JP2003258587A - Multilayer lc filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer LC filter which can provide the desired filter characteristics without an increase in size thereof and which provides an attenua tion peak on the higher-frequency side of its pass band. <P>SOLUTION: The multilayer LC filter includes a terminal layer 3, and a plurality of capacitor electrode layers 4, 5, 6 laminated together on the terminal layer 3. An inductor layer 8 is disposed above the capacitor electrode layers to thereby form a laminated body 2. First and second strip-shaped side-surface electrodes 10b, 10b are formed on opposite side surfaces of the laminated body 2, and are connected to input output terminals 17, 18 of the terminal layer 3 respectively. The distal ends of the first and second strip-shaped side-surface electrodes 10b, 10b extend to the corresponding side surfaces of the capacitor electrode layers 4, 5, 6, but do not reach the side surfaces off the inductor layer 8. Thus, the distance between the resonator inductors L1, L2 and the strip-shaped side-surface electrodes 10b, 10b are increased, and as a result, very little stray capacitance is generated between the resonator inductors L1, L2 and the strip-shaped side-surface electrodes 10b, 10b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated LC filter used in mobile communication equipment such as mobile phones.

[0002]

2. Description of the Related Art Conventionally, a laminated LC used for mobile communication equipment such as a mobile phone, which is small in size, low in loss and excellent in mass productivity.
Filters are well known. This laminated LC filter generally has a structure in which a plurality of electrodes are laminated with a dielectric layer interposed. Such a laminated LC filter A
Is, as shown in FIG. 6, the terminal layers c,
Ground electrode layer d, inductor layer e, capacitor layer f,
g, h, i, j, and a ground electrode layer k, and constitute a laminated body a having a plurality of electrodes therein. Here, a plurality of terminals m such as an input terminal, an output terminal, and a ground terminal are exposed and formed on the terminal layer c.

Further, as shown in FIG. 7, each terminal m
The side surface electrodes b extending from are formed in strips on the side surfaces of the laminated body a. This strip side electrode b is a laminated body a
To the uppermost surface in the stacking direction, so that the stacked LC filter A can be reliably arranged on the predetermined mounting surface.

[0004]

However, in the frequency characteristics of the above-mentioned laminated LC filter having the conventional structure, although the attenuation pole having a large attenuation amount is polarized on the low frequency side of the pass frequency band, On the high frequency side, the attenuation pole was not properly polarized, and there was a problem of deterioration of the attenuation on the high frequency side. Since the presence or absence of the attenuation pole on the high frequency side has a great influence on whether the filter performance is good or bad, there has been a strong demand for solving such a problem.

The above-mentioned problem of deterioration of attenuation on the high frequency side is caused by the fact that the electrodes inside the laminated body and the strip-shaped side surface electrodes formed on the outer surface of the laminated body are close to each other, and the stray capacitance is distributed in a distributed manner between these electrodes. It is considered to be invited when it occurs. In particular,
A stray capacitance is likely to be generated between each of the ground electrode and the inductor electrode, which are widely patterned near the outer periphery of the laminate, and the side electrode. Here, in order to solve this problem, a configuration may be proposed in which the electrodes inside the laminate are separated from the side electrodes as much as possible. For example, without changing the size of the laminated body, the pattern area of the internal electrode is reduced to form the laminated body from the center of the laminated body, or conversely,
It is conceivable to increase the size of the laminate itself without changing the pattern area of the electrodes. However, even when such a means is applied, the filter characteristics are deteriorated in the former configuration, and the laminated LC is used in the latter configuration.
The filter itself becomes large.

Therefore, the present invention has been made in view of the above-mentioned problems, and it is possible to obtain desired filter characteristics without increasing the size and to polarize the attenuation pole on the high frequency side of the pass frequency band. An object is to provide a laminated LC filter.

[0007]

According to the present invention, there is provided a first resonator inductor and a second resonator inductor which are formed of a laminated body in which a plurality of dielectric layers are laminated, and which are formed on the same dielectric layer, and A first LC resonant circuit having a first resonator inductor and a second L resonant circuit having the second resonator inductor.
In a laminated LC filter including a C resonance circuit, an input terminal and an output terminal formed on the surface of the laminated body,
A capacitive laminated portion configured by alternately laminating a plurality of capacitor electrodes and a plurality of dielectric layers, a first ground electrode formed between the capacitive laminated portion and the inductor, and a side surface of the laminated body. A strip-shaped side electrode connected to one of the input terminal and the output terminal, the strip-shaped side surface electrode being formed on the side surface of the first ground and the inductor. It is a laminated LC filter characterized by the absence thereof.

