JPH08288706A - Lamination type dielectric filter - Google Patents

Abstract

PURPOSE: To obtain a miniaturized lamination type dielectric filter reduced at its conductor loss by arranging a connection electrode, an input electrode, an output electrode, and a turning capacity ground electrode between the layers of respective resonance elements constituting two-layered structure. CONSTITUTION: Resonance elements 21, 22 respectively consists of two strip lines 71, 72 and 73, 74 formed on positions corresponding to the upper faces of two dielectric layers 14, 15. A connection electrode 91, an input electrode 41 and an output electrode 42 are formed on the upper face of another dielectric layer 13 inserted between the layers 14, 15. A turning capacity ground electrode also is similarly formed. A face opposing interval between the two strip lines 71, 72 and 73, 74 respectively superposed in the vertical direction, the two strip lines 72, 72 and 73, 74 are respectively functioned as single resonance elements even if their released end side is not short-circuited. Since the connection electrode 91 or the like is formed between two opposite strip lines, electric lines of fore are not interrupted, no-load Q can be increased, the length of the elements 21, 23 can be shortened, and the lamination type filter 1 can be miniaturized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency circuit filter used for a high frequency circuit wireless device such as a mobile phone, and a laminated dielectric filter preferably used for an antenna duplexer and the like.

[0002]

2. Description of the Related Art As a filter in a low frequency band,
Centralized L consisting of lumped element coil and capacitor
The one using a C resonance circuit is generally used.
However, in the microwave band of several hundred MHz to several GHz, it is extremely difficult to obtain a coil or a capacitor of a lumped constant element. Therefore, normally, a resonant circuit configured by opening or shorting the terminal of the distributed constant circuit is used. Things are used. As such a filter, a laminated type filter in which a dielectric is arranged between a ground electrode and a strip-shaped resonance element is generally used. Since the multilayer filter using such a so-called strip line is relatively small, it is widely used in mobile communication devices such as mobile phones.

2 and 3 show an example of the above laminated dielectric filter. The filter 1 consists of five layers of dielectrics 11, 13, 14, 15, 17. Dielectric layer 14
Resonant elements 21, 22, and 23 are formed on the upper side, one end of each of the resonant elements 21, 22, and 23 is connected to the ground electrode 70, and the other end is an electrode 3 also formed on the dielectric layer 14.
It faces 1, 32, and 33 at a constant interval. Electrodes 31, 3
The other ends of 2, 33 are connected to the ground electrode 70. The input electrode 41 is formed on the dielectric layer 15, and the dielectric layer 15
It opposes the resonance element 21 with the element sandwiched therebetween. An output electrode 42 is formed on the dielectric layer 13 and faces the resonance element 23 with the dielectric layer 14 in between. The ground electrode 70 is formed on the entire surface of the filter except the input terminal portion 61 and the output terminal portion 62. The input terminal 51 is formed in the input terminal portion 61 and is insulated from the ground electrode 70.
1 is connected. On the other hand, the output terminal 52 is connected to the output terminal section 6
2 and is connected to the output electrode 42 while being insulated from the ground electrode 70.

FIG. 4 shows an equivalent circuit of the above multilayer filter. In FIG. 4, reference numerals 121, 122, and 12
3 is the resonant elements 21, 22 and 23 and the electrode 3 respectively.
The capacitance is 1, 32, and 33. Also, reference numeral 11
Reference numerals 1 and 112 are capacitances of the resonant elements 21 and 23, the input electrode 41, and the output electrode 42, respectively.
Reference numerals 132 and 133 denote the resonance elements 21 and 2 respectively.
It is an inductance indicating inductive coupling between the resonance elements 22 and 23 and between the resonance elements 22 and 23, and constitutes a bandpass filter. Further, the capacitance and the inductance of the parallel resonant circuit when the resonant elements 21, 22, and 23 are equivalently converted,
Reference numerals 211, 221, 231, and 21 respectively
Shown as 2, 222, 232.

