WO2012121038A1

WO2012121038A1 - Filter

Info

Publication number: WO2012121038A1
Application number: PCT/JP2012/054717
Authority: WO
Inventors: 岸本健
Original assignee: 株式会社村田製作所
Priority date: 2011-03-07
Filing date: 2012-02-27
Publication date: 2012-09-13
Also published as: CN103329434A; TWI577131B; TW201249102A; CN103329434B

Abstract

First and second series inductors (L1A, L1B) are serially connected between first and second output terminals (Port1, Port2), forming a signal line. The connection point of the first and second series inductors (L1A, L1B) is connected to a ground potential via a shunt inductor (L2). The shunt inductor (L2) is positioned with respect to the first and second series inductors (L1A, L1B) such that the electromagnetic binding quantity of the first series inductor (L1A) to the shunt inductor (L2) and the electromagnetic binding quantity of the second series inductor (L1B) to the shunt inductor (L2) are the same.

Description

filter

The present invention relates to a filter having a configuration including an inductor.

Conventionally, various filters having a configuration including an inductor have been devised. Among them, a filter composed of a so-called T-type circuit in which two series inductors are connected in series to a signal line and a shunt inductor is connected between the connection point of these series inductors and the ground is described in Patent Document 1, for example. Has been.

When a T-type circuit using such a series inductor and a shunt inductor is realized on a multilayer substrate, as shown in Patent Document 1, each inductor may be formed of an inner layer electrode pattern of the multilayer substrate. When each inductor is formed by the inner layer electrode pattern, conventionally, as shown in Patent Document 1, the series inductor formation layer is different from the shunt inductor formation layer, and the series inductor and the shunt inductor are not electromagnetically coupled. Thus, a ground electrode is formed between these formation layers.

JP 2007-129565 A

However, in the configuration shown in Patent Document 1 described above, since the ground electrode layer must be provided between the formation layer of the shunt inductor and the formation layer of the series inductor, the laminate becomes thicker by the ground electrode layer, and the series The wiring pattern connecting the inductor and the shunt inductor and the position of the conductive via hole must also be devised. Therefore, it is difficult to realize a low-profile and small-sized laminate, and the degree of design freedom is low.

Even if the ground electrode layer is not provided, electromagnetic coupling can be suppressed if the series inductor formation layer and the shunt inductor formation layer are separated from each other. It becomes impossible to make it thinner and thinner.

An object of the present invention is to realize a filter that can reduce the thickness and thickness of a multilayer body without reducing the degree of freedom in design even in a configuration having a series inductor and a shunt inductor.

According to the present invention, a first series inductor and a second series inductor connected in series between a first input / output terminal and a second input / output terminal, and a connection point between the first series inductor and the second series inductor are connected to a ground potential. And a shunt inductor connected to the filter. The shunt inductor of this filter is arranged to be electromagnetically coupled to both the first series inductor and the second series inductor.

In this configuration, the electromagnetic coupling amount of the shunt inductor with respect to both the first series inductor and the second series inductor can be adjusted, and the substantial inductance with respect to the transmission signal of the shunt inductor is adjusted according to the coupling amount. The characteristics can be adjusted. At this time, since it is not necessary to interpose a ground potential, pattern design corresponding to a desired inductance and shape can be performed more easily than the conventional configuration.

In the filter of the present invention, it is preferable that the shunt inductor has an electromagnetic field coupling amount with respect to the first series inductor and an electromagnetic field coupling amount with respect to the second series inductor.

With this configuration, only the inductance of the shunt inductor can be adjusted without changing the inductance of the first series inductor and the second series inductor.

Also, the filter of the present invention preferably has the following configuration. A laminated body formed by laminating a plurality of dielectric layers, an electrode pattern of a first series inductor formed in the laminated body, an electrode pattern of a second series inductor, and an electrode pattern of a shunt inductor are provided. The dielectric layer in which the electrode pattern of the first series inductor and the electrode pattern of the second series inductor are formed is different from the dielectric layer in which the electrode pattern of the shunt inductor is formed. When viewed from the top surface side of the multilayer body, the electrode pattern of the shunt inductor is disposed so as to partially overlap the electrode pattern of the first series inductor and the electrode pattern of the second series inductor.

In this configuration, electromagnetic coupling between each of the first series inductor and the second series inductor and the shunt inductor is realized along the stacking direction.

Also, the filter of the present invention preferably has the following configuration. A laminate formed by laminating a plurality of dielectric layers, a dielectric layer formed with an electrode pattern of a first series inductor formed in the laminate, and a dielectric layer formed with an electrode pattern of a shunt inductor at least Partially match. Further, the dielectric layer on which the electrode pattern of the second series inductor is formed and the dielectric layer on which the electrode pattern of the shunt inductor is formed at least partially coincide. The shunt inductor is electromagnetically coupled to the first series inductor and the second series inductor by electromagnetic coupling within the layer.

