JPH1117404A - Filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter miniaturized by reducing a plane area and a thickness. SOLUTION: A dielectric base body 1 is constituted by laminating plural dielectric layers 11-13. A first resonance electrode 21 and a second resonance electrode 22 are respectively arranged on both surfaces in the layer thickness direction to one of the dielectric layer 11 for constituting the dielectric base body 1 and provided with the shape of being bent at least once. Bent tip parts are turned to open end parts 211 and 221, only the open end parts 211 and 221 are overlapped with each other through the dielectric layer and an intermediate part is electrically connected to input/output terminals 24 and 25 provided on the side face of the dielectric base body 1. A shield electrode 23 is provided on the other dielectric layers 12 and 13 for covering the first resonance electrode 21 and the second resonance electrode 22 and the other end parts of the first resonance electrode 21 and the second resonance electrode 22 are connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter. More specifically, the present invention relates to a laminated dielectric filter having a band-pass filter characteristic for communication used in, for example, a mobile phone.

[0002]

2. Description of the Related Art As mobile phones become smaller and thinner,
2. Description of the Related Art A communication filter used for a mobile phone or the like is required to have a small size, light weight, and a laminated filter capable of obtaining good characteristics. In a conventional laminated dielectric filter, two quarter-wavelength resonators are provided at an interval on the same surface of a dielectric substrate, and another dielectric is provided on the surface of the dielectric substrate on which the resonator is formed. In this structure, the body substrates are stacked, and a shield electrode is formed on the outer main surface of each dielectric substrate so as to cover the resonator.
One end of each of the resonators is a short-circuit end connected to the side shield electrode, and the other end is an open end. Since the resonance frequency of this filter is determined by the resonator length, its size is determined by the resonance frequency, and it is difficult to reduce the size.

[0003] Japanese Patent Application Laid-Open No. 9-69701 discloses a 1/4 that can be miniaturized and has a small Q value even if it is miniaturized.
A filter using a wavelength resonator is disclosed. The filter described in this known document has a structure in which a dielectric substrate having a coupling control electrode is arranged between two dielectric substrates each having a spiral-shaped resonance electrode formed on one surface in a plate thickness direction, The increase in thickness due to the dielectric substrate having the coupling control electrode cannot be avoided.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a filter which is reduced in plane area and thickness to reduce its size.

[0005]

In order to solve the above-mentioned problems, a filter according to the present invention includes a dielectric substrate, a first resonance electrode, a second resonance electrode, and a shield electrode. The dielectric substrate is formed by laminating a plurality of dielectric layers. Each of the first resonance electrode and the second resonance electrode is arranged on one of the dielectric layers constituting the dielectric substrate on both sides in the layer thickness direction, and is bent at least once. An input / output device having a shape, a bent end portion serving as an open end portion, only the open end portion overlapping each other via the dielectric layer, and an intermediate portion provided on a side surface of the dielectric substrate. Connected to terminal.

The shield electrode is provided on another dielectric layer covering the first resonance electrode and the second resonance electrode, and the other ends of the first resonance electrode and the second resonance electrode are connected to each other. It is connected.

As described above, in the filter according to the present invention, each of the first resonance electrode and the second resonance electrode is arranged on one of the dielectric layers on both sides in the layer thickness direction. Are on the same surface of the dielectric substrate.
Compared with a conventional filter in which two resonators are provided at intervals, the plane area is significantly reduced.

Each of the first resonance electrode and the second resonance electrode has a shape bent at least once, so that the electrode length (1/1) required to determine the resonance frequency is set.
While maintaining (4 wavelengths), the substantial length of the resonance electrode with respect to the dielectric substrate or the dielectric layer can be reduced. For this reason, it is possible to reduce the size of the dielectric substrate and downsize the dielectric substrate.

