JP4901823B2 - Filter device, wireless communication module and wireless communication device using the same - Google Patents

Description

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

  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. 15, a short-circuit end and an open end are provided inside a dielectric chip 11 in which a large number of dielectric sheets 11 a are laminated and bonded and sintered and integrated. A plurality of resonator inner conductors 13 and inner insertion output electrodes 15b and 16b, which are arranged in an interdigital manner, are alternately arranged, and on the outer surface of the dielectric chip 11, the resonator outer conductor 12a and the outer input / output electrodes are arranged. In the stripline type multilayer dielectric filter provided with 15a and 16a, it is an interdigital type in which the short-circuit ends and the open ends of the resonator inner conductors 13a and 13d are alternated, and the adjacent resonator inner conductors 13a. A known example is one in which a short-circuit end connection pattern 14 that connects between the resonator outer conductors 12a and 12a in the vicinity of the short-circuit end 13d is embedded (see, for example, Patent Document 1). According to this, by setting the position of the layer forming the short-circuited end connection pattern 14 and the pattern shape such as the pattern width, the attenuation pole is set at an arbitrary frequency near the pass band, and a steep attenuation characteristic is 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 in a short distance of about 10 m. For example, according to US FCC (Federal Communication Commission) regulations It is planned to use a very wide frequency band of 3.1 to 10.6 GHz. In Japan, wireless LAN IEEE802.11. Dividing into a low band using a band of about 3.4 GHz to 4.8 GHz and a high band using a band of about 7.25 GHz to 10.25 GHz, avoiding 5.15 GHz to 5.25 GHz used in a. Standards have been 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. Therefore, a steep attenuation characteristic is 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 problems, and its purpose is to make it possible to generate attenuation poles more steeply on the low-frequency side and the high-frequency side than the passband, and more easily than the passband. Another object of the present invention is to provide a filter device that can sufficiently secure the attenuation amount on the low-frequency side and the high-frequency side, and can also be used for, for example, UWB.

  The filter device according to the present invention includes a laminate in which a plurality of dielectric layers are laminated, a first reference electrode disposed at a first end of the laminate, and a second end of the laminate. Are arranged side by side in a plan view so as to be electromagnetically coupled to each other in the stacked body, and each of the second reference electrodes is arranged in a short circuit end and the other end is an open end. The resonator electrode is disposed closer to the first end than the resonator electrode, and one end of the resonator electrode is opposed to the short-circuited end of the first-stage resonator electrode across the dielectric layer. A coupling electrically connected to the short-circuited end of the resonator electrode, the other end facing the short-circuited end of the resonator electrode at the final stage and electrically connected to the short-circuited end of the opposed resonator electrode An electrode and an input terminal for inputting a signal to the first-stage resonator electrode An output terminal for outputting a signal from the last-stage resonator electrode, and the coupling electrode has a branching portion that is grounded between the one end and the other end. .

  Moreover, the filter device of the present invention preferably has a ground reinforcement portion in which the coupling electrode is electrically connected to at least one of the first reference electrode and the second reference electrode in the above configuration.

  In the filter device of the present invention, in the above configuration, it is preferable that an internal reference electrode is formed so as to surround the plurality of resonator electrodes when the resonator electrodes are viewed in plan.

  In the filter device according to the present invention, the number of the resonator electrodes is four or more in the configuration described above, and the ground reinforcement portion includes a short-circuit end portion of the resonator electrode other than the resonator electrodes at the first stage and the final stage. It is preferable to be opposed and electrically connected to the short-circuit end.

  In the filter device according to the present invention, in the configuration described above, the ground reinforcing portion is branched out to the outside of the resonator electrode in a plan view between the dielectric layers in which the coupling electrodes are arranged, and is pulled out to the internal reference. It is preferably formed along the electrodes.

  The filter device according to the present invention is characterized in that, in the above configuration, the ground reinforcing portion has a reference electrode facing portion facing the first reference electrode or the internal reference electrode.

  The filter device according to the present invention may be configured such that, in each of the above configurations, the first reference electrode is opposed to the first reference electrode with the dielectric layer interposed between the first reference electrode and the resonator electrode. It is preferable to have a plurality of capacitive electrodes electrically connected to the open ends of the resonator electrodes.

  In the filter device according to the present invention, in the above configuration, when the resonator electrode is viewed in plan, an internal reference electrode is formed so as to surround the plurality of resonator electrodes, and a part of the capacitor electrode is the dielectric electrode. It is preferable to dispose the body layer so as to face the internal reference electrode.

  In the filter device of the present invention, in each of the above configurations, the input terminal has a shape along the first-stage resonator electrode, and is opposed to the first-stage resonator electrode with the dielectric layer interposed therebetween. An internal input terminal that is disposed closer to the second end than the resonator electrode and electromagnetically couples with the first-stage resonator electrode, and is formed on the outer surface of the laminate, and the first-stage the input terminal is connected to the internal input terminal. An external input terminal connected on the open end side of the resonator electrode, and the output terminal has a shape along the resonator electrode of the final stage, and the resonance of the final stage across the dielectric layer An internal output terminal that is disposed on the second end side of the resonator electrode so as to face the resonator electrode and electromagnetically couples with the final-stage resonator electrode, and is formed on the outer surface of the laminate. The final stage of the resonator electrode is connected to the internal output terminal. It is preferable that the and a connected external output terminal in Hotan side.

  Moreover, the filter device of the present invention is arranged in the above-described configuration so as to be electromagnetically coupled to one of the resonator electrodes in the stacked body other than between the resonator electrodes, one end being a short-circuited end and the other end being It is preferred to have at least one damped resonator electrode that is open-ended.

  In the filter device according to the present invention, in the above configuration, the damped resonator electrode has a shape in which the open end is branched into a plurality, and the length from the short-circuited end to each tip of the open end is different. It is preferable.

  In the filter device according to the present invention, in each of the above configurations, when the resonator electrode is a first resonator electrode, the second resonator is closer to the second end than the first resonator electrode in the stacked body. A plurality of second resonator electrodes arranged through the dielectric layer and arranged side by side in plan view so as to be electromagnetically coupled to each other, each having one end short-circuited and the other end open-ended It is preferable to further comprise.

  In the filter device of the present invention, in each of the above configurations, the input terminal has a shape along the first resonator electrode in the first stage, and the first resonator electrode in the first stage with the dielectric layer interposed therebetween. And arranged on the second end side of the first resonator electrode and on the first end side of the second resonator electrode so as to face the second resonator electrode. And an internal input terminal that is electromagnetically coupled to the first resonator electrode and the second resonator electrode in the first stage, and is formed on an outer surface of the stacked body, and the first input in the first stage is formed on the internal input terminal. An external input terminal connected on the open end side of the resonator electrode, and the output terminal has a shape along the first resonator electrode of the final stage, with the dielectric layer interposed therebetween, The first resonance so as to face the first resonator electrode and the second resonator electrode The first resonator electrode and the second resonator at the final stage are arranged closer to the second end than the electrode and closer to the first end than the second resonator electrode. An internal output terminal that is electromagnetically coupled to the electrode, and an external output terminal that is formed on the outer surface of the multilayer body and is connected to the internal output terminal on the open end side of the first resonator electrode of the final stage. It is preferable to have.

  According to another aspect of the present invention, there is provided a wireless communication module including the filter device configured as described above. According to another aspect of the present invention, there is provided a wireless communication device including an RF unit including the filter device having the above-described configuration, a baseband unit connected to the RF unit, and an antenna connected to the RF unit. .

  According to the filter device of the present invention, since the coupling electrode has the branching portion that is grounded between the one end and the other end, the current from the branching point of the coupling electrode to the ground side increases, so that Since the coupling (inductive coupling and capacitive coupling) between the resonator electrode of the first stage and the resonator electrode of the final stage can be adjusted (smaller), an attenuation pole is formed at a position (frequency) closer to the pass band of the filter However, it is possible to obtain a filter device having excellent attenuation characteristics in which the attenuation amount of the frequency band on the low frequency side and the high frequency side is further increased than the attenuation poles on the low frequency side and the high frequency side.

  Also, according to the filter device of the present invention, when the coupling electrode has a ground reinforcement portion that is electrically connected to the reference electrode, the current from the branch point of the coupling electrode to the ground side (reference electrode) further increases. The coupling between the first-stage resonator electrode and the last-stage resonator electrode by the coupling electrode can be adjusted more efficiently.

  According to the filter device of the present invention, when the internal reference electrode is formed so as to surround the plurality of resonator electrodes when the resonator electrode is viewed in plan, the internal reference electrode is formed of the plurality of resonator electrodes. By surrounding the periphery in a ring shape, leakage of electromagnetic waves generated from the resonator electrode to the periphery can be reduced. This effect is particularly useful for preventing adverse effects on other regions of the module substrate when the filter device of the present invention is formed in a partial region of the module substrate.

  Further, according to the filter device of the present invention, the number of resonator electrodes is four or more, and the ground reinforcing portion is opposed to the short-circuited end portion of the resonator electrode other than the first-stage and final-stage resonator electrodes and is connected to the short-circuited end. When electrically connected, the coupling between the first-stage or final-stage resonator electrode and the resonator electrodes other than the first-stage and final-stage resonator electrodes can be strengthened. Attenuation of the high-frequency attenuation pole is further increased, and by forming an attenuation pole on the higher-frequency side than the high-frequency attenuation pole of the passband, the frequencies on the lower and higher frequencies of the passband A filter device having excellent attenuation characteristics in which the attenuation amount of the band is further increased can be obtained.

  According to the filter device of the present invention, the ground reinforcing portion is formed along the internal reference electrode by branching out to the outside of the resonator electrode in plan view between the dielectric layers where the coupling electrodes are arranged. When it is, since the overlap between the ground reinforcement portion and the resonator electrode in plan view is reduced and interference with the resonator electrode is reduced, it becomes a filter device having excellent filter characteristics without secondary effects, Since the coupling between the ground enhancement portion and the internal reference electrode is increased, the attenuation amount on the high band side and low band side of the pass band of the filter is further increased.