In this configuration, electromagnetic coupling between each of the first series inductor and the second series inductor and the shunt inductor is realized in the plane of the dielectric layer.

Further, in the filter of the present invention, the current direction of the first series inductor and the second series inductor and the current direction of the shunt inductor can be made the same when viewed from the top surface side of the multilayer body.

In this configuration, the inductance of the shunt inductor is reduced. That is, without changing the shape of the shunt inductor, the inductance can be made smaller than the configuration in which each series inductor is not electromagnetically coupled.

Further, the filter of the present invention can be configured such that the current direction of the first series inductor and the second series inductor and the current direction of the shunt inductor are reversed when viewed from the top surface side of the multilayer body.

In this configuration, the inductance of the shunt inductor is increased. That is, without changing the shape of the shunt inductor, the inductance can be made larger than the configuration in which each series inductor is not electromagnetically coupled. In other words, the shape for obtaining the same inductance as that of the configuration in which each series inductor is not electromagnetically coupled can be reduced. Alternatively, the electrode width can be widened as a shape for obtaining the same inductance as the configuration in which each series inductor is not electromagnetically coupled.

Further, in the filter of the present invention, it is preferable to provide a capacitor with a first series inductor, a second series inductor, and a shunt inductor so as to have a band pass characteristic. In this configuration, a bandpass filter can be realized using the above-described inductor connection configuration.

Also, the filter of the present invention preferably has the following configuration. A first capacitor connected in series between the first input / output terminal and the first series inductor, a second input / output terminal, and a second series inductor together with the first series inductor, the second series inductor, and the shunt inductor. A second capacitor connected in series between the second capacitor, a third capacitor connected between the shunt inductor and the ground potential, a connection point between the first series inductor and the first capacitor, and a connection between the shunt inductor and the third capacitor. A fourth capacitor for connecting the points, a fifth capacitor for connecting a connection point between the second series inductor and the second capacitor, a connection point between the shunt inductor and the third capacitor, a first input / output terminal and a second input / output And a sixth capacitor connected in series with the terminal, and a filter having a bandpass characteristic.When viewed from the top surface side of the multilayer body, the formation region of the first series inductor, the first capacitor, and the fourth capacitor does not overlap the formation region of the second series inductor, the second capacitor, and the fifth capacitor. Placed in.

This configuration shows a more specific configuration of the band-pass filter using the above-described inductor connection configuration. And by using the above-mentioned laminated structure, unnecessary coupling can be suppressed and a bandpass filter having excellent characteristics can be realized.

In the filter of the present invention, it is also possible to form a filter having a high-pass characteristic by including a capacitor together with the first series inductor, the second series inductor, and the shunt inductor. In this configuration, a bandpass filter can be realized using the above-described inductor connection configuration.

∙ Realizes a filter that can reduce the thickness and thickness of the multilayer body without reducing the degree of freedom in design, even if it has a series inductor and shunt inductor.

FIG. 3 is an equivalent circuit diagram of a T-type inductor circuit according to an embodiment of the present invention and a circuit diagram for easily showing an electromagnetic field coupling relationship. It is a disassembled perspective view of the laminated body 101 which implement | achieves the T type inductor circuit of this embodiment. It is a stacking figure of the laminated body 101 which implement | achieves the T type inductor circuit of this embodiment. It is an equivalent circuit diagram of the band pass filter of this embodiment. It is a stacking figure of the band pass filter of this embodiment. It is a pass characteristic figure of the band pass filter containing the T type inductor circuit of this embodiment, and the band pass filter of the conventional structure. It is an equivalent circuit diagram of the high pass filter concerning the embodiment of the present invention. It is a stacking figure of the high pass filter of this embodiment. FIG. 6 is a partial stacking diagram illustrating an example of a laminated structure in a case where two series inductors L1A and L1B are electromagnetically coupled to a shunt inductor L2 with a single dielectric layer. FIG. 5 is a partial stacking diagram illustrating an example of a laminated structure in the case where two series inductors L1A and L1B are electromagnetically coupled to shunt inductors L2 in different dielectric layers.

A filter circuit according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is an equivalent circuit diagram of a T-type inductor circuit used in the filter circuit of the present embodiment, and FIG. 1B is a circuit diagram showing the electromagnetic field coupling relationship of the T-type inductor circuit in an easy-to-understand manner. .