Each of the first resonance electrode and the second resonance electrode has an open end at the bent end, and only the open ends overlap with each other via the dielectric layer. A coupling capacitance for the first resonance electrode and the second resonance electrode is generated therebetween. In this case, since only the open ends overlap with each other via the dielectric layer, an appropriate coupling capacity can be obtained, and the dielectric substrate having the coupling control electrode which is essential in Japanese Patent Application Laid-Open No. 9-69701 is unnecessary. . For this reason, the thickness of the entire dielectric substrate can be reduced, the size can be significantly reduced, and the size can be reduced, in addition to the size reduction due to the reduction of the plane area.

[0010] The shield electrode is provided on another dielectric layer covering the first resonance electrode and the second resonance electrode, and the other end of the first resonance electrode and the second resonance electrode are connected to each other. Therefore, a resonance circuit is formed between the shield electrode and the first resonance electrode and the second resonance electrode by the dielectric constant of the dielectric layer, the length of the resonance electrode, and the like.

Each of the first resonance electrode and the second resonance electrode has an intermediate portion coupled to an input / output terminal provided on a side surface of the dielectric substrate, so that the input / output terminal is connected to an external circuit. Terminal.

As one preferred embodiment, the first resonance electrode and the second resonance electrode are formed such that the width of the open end is wider than other portions. According to this structure, the overlapping area of the open ends can be increased, and the amount of capacitive coupling can be increased.

In another preferred embodiment, the shield electrode includes a main shield portion and a side shield portion, wherein the main shield portion faces the first resonance electrode and the second resonance electrode, Is provided on the side surface of the dielectric substrate. In such a shield electrode structure, the distance between the side of the open end and the side shield is made shorter than the distance between the open end and the main shield. Thus, the capacitance between the open end and the shield electrode can be increased, and the size of the filter can be further reduced. In addition, by reducing the distance between the open end and the shield electrode, the capacity of the open end is increased, so that the length of the resonant electrode is shorter than 1/4 wavelength of the resonance frequency, and the filter can be downsized. become.

[0014]

FIG. 1 is an exploded perspective view of a filter according to the present invention, FIG. 2 is an external perspective view of the filter shown in FIG. 1, and FIG. 3 is a simplified equivalent of the filter shown in FIGS. The circuit diagrams are respectively shown. As shown in the drawing, the filter according to the present invention includes a dielectric substrate 1 and a first resonance electrode 2.
1, a second resonance electrode 22, and a shield electrode 23.

The dielectric substrate 1 includes a plurality of dielectric layers 11, 1
2 and 13 are laminated. Dielectric layer 11
13 to 13 may be made of any of an organic dielectric material and a ceramic dielectric material. When a ceramic dielectric material is used, the dielectric substrate 1 can have a structure in which the dielectric layers 11 to 13 are integrally sintered.

The shapes, structures and relative positional relationships of the first resonance electrode 21 and the second resonance electrode 22 are shown in detail in FIG. In FIG. 4, the first resonance electrode 21 formed on one surface of the dielectric layer 11 and the second resonance electrode 22 formed on the other surface of the dielectric layer 11 are replaced with one surface of the dielectric layer 13. , Dielectric layers 11 and 13 are shown side by side. As shown in the drawing, the first resonance electrode 21 is disposed on one surface of the dielectric layer 11 constituting the dielectric substrate 1 in the layer thickness direction, and has a shape bent at least once. The illustrated first resonance electrode 21 is provided on the dielectric layer 1.
When the horizontal direction W and the vertical direction L are imagined on one surface in the layer thickness direction, at the first bending position P11 located at a substantially intermediate portion in the vertical direction L, the first bending position P11 is bent at a substantially outer right angle in the horizontal direction W, Is bent in the vertical direction L at a bending position P12, and further, at a third bending position P13, in a direction opposite to the bending direction at the first bending position P11. The bent end forms an open end 211.

The second resonance electrode 22 is connected to the first resonance electrode 2
It has an arrangement and pattern symmetrical to 1. Specifically, at a first bending position P21 located at a substantially middle portion in the vertical direction L, the first bending position P21 is bent at a substantially right angle in the horizontal direction L, and at a second bending position P22, the first bending position P21 is bent in the vertical direction L. The third bending position P33 is bent in a direction opposite to the bending direction at the first bending position P21. The bent end forms an open end 221.