  Further, according to the filter device of the present invention, when the ground reinforcement portion has the reference electrode facing portion facing the first reference electrode or the internal reference electrode, the reference electrode facing portion and the reference electrode or the internal reference electrode are coupled. Since the impedance of the reference electrode facing portion is reduced, the coupling between the first-stage resonator electrode and the last-stage resonator electrode by the coupling electrode can be adjusted (smaller) more easily, and the passband of the filter The amount of attenuation on the high-frequency side and low-frequency side is further increased.

  Further, according to the filter device of the present invention, the first reference electrode and the resonator electrode are opposed to the first reference electrode with the dielectric layer interposed therebetween, and at the open ends of the plurality of resonator electrodes, respectively. In the case of having a plurality of electrically connected capacitive electrodes, the distance between the capacitive electrode and the first reference electrode is shorter than the distance between the resonator electrode and the first reference electrode, thereby the resonator electrode and the first reference electrode. Since the coupling between the reference electrode and the reference electrode becomes stronger and the C-coupling of the resonator electrode is strengthened, the length of each resonator electrode can be shortened, and a smaller filter device can be provided.

  According to the filter device of the present invention, when the resonator electrode is viewed in plan, the internal reference electrode is formed so as to surround the plurality of resonator electrodes, and a part of the capacitor electrode sandwiches the dielectric layer. When arranged so as to face the internal reference electrode, the internal reference electrode is formed between the same dielectric layers as the dielectric layer on which the resonator electrode is formed, so that the capacitive electrode is coupled to the internal reference electrode. When facing each other, the wiring length of a through conductor or the like for electrical connection between the resonator electrode and the capacitor electrode can be shortened. Therefore, unnecessary inductance due to this wiring can be reduced, and the sub inductance due to the inductance of the wiring between the electrodes can be reduced. It can be set as the filter apparatus which has the outstanding filter characteristic without the next resonance.

  In addition, according to the filter device of the present invention, the input terminal has a shape along the first stage of the resonator electrode, and the second terminal is located more than the resonator electrode so as to face the first stage of the resonator electrode with the dielectric layer interposed therebetween. An internal input terminal disposed on the end side and electromagnetically coupled to the first stage of the resonator electrode, and an external input formed on the outer surface of the laminate and connected to the internal input terminal on the open end side of the first stage of the resonator electrode And the output terminal has a shape along the final stage of the resonator electrode and is located on the second end side of the resonator electrode so as to face the final stage of the resonator electrode with the dielectric layer interposed therebetween. An internal output terminal that is electromagnetically coupled to the final stage of the resonator electrode, and an external output terminal that is formed on the outer surface of the laminate and connected to the internal output terminal on the open end side of the final stage of the resonator electrode Between the input terminal and the first-stage resonator electrode, and the output terminal. Since the coupling by the magnetic field and the coupling by the electric field are added to the final-stage resonator electrode, a strong coupling is generated. Thus, a band that can be realized by a filter using a conventional quarter-wave resonator is obtained. Even in a wider passband, it has a flat and low-loss pass characteristic over the entire wide passband without greatly increasing the insertion loss at frequencies located between the resonance frequencies of the respective resonance modes. A filter device can be provided.

  Further, according to the filter device of the present invention, at least one in which the one end is a short-circuited end and the other end is an open end is disposed so as to be electromagnetically coupled to one of the resonator electrodes in the laminated body other than between the resonator electrodes. When there are two damped resonator electrodes, the damped resonator electrode can form an damped pole that functions as a reaction resonator (notch filter) between the damped pole of the resonator electrode and the passband, so that the desired pass A filter device having a steep attenuation characteristic that has a band and eliminates an unnecessary signal at a specific frequency can be obtained.

  Further, according to the filter device of the present invention, the damped resonator electrode has a shape in which the open end is branched into a plurality, and the length from the short-circuited end to each tip of the open end is different. Since a plurality of attenuation poles can be formed according to the electrical length from the short-circuited end to the open end branched off, the length from the shorted end to the open end branched off can be adjusted. By adjusting the positions of the plurality of attenuation poles, a filter device having a steeper attenuation characteristic can be easily obtained.

  Further, according to the filter device of the present invention, when the above resonator electrode is the first resonator electrode, the dielectric material is located on the second end side of the first resonator electrode in the multilayer body. A plurality of second resonator electrodes arranged in layers and aligned side by side in plan view so as to be electromagnetically coupled to each other, each having one end short-circuited and the other end open; Insertion is made at a frequency located between the resonance frequencies of the respective resonance modes over two very wide passbands formed by the plurality of first resonator electrodes and the plurality of second resonator electrodes. A flat and low-loss passing characteristic with little increase in loss can be obtained.

  Also, according to the filter device of the present invention, the first-stage first resonator electrode and the second-resonator electrode disposed between the first-stage first resonator electrode and the second-resonator electrode, and the electromagnetic field The internal input terminal to be coupled is disposed between the first resonator electrode and the second resonator electrode in the final stage, and is electromagnetically coupled to the first resonator electrode and the second resonator electrode in the final stage. When an internal output terminal is provided, the internal input terminal is broadside coupled to the first resonator electrode of the first stage and the second resonator electrode of the first stage and coupled to the interdigital type. In addition to the strong electromagnetic coupling, the coupling by the electric field and the coupling by the magnetic field are added together by the interdigital type coupling, and the electromagnetic coupling is stronger. Therefore, the internal input terminal, the first resonator electrode of the first stage, and the second of the first stage Both It can be attached very strongly to the vessel electrode.

  According to the wireless communication module of the present invention and the wireless communication device of the present invention, the loss of the signal passing over the entire wide passband is small, and the attenuation in the stopband is reduced by the attenuation pole formed near the passband. By using the sufficiently secured filter device of the present invention for filtering the transmission signal and the reception signal, the attenuation of the reception signal and the transmission signal passing through the filter device is reduced and the noise is also reduced. For this reason, 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. Furthermore, since two communication bands can be covered with one filter, a wireless communication module and a wireless communication device that are small in size and low in manufacturing cost can be obtained.

  The filter device of the present invention will be described in detail below. 1 to 6 are exploded perspective views showing examples of embodiments of the filter device of the present invention. 1 to 6, reference numeral 1a denotes a dielectric layer, 1 denotes a laminated body in which a dielectric layer 1a is laminated, 2a denotes a first reference electrode, 2b denotes a second reference electrode, 9 denotes an internal reference electrode, 3a 3d is a resonator electrode (first resonator electrode), 3a is a first-stage resonator electrode (first-stage first resonator electrode), and 3d is a final-stage resonator electrode (final-stage first resonator electrode). Electrode), 4 is a coupling electrode, 4a is a ground reinforcement portion, 4b is a reference electrode facing portion, 5 is an input terminal, 5a is an external input terminal, 5b is an internal input terminal, 6 is an output terminal, 6a is an external output terminal, 6b Is an internal output terminal, and 7 is a capacitance electrode. A broken line indicates a through conductor penetrating through the dielectric layer 1a for electrically connecting the conductor layers (for example, the first-stage first resonator electrode 3a and the input terminal 5) located above and below the dielectric layer 1a. It shows that there is.

  The filter device according to the present embodiment includes a multilayer body 1 in which a plurality of dielectric layers 1 a are laminated, a first reference electrode 2 a disposed at a first end of the multilayer body 1, and the multilayer body 1. And the second reference electrode 2b disposed at the second end of the first and second reference electrodes 2b are aligned side by side in a plan view so as to be electromagnetically coupled to each other in the laminate 1, each having one end shorted and the other end open. The first resonator electrodes 3a to 3d, and the first resonator electrodes 3a to 3d, which are disposed on the first end side of the resonator electrodes 3a to 3d, with one end of the first resonator electrode 3a sandwiching the dielectric layer 1a. While facing the short-circuited end, it is electrically connected to the short-circuited end of the first-stage first resonator electrode 3a facing the other, and the other end is opposed to the short-circuited end of the first-stage resonator electrode 3d. In addition, the coupling electrode 4 electrically connected to the short-circuited end of the opposing first resonator electrode 3d , An input terminal 5 for inputting a signal to the first resonator electrode 3a of the first stage, and an output terminal 6 for outputting a signal from the first resonator electrode 3d of the final stage. The coupling electrode 4 has a branch portion that is grounded between one end and the other end.

  According to the filter device of the present embodiment, since the coupling electrode 4 has a branch portion that is grounded between one end and the other end, the current from the branch point of the coupling electrode 4 to the ground side increases. The coupling (inductive coupling and capacitive coupling) between the first-stage first resonator electrode 3a and the last-stage resonator electrode by the electrode 4 can be adjusted (reduced). For this reason, the attenuation pole is formed at a position (frequency) closer to the pass band of the filter, and the attenuation in the low frequency band and the high frequency band is further increased than the low frequency and high frequency attenuation poles. A filter device having an attenuation characteristic can be obtained.

  In particular, when the coupling electrode 4 has a ground reinforcement portion 4a electrically connected to the first reference electrode 2a, the current from the branch point of the coupling electrode 4 to the ground side (first reference electrode 2a) further increases. Therefore, the coupling (inductive coupling and capacitive coupling) of the first-stage first resonator electrode 3a and the final-stage first resonator electrode 3d by the coupling electrode 4 can be adjusted (smaller) more efficiently. Can do.

  The first reference electrode 2a and the second reference electrode 2b are disposed on almost the entire surface excluding the periphery of the input terminal 5 and the output terminal 6 on the upper and lower surfaces of the laminate 1 in which the dielectric layers 1a are laminated. , Connected to ground potential.

  The first resonator electrodes 3 a, 3 b, 3 c, 3 d are arranged side by side between one layer of the multilayer body 1 and are electromagnetically coupled (edge coupled) to each other. In order to create an attenuation pole in the vicinity of the pass band, it is necessary to have three or more first resonator electrodes. When there are two or less first resonator electrodes, an attenuation pole that is an effect of the coupling electrode is required. I can't make it. Therefore, it is necessary to have three or more first resonator electrodes as in this embodiment.