As shown in FIG. 1, in the T-type inductor circuit of the present embodiment, the first series inductor L1A and the second series inductor L1B are connected to the signal line connecting the first input / output terminal Port1 and the second input / output terminal Port2. Are connected in series. More specifically, the first series inductor L1A and the second series inductor L1B are connected in series in this order from the first input / output terminal Port1 side to the second input / output terminal Port2 side.

The connection point between the first series inductor L1A and the second series inductor L1B is connected to the ground potential by the shunt inductor L2.

In such a T-type inductor circuit, as shown in FIG. 1B, the shunt inductor L2 is configured by a series circuit of a partial inductor L2A ′, a partial inductor L2 ″, and a partial inductor L2B ′.

The partial inductor L2A 'is electromagnetically coupled to the first series inductor L1A. The partial inductor L2 ″ is not electromagnetically coupled to the first series inductor L1A and the second series inductor L1B. The partial inductor L2B ′ is electromagnetically coupled to the second series inductor L1B.

The electromagnetic field coupling amount between the partial inductor L2A 'and the first series inductor L1A is the same as the electromagnetic field coupling amount between the partial inductor L2B' and the second series inductor L1B.

By configuring in such a T-type inductor circuit, the first series inductor L1A, the second series inductor L1B, and the shunt inductor are electromagnetically coupled, and a mutual inductance M is generated in each.

However, the mutual inductance M generated in the first series inductor L1A connected in series with the signal line cancels out the mutual inductance M generated in the second series inductor L1B. Therefore, even if the first series inductor L1A and the second series inductor L1B generate the mutual inductance M with respect to the shunt inductor L2, the substantial inductance value of the composite inductor connected in series to the signal line does not change.

On the other hand, if the shunt inductor L2 is an inductance L (L2) as an element in a state where the mutual inductance M does not occur, the substantial inductance becomes L (L2) -2M due to the mutual inductance M.

Here, if the shunt inductor L2 is electromagnetically coupled to the first and second series inductors L1A and L1B so that the mutual inductance M becomes a positive value, the substantial shape of the shunt inductor L2 is not changed without changing the shape. Inductance can be reduced.

Further, if the shunt inductor is electromagnetically coupled to the first and second series inductors L1A and L1B so that the mutual inductance M becomes a negative value, the substantial inductance of the shunt inductor L2 can be obtained without changing the shape. Can be bigger.

As described above, the inventor of the present invention uses the T-type inductor circuit having the circuit configuration of the present embodiment, and thus cannot be realized with the conventionally considered T-type inductor circuit without changing the shape of each inductor. It was found that only the inductance of the shunt inductor was changed without changing the inductance of the series inductor connected in series to the signal line. Thereby, the filter characteristic of the filter provided with the T-type inductor circuit can be adjusted without changing the shape of each inductor. Moreover, the shape can be changed even with filters having the same characteristics. For example, a filter having the same characteristics can be formed in a smaller size.

The T-type inductor circuit having such a configuration can be realized by the following structure using a multilayer body. FIG. 2 is an exploded perspective view of the multilayer body 101 that realizes the T-type inductor circuit of the present embodiment. FIG. 3 is a stack diagram of the multilayer body 101 that realizes the T-type inductor circuit of the present embodiment. FIG. 3 is a view of each dielectric layer viewed in the stacking direction of the stacked body 101, that is, a view viewed from a direction orthogonal to the top surface or the bottom surface of the stacked body 101. 2 and 3, only the portion of the T-type inductor circuit is shown, and the other dielectric layers, other electrode patterns, and mounting electrodes constituting the multilayer body 101 are not shown.

The laminated body 100 is formed by laminating five dielectric layers PL1, PL2, PL3, PL4, and PL5. On the dielectric layer PL1, which is the first layer, linear linear electrodes 101 are formed along the first direction (the direction from the left back to the right front in FIG. 2, the horizontal direction in FIG. 3). . The linear electrode 101 has a structure in which

linear electrodes

101A and 101B are continuously formed.

The end of the linear electrode 101A opposite to the side connected to the linear electrode 101B is connected to a conductive via hole VH13A that penetrates the dielectric layers PL1 and PL2. The end of the linear electrode 101B opposite to the side connected to the linear electrode 101A is connected to a conductive via hole VH13B that penetrates the dielectric layers PL1 and PL2.

The connection point of the

linear electrodes

101A and 101B is connected to the dielectric via a short-distance wiring electrode extending in a second direction perpendicular to these (in the direction from the left front to the right back in FIG. 2, the vertical direction in FIG. 3). The conductive via hole VH12 that penetrates the layer PL1 is connected.