In recent years, there has been a demand for further miniaturization of these devices, and the mounting density of electronic components inside the devices has been increasing. Therefore, the development of a smaller-sized laminated filter is also awaited. In the above multilayer filter, the capacitances 121, 122, 1 are provided between the resonant elements 21, 22, 23 and the electrodes 31, 32, 33.
By providing 23, downsizing of the filter is realized to some extent. That is, the capacitances 121, 122, 123
Are capacitances 211, 221 of the parallel resonant circuit,
231 is added, but since the resonance frequency f ₀ and the capacitance C and the inductance L of the parallel resonance circuit are represented by the formula f ₀ = 1 / 2π√LC, In order to obtain a constant resonance frequency f ₀ , the value of the inductance L can be reduced, so that the lengths of the resonance elements 21, 22 and 23 can be shortened.

However, if the length of the resonant element is too short, the resonant elements are more strongly inductively coupled to each other, so that the characteristics of the filter are widened, and a filter having a desired bandwidth cannot be obtained. It was

In order to solve the above problem, for example, as shown in FIG. 5, a first resonant element 21 and a second resonant element 23 are provided adjacent to each other, and a coupling electrode 91 and a dielectric 15 are provided. It is effective to face them through. An equivalent circuit of the laminated filter shown in FIG. 5 is shown in FIG. In FIG. 6, by providing the coupling electrode 91,
Capacitances 151 and 15 formed between the coupling electrode 91 and the first resonance element 21 and the second resonance element 23, respectively.
2 will be connected in parallel with the inductive coupling 131 between the first resonant element 21 and the second resonant element 23. Therefore, the inductive coupling 131 between the first resonance element 21 and the second resonance element 23 can be suppressed by these capacitances, and even if the length of the resonance element is shortened, the filter characteristic has a wide band. Can be prevented. In addition, the inductive coupling 131 is changed by changing the overlapping area and the distance between the first resonant element 21 and the second resonant element 23 and the coupling electrode 91.
Can be adjusted, and a filter having a desired bandwidth can be obtained.

Further, by providing the coupling electrode 91, it is possible to insert the parallel resonant circuit including the electrostatic capacitances 151 and 152 and the inductance between the first resonant element 21 and the second resonant element 23. Become. Since the impedance of this parallel resonant circuit changes from inductive to capacitive before and after the parallel resonant point, adjusting the values of the electrostatic capacitances 151 and 152 makes the coupling between the resonant elements inductive and capacitive. You can also do Considering the case where the coupling between the resonant elements is inductive, a filter having an attenuation pole on the high frequency side of the pass band is obtained because there is a parallel resonance point on the high frequency side of the pass band. If the coupling between them is made capacitive, there will be a parallel resonance point on the low frequency side of the pass band, and a filter with an attenuation pole on the low frequency side of the pass band will be obtained. Can be improved.

[0009]

However, when the coupling electrode 91 is provided, the lines of electric force from the resonant elements 21 and 23 are shielded by the coupling electrode 91, so that part thereof becomes difficult to function as a resonant element. The same applies to the overlapping portion of the input electrode 41 and the output electrode 42 and the resonant element. Therefore, there is a problem that the conductor loss becomes large. In addition, in order to obtain a desired resonance frequency, it is necessary to always lengthen the resonance element by the amount of supplementing the overlap with the coupling electrode or the like, and the coupling electrode or the like is required for further miniaturization of the multilayer filter. There was also a problem that it hindered us.

[0010]

Means for Solving the Problems The present invention solves the above-mentioned inconveniences, maintains the advantages of the conventional multilayer dielectric filter, has a small conductor loss, and has a shorter resonant element length and a smaller size. It is an object of the present invention to provide a laminated dielectric filter of.