  It is preferable that the distance between adjacent first resonator electrodes 3a, 3b, 3b, 3c, 3c, 3d is small because strong coupling can be obtained and the pass band can be easily widened. In order to form them well at regular intervals so as not to short-circuit each other, for example, the thickness is set to about 0.05 to 0.5 mm. The first resonator electrodes 3a, 3b, 3c, and 3d are preferably formed in an elongated band shape so that they are arranged side by side and are electromagnetically coupled to each other. The first resonator electrodes 3a to 3d have only to be aligned side by side in a plan view so as to be electromagnetically coupled to each other in the multilayer body 1. As shown in FIG. 1, four first resonator electrodes 3a to 3d may be arranged between one dielectric layer 1a and 1a. However, the first resonator electrodes 3a and 3c are arranged as one dielectric. The resonator electrodes 3b and 3d may be arranged between the layers 1a and 1a, and the resonator electrodes 3b and 3d may be arranged between the other dielectric layers 1a and 1a via the dielectric layer 1a. This arrangement is preferable because the possibility of a short circuit between adjacent resonator electrodes is suppressed and the formation thereof is facilitated, but the number of dielectric layers 1a is increased and the thickness of the filter device is increased. Become.

  When the first resonator electrodes 3a to 3d are arranged in an interdigital manner as in the examples shown in FIGS. 1 to 6, the coupling between the first resonator electrodes 3a to 3d is the coupling between the magnetic field and the electric field. Are added to each other to produce stronger coupling between the first resonator electrodes 3a to 3d, thereby reducing the frequency interval between the resonance frequencies in the respective resonance modes to the conventional quarter wavelength. The filter device can be adjusted beyond the band that can be realized by a filter using a resonator, and a filter device having a wide pass band can be obtained. Further, the coupling between the first resonator electrodes 3a to 3d arranged in the interdigital type is a strong magnetic field coupling, and it is not necessary to increase the magnetic field by reducing the pattern width of the first resonator electrodes 3a to 3d. By increasing the pattern width of the first resonator electrodes 3a to 3d, the electrical resistance of the first resonator electrodes 3a to 3d is reduced, and the Q value (quality factor) indicating the sharpness of the sharp resonance of the resonator Can be high. As a result, a filter device having a wide passband and a steep attenuation characteristic, for example, suitable for a bandpass filter for UWB applications can be obtained.

  In addition, when the first resonator electrodes 3a to 3d are arranged in the comb line type, since the coupling between the first resonator electrodes 3a to 3d is weaker than the interdigital type, the pass band is narrow and steep. Since the characteristics can be obtained and the pattern width of each of the first resonator electrodes 3a to 3d can be reduced, the filter device can be reduced in size, so that the filter device is suitable for relatively small wireless devices such as mobile phones and wireless LANs.

  In the interdigital type and the combline type, when the coupling between the first resonator electrodes 3a to 3d is made approximately the same, the first resonator electrode 3a at the first stage and the first resonator electrode 3d at the final stage are connected. Since the coupling is usually weaker in the interdigital type, and the number of stages of the first resonator electrodes 3a to 3d is larger, the effect of the coupling electrode 4 becomes more remarkable in the case of the interdigital type having many stages. .

  In the example shown in FIGS. 1 to 6, four first resonator electrodes 3a to 3d are provided, but five or more resonator electrodes may be provided as long as the number does not increase loss. . In the UWB low band application, four are preferable from the balance of loss and attenuation characteristics.

  The first resonator electrodes 3a, 3b, 3c, and 3d form a stripline resonator together with the first reference electrode 2a and the second reference electrode 2b, and the short-circuited end is the first reference electrode 2a or the first reference electrode 2a. The second reference electrode 2b is connected to the ground potential to function as a quarter wavelength resonator. The first resonator electrodes 3a, 3b, 3c, 3d and the first reference electrode 2a or the second reference electrode 2b are connected to each other as shown in FIGS. A conductor layer for connecting the short-circuit ends of the first resonator electrodes 3a, 3b, 3c, 3d is provided between the layers on which 3d is formed, and this conductor layer and a through conductor (not shown) can be connected, What is necessary is just to connect by the end surface conductor (not shown) which extended the conductor layer to the edge part of the dielectric material layer 1a, and was formed in the end surface (side surface of the laminated body 1) of the dielectric material layer 1a. When the conductor layer for connecting the short-circuit ends of the first resonator electrodes 3a, 3b, 3c, and 3d is not provided, each of the first resonator electrodes 3a, 3b, 3c, and 3d is connected by a through conductor. May be connected to the first reference electrodes 2a and 2a, or the short-circuit ends of the first resonator electrodes 3a to 3d may be extended to the end of the dielectric layer 1a to end the end surface of the dielectric layer 1a (the side surface of the multilayer body 1). ) May be connected to the first reference electrodes 2a and 2a by end face conductors formed in the above. When connected by the end face conductor, the end face conductor can be made to function as a shield layer that reduces leakage of electromagnetic waves generated from the first resonator electrodes 3a to 3d to the surroundings. Alternatively, it is preferable to arrange more than double around the first resonator electrodes 3a to 3d and arrange the through conductors as close to the first resonator electrodes 3a to 3d as possible as viewed from the side because the function of the shield becomes more remarkable. As shown in FIGS. 1 and 2, when a conductor layer for connecting the short-circuit ends of the first resonator electrodes 3a, 3b, 3c, 3d is provided, the first resonator electrodes 3a, 3b, 3c, This is preferable because it is easy to connect the 3d short-circuit end to the first reference electrodes 2a and 2a.

  Further, as in the example shown in FIGS. 4 and 5, the filter device of the present embodiment has a first resonance between the dielectric layers 1 a in which the first resonator electrodes 3 a to 3 d are formed in the above configuration. When the resonator electrodes 3a to 3d are viewed in plan, the internal reference electrode 9 is preferably formed so as to surround the plurality of first resonator electrodes 3a to 3d. In this way, the internal reference electrode 9 surrounds the first resonator electrodes 3a to 3d, thereby reducing leakage of electromagnetic waves generated from the first resonator electrodes 3a to 3d to the surroundings. Can do.

  This effect is particularly useful in preventing adverse effects on other regions of the module substrate when the filter device is formed in a partial region of the module substrate. The internal reference electrode 9 includes a conductor layer for connecting the short-circuit ends of the first resonator electrodes 3a, 3b, 3c, and 3d described above, and an array of the first resonator electrodes 3a, 3b, 3c, and 3d. It is an annular thing consisting of a conductor layer formed on both sides. The connection between the first reference electrode 2a and the first resonator electrodes 3a, 3b, 3c, 3d is located on both sides of the array of the first resonator electrodes 3a, 3b, 3c, 3d of the internal reference electrode 9. If it is performed even in the portion, leakage of electromagnetic waves generated from the first resonator electrodes 3a to 3d to the surroundings can be more effectively reduced.

  The distance between the internal reference electrode 9 and the first resonator electrodes 3a and 3d affects the magnetic field generated by the first resonator electrodes 3a and 3d, so that the Q value of the filter decreases and the loss of the passband increases. In order not to be staggered, it is only necessary to have a distance through which the magnetic flux generated by the first resonator electrodes 3a and 3d can pass, and is larger than the distance between the first resonator electrodes 3a and 3d and the first reference electrode 2a. preferable.

  The coupling electrode 4 is provided to strengthen the coupling between the first resonator electrode 3a in the first stage and the first resonator electrode 3d in the last stage, which are weakly coupled. For example, in the example illustrated in FIG. When the coupling between the second-stage resonator electrode 3b and the third-stage resonator electrode 3c increases, the basic structure formed by the first resonator electrodes 3a to 3d and the first reference electrodes 2a and 2a is increased. The filter characteristics in the passband change, for example, the center frequency of the filter shifts, and the design of the attenuation characteristics by adding the coupling electrode 4 becomes complicated. If the line width of the pattern connecting the portion facing the first resonator electrode 3a at the first stage and the portion facing the first resonator electrode 3d at the last stage in the coupling electrode 4 is large, the coupling electrode 4 itself Since it functions like a reference electrode, it affects the magnetic field generated by the first resonator electrodes 3a to 3d, thereby lowering the Q value of the filter and increasing the loss in the passband.

  Therefore, the portion connecting the portion facing the first-stage first resonator electrode 3a and the portion facing the first-stage first resonator electrode 3d is the second-stage and third-stage resonator electrodes 3b. In order to reduce the area facing 3c and make the coupling as small as possible, it is preferable to provide a pattern with a small width so as to be orthogonal to the second and third stage resonator electrodes 3b and 3c. Further, in order to reduce the coupling by increasing the distance to the portion facing the first resonator electrode 3a in the first stage and the first resonator electrode 3d in the last stage, one or more layers of this orthogonal portion are added. The dielectric layer 1a is sandwiched between the first resonator electrode 3a and the first resonator electrode 3d. The first resonator electrode 3a is connected to the first resonator electrode 3a and the first resonator electrode 3d. Good.

  Depending on the number of dielectric layers 1a between the coupling electrode 4 and the first resonator electrodes 3a and 3d, the distance between the coupling electrode 4 and the first resonator electrodes 3a and 3d can be changed, The area where the coupling electrode 4 and the first resonator electrodes 3a and 3d overlap is changed depending on the pattern shape such as the pattern width and the length of the pattern 4 and the position in plan view. The degree of electromagnetic field coupling between the resonator electrodes 3a and 3d can be adjusted, and the frequency at which the attenuation pole is generated can be arbitrarily set. Sufficient coupling is obtained between the first resonator electrodes 3a and 3d, and the first resonator electrode 3a in the first stage and the first resonator electrode 3d in the final stage are caused by a positional shift when the filter device is manufactured. The portion of the coupling electrode 4 facing the first resonator electrode 3a at the first stage and the first resonator electrode 3d at the final stage so that the coupling with the other resonator electrodes 3b and 3c does not occur. It is preferable that the portion facing the first and second resonator electrodes 3a and 3d has a strip shape that is narrower than the first resonator electrodes 3a and 3d.