As described above, the two strip-shaped side surface electrodes connected to one of the input terminal and the output terminal are formed in a range that does not reach the side surfaces of the ground electrode and the inductor. The ground electrode and each strip-shaped side electrode are formed to be spaced apart from each other, and further, the resonator inductor of the inductor and each strip-shaped side electrode are formed to be spaced apart from each other,
In both cases, stray capacitance is less likely to occur between them. In addition,
The first ground electrode and the side surface of the inductor indicate a portion corresponding to the side surface of the laminated body in a horizontal cross section formed when the laminated body is cut in the horizontal direction including the first ground electrode or the inductor.

Further, the present invention comprises a first LC resonance circuit having a first resonator inductor and a second LC resonance circuit having a second resonator inductor, the first LC resonance circuit having a first resonator inductor and the second LC resonator circuit having a first resonator inductor. In a laminated LC filter including:
An input terminal and an output terminal formed on the surface of the laminated body, a capacitive laminated portion formed by alternately laminating a plurality of capacitor electrodes and a plurality of dielectric layers, and the same dielectric layer above the capacitive laminated portion. A first ground disposed between the first resonator inductor, the second resonator inductor, and the capacitive laminated portion, the first resonator inductor, and the second resonator inductor, which are disposed above. An electrode and a laminated type in which two strip-shaped side electrodes, one end of which is connected to an input terminal or an output terminal and whose other end does not reach the side surface of the first ground electrode, are arranged on the side surface of the laminated body. LC
It is a filter. Here, the side surface of the first ground electrode refers to a portion corresponding to the side surface of the stacked body in a horizontal cross section formed when the stacked body including the first ground electrode is cut in the horizontal direction.

As described above, the strip-shaped side surface electrode having the other end reaching the side surface of the capacitive laminated portion is provided, and the strip-shaped side surface electrode is not provided on the side surface of the first ground electrode. The electrode and the strip-shaped side surface electrode are formed so as to be separated from each other, and further, the resonator inductor of the inductor layer and the strip-shaped side surface electrode are formed so as to be separated from each other, which makes it difficult for stray capacitance to occur between them. .

The capacitor electrode patterned on the capacitor layer of the laminated LC filter according to the present invention has a smaller pattern area than the resonator inductor patterned on the inductor layer, and the capacitor electrode of the dielectric layer. It is formed from the center. Therefore, the distance between the capacitor electrode and the strip-shaped side surface electrode is sufficiently secured, so that stray capacitance is unlikely to occur between them. Therefore, even if the other end of the strip-shaped side surface electrode is located on the side surface of the capacitive laminated portion, the problem of deterioration of attenuation on the high frequency side does not occur.

Here, the first LC resonance circuit includes a first resonator capacitor, the second LC resonance circuit includes a second resonator capacitor, and the first resonator inductor and the second resonator inductor are included. A first ground electrode formed on a dielectric layer below the first resonator electrode, and a second ground electrode formed on the dielectric layer above the first resonator inductor and the second resonator inductor. A laminated LC filter, wherein the laminated body comprises a first resonator capacitor, a second resonator capacitor, and a frequency adjuster by laminating the dielectric layer, each capacitor electrode of a capacitor laminated portion, and a first ground electrode. A configuration that carries a capacitor for use is proposed.

With this structure, the laminated LC
Due to the frequency characteristics of the filter, the attenuation pole can be preferably polarized on the high frequency side of the pass frequency band. For example, as shown in FIG. 4A, when the strip-shaped side surface electrode is formed up to the side surface of the capacitive laminated portion, the attenuation pole can be polarized on the high frequency side.