That is, according to the present invention, the earth electrode provided on a part of the surface of the body formed by laminating the dielectric layers, and the first resonance element provided inside the body and having one end short-circuited with the earth electrode. , A second resonance element that is provided adjacent to the first resonance element and has one end short-circuited to the ground electrode, a coupling that faces a part of the first resonance element and the second resonance element through a dielectric layer An electrode, an input electrode facing a part of the first resonant element through the dielectric layer, an output electrode facing a part of the second resonant element through the dielectric layer, a part of the surface of the main body An input terminal portion that is insulated from the ground electrode and short-circuits with the input electrode, and an output terminal portion that is insulated from the ground electrode and is short-circuited with the output electrode on a part of the surface of the main body. A laminated dielectric filter, wherein the first resonant element is
The pair of strip lines are provided on the upper surface of each of the pair of dielectric layers so as to overlap each other. The second resonant element includes the first resonant element on each upper surface of the pair of dielectric layers. And a pair of strip lines provided adjacent to each other so as to overlap each other, the distance between the upper surfaces of the pair of dielectric layers is 500 μm or less, and the coupling electrode, the input electrode and the output are provided. There is provided a laminated dielectric filter in which a working electrode is provided on the upper surface of another dielectric layer interposed between the pair of dielectric layers.

In the multilayer dielectric filter of the present invention, the open ends of the four strip lines forming the first resonant element and the second resonant element are opposed to each other at a fixed interval at one end thereof. Individual electrodes may be provided on the top surface of the dielectric layer with each stripline. Each of the electrodes is short-circuited with the ground electrode at the other end. A first tuning capacitance ground electrode and a second tuning capacitance ground electrode may be provided on the upper surface of the other dielectric layer, and each tuning capacitance ground electrode has a first tuning capacitance ground electrode at one end thereof. The resonance element and the second resonance element overlap with the open ends of the resonance element and the dielectric layer, and are short-circuited to the ground electrode on the open end side of the resonance element at the other end.

[0013]

As shown in FIG. 1 and FIG. 7, the laminated dielectric filter of the present invention is provided adjacent to the inside of the main body 500 and the main body 500 configured by laminating a large number of dielectric layers 11 to 17. First resonant element 21 and second resonant element 2
3, the coupling electrode 91 facing the respective resonance elements 21 and 23 via the dielectric layers 13 and 15, the first resonance element 21 and the second resonance element 23, and the dielectric layers 13 and 15 respectively.
It has an input electrode 41 and an output electrode 42 facing each other. The ground electrode 70 is formed on a part of the surface of the main body 500.
Is provided, and each of the resonance elements 21 and 23 is short-circuited with the ground electrode 70 at one end thereof. Further, the input electrode 41 and the output electrode 42 are connected to an input terminal portion 61 and an output terminal portion 62 which are provided on a part of the surface of the main body 500 so as to be insulated from the ground electrode 70. Each of the resonant elements 21 and 23 is composed of two strip lines 71 and 72, 73 and 74 provided at corresponding positions on the upper surfaces of the two dielectric layers 14 and 15.
Coupling electrode 91, input electrode 41, and output electrode 4
2 is provided on the upper surface of another dielectric layer 13 interposed between the two dielectric layers 14 and 15 described above. The same applies to the case where the tuning capacitance ground electrode is provided. Strip line 71
The distance between the upper surfaces of the two dielectric layers 14 and 15 provided with ˜74 is adjusted to 500 μm or less.

The two strip lines 71 and 72, 73 and 74 which are vertically overlapped with each other function as a single resonance element without short-circuiting the open end sides thereof, because the face-to-face spacing is small. Further, since the coupling electrode 91 and the like are provided between the two opposing strip lines, there is no shielding of the lines of electric force, the unloaded Q can be increased, and the resonant element 2
The lengths of 1 and 23 can be shortened, and the multilayer filter 1 can be downsized.

2 provided with strip lines 71 to 74
The distance between the upper surfaces of the dielectric layers 14 and 15 is preferably 500 μm or less, more preferably 200 μm or less. If the spacing is greater than 500 μm,
This is because it is difficult for the two opposing strip lines to function as a single resonant element.