  In addition, the coupling electrode 4 includes a ground reinforcement portion 4a that branches between one end and the other end thereof and is electrically connected to the first reference electrode 2a. The length to the end of the coupling electrode 4 is preferably longer than the length from one end of the coupling electrode 4 to the other end. This is because if the length from one end of the coupling electrode 4 to the end of the ground reinforcing portion 4a is shorter, current hardly flows from one end to the other end of the coupling electrode 4, and the function of the coupling electrode 4 is greatly reduced. Because it will end up.

  For this reason, the shape of the ground reinforcing portion 4a is more than that of the example shown in FIG. 2, which is branched from the coupling electrode 4 and penetrates the insulating layer 1a to connect to the first reference electrode 2a. As in the example shown in FIG. 1, the shape branched between the dielectric layers 1a and 1a where the coupling electrode 4 is disposed may be easier to form longer. In this way, for example, when the coupling electrode 4 is formed by printing a conductive paste on a ceramic green sheet, the ground reinforcement portion 4a can be formed at the same time. In this case, the electrical connection between the ground reinforcing portion 4a and the first reference electrode 2a is branched and extended between the dielectric layers 1a and 1a, and then penetrates through the insulating layer 1a to form the first reference electrode 2a. As shown in the example shown in FIG. 1, the short-circuit ends of the first resonator electrodes 3a to 3d are connected to each other and the conductor is electrically connected to the first reference electrode 2a. You may connect to the layers.

  7 is a top view of the insulating layer 1a on which the first resonator electrodes 3a to 3d and the internal reference electrode 9 are formed as in the example shown in FIG. An example of the overlap of 3d and the coupling electrode 4 (shown by a broken line) formed on the insulating layer 1a therebelow is shown.

  The position where the ground reinforcing portion 4a branches from the coupling electrode 4 is such that the length from one end of the coupling electrode 4 to the end portion of the ground reinforcing portion 4a is longer than the length from one end of the coupling electrode 4 to the other end. 7 (a), (b), (d), (e), and (f), the ground reinforcing portion 4a is interposed between the dielectric layers 1a and 1a where the coupling electrode 4 is disposed. What is necessary is just to pull out outside 1st resonator electrode 3a, 3b, 3c, 3d by planar view. In the case of the example shown in FIG. 7C, the length from one end of the coupling electrode 4 to the end of the ground reinforcement portion 4a is shortened. Further, in the case of the example shown in FIG. 7C, by overlapping the resonator electrodes 3b and 3c, the first-stage first resonator electrode 3a and the two-stage resonator electrode 3b (the open end is opposite in direction) Further, since the first resonator electrode 3d at the final stage and the resonator electrode 3c at the third stage are coupled to each other, they interfere with each other and the resonance characteristics deteriorate.

  When branching between a portion facing the first resonator electrode 3a in the first stage and a portion facing the first resonator electrode 3d in the last stage, as shown in FIG. It must branch between the first resonator electrode 3a and the two-stage resonator electrode 3b or between the first-stage resonator electrode 3d and the three-stage resonator electrode 3c, and the manufacturing process. In view of the positional deviation at, it is difficult to provide a branch point within this narrow interval so as not to overlap with the resonator electrodes 3b and 3c. For this reason, as shown in FIGS. 7A, 7B, 7D, and 7F, the portion of the coupling electrode 4 facing the first resonator electrode 3a at the first stage or the last stage. It is preferable to branch off from a portion facing the first resonator electrode 3d. In the example shown in FIG. 7B, the ground reinforcing portion 4a overlaps with the resonator electrode, although it is slightly, so that the first stage of the coupling electrode 4 is the same as the example shown in FIGS. 7A, 7D, and 7F. It is more preferable to branch from the portion facing the first resonator electrode 3a or the portion facing the first resonator electrode 3d at the final stage, and to draw out to the outside of the first resonator electrode 3a or 3d facing each other. preferable.

  FIG. 8 is a plan view of the top surface of the insulating layer 1a on which the first resonator electrodes 3a to 3d as shown in FIG. 3 are formed, and the first resonator electrodes 3a to 3d and the layers below the first resonator electrodes 3a to 3d. An example of overlapping with the coupling electrode 4 (shown by a broken line) formed on the insulating layer 1a is shown.

  In the filter device of the present embodiment, as shown in the example shown in FIG. 8, the first resonator electrodes 3a to 3d are four or more, and the ground reinforcement portion 4a is the first-stage and final-stage first resonator electrodes. It is preferable to face the short-circuited ends of the resonator electrodes 3b and 3c other than 3a and 3d and be electrically connected to the short-circuited ends. In this way, the coupling between the first-stage first resonator electrode 3a and the third-stage resonator electrode 3c, or the coupling between the first-stage resonator electrode 3d and the second-stage resonator electrode 3b. Since the attenuation pole is formed at a position (frequency) closer to the pass band of the filter, the attenuation amount in the lower frequency band and the higher frequency band than the lower frequency band and the higher frequency attenuation pole. Thus, a filter device having an excellent attenuation characteristic that is further increased can be obtained.

  As in the example shown in FIG. 8A, the portion of the coupling electrode 4 that faces the short-circuit end of the first resonator electrode 3a at the first stage and the ground that opposes the short-circuit end of the third-stage resonator electrode 3c. The reinforcing portion 7a is electrically connected to the short-circuit ends that are close to each other side by side, and the portion of the coupling electrode 4 that faces the short-circuit end portion of the first-stage first resonator electrode 3a and the second-stage resonator electrode The portion of the coupling electrode 4 facing the short-circuit end portion of the first resonator electrode 3a and the resonator from the loop-shaped current path passing through the ground reinforcement portion 7a facing the short-circuit end portion 3b and the internal reference electrode 9 Since the loop-shaped current path passing through the ground reinforcing portion 7a and the internal reference electrode 9 facing the short-circuit end of the electrode 3c is shorter, the first-stage first resonator electrode 3a and the second-stage resonator electrode described above are used. The influence of the coupling with 3b is small, and the first-stage first resonator electrode 3a and the third-stage Towards the effect of coupling between the resonator electrodes 3c becomes stronger becomes remarkable. Similarly, the influence of the coupling of the first-stage resonator electrode 3d and the third-stage resonator electrode 3c is small, and the first-stage resonator electrode 3d and the second-stage resonator electrode of the last stage are small. The above effect due to the strengthening of the bond with 3b becomes more prominent.

  Influence due to coupling of first-stage first resonator electrode 3a and second-stage resonator electrode 3b, and influence due to coupling of first-stage resonator electrode 3d and third-stage resonator electrode 3c. 8b, the ground reinforcing portion 4a branches from a portion of the coupling electrode 4 that faces the first resonator electrode 3a at the first stage of the coupling electrode 4 so that the third stage resonance occurs. So as to face the short-circuited end of the resonator electrode 3c, branch from the portion facing the first resonator electrode 3d at the final stage, and to face the short-circuited end of the second-stage resonator electrode 3b Preferably formed. In this case, the coupling between the first-stage first resonator electrode 3a and the second-stage resonator electrode 3b and the coupling between the last-stage first resonator electrode 3d and the third-stage resonator electrode 3c are small. As shown, the portion of the coupling electrode 4 that faces the first resonator electrode 3a at the first stage and the portion that faces the short-circuited end of the resonator electrode 3c at the third stage and the first of the final stage. The width of the portion connecting the portion facing the resonator electrode 3d and the portion facing the short-circuited end of the second-stage resonator electrode 3b is reduced to such an extent that the inductance does not become too large. Is preferably about 0.1 mm.

  In the filter device according to the present embodiment, the ground reinforcing portion 4a is opposed to the short-circuited ends of the resonator electrodes 3b and 3c other than the first-stage and final-stage first resonator electrodes 3a and 3d and is electrically connected to the short-circuited end. When not connected, the ground reinforcing portion 4a is flat between the dielectric layers 1a and 1a on which the coupling electrode 4 is disposed, as in the example shown in FIGS. 7 (a), (b), and (e). It is preferable that the first resonator electrodes 3 a, 3 b, 3 c, and 3 d are branched and drawn out from the first resonator electrodes 3 a, 3 b, 3 c, and 3 d when viewed. With such a configuration, the overlap between the ground reinforcing portions 4a, 4a and the first resonator electrodes 3a, 3b, 3c, 3d is reduced in plan view, and the first resonator electrodes 3a, 3b, 3c, 3d are reduced. Therefore, the filter device has excellent filter characteristics with no secondary effects. Further, since the coupling between the ground reinforcement portions 4a and 4a and the internal reference electrode 9 is increased, the attenuation amount on the high band side and low band side of the pass band of the filter is further increased.

  7 (a), (d), (f) in order to prevent the ground reinforcing portions 4a, 4a and the first resonator electrodes 3a, 3b, 3c, 3d from easily overlapping in plan view. As shown in the example, the first resonator electrode 3a that faces the first resonator electrode 3a at the first stage of the coupling electrode 4 or the part that faces the first resonator electrode 3d at the last stage, respectively. Or it is more preferable to pull out outside 3d.

  Further, in order to further increase the coupling between the ground reinforcing portions 4a and 4a and the internal reference electrode 9, the length of the ground reinforcing portions 4a and 4a is increased or the width is increased, as shown in FIG. As shown in the example, the reference electrode facing portions 4b and 4b may be drawn out further to the outside so that the ground reinforcing portions 4a and 4a and the internal reference electrode 9 overlap (oppose) in a plan view. When the internal reference electrode 9 is provided as in the example shown in FIG. 5, the reference electrode facing portions 4 b and 4 b that face the first reference electrodes 2 a and 2 a may be provided in the ground reinforcement portions 4 a and 4 a. It is preferable that the reference electrode facing portion 4b is provided so as to mainly face the shorter one of the internal reference electrode 9 or the first reference electrodes 2a and 2a, because stronger coupling can be obtained.

  On the other hand, when the internal reference electrode 9 is not provided as in the example shown in FIG. 1, a reference electrode facing portion 4b that faces the first reference electrodes 2a and 2a may be provided in the ground reinforcement portions 4a and 4a. . In this case, as in the example shown in FIG. 6, the ground reinforcing portions 4 a and 4 a are not branched and drawn out between the dielectric layers 1 a and 1 a where the coupling electrode 4 is disposed, but the first reference electrode 2 a, Reference electrode facing portions 4b and 4b may be provided between the dielectric layers 1a and 1a close to 2a. At this time, the electrical connection of the reference electrode facing portions 4b, 4b to the first reference electrodes 2a, 2a may be directly connected to the first reference electrodes 2a, 2a or to the internal reference electrode 9. By doing so, the first reference electrodes 2a and 2a may be electrically connected. In this case, the internal reference electrode 9 may be directly connected, or the coupling electrode 4 may be connected to the internal reference electrode 9.