Further, the capacitive laminated portion is arranged in order from the lower side.
A first capacitor electrode having a central electrode formed on a dielectric layer, a second capacitor electrode having a first input / output electrode and a second input / output electrode formed on a dielectric layer, and a dielectric A third capacitor electrode having a first shared electrode and a second shared electrode formed on the body layer is laminated, and a first input / output coupling capacitor and a second input / output coupling are provided as a frequency adjustment capacitor. A laminated LC filter comprising a capacitor, a pole generating capacitor, and an inter-stage coupling capacitor, for pole generation comprising the central electrode, the first input / output electrode, and the second input / output electrode. A first input / output coupling capacitor composed of a capacitor, a first input / output electrode and a first common electrode, and a second input / output coupling capacitor composed of a second input / output electrode and a second common electrode , First shared electrode An interstage coupling capacitor composed of a second shared electrode, a first resonator capacitor composed of a first shared electrode and a first ground electrode, a second shared electrode and a first ground electrode A configuration with a second resonator capacitor is proposed. With such a configuration, it is possible to appropriately polarize the attenuation pole on the low frequency side and the high frequency side of the pass frequency band in the frequency characteristics of the laminated LC filter.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the laminated LC filter 1 of the present invention will be described with reference to the accompanying drawings. In the present invention, the terminal layer 3 indicates the dielectric layer 15a and the input terminal 17 and the output terminal 18 formed on the surface thereof. The first capacitor electrode layer 4, the second capacitor electrode layer 5, and the third capacitor electrode layer 6, that is, the capacitor electrode layers are respectively the dielectric layers 15b, 15c, 15d and the central electrode 21, the first electrode formed on the surface thereof. The capacitor electrodes of the output electrode 22, the second input / output electrode 23, the first common electrode 24, and the second common electrode 25 are shown. The inductor layer 8 is a dielectric layer 15f
And a first resonator inductor L1 formed on its surface
And the second resonator inductor L2 (inductor).
The first ground electrode layer 7, which is a ground layer, is the dielectric layer 1
5e and the first ground electrode 26 formed on the surface thereof
The second ground electrode layer 9 represents the dielectric layer 15g and the second ground electrode 28 formed on the surface thereof.

The laminated LC filter 1 according to the present invention includes two-stage LC resonance circuits 12 and 13 (see FIG. 3) and, as shown in FIG. 1, has a multilayer structure and a dielectric layer 15 A plurality of electrodes are laminated so as to be interposed. Further, as shown in FIG. 2, a side surface electrode 10 is provided on each side surface of the laminated body 2 having a substantially rectangular cross section.

Here, the laminate 2 will be described with reference to FIG. The terminal layer 3 is formed on the lowermost layer of the laminate 2. On the upper layer of the terminal layer 3, there is formed a capacitor laminated portion 11 formed by collectively laminating a plurality of capacitor electrode layers 4, 5, and 6. Furthermore, this capacitance stacking unit 1
A first ground electrode layer 7, an inductor layer 8, a second ground electrode layer 9, and a dielectric layer 15h on which no electrode is formed are sequentially formed on the first layer 1.

In the terminal layer 3, the input terminal 17, the output terminal 18, and the ground terminals 19 and 19 are the dielectric layers 15a.
(Layered product front side) is patterned. The input terminal 17 and the output terminal 18 are formed at the centers of the opposing outer peripheral edges of the dielectric layer 15a. The ground terminals 19 and 19 are formed in strips along the edges where the input terminal 17 and the output terminal 18 are not formed.
The ground terminals 19 and 19 are grounded.

A capacitor laminated portion 11 is formed above the terminal layer 3. The capacitive laminated portion 11 is composed of a first capacitor electrode layer 4, a second capacitor electrode layer 5, and a third capacitor electrode layer 6. Each capacitor electrode layer 4, 5, 6 is formed by patterning various capacitor electrodes 21, 22, 23, 24, 25 on the dielectric layers 15b, c, d.

That is, a strip-shaped central electrode 21 is formed in the center of the first capacitor electrode layer 4. The second capacitor electrode layer 5 has a first input / output electrode 22 that extends in the center direction from the opposing outer peripheral edges and has a rectangular shape.
And the second input / output electrode 23 are formed. Further, a substantially rectangular first shared electrode 24 and a second shared electrode 25, which are connected to the ground terminal 19 of the terminal layer 3 and the like, are formed on the third capacitor electrode layer 6.