When the lengths of the resonance elements 21 and 23 are shortened, as described above, the resonance elements are more strongly inductively coupled to each other, so that the characteristics of the filter 1 are broadened. However, in the present invention, as shown in the equivalent circuit diagram of FIG.
Since the capacitance 152 formed between each of the one and four strip lines 71 to 74 is connected in parallel with the inductive coupling between the resonant elements 21 and 23, the inductive coupling can be appropriately suppressed. it can. The capacitance can be adjusted by changing the overlapping area and the distance between the strip lines 71 to 74 and the coupling electrode 91.

As shown in FIG. 1, each resonance element 21, 2
The electrodes 31 and 33 facing the respective open ends of the strip lines 71 to 74 forming the strip 3 at a constant interval are provided on the upper surfaces of the dielectric layers 14 and 15 provided with the strip lines, and the electrodes 31 and 33 are provided. The other end of the ground electrode 7
By shorting to 0, the length of the resonant elements 21 and 23 can be shortened.

Further, as shown in FIG. 9, a region 201 on the surface of the main body 1 where the first resonance element 21 and the ground electrode 70 are short-circuited, and a main body where the second resonance element 23 and the ground electrode 70 are short-circuited. By providing the region 75 where the dielectric is exposed between the region 203 on the first surface and the peripheral region, a current flows to form an inductance, and the first resonance element 21 and the second resonance element 23 are formed. It becomes possible to adjust the strength of the inductive coupling of each separately. Therefore, the band width and the position of the attenuation pole can be changed separately for the entire filter, and desired filter characteristics can be easily obtained.

Further, as shown in FIG. 10, inner layer ground electrodes 81 and 82 are provided to face the open ends of the first resonant element 21 and the second resonant element 23, respectively, with the dielectric layers 14 and 16 interposed therebetween. As shown in the equivalent circuit diagram of FIG. 11, the open end of the first resonant element 21 and the inner layer ground electrode 8
Capacitances 141 and 142 formed between
Is added to the capacitance 211 of the parallel resonant circuit when the first resonant element 21 is equivalently converted, and the second resonant element 23
Capacitances 145 and 146 formed between the open ends of the second resonance element 23 and the inner-layer ground electrodes 81 and 82 are added to the capacitance 231 of the parallel resonance circuit when the second resonance element 23 is equivalently converted. Therefore, the inductance required to realize the same resonance frequency can be small, and the length of the resonance elements 21 and 23 can be further shortened. Further, as shown in FIG. 16, instead of the inner-layer earth electrode, the tuning capacitance earth which faces the open ends of the first resonance element 21 and the second resonance element 23 with the dielectric layers 13 and 15 interposed therebetween, respectively. Similarly, by providing the electrodes 233 and 234 on the dielectric layer 13, the resonant elements 21 and 23 are also provided.
The length of can be further shortened.

Next, a method of manufacturing the laminated dielectric filter of the present invention will be described. First, ceramic powder is molded to produce a dielectric layer. Next, a conductor paste is applied to the surface of the dielectric layer to form strip lines, input electrodes, output electrodes, coupling electrodes and the like that form the resonance element. After each dielectric layer is laminated, it is fired to be densified. Finally, a ground electrode composed of a silver electrode, and an input terminal portion and an output terminal portion are printed on the surface of the laminated body obtained by firing and baked at 850 ° C.

The conductor paste forming the resonance element, the input electrode, the output electrode, and the coupling electrode preferably has a low specific resistance, and specifically, an Ag-based or Cu-based conductor is used. It is preferable. The same applies to the case where the conductor and the inner layer electrode are provided.

