnetically coupled to the other end, the input coupling electrode or the output coupling electrode the end faces is not opposed that across the first stage or the dielectric layer prior to SL to the resonator electrodes other than the resonator electrode of the final stage, coupled to said input coupling electrode and the output coupling electrodes opposed to electromagnetically coupled without intervening between A filter device comprising an electrode.   A connecting portion that connects the one end portion and the other end portion of the coupling electrode is further away from the electric signal input point or the electric signal output point than a center in the length direction of the input coupling electrode or the output coupling electrode. The filter device according to claim 1, wherein the filter device is disposed on the other side.   3. The filter device according to claim 1, wherein there are two coupling electrodes, one that is electromagnetically coupled to the input coupling electrode and one that is coupled to the output coupling electrode. 4.   4. An internal ground electrode formed so as to surround an odd number of the resonator electrodes in a plan view is provided between the dielectric layers in which the resonator electrodes are arranged. The filter apparatus of crab. It has a plurality of capacitance electrodes which are opposed to the ground electrode with the dielectric layer interposed between the ground electrode and the resonator electrode, and are respectively connected to open ends of the plurality of resonator electrodes. The filter device according to any one of claims 1 to 4.   6. The filter device according to claim 5, wherein a part of the capacitive electrode is disposed so as to be electromagnetically coupled to face the internal ground electrode with the dielectric layer interposed therebetween.   Electromagnetically coupled opposite to the capacitor electrode connected to the first-stage resonator electrode across the dielectric layer, and an auxiliary input coupling electrode connected to the input coupling electrode, and the dielectric layer sandwiched between 7. An auxiliary output coupling electrode connected to the output coupling electrode by being electromagnetically coupled opposite to the capacitive electrode connected to the resonator electrode at the final stage. The filter device according to 1.   A wireless communication module comprising the filter device according to claim 1.   A radio comprising: an RF unit including the filter device according to claim 1; a baseband unit connected to the RF unit; and an antenna connected to the RF unit. Communication equipment.

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