Next, the first ground electrode layer 7 is formed above the capacitive laminated portion 11. This first ground electrode layer 7
Is formed by patterning a first ground electrode 26, which is grounded, over a wide area on the dielectric layer 15e.

An inductor layer 8 is formed above the first ground electrode layer 7. This inductor layer 8 is the first L
The first resonator inductor L1 and the second resonator inductor L2 included in the C resonance circuit 12 and the second LC resonance circuit 13
And are patterned on the dielectric layer 15f. The first and second resonator inductors L1 and L2 are patterned so that two strip electrodes are parallel to each other, and magnetic field coupling is generated between the electrodes. In addition, the first resonator inductor L1 corresponds to the first common electrode electrode 2 of the third capacitor electrode layer 6.
4 and the second resonator inductor L2 is connected to the second common electrode 25 of the third capacitor electrode layer 6. Further, the resonator inductors L1 and L2 are connected via the extraction electrode 27 that is coupled to the resonator inductors L1 and L2.
It is connected to the ground terminal 19 of the terminal layer 3.

A second ground electrode layer 9 is formed above the inductor layer 8. This second ground electrode layer 9
Includes a second ground electrode 28. That is, in the first ground electrode layer 7 and the second ground electrode layer 9,
The inductor layer 8 is sandwiched. With such a configuration, it is possible to improve the shield property of the magnetic field coupling generated in the inductor layer 8, and thus the laminated LC
It is possible to improve the filter characteristics of the filter 1.

Above the second ground electrode layer 9,
A dielectric layer 15h is formed in which the electrodes are not patterned.

The laminated body 2 having the above-mentioned structure is preferably obtained by patterning a predetermined electrode on the dielectric sheet by a screen printing method which is a known technique, laminating a plurality of these dielectric sheets and firing them. .

As the dielectric sheet, it is preferable that the dielectric material is formed into a sheet shape by kneading the dielectric powder and the magnetic powder together with a binder and the like. Also, each electrode is A
A paste-like conductive material such as g, Pd, Cu, Ni, Au, Ag-Pd is preferably used.

An equivalent circuit diagram of the laminated LC filter 1 is shown in FIG. Multilayer LC filter 1 according to the present invention
Has an input / output line M connecting the input terminal 17 and the output terminal 18. A first input / output coupling capacitor C11, a second input / output coupling capacitor C12, and each input / output coupling capacitor C1 are provided on the input / output line M to which the high frequency voltage is applied.
1, C12 is an interstage coupling capacitor C1 connected between
4 and 4 are connected in series.

The first input / output coupling capacitor C11 is
It is composed of the first input / output electrode 22 of the second capacitor electrode layer 5 and the first common electrode 24 of the third capacitor electrode layer 6,
The second input / output coupling capacitor C12 includes the second input / output electrode 23 of the second capacitor electrode layer 5 and the second common electrode 25 of the third capacitor electrode layer 6.

The interstage coupling capacitor C14 is composed of the first common electrode 24 and the second common electrode 2 of the third capacitor electrode layer 6.
And 5 are distributed.

A first LC resonance circuit 12 and a second LC resonance circuit 13 are connected between the first and second input / output coupling capacitors C11 and C12 and the inter-stage coupling capacitor C14, respectively. . Then, each LC resonance circuit 1
2 and 13 are grounded respectively.

Here, the first LC resonance circuit 12 comprises a first resonator capacitor C1 and a first resonator inductor L1, and the second LC resonance circuit 13 comprises a second resonator capacitor C2.
And a second resonator inductor L2. The first resonator capacitor C1 and the first resonator inductor L1 are connected in parallel, and the second resonator capacitor C2 and the second resonator inductor L2 are connected in parallel.

Here, the first and second resonator inductors L
Both 1 and L2 are provided in the inductor layer 8 and magnetic field coupling is generated between the first and second resonator inductors L1 and L2. On the other hand, the first resonator capacitor C1 is composed of the first common electrode 24 of the third capacitor electrode layer 6 and the first ground electrode 26 of the first ground electrode layer 7, and the second resonator capacitor C2 is It is composed of the second common electrode 25 of the third capacitor electrode layer 6 and the first ground electrode 26 of the first ground electrode layer 7.