  That is, in the filter device of the present embodiment, in the above configuration, the ground reinforcement portion 4a preferably has the reference electrode facing portion 4b facing the first reference electrodes 2a, 2a or the internal reference electrode 9. As a result, the coupling between the reference electrode facing portion 4b and the first reference electrodes 2a, 2a or the internal reference electrode 9 is increased, and the impedance of the reference electrode facing portion 9 is decreased. The coupling between the resonator electrode 3a and the first resonator electrode 3d at the final stage can be adjusted (decreased) more easily, and the attenuation on the high band side and low band side of the pass band of the filter is further increased. .

  In order to make such an effect more prominent, the reference electrode facing portions 4b and 4b are shaped and arranged so that the coupling with the first reference electrodes 2a and 2a or the internal reference electrode 9 is as large as possible. Is good. Further, since the reference electrode facing portions 4b and 4b are a part of the ground reinforcing portion 4a, as described above, the shape and the coupling with the first resonator electrodes 3a, 3b, 3c and 3d are minimized. Arrangement is good.

  For this reason, when the ground reinforcing portion 4a is branched and pulled out between the dielectric layers 1a and 1a in which the coupling electrode 4 is disposed as in the example shown in FIG. 7 (f), the first resonator It is preferable to provide reference electrode facing portions 4b and 4b having a large area by being drawn outside the electrode 3a or 3d. Further, as in the example shown in FIG. 6, the ground reinforcing portion 4a is drawn out by a through conductor extending from the coupling electrode 4 toward the first reference electrode 2a, and the reference electrode facing portion 4b is interposed between the dielectric layers 1a and 1a. , 4b should be such that the reference electrode facing portions 4b, 4b do not go inward from the first resonator electrode 3a at the first stage and the first resonator electrode 3d at the last stage in plan view. . Since the coupling electrode 4 exists between the reference electrode facing portions 4b and 4b and the first resonator electrode 3a at the first stage and the first resonator electrode 3d at the final stage, the reference electrode facing portions 4b and 4b Since the coupling between the first resonator electrode 3a at the first stage and the first resonator electrode 3d at the last stage is small, the first resonator electrode 3a at the first stage and the first resonance at the last stage in plan view. The reference electrode facing portion 4b having a large area is preferably provided so as to protrude outward from the electrode 3d. In order to suppress the influence of the coupling between the coupling electrode 4 and the first resonator electrodes 3 a, 3 b, 3 c, 3 d as much as possible, the reference electrode facing portion 4 b is configured such that the first resonator electrode 3 a of the first stage of the coupling electrode 4 or the final It is preferable that the width is equal to or less than the width and length of the portion facing the first resonator electrode 3d in the step so that the portion does not protrude from this portion when seen in a plan view.

  Further, although depending on the dielectric constant of the dielectric layer 1a and the like, it is preferable that the reference electrode facing portion 4b is provided between the coupling electrode 4 and the first reference electrodes 2a and 2a so that the coupling electrode 4 is disposed. Compared with the case where the reference electrode facing portion 4b is provided outside the first resonator electrodes 3a to 3d between the body layers 1a and 1a, the wiring length can be normally shortened. Can be reduced, which is preferable.

  In the example shown in FIGS. 1 to 7, the ground reinforcing portions 4 a and 4 a are both provided at both ends of the coupling electrode 4, but if there is at least one, the above-described effects can be obtained. Considering the balance of the input / output current of the coupling electrode 4 (impedance balance), the amount of coupling between the first resonator electrode 3a in the first stage and one end of the coupling electrode 4 and the first resonator electrode 3d in the final stage. Therefore, it is preferable to provide the same ground reinforcement portions 4a at the same distance from one end and the other end of the coupling electrode 4, respectively. Increasing the number of ground reinforcement portions 4a increases the effect. However, if the coupling between the first resonator electrode 3a at the first stage and the first resonator electrode 3d at the last stage by the coupling electrode 4 becomes too small, it passes through. The positions (frequency) of the attenuation poles on the low band side and high band side of the band are shifted to the low band side and the high band side, respectively, so one is provided at each of the one end and the other end of the coupling electrode 4. More preferred.

  Further, in the filter device of the present embodiment, the dielectric layer 1a between the first reference electrode 2a and the first resonator electrodes 3a to 3d, as in the example shown in FIGS. It is preferable to have a plurality of capacitive electrodes 7 that face the first reference electrode 2a across the electrode and are electrically connected to the open ends of the first resonator electrodes 3a to 3d, respectively. As a result, the distance between the capacitive electrode 7 and the first reference electrode 2a is shorter than the distance between the first resonator electrodes 3a to 3d and the first reference electrode 2a, thereby the first resonator electrodes 3a to 3d. And the first reference electrode 2a become stronger and the C coupling between the first resonator electrodes 3a to 3d and the first reference electrode 2a is strengthened, so that each first resonator electrode The length of 3a-3d can be shortened, and a more compact filter device can be provided.

  Further, in the filter device of the present embodiment, in the configuration described above, as in the example shown in FIG. 5, a part of the capacitor electrode 7 is disposed so as to face the internal reference electrode 9 with the dielectric layer 1a interposed therebetween. It is preferable. FIG. 9 is a cross-sectional view showing an example of the AA cross section of the filter device shown in FIG. The internal reference electrode 9 is formed between the same dielectric layers 1a and 1a as the dielectric layers 1a and 1a on which the first resonator electrodes 3a to 3d are formed. When opposed so as to be coupled, the first electrode is compared with the case where the capacitive electrode 7 is opposed so as to be coupled only with the first reference electrode 2a (in the case of the capacitive electrode 7a indicated by a broken line in FIG. 9). Since the wiring length of a through conductor or the like for electrical connection between the resonator electrodes 3a to 3d and the capacitor electrode 7 can be shortened, unnecessary inductance due to this wiring can be reduced, and secondary resonance due to the inductance can be reduced. Thus, a filter device having excellent filter characteristics can be obtained. In addition, even when the wiring length of a through conductor or the like that electrically connects the first resonator electrodes 3 a to 3 d and the capacitive electrode 7 is the same, the electrostatic capacitance between the capacitive electrode 7 and the internal reference electrode 9 is not limited. Since the capacitance is added, the capacitance between the open ends of the first resonator electrodes 3a to 3d and the ground potential is further increased, and the length of the first resonator electrodes 3a to 3d can be shortened. Therefore, a filter device as a smaller bandpass filter can be obtained.

  The capacitive electrode 7 and the first resonator electrodes 3a to 3d are electrically connected by a through conductor. When the capacitor electrode 7 and the first resonator electrodes 3a to 3d overlap in plan view, the coupling between the first resonator electrodes 3a to 3d and the first reference electrode 2a is reduced by the overlapped area. For example, if the capacitor electrode 7 connected to the first resonator electrode 3a and the other resonator electrodes 3b to 3d overlap in plan view, the first resonator electrode 3a in the first stage and the other resonator Since the amount of coupling with the electrodes 3b to 3d changes, the first electrode electrodes 3a to 3d are formed by making the capacitive electrode 7 into an elongated shape such as a rectangle or an ellipse as in the examples shown in FIGS. Are connected to one end of the capacitor electrode 7, and the other end of the capacitor electrode 7 is preferably directed in the direction of extending the open ends of the first resonator electrodes 3a to 3d.

  In the example shown in FIG. 4 and FIG. 5, the capacitor electrodes 7 are provided one below each of the first resonator electrodes 3 a to 3 d with the dielectric layer 1 a interposed therebetween. It may be provided above and below the resonator electrodes 3a to 3d, or one above each of the first resonator electrodes 3a to 3d, or one above or below.

  The input terminal 5 and the output terminal 6 may be electrically connected by a wiring conductor such as a through conductor, as in the examples shown in FIGS. 1, 2 and 4, but the first is sandwiched between the dielectric layers 1a. The resonator electrodes 3a and 3d may be disposed so as to face each other, and the first resonator electrodes 3a and 3d may be electromagnetically coupled to each other. In this case, as in the example shown in FIGS. 3 and 5, the input terminal 5 is shaped along the first-stage first resonator electrode 3a, and the first-stage first resonator electrode with the dielectric layer 1a interposed therebetween. An internal input terminal 5b disposed on the second end side of the first-stage first resonator electrode 3a so as to oppose the first-stage first resonator electrode 3a and electromagnetically coupled to the first-stage first resonator electrode 3a; And an external input terminal 5a connected to the internal input terminal 5b on the open end side of the first-stage first resonator electrode 3a, and the output terminal 6 is the first-stage first resonance. In the shape along the resonator electrode 3d, the first resonator electrode 3d in the final stage is disposed on the second end side so as to face the final stage 3d of the resonator electrode 3 with the dielectric layer 1a interposed therebetween. Are formed on the outer surface of the laminate 1 and the internal output terminal 6b that is electromagnetically coupled to the first resonator electrode 3d in the final stage. Preferably it is provided with a first external output terminal 6a connected at the open end side of the resonator electrodes 3d of the final stage to the internal output terminal 6b.

  With such a configuration, coupling between the input terminal 5 and the first resonator electrode 3a in the first stage and coupling between the output terminal 6 and the first resonator electrode 3d in the last stage by the magnetic field and the coupling by the electric field are achieved. Are added to each other, and strong coupling occurs. Therefore, even if the passband is wider than the band that can be realized by a filter using a conventional quarter-wave resonator, the frequency is located between the resonance frequencies of the respective resonance modes. Thus, it is possible to provide a filter device having a flat and low-loss pass characteristic over the entire wide passband without greatly increasing the insertion loss at. As a result, the filter device has a wide passband and has a steep attenuation characteristic, and is suitable for a bandpass filter for UWB applications, for example.