In each of the first resonance electrode 21 and the second resonance electrode 22, only the open ends 211 and 221 overlap each other with the overlap width ΔW01 via the dielectric layer 11. First resonance electrode 21 and second resonance electrode 2
Each of 2 has an intermediate portion coupled to input / output terminals 24 and 25 provided on the side surface of the dielectric substrate 1. In the embodiment, the respective intermediate portions of the first resonance electrode 21 and the second resonance electrode 22 are connected by the lead electrodes 212 and 222.
Although a structure in which the lead electrodes 212 and 222 are directly connected to the input / output terminals 24 and 25 is shown, a structure in which the lead electrodes 212 and 222 are capacitively or inductively coupled to the input / output terminals 24 and 25 may be used.

Further, an electrode portion of the first resonance electrode 21 from the side shield electrode 233 to the first bending position P11, and an electrode portion of the second resonance electrode 21 from the side shield electrode 233 to the first bending position P21. Are opposed to each other with an interval ΔW02 viewed in a direction parallel to the plane.

Referring again to FIGS. 1 and 2, the shield electrode 23 is provided on the other dielectric layers 12 and 13 covering the first resonance electrode 21 and the second resonance electrode 22. The illustrated shield electrode 23 includes main shield parts 231 and 232 and side shield parts 233 and 234. The main shield portions 231 and 232 face the first resonance electrode 21 and the second resonance electrode 22. The side shield portions 233 and 234 are provided on the side surface of the dielectric substrate 1 which is a laminate of the dielectric layers 11 to 13. More specifically, the main shield part 231 is formed on one surface of the dielectric layer 12 covering the first resonance electrode 21 with gaps G1 and G2 from both sides in the horizontal direction W. The main shield part 232 is formed of the dielectric layer 13 covering the second resonance electrode 22.
Are formed with gaps G3 and G4 from both sides in the horizontal direction W. Side shield parts 233, 234
Are provided so that the main shield portions 231 and 232 are continuous on both side surfaces of the dielectric substrate 1 in the longitudinal direction L. The other end of the first resonance electrode 21 and the second resonance electrode 22 is led out to the side surface and connected to the side surface electrode 213,
Configure the short-circuit end.

The input / output terminals 24 and 25 are connected to the main shield 2
The gaps G5 and G6 are formed between the dielectric bases 1 and 31 at different side positions. Although not shown, a similar gap is maintained between the input / output terminals 24 and 25 and the main shield part 232 on the back side.

Next, referring to the simplified equivalent circuit of FIG.
The first resonance electrode 21 forms a resonance circuit by a parallel circuit of the capacitor C1 and the inductance L1, and the second resonance electrode 22 forms a resonance circuit by a parallel circuit of the capacitor C2 and the inductance L2.
The capacitor C1 is composed of the first resonance electrode 21 and the main shield 2
The distribution capacitance generated depending on the dielectric constant of the dielectric layer 11 is expressed as a lumped constant between the reference numeral 31 and the reference numeral 31. The inductance L1 is generated depending on the dimension of the first resonance electrode 21. The capacitor C2 expresses a distributed capacitance generated between the second resonance electrode 22 and the main shield part 232 depending on the dielectric constant of the dielectric layer 11 as a lumped constant. The inductance L2 is generated depending on the dimension of the first resonance electrode 21. The mutual inductance M mainly depends on the electrode portion from the side shield electrode 233 to the first bent position P11 in the first resonance electrode 21 and the first bent position P from the side shield electrode 233 in the second resonance electrode.
It occurs between the electrode portion reaching 21. Coupling capacity Ca
Occurs between the open ends 211 and 221 depending on the facing area thereof, the dielectric constant of the dielectric layer 11, and the layer thickness.

As described above, in the filter according to the present invention, the first resonance electrode 21 and the second resonance electrode 22
Are arranged on both sides of the dielectric layer 11 in the thickness direction of the dielectric layer 11, respectively, so that compared with a conventional filter in which two resonators are provided at an interval on the same surface of a dielectric substrate. , The plane area is significantly reduced.