That is, the first resonator capacitor C1, the second resonator capacitor C2, the second resonator capacitor C2, the second resonator capacitor C2, One input / output coupling capacitor C11,
The second input / output coupling capacitor C12, the pole generation capacitor C13, and the inter-stage coupling capacitor C14 are carried.

A pole generating capacitor C13 is connected in parallel between the input terminal 17 and the output terminal 18. The pole generating capacitor C13 is composed of the central electrode 21 of the capacitor layer 4, the first input / output electrode 22 of the capacitor layer 5, and the second input / output electrode 23.

The resonator capacitors C1 and C2
Are LC resonance circuits 12 and 13, and include the input / output coupling capacitors C11 and C12 and the pole generating capacitor C1.
3 and the inter-stage coupling capacitor C14 are provided as capacitors for frequency adjustment.

Next, the side surface electrode 10, which is an essential part of the present invention, will be described in detail. As shown in FIG. 2, the side surface electrode 10 is coupled to the input terminal 17, the output terminal 18, and the ground terminals 19 and 19 exposed on the terminal layer 3, and is laminated on each side surface of the above-described laminated body 2. Has been extended in the direction.

Here, the ground terminals 19, 1 of the terminal layer 3
The ground side surface electrodes 10a and 10c, which are formed on two side surfaces facing each other and which are coupled to the sheet 9, are each extended to the uppermost surface of the laminated body 2 in the laminating direction.

The connecting side surface electrode 101a includes the resonator inductor L1 and the first common electrode 245, and the connecting side surface electrode 101b.
Is connected to the resonator inductor L2 and the second shared electrode 25.

On the other hand, the two strip-shaped side surface electrodes 10b, 10b, which are connected to the input terminal 17 and the output terminal 18 and are arranged on the two side surfaces facing each other, have the other end at the capacitive laminated portion 1
The first side surface is not extended to the uppermost surface. That is, the strip-shaped side surface electrodes 10b and 10b are formed on the side surface of the first ground electrode (the portion corresponding to the side surface of the stacked body in the horizontal cross section formed by cutting the stacked body in the horizontal direction including the first ground electrode). It is not configured. That is, the laminated LC filter 1 according to the present invention
Are strip-shaped side surface electrodes 10b, 10 on the side surfaces of the first ground electrode layer 7, the inductor layer 8, and the second ground electrode layer 9.
This is a configuration in which b is not formed.

The electrodes 26, 27, L1, L2 and 28 patterned on the first ground electrode layer 7, the inductor layer 8 and the second ground electrode layer 9 are extended to near the side surface of the laminate 2. Therefore, each layer 7,
If the strip-shaped side surface electrodes 10b, 10b are formed at the side surface positions of 8, 9, the electrodes 26, 27, L of the layers 7, 8, 9 are formed.
Stray capacitance is generated between 1, L2, 28 and the strip-shaped side surface electrodes 10b, 10b. Side surfaces of the first ground electrode, the inductor, and the second ground electrode (including the first ground electrode, the inductor, or the second ground electrode for the laminated body,
In the horizontal section formed by cutting in the horizontal direction, the strip side surface electrodes 10b, 10
When b is formed, each electrode 26, 27, L1, L2, 28
A stray capacitance is generated between the electrode and the strip-shaped side surface electrode. However, the resonator inductors L1 and L2 and the strip-shaped side electrode 10
b and 10b, and the ground electrodes 26 and 28 and the strip-shaped side electrodes 10b and 10b are separated from each other as much as possible, it is difficult for stray capacitance to occur between them. As a result, the filter characteristics of the laminated LC filter 1 are improved.

Here, according to FIGS. 4 and 5, the strip-shaped side surface electrode 10 of the laminated LC filter 1 according to the present invention.
Changes in frequency characteristics when the band lengths of b and 10b are changed will be described. In the waveform diagrams shown in FIGS. 4 and 5, the vertical axis represents the attenuation amount (unit: db), and the lower the attenuation amount, the greater the attenuation amount. The horizontal axis is frequency (unit: GH
z), and the frequency is higher toward the right.

FIG. 4A shows an input terminal 17 and an output terminal 18.
Strip side electrodes 10b, 10b respectively extending from the
Shows the frequency characteristic of the laminated LC filter 1 formed up to the side surface of the third capacitor electrode layer 6 that forms the inter-stage coupling capacitor C14. In such a case, the attenuation pole x is polarized on the high frequency side of the pass frequency band.