In the second layer PL2 on the lower layer side of the first layer PL1, the wound linear electrode 102 constituting the shunt inductor L2 is formed. The linear electrode 102 includes

linear electrodes

121 and 122 parallel to the second direction, and a linear electrode 123 parallel to the first direction. These

linear electrodes

121, 122, 123 correspond to each part of the shunt inductor L2 as follows from the structure below the dielectric layer PL3 described later. The linear electrode 121 corresponds to the partial inductor L2A ′ of the above shunt inductor L2, the linear electrode 122 corresponds to the partial inductor L2B ′ of the above shunt inductor L2, and the linear electrode 123 corresponds to the partial shunt inductor L2. This corresponds to the inductor L2 ″.

One end of the linear electrode 121 is connected to the conductive via hole VH12. The other end of the linear electrode 121 is connected to one end of the linear electrode 123. One end of the linear electrode 122 is connected to the other end of the linear electrode 123, and the other end of the linear electrode 122 is connected to an electrode having a ground potential through a conductive via hole (not shown).

The third layer PL3 on the lower layer side of the second layer PL2 constitutes the wound linear electrode 103A constituting a part of the first series inductor L1A and a part of the second series inductor L1B. A wound linear electrode 103B is formed. The

linear electrodes

103A and 103B are formed at a predetermined interval along the first direction.

The linear electrode 103A includes two

linear portions

131A and 133A that are parallel to the second direction, and an intermediate linear portion 132A that connects the

linear portions

131A and 133A and is parallel to the first direction. The end of the linear portion 131A opposite to the side connected to the intermediate linear portion 132A is connected to a conductive via hole VH13A that penetrates the dielectric layers PL1 and PL2. The end of the linear portion 133A opposite to the side connected to the intermediate linear portion 132A is connected to a conductive via hole VH34A that penetrates the dielectric layer PL3.

Here, the linear portion 133A is viewed from the linear electrode 121 of the linear electrode 102 formed on the dielectric layer PL2 and the top surface side of the stacked body 100 (when viewing each dielectric layer in plan view), It is formed to overlap. With this configuration, the linear portion 133A configuring the first series inductor L1A and the linear electrode 121 configuring the partial inductor L2A ′ of the shunt inductor L2 are electromagnetically coupled along the stacking direction. Thereby, the mutual inductance M can be generated between the first series inductor L1A 'and the shunt inductor L2A'.

The linear electrode 103B includes two

linear portions

131B and 133B that are parallel to the second direction, and an intermediate linear portion 132B that connects the

linear portions

131B and 133B and is parallel to the first direction. The end of the linear portion 131B opposite to the side connected to the intermediate linear portion 132B is connected to a conductive via hole VH13B that penetrates the dielectric layers PL1 and PL2. The end of the linear portion 133B opposite to the side connected to the intermediate linear portion 132B is connected to a conductive via hole VH34B that penetrates the dielectric layer PL3.

Here, the linear portion 133B is viewed from the linear electrode 122 of the linear electrode 102 formed on the dielectric layer PL2 and the top surface side of the stacked body 100 (when viewing each dielectric layer in plan view), It is formed to overlap. With this configuration, the linear portion 133B configuring the second series inductor L1B and the linear electrode 122 configuring the partial inductor L2B ′ of the shunt inductor L2 are electromagnetically coupled along the stacking direction. Thereby, the mutual inductance M can be generated between the second series inductor L1B 'and the shunt inductor L2B'.

In the fourth layer PL4 on the lower layer side of the third layer PL3, a wound linear electrode 104A constituting a part of the first series inductor L1A and a part of the second series inductor L1B are constituted. A wound linear electrode 104B is formed. The

linear electrodes

104A and 104B are formed at a predetermined interval along the first direction.

One end of the linear electrode 104A is connected to the conductive via hole VH34A. The other end of the linear electrode 104A is connected to a conductive via hole VH45A that penetrates the dielectric layer PL4. The linear electrode 104A is formed in substantially the same region as the linear electrode 103A when viewed from the top surface side of the multilayer body 100, and is formed so as to partially overlap.

One end of the linear electrode 104B is connected to the conductive via hole VH34B. The other end of the linear electrode 104B is connected to a conductive via hole VH45B that penetrates the dielectric layer PL4.

The fifth layer PL5 on the lower layer side of the fourth layer PL4 has a linear electrode 105A constituting a part of the first series inductor L1A and a linear electrode 105B constituting a part of the second series inductor L1B. And are formed. The

linear electrodes

105A and 105B are formed at a predetermined interval along the first direction.

One end of the linear electrode 105A is connected to the conductive via hole VH45A. The other end of the linear electrode 105A is connected to the electrode constituting the first input / output terminal Port1 through a conductive via hole (not shown).

One end of the linear electrode 105B is connected to the conductive via hole VH45B. The other end of the linear electrode 105B is connected to the electrode constituting the second input / output terminal Port2 through a conductive via hole (not shown).