As the dielectric, a ceramic dielectric having high reliability and having a large permittivity εγ, which can be easily downsized, is used. However, when Ag-based or Cu-based conductors are used, their melting points (1100 ° C. or less) are low, and it is difficult to fire them at the same time as ordinary dielectric materials. It is necessary to use a dielectric material that can be fired. In addition, due to the characteristics of the device as a microwave filter, the temperature characteristic (temperature coefficient) of the resonance frequency of the formed parallel resonance circuit is ± 50 ppm / ° C.
It is preferable to use the following dielectric materials.
Examples of such a dielectric material include glass-based materials such as a mixture of cordierite-based glass powder and TiO ₂ powder, and Nd ₂ Ti ₂ O ₇ powder, and BaO—TiO ₂ —.
Re ₂ O ₃ -Bi ₂ O ₃ based compositions (Re: rare earth component) to that added some glass forming component or glass powder, barium oxide - titanium oxide - slight glass neodymium oxide based dielectric ceramic composition powder Some have powder added.

[0023]

EXAMPLES The present invention will be described below in more detail with reference to the illustrated examples, but the present invention is not limited to these examples.

Example 1 FIGS. 10 and 9 show an example of the above laminated dielectric filter. In the filter 1 shown in the figure, the main body 500 is configured by laminating a large number of dielectric layers 11 to 17, and includes a first resonant element 21 and a second resonant element 2
3 is two strip lines 71 and 72, 73 and 74 provided at the corresponding positions on the upper surfaces of the two dielectric layers 14 and 15.
Each is composed of Each strip line 71
˜74 are short-circuited at one end to the ground electrode 70 provided on the surface of the main body 500. Resonant elements 21, 23
The distances between the two strip lines 71 and 72 and 73 and 74 that constitute the above are adjusted to 500 μm or less.

The coupling electrode 91, the input electrode 41, and the output electrode 42 are provided on the upper surface of another dielectric layer 13 interposed between the two dielectric layers 14 and 15 described above.
The coupling electrode 91, the input electrode 41, and the output electrode 42 are
The resonator elements 21 and 23 are opposed to each other via the dielectric layers 14 and 15. The input electrode 41 and the output electrode 42 are the main body 5
00 is connected to an input terminal portion 61 and an output terminal portion 62, which are provided on a part of the surface of 00 to be insulated from the ground electrode 70.

The electrodes 31 and 33 are connected to the strip line 7
1 to 74 are provided on the upper surfaces of the dielectric layers 14 and 15 and face the open ends of the strip lines 71 to 74 forming the resonant elements 21 and 23 at regular intervals and the other end is grounded. It is short-circuited to the electrode 70.

The inner-layer ground electrodes 81 and 82 are provided on the upper surfaces of the dielectric layers 12 and 16, respectively, and the open ends of the first resonant element 21 and the second resonant element 23 and the dielectric layers 14 and 16, respectively. The two electrodes are opposed to each other and are short-circuited to the ground electrode 70.

A region 201 on the surface of the body 500 where the first resonant element 21 and the ground electrode 70 are short-circuited, and a region 203 on the surface of the body 500 where the second resonant element 21 and the ground electrode 70 are short-circuited. A region 75 where the dielectric is exposed is provided between them.

It should be noted that FIG. 12 shows A- of the filter of this example.
A'sectional view is shown. The filter 1 of this example has a length of 3.2 mm,
The width is 4.5 mm and the height is 2 mm, and a ground electrode having a thickness of 0.02 mm is provided on the surface of the laminated body including the dielectric layers. Strip line 7 that constitutes each resonant element
The length of 1, 73 is 2.6 mm, and the distance between both resonant elements is 2.
It was set to 04 mm. The width of the strip line was set to 0.6 mm, but the portion facing the inner layer grounds 81 and 82 was 0.8 mm.
It was 6 mm.