Since each of the first resonance electrode 21 and the second resonance electrode 22 has a shape bent at least once, the electrode length (1/4 wavelength) required to determine the resonance frequency While the length of the resonance electrodes 21 and 22 relative to the dielectric substrate 1 or the dielectric layers 11 to 13 can be reduced. For this reason, the dielectric substrate 1 can be reduced in size and downsized.

More specifically, referring to FIG. 4, in this embodiment, in the case of the embodiment bent at the first bending position P11 to the third bending position P13, the first side position is changed from the side shield electrode 233 to the first side position. D11 to the bending position P11 (average distance viewed at the center of the electrode width, the same applies hereinafter)
And a distance D12 from the first bending position P11 to the second bending position P12, a distance D13 from the second bending position P12 to the third bending position P13, and a distance from the third bending position P13 to the leading edge. The sum of D14, D = D11 + D12 + D13 + D14, can be regarded as substantially the electrode length (1/4 wavelength) required to determine the resonance frequency. Dielectric substrate 1 or dielectric layers 11 to
The substantial length D01 of the resonance electrode with respect to 13 is smaller than this electrode length D. Therefore, it is possible to reduce the substantial length D01 of the resonance electrode with respect to the dielectric substrate 1 or the dielectric layers 11 to 13 while securing the electrode length D (1/4 wavelength) necessary for determining the resonance frequency. it can. Although the description is omitted, the same applies to the second resonance electrode 22.

Each of the first resonance electrode 21 and the second resonance electrode 22 has an open end 2
11 and 221 and only the open ends 211 and 221 overlap each other with the dielectric layer 11 interposed therebetween, so that the first resonance electrode 21 and the second resonance electrode 22 are located between the open ends 211 and 221. (See FIG. 3). In this case, since only the open ends 211 and 221 overlap with each other via the dielectric layer 11, an appropriate coupling capacitance Ca is obtained, and the dielectric having the coupling control electrode which is indispensable in JP-A-9-69701. No substrate is required. For this reason, the thickness of the dielectric substrate 1 as a whole can be reduced, and the size can be significantly reduced, and the size can be reduced, in addition to the size reduction due to the reduction of the plane area.

The shield electrode 23 is a first resonance electrode 21
And the other end of the first resonance electrode 21 and the second resonance electrode 22 are connected to the dielectric layers 12 and 13 covering the second resonance electrode 22. And the first resonance electrode 21 and the second resonance electrode 2
2, a resonance circuit is formed by the dielectric constant of the dielectric layer and the length of the resonance electrode.

Since each of the first resonance electrode 21 and the second resonance electrode 22 has an intermediate portion coupled to input / output terminals 24 and 25 provided on the side surface of the dielectric substrate 1, the input / output terminals 24 and 25 are provided. , 25 can be used as terminals for connecting to an external circuit.

Referring to FIG. 4, the first resonance electrode 21 and the second resonance electrode 22 are formed such that the widths W11 and W21 of the open ends 211 and 221 are wider than the widths W12 and W22 of the other portions. Have been. According to this structure, the overlapping area of the open ends 211 and 221 is increased, and the capacitance coupling amount C is increased.
a (see FIG. 3) can be increased.

Further, in the embodiment shown in FIGS. 1 to 3, the shield electrode 23 includes main shield portions 231 and 232 and side shield portions 233 and 234.
Reference numerals 31 and 232 face the first resonance electrode 21 and the second resonance electrode 22, respectively. Side shield part 233, 2
Reference numeral 34 is provided on the side surface of the dielectric substrate 1. In such a shield electrode structure, as shown in FIG. 4, the distance G between the side of the open end 211 and the side shield part 234 is determined.
01, G02, the distance between the open ends 211, 221 and the main shield parts 231, 232, that is, the dielectric layer 1
2 and the thickness t2 of the dielectric layer 13 (see FIGS. 1 and 2). Thereby, the capacity between the open ends 211 and 221 and the main shield parts 231 and 232 can be increased, and the size of the filter can be further reduced. Also, by reducing the distance between the open ends 211 and 221 and the main shield parts 231 and 231, the open ends 211 and 221 are reduced.
, The lengths D01 and D02 of the resonance electrodes are shorter than １ ／ wavelength of the resonance frequency, and the size of the filter can be reduced.