In such a configuration, when the first series inductor L1A, the second series inductor L1B, and the shunt inductor L2 are electromagnetically coupled so that the direction of current flow is the same when viewed from the top surface side of the multilayer body. The mutual inductance M becomes a positive value. If the first series inductor L1A, the second series inductor L1B, and the shunt inductor L2 are electromagnetically coupled so that the direction of current flow is reversed when viewed from the top side of the multilayer body, the mutual inductance M is negative. Value. Therefore, if each inductor is disposed so as to define the relationship between these current directions, characteristics corresponding to the respective shapes can be obtained.

By using the configuration as described above, it is possible to realize a T-type inductor circuit capable of adjusting the characteristics by intentionally generating the mutual inductance M as described above.

And by using this structure, since it is not necessary to provide a ground electrode layer for preventing electromagnetic field coupling between the first and second series inductors L1A and L1B and the shunt inductor L2, the stacked body can be reduced in height. Further, since it is not necessary to separate the first and second series inductors L1A and L1B and the shunt inductor L2 from above and below the ground electrode layer, the wiring pattern of the routing electrode for connecting them in a T-type like an equivalent circuit Simple and easy pattern.

The T-type inductor circuit having such a circuit configuration and structure can be used for the following bandpass filter. FIG. 4 is an equivalent circuit diagram of the bandpass filter of the present embodiment. FIG. 5 is a stack diagram of the band-pass filter of this embodiment. FIG. 5 also shows an electrode pattern constituting a circuit different from the bandpass filter of this embodiment, and only the portion related to the bandpass filter will be described below. In FIG. 5, the circles described in the dielectric layers PL101 to PL112 indicate conductive via holes. In FIG. 5, only the dielectric layer related to the bandpass filter is shown, and the illustration of the configuration other than the dielectric layer realizing the bandpass filter is omitted or the description is omitted.

First, the circuit configuration will be described with reference to FIG.
As described above, the band-pass filter of the present embodiment includes a series circuit of the first series inductor L1A and the second series inductor L1B, and the connection point of the first series inductor L1A and the second series inductor L1B is determined by the shunt inductor L2. Connected to ground potential.

A first series capacitor C1A is connected between the first series inductor L1A and the first input / output terminal Port1. A second series capacitor C1B is connected between the second series inductor L1B and the second input / output terminal Port2.

A first shunt capacitor C3 is connected between the shunt inductor L2 and the grant potential.

The connection point between the first series inductor L1A and the first series capacitor C1A is connected to the connection point between the shunt inductor L2 and the first shunt capacitor C3 via the second shunt capacitor C2A.

The connection point between the second series inductor L1B and the second series capacitor C1B is connected to the connection point between the shunt inductor L2 and the first shunt capacitor C3 via the third shunt capacitor C2B.

A third series capacitor C0 is connected between the first input / output terminal Port and the second input / output terminal Port2.

Next, the laminated structure will be described with reference to FIG.
A plate electrode for the third series capacitor C0 is formed on the dielectric layer PL101, which is the first layer as a bandpass filter.

On the dielectric layer PL102, plate electrodes for the third series capacitor C0, the first series capacitor C1A, and the second series capacitor C1B are formed.

The dielectric layer PL103 corresponds to the above-described dielectric layer PL1, and is formed with a linear electrode for routing the T-type inductor circuit.

The dielectric layer PL104 corresponds to the above-described dielectric layer PL2, and a linear electrode for the shunt inductor L2 is formed.

The dielectric layer PL105 is formed with a routing electrode for connecting the shunt inductor L2 to the ground potential.

The dielectric layers PL106, PL107, and PL108 correspond to the above-described dielectric layers PL3, PL4, and PL5, respectively, and the linear electrodes for the first series inductor L1A and the second series inductor L1B have a spiral direction in the stacking direction. It is formed to become.

In the dielectric layer PL109, a common plate electrode is formed for the first series capacitor C1A and the second shunt capacitor C2A. The dielectric layer PL109 is provided with a common plate electrode for the second series capacitor C1B and the third shunt capacitor C2B.

The dielectric layer PL110 is provided with a plate electrode for the second shunt capacitor C2A and a plate electrode for the third shunt capacitor C2B.

The dielectric layer PL111 is formed with a plate electrode for the first series capacitor C1A and a plate electrode for the second series capacitor C1B.

A flat plate electrode for the first shunt capacitor C3 is formed on the dielectric layer PL112. The other plate electrode for the first shunt capacitor C3 is a ground electrode formed on a dielectric layer (not shown).