The laminated dielectric filter was manufactured as follows. First, MgO: 18 wt% -Al ₂ O _{3: 3}
7 wt% -SiO _2: 37 wt% -B ₂ O _3: 5 wt% -
TiO _2: 3 wt% and 73 wt% glass powder having a composition, commercially available TiO ₂ powder 17 wt%, Nd ₂ Ti ₂ O ₇ powder 10 wt% were mixed thoroughly to obtain a mixed powder. As the Nd ₂ Ti ₂ O ₇ powder, Nd ₂ O ₃ powder and TiO ₂ powder were calcined at 1200 ° C. and then pulverized. Next, an acrylic organic binder, a plasticizer, toluene and an alcohol solvent were added to this powder, and the mixture was sufficiently mixed with alumina boulders to obtain a slurry. The slurry was molded into a green sheet having a thickness of 0.2 to 0.5 mm by a doctor blade method to form a dielectric layer.

Silver paste is used for the green sheet,
After printing patterns such as strip lines and coupling electrodes, green sheets were laminated and fired at 900 ° C. to obtain a laminate. Next, a ground electrode made of a silver electrode, and an input terminal portion and an output terminal portion are printed on the surface of the laminated body,
The laminated dielectric filter was obtained by baking at 0 ° C. FIG.
3 shows the frequency characteristics of this laminated dielectric filter. In FIG. 13, a is a graph showing impedance characteristics by return loss, and b is a graph showing filter characteristics.

Comparative Example 1 A laminated dielectric filter having the same material and dimensions as those of Example 1 was manufactured by the same method as that of Example 1. The patterns of strip lines, coupling electrodes, etc. were also the same as in Example 1. However, as shown in FIG. 14, the coupling electrode 91, the two dielectric layers 14 and 15 in which the input electrode 41 and the output electrode 42 are provided at positions corresponding to each other, and the strip lines 71 and 73 are provided. The dielectric layer 13 is disposed above and below the dielectric layer 13. Therefore, the first resonant element 21 and the second resonant element 23 are each composed of one strip line 71, 73.

FIG. 15 shows frequency characteristics of the laminated dielectric filter of this example. In FIG. 15, a is a graph showing impedance characteristics by return loss, and b is a graph showing filter characteristics.

From FIGS. 13 and 15, it can be seen that the center frequency of the filter of the comparative example is about 1706 MHz, whereas the center frequency of the filter of the example is about 1566 MHz. Therefore, in the filter of the embodiment,
The length of the resonant element required to obtain the same resonant frequency can be made shorter than that of the filter of the comparative example.

The bandwidth of the filter of the comparative example is about 11
It can be seen that the bandwidth of the filter of the first embodiment is about 103 MHz and the load Q is 15 while the load is 8 MHz and the load Q is 14. Normally, when the bandwidth is narrowed, the load Q is increased and the insertion loss is increased. However, in the filter of the embodiment, it is possible to reduce the insertion loss while narrowing the bandwidth. The reason why the insertion loss is smaller than that of the filter of the comparative example is that the unloaded Q of the resonant element is improved, and the increased unloaded Q is that the lines of electric force from the resonant element are not shielded. Because.

[0036]

In the laminated dielectric filter of the present invention, the coupling electrode, the input electrode, the output electrode, and the tuning capacitance ground electrode are arranged between the layers of each resonance element having a two-layer structure. The lines of electric force from the resonance element are not shielded by the coupling electrode or the like, and the resonance element can exhibit the function as the resonance element even in the overlapping portion with the coupling electrode or the like.
Therefore, it is possible to obtain a multilayer dielectric filter which has a band characteristic equivalent to that of the conventional multilayer dielectric filter in which the coupling electrode and the like are arranged outside the resonant element, and which is smaller and has a smaller conductor loss.

[Brief description of drawings]

FIG. 1 is a schematic development view showing an example of a laminated dielectric filter of the present invention.

FIG. 2 is a schematic development view showing an example of a conventional laminated dielectric filter.

FIG. 3 is a perspective view showing an example of a conventional laminated dielectric filter.

FIG. 4 is an equivalent circuit diagram of an example of a conventional laminated dielectric filter.

FIG. 5 is a schematic development view showing another example of a conventional laminated dielectric filter.

FIG. 6 is an equivalent circuit diagram of another example of a conventional multilayer dielectric filter.

FIG. 7 is a perspective view showing an example of a laminated dielectric filter of the present invention.