  The connection between the internal input terminal 5b and the external input terminal 5a and the connection between the internal output terminal 6b and the external output terminal 6a are through conductors penetrating the dielectric layer 1a as in the examples shown in FIGS. Just do it. Further, the internal input terminal 5b, the external input terminal 5a, the internal output terminal 6b, and the external output terminal 6a can be extended to the ends of the dielectric layer 1a and connected by end face conductors. When the connection between the first resonator electrodes 3a to 3d and the first reference electrodes 2a and 2a is performed by an end surface conductor, the end surface conductor can be formed simultaneously with other electrodes by printing a conductor paste or the like. Convenient above.

  FIG. 10 is an exploded perspective view similar to FIG. 1, and in FIG. 10, 8 is a damped resonator electrode. As in the example shown in FIG. 10, the filter device of the present embodiment has the first configuration in the stacked body 1 other than between the first resonator electrodes 3 a, 3 b, 3 b, 3 c, 3 c, 3 d in the above-described configurations. It is preferable to have at least one damped resonator electrode 8 disposed so as to be electromagnetically coupled to one of the resonator electrodes 3a to 3d, one end being a short-circuited end and the other end being an open end. Since the attenuation resonator electrode 8 can form an attenuation pole that functions as a reaction resonator (notch filter) between the attenuation pole and the pass band of the first resonator electrodes 3a to 3d, a desired pass band can be obtained. It is possible to provide a filter device having a steep attenuation characteristic that has an unnecessary signal at a specific frequency.

  The damped resonator electrode 8 is formed in the multilayer body 1 other than between the first resonator electrodes 3a to 3d, for example, as shown in FIG. 10, in the dielectric layer 1a / a in which the first resonator electrodes 3a to 3d are formed. Between the dielectric layers 1a and 1a different from between 1a, it is arranged so as to be electromagnetically coupled to one of the first resonator electrodes 3a to 3d, and one end is connected to the first reference electrodes 2a and 2a. The other end is an open end that is not connected to the other end. The connection between the damped resonator electrode 8 and the first reference electrodes 2a and 2a is performed by extending the short-circuited end of the damped resonator electrode 8 to the end of the dielectric layer 1a as shown in FIG. It may be connected by an end face conductor (not shown) formed on the end face 1a (side face of the laminated body 1), or may be connected by a through conductor.

  The damped resonator electrode 8 is electromagnetically coupled to one of the first resonator electrodes 3a to 3d. A desired attenuation characteristic can be obtained by adjusting the coupling amount. For example, when a desired coupling amount is not obtained, even if a steep attenuation characteristic is obtained outside the pass band and in a band very close to the cutoff frequency, the high-frequency side of the attenuation pole by the attenuation resonator electrode 8 is obtained. While the damping characteristic jumps (between the attenuation poles), when the desired coupling amount is obtained, such a damping characteristic jump does not occur, and a steep and no jumping damping characteristic can be obtained. it can.

  The number of the damped resonator electrodes 8 is preferably set in a pair so as to be symmetric with respect to the center of the region where the resonator electrode 3 is formed. In this way, even when a positional deviation occurs when the filter device is manufactured, even if the coupling between the damped resonator electrode 8 and the resonator electrode 3 changes in a direction in which one is strengthened, the other is Since the total coupling amount does not change greatly because it changes in a weakening direction, it is easy to make a product with a small deviation from the design value.

  Further, in the filter device of the present embodiment, in the above configuration, the damped resonator electrode 8 has a shape in which the open end is branched into a plurality, and the length from the short-circuited end to each tip of the open end is different. preferable. From this, a plurality of attenuation poles can be formed according to the electrical length from the short-circuited end of the damped resonator electrode 8 to each end of the open end branched off, so that each end of the open end branched off from the short-circuited end can be formed. By adjusting the positions of the plurality of attenuation poles, the filter device having a steeper attenuation characteristic can be easily obtained.

  The shape of the damped resonator electrode 8 may be adjusted in accordance with the amount of coupling with the first resonator electrodes 3a to 3d, but as a whole, a band shape along the first resonator electrodes 3a to 3d. It is preferable that the open end is branched into a plurality.

  The shape of the open end of the damped resonator electrode 8 is not particularly limited as long as the length from the short-circuited end to each end of the open end is different, and the shape from the short-circuited end is not particularly limited. (A so-called curved Y-shape in this example) may be used, and the main body from the short-circuit end to the open end may be similarly curved. Further, the number of branches may be branched not only to two but also to three or more than that. The length from the short-circuited end to the tip of each open end and the number of branches may be set according to the required attenuation frequency and the number of attenuation poles depending on the required filter characteristics.

  Planar arrangement of the coupling electrode 4, the input terminal 5, the output terminal 6, the capacitive electrode 7, and the damped resonator electrode 8 with respect to the first resonator electrodes 3 a to 3 d and the distance from each other (dielectrics interposed therebetween) The thickness of the layer 1a or the number of layers) is not particularly limited, and may be set so as to adjust the coupling between each electrode and the first resonator electrodes 3a to 3d so as to obtain a desired attenuation characteristic.

  11 is an exploded perspective view similar to FIG. 1. In FIG. 11, 3e to 3h are second resonator electrodes, 3e is a first resonator electrode of the first stage, and 3h is a second resonator of the last stage. Electrode. As shown in FIG. 11, the filter device of the present embodiment is disposed on the second end side of the first resonator electrodes 3 a to 3 d in the multilayer body 1 via the dielectric layer 1 a, It further includes a plurality of second resonator electrodes 3e to 3h which are aligned side by side in a plan view so as to be electromagnetically coupled to each other, one end of which is a short-circuited end and the other end is an open end. By providing such second resonator electrodes 3e to 3h, an extremely wide 2 formed by the plurality of first resonator electrodes 3a to 3d and the plurality of second resonator electrodes 3e to 3h. A flat and low-loss pass characteristic with little increase in insertion loss can be obtained at frequencies located between the resonance frequencies of the respective resonance modes over the entire two pass bands.

  As for the second resonator electrodes 3e to 3h, similarly to the first resonator electrodes 3a to 3d, the coupling electrode 4, the input terminal 5, the output terminal 6, and the second resonator electrodes 3e to 3h, The arrangement of the capacitor electrode 7 and the damped resonator electrode 8 and the distance from each other (the thickness or number of layers of the dielectric layer 1a interposed therebetween) are not particularly limited, and the desired attenuation characteristics are obtained. What is necessary is just to set so that the coupling | bonding of each electrode and 2nd resonator electrode 3e-3h may be adjusted.

  In the filter device of this embodiment, the input terminal 5 for inputting a signal to the first resonator electrode 3a at the first stage and the second resonator electrode 3e at the first stage and the first resonator electrode 3d at the final stage. And an output terminal 6 for outputting a signal from the second resonator electrode 3h at the final stage.

  The input terminal 5 has a shape along the first resonator electrode 3a of the first stage, and is arranged so as to face the first resonator electrode 3a and the second resonator electrode 3e of the first stage across the dielectric layer 1a. The first resonator electrode 3a of the first stage is disposed on the second end side of the first resonator electrodes 3a to 3d and on the first end side of the second resonator electrodes 3e to 3h. An internal input terminal 5a that is electromagnetically coupled to the second resonator electrode 3e, and is formed on the outer surface of the multilayer body 1, and is connected to the internal input terminal 5a on the open end side of the first-stage first resonator electrode 3a. And an external input terminal 5b.

  The output terminal 6 has a shape along the first resonator electrode 3d in the final stage, and faces the first resonator electrode 3d and the second resonator electrode 3h in the final stage with the dielectric layer 1a interposed therebetween. Are arranged on the second end side of the first resonator electrodes 3a to 3d and on the first end side of the second resonator electrodes 3e to 3h, and the first resonance in the final stage. An internal output terminal 6a electromagnetically coupled to the resonator electrode 3d and the second resonator electrode 3h, and an open end of the first resonator electrode 3d at the final stage formed on the outer surface of the laminate 1 and connected to the internal output terminal 6a. And an external output terminal 6b connected on the side.

  By providing the input terminal 5 and the output terminal 6 as described above, the internal input terminal 5a is broadside-coupled to the first-stage first resonator electrode 3a and the first-stage second resonator electrode 3e and is interdigital type. In addition to the strong electromagnetic field coupling by the broadside coupling, the coupling by the electric field and the coupling by the magnetic field are added by the interdigital coupling, and the electromagnetic coupling is further strengthened, so that the internal input terminal 5a and the first stage The first resonator electrode 3a and the first-stage second resonator electrode 3e can be very strongly coupled.

Examples of the dielectric layer 1a include ceramic materials such as alumina, mullite, aluminum nitride, BaO—TiO ₂ , CaO—TiO ₂ , MgO—TiO ₂ and 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.

  1st reference electrode 2a, 2nd reference electrode 2b, internal reference electrode 9, 1st resonator electrode 3a-3d, 2nd resonator electrode 3e-3h, coupling electrode 4, input terminal 5, output terminal 6 When the dielectric layer 1a is made of a ceramic material, the capacitor electrode 7 and the damped resonator electrode 8 are formed of a metallized layer containing a metal such as W, Mo, Mo—Mn, Au, Ag, or Cu as a main component. be able to. 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. These thicknesses and widths are set according to the frequency and application of the transmitted high-frequency signal.

  Dielectric layer 1a, first reference electrode 2a, second reference electrode 2b, internal reference electrode 9, first resonator electrodes 3a-3d, second resonator electrodes 3e-3h, coupling electrode 4, input terminal 5, the output terminal 6, the capacitor electrode 7, and the damped resonator electrode 8 may be formed by a conventionally known method. For example, if the dielectric layer 1a is made of glass ceramics, first prepare green sheets of glass ceramics to be the dielectric layers 1a, and print a conductor paste such as Ag in a predetermined shape on the green sheets by screen printing. The first reference electrode 2a, the second reference electrode 2b, the internal reference electrode 9, the first resonator electrodes 3a to 3d, the second resonator electrodes 3e to 3h, the coupling electrode 4, the input terminal 5, The electrode patterns of the output terminal 6, the capacitor electrode 7, and the damped resonator electrode 8 are formed. Next, a laminated body is produced by stacking and pressing the green sheets on which these electrode patterns are formed, and the laminated body 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, a first reference electrode 2a, a second reference electrode 2b, an internal reference electrode 9, first resonator electrodes 3a to 3d on an organic resin sheet, Transfer the Cu foil processed into each electrode pattern shape of the second resonator electrodes 3e to 3h, the ground reinforcement portion 4a, the input terminal 5, the output terminal 6, the coupling electrode 4, the capacitive electrode 7, and the damped resonator electrode 8, It forms by laminating | stacking the organic resin sheet to which Cu foil was transcribe | transferred, and adhere | attaching with an adhesive agent.