By using the bandpass filter having such a configuration, the electromagnetic coupling between the series inductors L1A and L1B and the shunt inductor L2 can be adjusted to adjust the filter characteristics. FIG. 6 is a pass characteristic diagram of the bandpass filter of the present embodiment and the bandpass filter of the conventional configuration. 6A and 6D are pass characteristics diagrams of a bandpass filter having a conventional configuration. FIG. 6B is a pass characteristic diagram when the series inductor and the shunt inductor are electromagnetically coupled so that the mutual inductance M has a positive value with the same circuit configuration as FIG. FIG. 6C is a pass characteristic diagram when the series inductor and the shunt inductor are electromagnetically coupled so that the mutual inductance M has a negative value with the same circuit configuration as FIG. FIG. 6D is a pass characteristic diagram when the inductance value of the shunt inductor is changed with respect to FIG. The bandpass filter shown in FIG. 6 is a bandpass filter composed of the equivalent circuit shown in FIG. Further, the filter characteristics shown in FIG. 6 are obtained by simulation. The specific element value of each circuit element is set as follows. In FIGS. 6A, 6B, 6C, and 6D, the inductance of the first series inductor L1A and the second series inductor L1B is 2.0 nH. The capacitance of the first series capacitor C1A, the second series capacitor C1B, the second shunt capacitor C2A, and the third shunt capacitor C2B is 0.75 pF, and the capacitance of the third series capacitance Co is 0.24 pF. The first shunt capacitor C3 is in a conductive state (capacitance is 0F).

On the other hand, in FIGS. 6A, 6B, and 6C, the inductance of the shunt inductor L2 is 1.1 nH. 6B and 6C, the inductances of the partial inductors L2A ′ and L2B ′ of the shunt inductor L2 are 0.5 nH, and the inductance of the partial inductor L2 ″ is 0.1 nH. Then, the inductance of the shunt inductor L2 is 1.3 nH.

In FIGS. 6B and 6C, the coupling coefficient K between the first series inductor L1A and the second series inductor L1B and the shunt inductor L2 is set to 0.1. In this case, the absolute value of the mutual inductance M is 0.1 nH.

As a result of performing such a simulation, as shown in FIGS. 6A, 6B, and 6C, by adjusting the electromagnetic coupling between the series inductor and the shunt inductor even in the same circuit configuration, Bandpass filters with different pass characteristics can be configured.

Specifically, the inductance between the two series inductors and the shunt inductor is determined, and the pass characteristic that prevents the electromagnetic coupling between the series inductor and the shunt inductor as shown in FIG. When the mutual inductance M is set to a positive value as shown in FIG. 6B, the inductance for the signal of the shunt inductor is reduced by twice the mutual inductance M, and a narrower band characteristic can be obtained. In addition, the attenuation amount of the attenuation pole on the low frequency side can be increased. In addition, when the mutual inductance M is set to a positive value as shown in FIG. 6C, the inductance for the signal of the shunt inductor is increased by twice the mutual inductance M, so that the characteristics can be made wider. it can.

In addition, as shown in FIGS. 6C and 6D, by adjusting the electromagnetic coupling between the series inductor and the shunt inductor, even if the inductance of the shunt inductor is different, the band pass having the same pass characteristic is obtained. You can configure filters. Specifically, in FIG. 6C, although the no-signal inductance of the shunt inductor L2 is 1.1 nH, the shunt inductor L2 shown in FIG. 6D has an inductance of 1.3 nH. The same pass characteristics can be obtained. This is equivalent to an increase of 0.2 nH, which is twice that of the mutual inductance M of 0.1 nH. In this way, by adjusting the amount of electromagnetic coupling between the first series inductor L1A and second series inductor L1B and the shunt inductor L2, they are not electromagnetically coupled, and a filter characteristic consisting of inductances of different shunt inductors is realized. it can.

In particular, by coupling the shunt inductor so that the inductance of the shunt inductor is increased, the inductance can be increased even when the same wound wire electrode having the same electrode width and the same electrode length is used. Conversely, if the same inductance is realized, the electrode length can be shortened. Thereby, a laminated body can be reduced in size. If the same inductance is realized, the electrode width can be increased. Thereby, transmission loss can be reduced and the Q value of the filter can be improved.

Also, as described above, since it is not necessary to provide a ground electrode layer between the dielectric layer of the series inductor and the dielectric layer of the shunt inductor, the laminate can be thinned.

In the laminated configuration of the bandpass filter described above, the region where the first series inductor L1A, the first series capacitor C1A, and the second shunt capacitor C2A are formed is configured to overlap when the multilayer body is viewed from the top surface side. . On the other hand, the region where the second series inductor L1B, the second series capacitor C1B, and the third shunt capacitor C2B are formed is configured to overlap when the multilayer body is viewed from the top surface side. And these two area | regions are comprised so that a laminated body may not overlap, seeing from a top | upper surface side. Such a stacked configuration can prevent unnecessary electromagnetic coupling between circuit elements in the stacked substrate. Thereby, the band pass filter which consists of the above-mentioned characteristic is realizable more correctly.