FIG. 4B shows the strip-shaped side surface electrodes 10b, 10b.
The other end of b shows the frequency characteristic of the laminated LC filter 1 formed up to the side surface of the second capacitor electrode layer 5 for generating the pole generating capacitor C13. Even in such a case,
The attenuation pole x is polarized on the high frequency side of the pass frequency band.

Multilayer LC filter 1 shown in FIG.
When the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the capacitive laminated portion 11 as described above, the attenuation pole x is preferably polarized on the high frequency side of the pass frequency band. . The strip length of the strip-shaped side surface electrodes 10b and 10b can be set to any length as long as the other end is at the side surface position of the capacitive laminated portion 11.

On the other hand, the case where the other ends of the strip-shaped side surface electrodes 10b, 10b are formed on the side surface of the upper layer than the side surface of the capacitive laminated portion 11 is shown. FIG. 5A shows the strip-shaped side surface electrodes 10b, 10b.
2 shows the frequency characteristics of the laminated LC filter 1 in which the other end of is formed up to the side surface of the first ground electrode layer 7. In such a case, the attenuation pole x is not polarized on the high frequency side of the pass frequency band.

Further, FIGS. 5B and 5C respectively show
The other end of the strip-shaped side surface electrodes 10b, 10b is the inductor layer 8
Laminated LC filter 1 in which the second ground electrode layer (second ground electrode) 9 is formed up to the side surface of the (inductor)
The frequency characteristics of are shown. Even in such a case, the attenuation pole x is not polarized on the high frequency side of the pass frequency band. As described above, the other ends of the strip-shaped side surface electrodes 10b, 10b have the other ends of the first ground electrode layer 7, the inductor layer 8, and the second ground electrode layer 9 above the capacitive laminated portion 11.
If the structure is formed up to the side surface of, the attenuation pole x is not preferably polarized on the high frequency side of the pass frequency band. That is, when the strip-shaped side surface electrode is formed on the side surface of the first ground electrode, the attenuation pole x is not preferably polarized on the high frequency side of the pass frequency band.

In this way, the input terminal 17 and the output terminal 1
Since the other ends of the strip-shaped side surface electrodes 10b and 10b respectively connected to 8 are located only on the side surfaces of the capacitive laminated portion 11, the attenuation pole x is preferably polarized on the high frequency side of the pass frequency band. Therefore, the filter characteristics of the laminated LC filter 1 are improved.

The number of capacitor layers in the capacitive laminated portion 11 can be changed as appropriate. Further, the configuration of the laminated LC filter 1 can be appropriately changed within the scope of the gist of the present invention.

[0049]

The present invention comprises a laminated body in which a plurality of dielectric layers are laminated, and an input terminal and an output terminal formed on the surface of the laminated body, a plurality of capacitor electrodes and a plurality of dielectric layers are alternately laminated. To form a capacitive laminated portion configured by
An inductor (a first resonator inductor and a second resonator inductor) is arranged above the capacitance laminated portion to form a laminated body, and a first ground electrode is arranged between the inductor and the capacitance laminated portion. A laminated LC filter comprising a laminated body, further comprising two strip-shaped side surface electrodes, one end of which is connected to an input terminal or an output terminal and the other end of which does not reach the side surface of the first ground electrode, on the side surface of the laminated body. Since it is provided, the strip-shaped side surface electrode is not provided on the side surface of the inductor layer (or the strip-shaped side surface electrode is not formed on the first ground electrode and the side surface of the inductor). Therefore, the resonator inductor (inductor) of the inductor layer and the strip-shaped side surface electrode are formed so as to be separated from each other, and there is an effect that stray capacitance is less likely to occur between them.

Here, the first resonator capacitor, the second resonator capacitor, and the frequency adjusting capacitor are carried by laminating the dielectric layer, each capacitor electrode of the capacitor laminated portion, and the first ground electrode. In this case, the attenuation pole can be preferably polarized on the high frequency side of the pass frequency band. Therefore, the filter characteristics of the laminated LC filter are dramatically improved.