Next, a filter according to the present invention was prepared using a dielectric material having a relative dielectric constant of 90, and compared with a conventional filter. In a conventional filter, two quarter-wavelength resonators are provided at intervals on the same surface of a dielectric substrate, and another dielectric substrate is provided on the surface of the dielectric substrate on which the resonator is formed. They are laminated and have a structure in which a shield electrode is formed on the outer main surface of each dielectric substrate so as to cover the resonator. The dielectric substrate had a thickness of 0.75 mm and a relative dielectric constant of 90. The distance between the open ends of the resonator was 0.15 mm, and the center frequency was 1.
The frequency was set to 9 GHz. The external size of this filter is 4.5 × 3.2
× 1.5 mm.

As the filter according to the present invention, the dielectric layer 1
Filters having a center frequency of 1.9 GHz were prepared with thicknesses of 1 to 13 each being 0.5 mm. First resonance electrode 21
Open end 211 of the second resonance electrode 22
Since the distance between the first filter 21 and the first filter 21 is 0.5 mm, the thickness of the dielectric layer 11 is 0.5 mm.
-221 is open. Therefore, the open end 21
The widths W11, W21 of 1,221 (see FIG. 4) were set to 0.4 mm, which is twice the line widths W12, W22 of other portions = 0.2 mm, and the capacitive coupling Ca (see FIG. 3) was increased. The size of the obtained filter was 2.5 × 3.2 × 1.5 mm, which was about 40% smaller than the conventional filter.

FIG. 5 is an exploded perspective view showing another embodiment of the filter according to the present invention, and FIG. 6 is an external perspective view of the filter shown in FIG. In the drawings, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals. First resonance electrode 2
The shape or structure of the first and second resonance electrodes 22 and their relative positional relationships are shown in detail in FIG. FIG.
Referring to, the first resonance electrode 21 is disposed on one surface of the dielectric layer 11 constituting the dielectric substrate 1 in the layer thickness direction, and has a shape bent once. Specifically, the first resonance electrode 21 is bent at a bending position P <b> 11 at a substantially outer right angle in the lateral direction W, and the bent end portion is the open end portion 211.

The second resonance electrode 22 is connected to the first resonance electrode 2
It has an arrangement and pattern symmetrical to 1. More specifically, at the bending position P21, it is bent at a substantially right angle in the lateral direction L, and the bent front end is the open end 221.
It has become.

In each of the first resonance electrode 21 and the second resonance electrode 22, only the open ends 211 and 221 overlap each other with the overlap width ΔW01 via the dielectric layer 11. First resonance electrode 21 and second resonance electrode 2
Each of 2 has an intermediate portion coupled to input / output terminals 24 and 25 provided on the side surface of the dielectric substrate 1. In the embodiment, the respective intermediate portions of the first resonance electrode 21 and the second resonance electrode 22 are connected by the lead electrodes 212 and 222.
Although the structure in which the lead electrodes 212 and 222 are directly connected to the input / output terminals 24 and 25 is shown, the structure may be such that the lead electrodes 212 and 222 are capacitively or inductively coupled to the input / output terminals 24 and 25 at intervals. As already mentioned.

Further, referring to FIG. 7, in the first resonance electrode 21, an electrode portion from the side shield electrode 233 to the first bending position P11, and in the second resonance electrode, the first bending from the side shield electrode 233 to the first bending position. Position P2
1 is opposed to the electrode portion with an interval ΔW02 viewed in the plane direction.

The other structure is substantially the same as that of the embodiment shown in FIGS. 1 to 4, and a description thereof will be omitted. Figure 5
The filter shown in FIG. 7 can also be represented by a simple equivalent circuit as shown in FIG.