FIG. 8 is an equivalent circuit diagram of an example of the laminated dielectric filter of the present invention.

FIG. 9 is a perspective view showing an example of a laminated dielectric filter of the present invention.

FIG. 10 is a schematic development view showing another example of the laminated dielectric filter of the present invention.

FIG. 11 is an equivalent circuit diagram of another example of the multilayer dielectric filter of the present invention.

12 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 13 is a graph showing frequency characteristics of an example of the laminated dielectric filter of the present invention.

FIG. 14 is a schematic development view showing still another example of a conventional laminated dielectric filter.

15 is a graph showing frequency characteristics of the filter of FIG.

FIG. 16 is a schematic development view showing still another example of the multilayer dielectric filter of the present invention.

[Explanation of symbols]

1 ... filter, 11, 12, 13, 14, 15, 1
6, 17 ... Dielectric layer, 21, 22, 23 ... Resonant element,
31, 32, 33 ... Electrodes, 41 ... Input electrodes, 42 ...
・ Output electrode, 51 ... Input terminal, 52 ... Output terminal, 6
DESCRIPTION OF SYMBOLS 1 ... Input terminal part, 62 ... Output terminal part, 70 ... Ground electrode, 71, 72, 73, 74 ... Strip line,
75 ... Exposed dielectric portion, 81, 82 ... Inner layer ground electrode,
91 ... Coupling electrodes, 111, 112 ... Capacitance, 12
1, 122, 123 ... Capacitance, 131, 132, 1
33 ... Inductance, 141, 142, 145, 1
46, 151, 152 ... Electrostatic capacitance, 171 ... Inductance, 201, 203 ... Short-circuit area, 211 ... Electrostatic capacitance, 212 ... Inductance, 221 ... Electrostatic capacitance, 2
22 ... Inductance, 231 ... Electrostatic capacity, 232 ...
Inductance 233 ... First tuning capacitance ground electrode, 234 ... Second tuning capacitance ground electrode, 500 ...
Laminate.

Claims (3)

[Claims] 1. A ground electrode provided on a part of the surface of a body formed by laminating dielectric layers, a first resonance element provided inside the body, and one end of which is short-circuited with the ground electrode. Second resonance element provided adjacent to the resonance element of which one end is short-circuited with the ground electrode, and a coupling electrode facing a part of the first resonance element and the second resonance element through a dielectric layer. , An input electrode facing a part of the first resonant element through the dielectric layer, an output electrode facing a part of the second resonant element through the dielectric layer, a surface of the main body An input terminal part that is insulated from the ground electrode and short-circuits the input electrode, and an output that is insulated from the ground electrode on a part of the surface of the body and short-circuited with the output electrode. A laminated dielectric filter having a terminal part, comprising: The element is composed of a pair of strip lines provided on the upper surfaces of the pair of dielectric layers so as to overlap each other, and the second resonant element is provided on the upper surface of each of the pair of dielectric layers. The pair of strip lines adjacent to the strip line constituting the first resonant element and overlapping each other is provided, and the distance between the upper surfaces of the pair of dielectric layers is 500 μm or less. An electrode, an input electrode, and an output electrode are provided on the upper surface of another dielectric layer interposed between the pair of dielectric layers. 2. The strip line includes four electrodes facing each open end of each of the four strip lines forming the first resonant element and the second resonant element at a constant interval. The multilayer dielectric filter according to claim 1, which is provided on an upper surface of a dielectric layer including, and each of the electrodes is short-circuited with the ground electrode at one end thereof. 3. A first tuning-capacitance ground electrode and a second tuning-capacitance ground electrode are provided on the upper surface of the other dielectric layer, and each tuning-capacitance ground electrode has its first end at the one end thereof. 3. The resonance element and the open end of the second resonance element are overlapped with each other through the dielectric layer, and short-circuited to the ground electrode on the open end side of the resonance element at the other end.
The laminated dielectric filter according to item 1.