Further, the capacitor laminated portion constitutes a pole generating capacitor with the central electrode, the first input / output electrode, and the second input / output electrode, and the first input / output electrode and the first common electrode To form a first input / output coupling capacitor, a second input / output electrode and a second common electrode to form a second input / output coupling capacitor, and a first common electrode and a second common electrode to form an interstage coupling capacitor. In the case where the first resonator capacitor is configured by the first common electrode and the first ground electrode, and the second resonator capacitor is configured by the second common electrode and the first ground electrode,
It is possible to separate the strip-shaped side surface electrode from the inductor and the ground electrode. As a result, stray capacitance is less likely to occur between the strip-shaped side surface electrode and the inductor and the ground electrode, and the attenuation pole can be preferably polarized on the low frequency side and the high frequency side of the pass frequency band. Become.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a laminated LC filter 1 according to the present invention.

FIG. 2 is an external perspective view showing a laminated LC filter 1 according to the present invention.

FIG. 3 is an equivalent circuit diagram of a laminated LC filter 1 according to the present invention.

FIG. 4B is a laminated LC in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the second capacitor electrode layer 5.
FIG. 6B is a waveform diagram showing the frequency characteristic of the filter 1, and B is a waveform diagram showing the frequency characteristic of the laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the first capacitor electrode layer 4. Is.

FIG. 5C shows that the other ends of the strip-shaped side electrodes 10b, 10b are
Multilayer LC formed up to the side surface of the first ground electrode layer 7
FIG. 4 is a waveform diagram showing the frequency characteristic of the filter 1, and D is a waveform diagram showing the frequency characteristic of the laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the inductor layer 8, E is a strip-shaped side surface electrode 10b, 10
FIG. 11 is a waveform diagram showing the frequency characteristic of the laminated LC filter 1 in which the other end of b is formed up to the side surface of the second ground electrode layer 9.

FIG. 6 is an exploded perspective view showing a conventional laminated LC filter A.

FIG. 7 is an external perspective view showing a conventional laminated LC filter A.

[Explanation of symbols]

1 Multilayer LC filter 2 laminate 3 terminal layers 4, 5, 6 First, second and third capacitor electrode layers 7,9 First and second ground electrode layers 8 Inductor layer 10 Side electrode 10a, 10c Ground side electrode 10b strip-shaped side electrode 11 Capacitive stacking unit 12, 13 First and second LC resonance circuit 15 Dielectric layer 17 input terminals 18 output terminals 19 ground terminal 21 Central electrode 22, 23 First and second input / output electrodes 24,25 First and second common electrode 26, 28 First and second ground electrodes C1, C2 First and second resonator capacitors C11, C12 First and second input / output coupling capacitors C13 pole generation capacitor C14 inter-stage coupling capacitor L1, L2 First and second resonator inductors

[Procedure amendment]

[Submission date] December 19, 2002 (2002.12.
19)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

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[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a laminated LC filter 1 according to the present invention.

FIG. 2 is an external perspective view showing a laminated LC filter 1 according to the present invention.

FIG. 3 is an equivalent circuit diagram of a laminated LC filter 1 according to the present invention.

FIG . 4A is a waveform diagram showing frequency characteristics of the laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the second capacitor electrode layer 5.

FIG . 4B is a waveform diagram showing frequency characteristics of the laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the first capacitor electrode layer 4.

5A is a waveform diagram showing frequency characteristics of the laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the first ground electrode layer 7. FIG.

FIG. 5B: A laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b, 10b are formed up to the side surface of the inductor layer 8.
It is a waveform diagram showing the frequency characteristics of.

FIG . 5C is a waveform diagram showing frequency characteristics of the laminated LC filter 1 in which the other ends of the strip-shaped side surface electrodes 10b and 10b are formed up to the side surface of the second ground electrode layer 9.

FIG. 6 is an exploded perspective view showing a conventional laminated LC filter A.

FIG. 7 is an external perspective view showing a conventional laminated LC filter A.