In the filters shown in FIGS. 5 to 7, the first resonance electrode 21 and the second resonance electrode 22 are respectively disposed on both sides of the dielectric layer 11 in the thickness direction. Thus, compared to a conventional filter in which two resonators are provided at an interval on the same surface of a dielectric substrate,
The plane area is significantly reduced.

Since each of the first resonance electrode 21 and the second resonance electrode 22 has a shape bent once, the electrode length (1/4) required to determine the resonance frequency is set.
With the wavelength maintained, the substantial length of the resonance electrodes 21 and 22 with respect to the dielectric substrate 1 or the dielectric layers 11 to 13 can be reduced. For this reason, the dielectric substrate 1 can be reduced in size and downsized.

More specifically, referring to FIG. 7, the distance D11 from the side shield electrode 233 to the first bending position P11 and the bending position P11 will be described.
Sum of distances D12 from 11 to the tip edge D = D11 + D
12 can be regarded as approximately the electrode length (1/4 wavelength) required to determine the resonance frequency. The substantial length D01 of the resonance electrode with respect to the dielectric substrate 1 or the dielectric layers 11 to 13 is smaller than the electrode length D. Therefore, it is possible to reduce the substantial length D01 of the resonance electrode with respect to the dielectric substrate 1 or the dielectric layers 11 to 13 while securing the electrode length D (1/4 wavelength) necessary for determining the resonance frequency. it can. Although the description is omitted, the same applies to the second resonance electrode 22.

Each of the first resonance electrode 21 and the second resonance electrode 22 has an open end 2
11 and 221 and only the open ends 211 and 221 overlap each other with the dielectric layer 11 interposed therebetween, so that the first resonance electrode 21 and the second resonance electrode 22 are located between the open ends 211 and 221. (See FIG. 3). In this case, since only the open ends 211 and 221 overlap with each other via the dielectric layer 11, an appropriate coupling capacitance Ca is obtained, and the dielectric having the coupling control electrode which is indispensable in JP-A-9-69701. No substrate is required. For this reason, the thickness of the dielectric substrate 1 as a whole can be reduced, and the size can be significantly reduced, and the size can be reduced, in addition to the size reduction due to the reduction of the plane area.

The shield electrode 23 is connected to the first resonance electrode 21
And the other end of the first resonance electrode 21 and the second resonance electrode 22 are connected to the dielectric layers 12 and 13 covering the second resonance electrode 22. And the first resonance electrode 21 and the second resonance electrode 2
2, a resonance circuit is formed by the dielectric constant of the dielectric layer and the length of the resonance electrode.

Each of the first resonance electrode 21 and the second resonance electrode 22 has an intermediate portion coupled to the input / output terminals 24 and 25 provided on the side surface of the dielectric substrate 1, so that the input / output terminals 24 , 25 can be used as terminals for connecting to an external circuit.

Referring to FIG. 7, the first resonance electrode 21 and the second resonance electrode 22 are formed such that the widths W11 and W21 of the open ends 211 and 221 are wider than the widths W12 and W22 of the other portions. Have been. According to this structure, the overlapping area of the open ends 211 and 221 is increased, and the capacitance coupling amount C is increased.
a (see FIG. 3) can be increased.

Further, in the embodiment shown in FIGS. 5 to 7, the shield electrode 23 includes main shield portions 231 and 232 and side shield portions 233 and 234.
Reference numerals 31 and 232 face the first resonance electrode 21 and the second resonance electrode 22, respectively. Side shield part 233, 2
Reference numeral 34 is provided on the side surface of the dielectric substrate 1. In such a shield electrode structure, as shown in FIG. 7, the distance G between the side of the open end 211 and the side shield part 234 is determined.
01, G02, the distance between the open ends 211, 221 and the main shield parts 231, 232, that is, the dielectric layer 1
2 and the thickness t2 of the dielectric layer 13 (see FIGS. 5 and 6). Thereby, the capacity between the open ends 211 and 221 and the main shield parts 231 and 232 can be increased, and the size of the filter can be further reduced. Also, by reducing the distance between the open ends 211 and 221 and the main shield parts 231 and 231, the open ends 211 and 221 are reduced.
, The lengths D01 and D02 of the resonance electrodes are shorter than １ ／ wavelength of the resonance frequency, and the size of the filter can be reduced.