In the above description, the band-pass filter has been described as an example. However, if a T-type inductor circuit is provided, for example, a high-pass filter as shown in FIGS. 7 and 8 can be realized. FIG. 7 is an equivalent circuit diagram of the high-pass filter according to the embodiment of the present invention. FIG. 8 is a stacking diagram of the high-pass filter of the present embodiment shown in FIG. In FIG. 8 as well, only the necessary portions are described in the same manner as in FIG. 5, the illustration of other portions is partially omitted, and further description is omitted. Further, the circles described in the respective dielectric layers PL201 to PL208 in FIG. 8 indicate conductive via holes.

First, the circuit configuration will be described with reference to FIG.

The high-pass filter includes series inductors L5A and L5B connected in series between the third input / output terminal Port3 and the fourth input / output terminal Port4. A capacitor C5A is connected in parallel to the series inductor L5A. A capacitor C5B is connected to the series inductor L5B. A connection point between the series inductor L5A and the series inductor L5B is connected to the ground potential via a series circuit of the shunt inductor L6 and the capacitor C6.

Next, the laminated structure will be described with reference to FIG.
Linear electrodes constituting the series inductors L5A and L5B are formed on the dielectric layer PL201 and the dielectric layer PL202, which are the first layers as high-pass filters.

Conductive via holes for wiring are formed in the dielectric layers PL203, PL204, and PL205.

In the dielectric layers PL206, PL207, and PL208, linear electrodes constituting the shunt inductor L6 are formed.

The linear electrodes constituting the series inductors L5A and L5B and the linear electrodes constituting the shunt inductor L6 are formed so as to partially overlap each other when viewed from the top surface side of the multilayer body. With this structure, mutual inductance is generated between the series inductors L5A and L5B and the shunt inductor L6. And by setting it as such a structure, the effect similar to the above-mentioned band pass filter can be acquired.

In the above description, electromagnetic field coupling is generated along the stacking direction between two series inductors connected in series to the signal line and a shunt inductor connected between these connection points and the ground potential. Although an example is shown, it can also be generated in the dielectric layer. FIG. 9 is a partial stack diagram showing an example of a laminated structure in the case where two series inductors L1A and L1B are electromagnetically coupled to the shunt inductor L2 with a single dielectric layer. FIG. 10 is a partial stacking diagram showing an example of a laminated structure in the case where two series inductors L1A and L1B are electromagnetically coupled to the shunt inductor L2 in different dielectric layers.

In the case of the configuration shown in FIG. 9, the linear electrodes constituting the first series inductor L1A and the second series inductor L1B span the dielectric layers PL1A, PL2A, PL3A, and have the same windings as those in FIGS. It is formed in a round shape. The linear electrode constituting the shunt inductor L2 is formed on the dielectric layer PL1A in the same winding shape as that in FIGS. At this time, the linear electrode constituting the shunt inductor L2 is disposed between the linear electrode constituting the first series inductor L1A and the linear electrode constituting the second series inductor L1B. Further, the linear electrodes constituting the shunt inductor L2 are arranged so that the distance to the linear electrodes constituting the first series inductor L1A is the same as the distance to the linear electrodes constituting the second series inductor L1B. It is installed. Furthermore, the length of the linear electrode that constitutes the shunt inductor L2 is the same as the length that faces the linear electrode that constitutes the first series inductor L1A, and the length that faces the linear electrode that constitutes the second series inductor L1B. It is arrange | positioned so that it may become.

In the case of the configuration shown in FIG. 10, the linear electrodes constituting the first series inductor L1A are formed in the same winding shape as in FIGS. 2 and 3 above over the dielectric layers PL2B, PL3B, and PL4B. Yes. The linear electrode constituting the second series inductor L1B is formed in a winding shape similar to that of FIGS. 2 and 3 described above over the dielectric layers PL1B, PL2B, and PL3B. The linear electrodes constituting the shunt inductor L2 are formed on the dielectric layers PL1B and PL2B in a winding shape similar to the above-described FIGS. At this time, the linear electrode constituting the shunt inductor L2 is disposed between the linear electrode constituting the first series inductor L1A and the linear electrode constituting the second series inductor L1B. Furthermore, the linear electrodes constituting the shunt inductor L2 are spaced from the linear electrodes constituting the first series inductor L1A in the dielectric layer PL2B and to the linear electrodes constituting the second series inductor L1B in the dielectric layer PL1B. It arrange | positions so that a space | interval may become the same. Still further, the linear electrode constituting the shunt inductor L2 has a length facing the linear electrode constituting the first series inductor L1A in the dielectric layer PL2B, and a line constituting the second series inductor L1B in the dielectric layer PL1B. It arrange | positions so that the length which opposes an electrode may become the same.