  The connection conductor that connects the first reference electrode 2a and the short-circuit ends of the first resonator electrodes 3a to 3d and connects the second reference electrode 2b and the short-circuit ends of the second resonator electrodes 3e to 3h is Each of the laminated dielectric layers 1a is formed in the form of a through conductor formed in the dielectric layer 1a located between them or an end face conductor formed on the end surface of the dielectric layer 1a. The degree of freedom in designing the filter device formed inside can be 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 the side conductors serving as the connection conductors are, for example, the first reference electrode 2a and the second reference electrode in the manufacturing method described above. Reference electrode 2b, internal reference electrode 9, first resonator electrodes 3a-3d, second resonator electrodes 3e-3h, coupling electrode 4, input terminal 5, output terminal 6, capacitance electrode 7, damped resonator electrode 8 Before forming each electrode pattern, a similar conductive paste can be formed by filling a through hole that has been formed in advance on the green sheet by die machining or laser processing by a printing method or the like. For example, after forming a green sheet laminate in which the short-circuit ends of the electrode patterns of the first resonator electrodes 3a to 3d and the second resonator electrodes 3e to 3h are exposed at the end faces, It can be formed by printing a strike on the side surface of the green sheet laminate. In addition, the end face conductor is formed with a through-hole having a width approximately equal to the width of the first resonator electrodes 3a to 3d and the second resonator electrodes 3e to 3h in the green sheet, and the first resonator electrodes 3a to 3a are formed. After the short-circuit ends of the electrode patterns of the 3d and the second resonator electrodes 3e to 3h are formed so as to be in contact with this through hole, a conductor paste is printed on the inner surface of the through hole before or after the green sheet is laminated or laminated. It can also be formed by filling the hole and cutting at the through hole portion.

  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 first resonator electrodes 3a to 3d and the second resonator electrodes 3e to 3h on the side surface of the multilayer body, the first resonator electrodes 3a to 3d and the second resonance electrode are exposed. The short-circuit ends of the electrode patterns of the resonator electrodes 3e to 3h are formed so as to be positioned at the ends of the green sheet (or organic resin sheet), or the first resonator electrodes 3a to 3d and the second resonator electrodes 3e to 3h. After the green sheet (organic resin sheet) on which the 3h electrode pattern is formed is laminated, the short-circuit ends of the electrode patterns of the first resonator electrodes 3a to 3d and the second resonator electrodes 3e to 3h are exposed to the side surface. The laminated body may be cut.

Specifically, a filter device as a bandpass filter having a passband center frequency of 3.9 GHz, which is used in the UWB low-band standard, has a configuration as shown in FIG. 3, for example, the dielectric layer 1a. Glass ceramics having a relative dielectric constant of 9.4, the first reference electrode 2a, the second reference electrode 2b, the internal reference electrode 9, the first resonator electrodes 3a to 3d, and the second resonator electrode 3e. ~ 3h, obtained by using Ag metallization for coupling electrode 4, input terminal 5, output terminal 6, capacitor electrode 7 and through conductor. Glass ceramics having a relative dielectric constant of 9.4 include, for example, 50 crystallized glasses mainly composed of PbO, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , ZnO and alkaline earth metal oxide as glass components. What consists of a mass% and 50 mass% of alumina as a filler component may be used.

  At this time, the dielectric layer 1a has a thickness of 400 μm, 75 μm, 75 μm, and 350 μm in order from the top. The first reference electrode 2a and the second reference electrode 2b have a dimension of 3.35 mm × 5.0 mm, and the internal reference electrode 9 has an outer dimension of 3.35 mm × 5.0 mm and an inner dimension (opening dimension). 2.945 mm × 3.5 mm. In this opening, first resonator electrodes 3a to 3d having dimensions of 0.4 mm × 3.35 mm are aligned side by side at intervals of 0.155 mm, 0.135 mm, and 0.155 mm, and each short-circuited end is an internal reference electrode. 9 are arranged such that the distance between each open end and the internal reference electrode 9 is 0.15 mm, and the distance between the first resonator electrodes 3a and 3d and the internal reference electrode 9 is 0.45 mm. The internal reference electrode 9 and the first reference electrode 2a located on the upper surface of the multilayer body 1 and the internal reference electrode 9 and the second reference electrode 2b located on the lower surface of the multilayer body 1 have a diameter of 0. Connect with a 1 mm through conductor.

  The input terminal 5 is arranged such that the internal input terminal 5b of 0.3 mm × 3.35 mm overlaps with the open end side of the first resonator electrode 3a of the first stage in a range of 0.3 mm × 3.35 mm in plan view. The external input terminal 5a of 0.2 mm × 0.2 mm is connected by a through conductor having a diameter of 0.1 mm. Similarly, the output terminal 6 is arranged such that the internal output terminal 6b of 0.3 mm × 3.35 mm overlaps with the open end side of the first resonator electrode 3d at the final stage by 0.3 mm × 3.35 mm in plan view. The external output terminal 6a of 0.2 mm × 0.2 mm is connected by a through conductor having a diameter of 0.1 mm. The coupling electrode 4 has a crank shape in which two opposing portions of 0.1 mm × 2.0 mm are connected by a connecting portion of 1.545 mm × 0.1 mm, and the two opposing portions are respectively the first resonator electrodes 3a in the first stage. And arranged so as to overlap the short-circuit end side of the first resonator electrode 3d in the final stage in a range of 0.1 mm × 1.8 mm in plan view, and has a diameter of 0.1 mm at the center of the portion overlapping the internal reference electrode 9. Connected to the internal reference electrode 9 by a through conductor.

  The ground reinforcement portions 4a and 4a are coupled with a 0.1 mm × 1.45 mm conductor layer spaced from the coupling electrode 4 to the outside of the first resonator electrodes 3a and 3d at both ends of the coupling electrode 4 by 0.31 mm. Same as the L-shape in which the facing part and the end part of the electrode 4 are aligned and arranged in parallel, and connected to each other by a conductor layer of 0.31 mm × 0.1 mm at a position of 1.35 mm from one end and the other end of the coupling electrode 4. Are connected to the internal reference electrode 9 by a through conductor having a diameter of 0.1 mm at the center of the portion overlapping the internal reference electrode 9.

  The capacitive electrode 7 is a convex shape in which two rectangles of 0.2 mm × 0.4 mm and 0.4 mm × 0.6 mm are connected, and overlaps with the internal reference electrode 9 in the range of 0.4 mm × 0.6 mm, It arrange | positions so that it may overlap with the open end part of resonator electrode 3a, 3b, 3c, 3d in the range of 0.2 mm x 0.25 mm by planar view, and it connects by the through-conductor with a diameter of 0.1 mm in the center of the overlapping part.

  The filter characteristics of the filter device of such an embodiment are as shown by a solid characteristic curve in the diagram of FIG. 12 (Example 1). In addition, with respect to the filter characteristics of the filter device of such an embodiment, the filter characteristics obtained in the filter device (comparative example) in which the coupling electrode 4 is not branched and grounded between one end and the other end are as follows: FIG. 12 shows a characteristic curve indicated by a broken line. In the diagram shown in FIG. 12, the vertical axis represents insertion loss (unit: dB), and the horizontal axis represents frequency (unit: GHz).

  From the filter characteristics shown in FIG. 12, it can be seen that the filter characteristics of the filter device of the present embodiment have attenuation characteristics in which the attenuation amounts on the high frequency side and the low frequency side are larger than the pass band.

  The filter characteristics of another example (Example 2) in which the ground reinforcement portions 4a and 4a are the same as the example shown in FIG. The diagram of FIG. 13 similar to FIG. 12 is as shown by a solid characteristic curve. The broken characteristic curve indicates the filter characteristic of the comparative example as in FIG. Specifically, the filter device according to the second embodiment is different from the filter according to the first embodiment in that the ground reinforcement portion 4a is provided with a conductor layer of 0.1 mm × 1.45 mm at both ends of the coupling electrode 4. Are spaced apart from each other by 0.99 mm to the inside of the first resonator electrodes 3 a and 3 d, and the center in the width direction is aligned with the resonator electrodes 3 b and 3 c, and the end is aligned in parallel with the opposing portion of the coupling electrode 4. The coupling electrode 4 was formed in an L shape connected by a conductor layer of 0.99 mm × 0.1 mm at a position of 1.35 mm from the one end and the other end.

  From the filter characteristics shown in FIG. 13, the filter characteristics of the filter device of the second embodiment are compared with the filter characteristics of the filter device of the first embodiment at the attenuation poles on the low band side and high band side of the pass band. The position (frequency) of the band is slightly adjusted to the low band side and the high band side to increase the attenuation amount of the attenuation pole, and on the high band side of the pass band, the highest attenuation pole is shifted to the pass band side. As a result, the two attenuation poles are in the same position, and one large attenuation pole is formed by reversing the phase. This further increases the attenuation amount of the low frequency band and high frequency band of the pass band. You can see that

  The filter device of the present embodiment has a ground reinforcement portion 4a that is electrically connected to the first reference electrode 2a while the coupling electrode 4 is branched between one end and the other end. Thereby, since the current from the branch point of the coupling electrode 4 to the ground side (first reference electrode 2a) can be greatly increased, while forming an attenuation pole at a position (frequency) closer to the pass band of the filter, It can be seen that it has excellent attenuation characteristics in which the attenuation amount of the frequency band on the low frequency side and the high frequency side is further increased than the attenuation pole on the low frequency side and the high frequency side. The ground reinforcement portions 4a and 4a are opposed to the short-circuited ends of the resonator electrodes 3b and 3c other than the first and last-stage first resonator electrodes 3a and 3d and are electrically connected to the short-circuited ends. Sometimes, the coupling between the first resonator electrode 3a, 3d at the first stage or the last stage and the first resonator electrode 3a, 3d other than the first and last stage resonator electrodes can be strengthened, so that the passband of the filter The attenuation amount of the low-frequency side and high-frequency side attenuation poles further increases, and by forming an attenuation pole on the high-frequency side further than the high-frequency side attenuation pole of the passband, It turns out that it has the outstanding attenuation | damping characteristic which the attenuation amount of the high frequency band increased further.