Also in the filter shown in this embodiment, the outer size is 3.1 × 2.4 × 1.5 mm, and the above-mentioned 4.5 ×
The size of the conventional filter with a size of 3.2 x 1.5 mm was reduced by about 40%.

FIG. 8 is an external perspective view showing still another embodiment of the filter according to the present invention. In the figure, the same components as those shown in the previous figures are denoted by the same reference numerals. A feature of this embodiment is that insulating layers 14 and 15 are provided on the surfaces of the dielectric layers 12 and 13. With such a structure, for example, gaps G5 and G6 formed between the main shield parts 231 and 232 and the input / output terminals 24 and 25 (see FIGS. 1, 2, and , FIG.
(See FIG. 2), the gaps G5 and G6 can be filled with the insulating layers 14 and 15 to increase the reliability of electrical insulation between the shield electrode 23 and the input / output terminals 24 and 25.

Although the contents of the present invention have been specifically described with reference to the preferred embodiments, the present invention is not limited to such embodiments and illustrations. The total number of dielectric layers and insulating layers constituting the dielectric substrate is not limited to the embodiment, and the number and shape of the resonance electrodes may be variously changed.

[0049]

As described above, according to the present invention, it is possible to provide a filter having a reduced plane area and a reduced thickness.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a filter according to the present invention.

FIG. 2 is an external perspective view of the filter shown in FIG.

FIG. 3 is a simplified equivalent circuit diagram of the filter shown in FIGS. 1 and 2.

FIG. 4 is a diagram showing shapes, structures, and relative positional relationships of a first resonance electrode and a second resonance electrode of the filter shown in FIGS. 1 and 2;

FIG. 5 is an exploded perspective view showing another embodiment of the filter according to the present invention.

6 is an external perspective view of the filter shown in FIG.

FIG. 7 is a diagram showing shapes or structures and relative positional relationships of a first resonance electrode and a second resonance electrode of the filter shown in FIGS. 5 and 6;

FIG. 8 is an external perspective view showing still another embodiment of the filter according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 dielectric substrate 11, 12, 13 dielectric layer 21 first resonance electrode 211 open end 22 second resonance electrode 221 open end 23 shield electrode 24, 25 input / output terminal

Claims (4)

[Claims] 1. A dielectric substrate, a first resonance electrode, and a second
Wherein the dielectric substrate is formed by laminating a plurality of dielectric layers, wherein each of the first resonance electrode and the second resonance electrode For one of the dielectric layers constituting the dielectric substrate, each of the dielectric layers is disposed on both surfaces in the layer thickness direction, has at least one bent shape, and has a bent end portion having an open end portion. And only the open ends overlap each other via the dielectric layer, and an intermediate portion is electrically coupled to an input / output terminal provided on a side surface of the dielectric substrate. The first resonance electrode is provided on another dielectric layer that covers the first resonance electrode and the second resonance electrode;
A filter to which the other ends of the resonance electrode and the second resonance electrode are connected. 2. The dielectric resonator according to claim 1, wherein the input / output terminal for the first resonance electrode and the second input / output terminal.
Wherein the input / output electrodes for the resonance electrodes are formed at different side positions of the dielectric substrate. 3. The dielectric resonator according to claim 1, wherein each of the first resonance electrode and the second resonance electrode has a wider width at the open end than at other portions. The filter being formed. 4. The dielectric resonator according to claim 1, wherein the shield electrode includes a main shield part and a side shield part, and the main shield part includes the first resonance electrode and a side shield part. The side shield portion is provided on a side surface of the dielectric substrate, and the distance between the side edge of the open end and the side shield portion is equal to the distance between the side shield portion and the second resonance electrode. A filter that is shorter than the distance between an end and the main shield.