9 and 10 can provide the same effects as the configuration in which electromagnetic coupling is performed in the stacking direction.

In the above description, the case where two series inductors connected in series to the signal line have the same electromagnetic field coupling amount to the shunt inductor is shown. It is also possible to adjust.

100: laminate, 101, 101A, 101B, 102, 121, 122, 123, 103A, 103B, 104A, 104B, 105A, 105B: linear electrodes, 131A, 131B, 133A, 133B: linear portions, 132A, 132B : Intermediate linear portion, L1A, L1B: Series inductor, L2: Shunt inductor, L2A ', L2B', L2 ": Partial inductor, PL1, PL2, PL3, PL4, PL5, PL101-PL112, PL201-PL208, PL1A- PL3A, PL1B-PL4B: Dielectric layer, VH12, VH13A, VH13B, VH34A, VH34B, VH45A, VH45B: Conductive via holes

Claims

A first series inductor and a second series inductor connected in series between the first input / output terminal and the second input / output terminal;
A shunt inductor for connecting a connection point between the first series inductor and the second series inductor to a ground potential,
The shunt inductor is a filter arranged to be electromagnetically coupled to both the first series inductor and the second series inductor.
The filter of claim 1,
The shunt inductor is a filter in which an electromagnetic coupling amount with respect to the first series inductor and an electromagnetic coupling amount with respect to the second series inductor coincide.
A filter according to claim 1 or claim 2, wherein
A laminate formed by laminating a plurality of dielectric layers;
An electrode pattern of the first series inductor formed in the multilayer body, an electrode pattern of the second series inductor, and an electrode pattern of the shunt inductor,
The dielectric layer in which the electrode pattern of the first series inductor and the electrode pattern of the second series inductor are formed is different from the dielectric layer in which the electrode pattern of the shunt inductor is formed.
When viewed from the top side of the multilayer body, the electrode pattern of the shunt inductor is disposed so as to partially overlap the electrode pattern of the first series inductor and the electrode pattern of the second series inductor. Has been a filter.
A filter according to claim 1 or claim 2, wherein
A laminate formed by laminating a plurality of dielectric layers;
An electrode pattern of the first series inductor formed in the multilayer body, an electrode pattern of the second series inductor, and an electrode pattern of the shunt inductor,
The dielectric layer on which the electrode pattern of the first series inductor is formed and the dielectric layer on which the electrode pattern of the shunt inductor is formed at least partially coincide with each other,
The dielectric layer on which the electrode pattern of the second series inductor is formed and the dielectric layer on which the electrode pattern of the shunt inductor is formed at least partially coincide with each other,
The filter, wherein the shunt inductor is electromagnetically coupled to the first series inductor and the second series inductor by electromagnetic coupling in a layer.
A filter according to claim 3 or claim 4, wherein
Seen from the top side of the laminate,
The filter in which the current direction of the first series inductor and the second series inductor is the same as the current direction of the shunt inductor.
A filter according to claim 3 or claim 4, wherein
Seen from the top side of the laminate,
A filter in which a current direction of the first series inductor and the second series inductor is opposite to a current direction of the shunt inductor.
The filter according to any one of claims 1 to 6,
A filter comprising a capacitor together with the first series inductor, the second series inductor, and the shunt inductor, and having a band pass characteristic.
A filter according to any one of claims 3 to 6,
Along with the first series inductor, the second series inductor, and the shunt inductor,
A first capacitor connected in series between the first input / output terminal and the first series inductor;
A second capacitor connected in series between the second input / output terminal and the second series inductor;
A third capacitor connected between the shunt inductor and the ground potential;
A connection point between the first series inductor and the first capacitor; a fourth capacitor connecting a connection point between the shunt inductor and the third capacitor;
A connection point between the second series inductor and the second capacitor; a fifth capacitor connecting a connection point between the shunt inductor and the third capacitor;
A sixth capacitor connected in series between the first input / output terminal and the second input / output terminal;
Has bandpass characteristics with
Seen from the top side of the laminate,
The formation region of the first series inductor, the first capacitor, and the fourth capacitor is disposed so as not to overlap the formation region of the second series inductor, the second capacitor, and the fifth capacitor. filter.
The filter according to any one of claims 1 to 6,
A filter comprising a capacitor together with the first series inductor, the second series inductor, and the shunt inductor, and having a high-pass characteristic.