[Explanation of symbols] 1 Multilayer LC filter 2 laminate 3 terminal layers 4, 5, 6 First, second and third capacitor electrode layers 7,9 First and second ground electrode layers 8 Inductor layer 10 Side electrode 10a, 10c Ground side electrode 10b strip-shaped side electrode 11 Capacitive stacking unit 12, 13 First and second LC resonance circuit 15 Dielectric layer 17 input terminals 18 output terminals 19 ground terminal 21 Central electrode 22, 23 First and second input / output electrodes 24,25 First and second common electrode 26, 28 First and second ground electrodes C1, C2 First and second resonator capacitors C11, C12 First and second input / output coupling capacitors C13 pole generation capacitor C14 inter-stage coupling capacitor L1, L2 First and second resonator inductors

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[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Correction target item name] Figure 5

[Correction method] Added

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[Fig. 5]

[Procedure amendment]

[Submission date] January 22, 2003 (2003.1.2
2)

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4a]

[Fig. 4B]

[Figure 5a]

[Fig. 5B]

[Fig. 5]

[Figure 7]

[Figure 6]

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5E070 AA05 AB07 CB02 CB12                 5E082 AA01 AB03 BB01 FF05 FG06                       FG26 FG54                 5J024 AA01 BA10 CA06 DA04 DA29                       DA35 EA03 KA03

Claims (4)

[Claims] 1. A first resonator inductor and a second resonator inductor which are formed of a laminated body in which a plurality of dielectric layers are laminated and are formed on the same dielectric layer, and the first resonator inductor. In a laminated LC filter including a first LC resonant circuit and a second LC resonant circuit including the second resonator inductor, an input terminal and an output terminal formed on the surface of the laminated body, and a plurality of capacitor electrodes And a plurality of dielectric layers that are alternately laminated, a first ground electrode that is formed between the capacitor laminate and the inductor, and a plurality of the plurality of dielectric layers that are formed on a side surface of the laminate. Any one of the capacitor electrodes and a strip-shaped side surface electrode connected to one of the input terminal and the output terminal, the strip-shaped side surface electrode being formed on the side surface of the first ground and the inductor. Multilayer LC filter, wherein no. 2. A first LC resonance circuit having a first resonator inductor and a second LC resonance circuit having a second resonator inductor, the first LC resonance circuit having a first resonator inductor and the second LC inductor having a second resonator inductor. In the laminated LC filter, an input terminal and an output terminal formed on the surface of the laminated body,
A capacitor laminated portion configured by alternately laminating a plurality of capacitor electrodes and a plurality of dielectric layers, the first resonator inductor and the first resonator inductor disposed on the same dielectric layer above the capacitor laminated portion. A two-resonator inductor, a first ground electrode disposed between the capacitive laminated portion, the first resonator inductor and the second resonator inductor, and an input terminal or a side surface of the laminated body. A laminated LC, wherein one end is connected to the output terminal and two strip-shaped side electrodes whose other end does not reach the side surface of the first ground electrode are arranged.
filter. 3. The first LC resonant circuit comprises a first resonator capacitor, the second LC resonant circuit comprises a second resonator capacitor, and below the first resonator inductor and the second resonator inductor. A first ground electrode formed on the dielectric layer, and a second ground electrode formed on the dielectric layer above the first resonator inductor and the second resonator inductor. In the LC filter, the laminated body includes a first resonator capacitor, a second resonator capacitor, and a frequency adjustment capacitor, each of which is composed of a dielectric layer, each capacitor electrode of the capacitor laminated portion, and a first ground electrode. The laminated LC filter according to claim 2, which is carried. 4. A first capacitor electrode layer having a center electrode formed on a dielectric layer, a first capacitor electrode layer formed on the dielectric layer, and a second input / output electrode, and A second capacitor electrode layer including an input / output electrode, and a third capacitor electrode layer including a first shared electrode and a second shared electrode formed on a dielectric layer are laminated, and a frequency is provided. Multilayer type L having a first input / output coupling capacitor, a second input / output coupling capacitor, a pole generating capacitor, and an inter-stage coupling capacitor as an adjusting capacitor.
A C filter, comprising a pole generating capacitor including the central electrode, the first input / output electrode, and the second input / output electrode, and a first input / output electrode and a first shared electrode. A first input / output coupling capacitor, a second input / output coupling capacitor composed of a second input / output electrode and a second common electrode, and an interstage coupling composed of a first common electrode and a second common electrode. A capacitor, a first resonator capacitor composed of a first common electrode and a first ground electrode, and a second resonator capacitor composed of a second common electrode and a first ground electrode. The laminated LC according to claim 3.
filter.