  Note that the conventional filter device has a structure that does not have the capacitor electrode 7 as compared with the comparative example. In such a conventional filter device, in order to have an attenuation pole at the same frequency as the filter device of this embodiment (and the filter device of the comparative example), the first resonator electrodes 3a to 3d are lengthened. In addition to an increase in the size of the filter device, there is a jump in the attenuation characteristic on the higher frequency side than the attenuation pole, and the filter is not sufficiently attenuated in the attenuation band relative to the band used in the wireless LAN. It becomes a characteristic.

  Next, the wireless module and the wireless communication device of the present invention will be described below. FIG. 14 is a cross-sectional view showing an example of an embodiment of the wireless module and the wireless communication device of the present invention. In FIG. 14, 10 is a filter device, 11 is an integrated circuit, 12 is a bump, 13 is a printed circuit board, 14 is an RF unit, 15 is a baseband unit, and 16 is an antenna.

  As shown in FIG. 14, the wireless communication module of the present embodiment is disposed on the filter device 10 according to any one of the above and the first end surface side (upper surface side in FIG. 14) of the filter device 10, and bumps The integrated circuit 11 electrically connected to the filter device 10 via 12, the second end face side (lower surface side in FIG. 14) of the filter device 10, and the filter device 10 via the bump 12 And a printed circuit board 13 which is electrically connected.

  In the present embodiment, the filter device 10 and a portion including the integrated circuit 11 that is disposed on the first end face side of the filter device 10 and is electrically connected to the filter device 10 via the bumps 12. Constitutes the RF unit 14, and the wireless communication device of the present embodiment is electrically connected to the RF unit 14, the printed circuit board 13 electrically connected to the RF unit 14, and the printed circuit board 13. The baseband part 15 connected in general and the antenna 16 electrically connected to the RF part 14 through the printed circuit board 13 are provided.

  According to the wireless communication module and the wireless communication device of the present embodiment, compared to the conventional filter device, while forming the attenuation pole at a frequency closer to the pass band of the filter, the attenuation band on the low frequency side and the high frequency side. Furthermore, the filter device according to any one of the above, which has an excellent attenuation characteristic in which the attenuation amount of the low frequency band and the high frequency band is increased. For this reason, the attenuation of the reception signal and the transmission signal passing through the filter device is reduced and the noise is also reduced. Thereby, 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. As a result, a high-performance wireless communication module and wireless communication device with high reception sensitivity and low power consumption can be obtained. Furthermore, since two communication bands can be covered with one filter, a wireless communication module and a wireless communication device that are small in size and low in manufacturing cost can be obtained.

  In the present embodiment, the integrated circuit 11 is disposed on the first end face side of the filter device 10 and is electrically connected to the filter device 10 via the bumps 12. The printed circuit board 13 is disposed on the second end face side of the filter device 10 and is electrically connected to the filter device 10 via the bumps 12. Here, the integrated circuit 11 is disposed on the first end face side of the base body using the substrate having the filter device 10 built therein, and is electrically connected to the base body via the bumps 12. It may be disposed on the second end face side and electrically connected to the base via the bumps 12.

It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. (A)-(f) is a top view which shows an example of embodiment in the filter apparatus of this invention, respectively. (A) And (b) is a top view which shows an example of embodiment in the filter apparatus of this invention, respectively. It is sectional drawing which shows an example of the AA cross section of the filter apparatus shown in FIG. It is a disassembled perspective view which shows typically an example of embodiment in the filter apparatus of this invention. It is a disassembled perspective view which shows typically an example of embodiment in 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 other filter apparatus of this invention. It is sectional drawing which shows an example of embodiment in the radio | wireless module and radio | wireless communication 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 2a ... 1st reference electrode 2b ... 2nd reference electrode 3a-3d ... 1st resonator electrode 3a ... 1st stage 1st 1 resonator electrode 3d... 1st resonator electrode 3e to 3h in the final stage 2nd resonator electrode 3e... 2nd resonator electrode 3h in the first stage 3h. 2. Resonator electrode 4 ... Coupling electrode 4a ... Ground strengthening part 4b ... Reference electrode facing part 5 ... Input terminal 5a ... External input terminal 5b ... Internal input terminal 6 ... Output terminal 6a ... External output terminal 6b ... Internal output terminal 7 ... Capacitance electrode 8 ... Damping resonator electrode 9 ... Internal reference electrode 10 ... Filter device 11 ... Integrated circuit 12 ... Bump 13 ... Printed circuit board 14 ... RF part 15 ... Baseband part 16 ... Ante Na

Claims (15)

A laminate in which a plurality of dielectric layers are laminated;
A first reference electrode disposed at a first end of the laminate;
A second reference electrode disposed at a second end of the laminate;
Three or more resonator electrodes arranged side by side in a plan view so as to be electromagnetically coupled to each other in the laminate, each having one end short-circuited and the other end open-ended;
The first electrode is disposed closer to the first end than the resonator electrode, with one end facing the short-circuited end of the first-stage resonator electrode across the dielectric layer and a short circuit between the opposed resonator electrodes. And a coupling electrode electrically connected to the short-circuited end of the resonator electrode opposite to the short-circuited end of the resonator electrode at the final stage,
An input terminal for inputting a signal to the first-stage resonator electrode;
A filter device including an output terminal for outputting a signal from the resonator electrode of the final stage,
The filter device according to claim 1, wherein the coupling electrode has a branch portion that is grounded between the one end and the other end. 2. The filter device according to claim 1, wherein the coupling electrode includes a ground reinforcement portion that is electrically connected to at least one of the first reference electrode and the second reference electrode. The filter device according to claim 2, wherein an internal reference electrode is formed so as to surround the plurality of resonator electrodes when the resonator electrodes are viewed in plan. The number of the resonator electrodes is four or more, and the ground reinforcing portion is opposed to the short-circuited end portion of the resonator electrode other than the first-stage and final-stage resonator electrodes and is electrically connected to the short-circuited end. The filter device according to claim 2, wherein: The ground reinforcing portion is formed along the internal reference electrode by branching out to the outside of the resonator electrode in plan view between the dielectric layers where the coupling electrode is disposed. The filter device according to claim 3. 4. The filter device according to claim 3, wherein the ground reinforcement portion includes a reference electrode facing portion facing the first reference electrode or the internal reference electrode. The first reference electrode and the resonator electrode are opposed to the first reference electrode with the dielectric layer interposed therebetween, and are electrically connected to the open ends of the plurality of resonator electrodes, respectively. The filter device according to claim 1, comprising a plurality of capacitive electrodes. When the resonator electrode is viewed in plan, an internal reference electrode is formed so as to surround the plurality of resonator electrodes, and a part of the capacitive electrode is opposed to the internal reference electrode with the dielectric layer in between. The filter device according to claim 7, wherein the filter device is disposed on the filter. The input terminal has a shape along the first-stage resonator electrode, and is disposed closer to the second end than the resonator electrode so as to face the first-stage resonator electrode with the dielectric layer interposed therebetween. An internal input terminal that is electromagnetically coupled to the first-stage resonator electrode, and an external input that is formed on the outer surface of the multilayer body and connected to the internal input terminal on the open end side of the first-stage resonator electrode. And the output terminal has a shape along the resonator electrode at the final stage, and is more than the resonator electrode so as to face the resonator electrode at the final stage across the dielectric layer. An internal output terminal disposed on the second end side and electromagnetically coupled to the final stage resonator electrode; and formed on an outer surface of the laminate, and the internal output terminal is connected to the final stage of the resonator electrode. An external output terminal connected on the open end side. Filter apparatus according to any one of claims 1 to 8, characterized in. It is arranged to be electromagnetically coupled to one of the resonator electrodes in the laminate other than between the resonator electrodes, and has at least one damped resonator electrode having one end short-circuited and the other end open. The filter device according to claim 1, wherein: The filter device according to claim 10, wherein the damped resonator electrode has a shape in which the open end is branched into a plurality, and the length from the short-circuited end to each tip of the open end is different. In the case where the resonator electrode is a first resonator electrode, the resonator electrode is disposed on the second end side with respect to the first resonator electrode in the stacked body and through the dielectric layer. 2. The apparatus according to claim 1, further comprising a plurality of second resonator electrodes arranged side by side in a plan view so as to be electromagnetically coupled, each having one end short-circuited and the other end open. Filter device. The input terminal has a shape along the first resonator electrode in the first stage, and is opposed to the first resonator electrode and the second resonator electrode in the first stage across the dielectric layer. The first resonator electrode at the first stage disposed on the second end side with respect to the first resonator electrode and on the first end side with respect to the second resonator electrode, and the first resonator electrode. An internal input terminal electromagnetically coupled to the two resonator electrodes, and an external input formed on the outer surface of the laminate and connected to the internal input terminal on the open end side of the first resonator electrode of the first stage A terminal,
The output terminal has a shape along the first resonator electrode in the final stage, and faces the first resonator electrode and the second resonator electrode in the final stage with the dielectric layer interposed therebetween. The first resonator electrode at the final stage is disposed closer to the second end than the first resonator electrode and closer to the first end than the second resonator electrode. And an internal output terminal that is electromagnetically coupled to the second resonator electrode, and is formed on the outer surface of the laminate, and is connected to the internal output terminal on the open end side of the first resonator electrode in the final stage. 13. The filter device according to claim 12, further comprising an external output terminal.   A wireless communication module comprising the filter device according to claim 1. A wireless communication device 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.

Images