JP2830638B2 - Resonator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator, and more particularly to, for example, a resonator used in a several GHz band.

[0002]

BACKGROUND ART As a conventional resonator, for example, a half strip line resonator having a wavelength as shown in FIGS. In the resonator 1, a line electrode 3 having both ends opened is formed on one main surface of a dielectric substrate 2, and a ground electrode is formed on the entire surface of the other main surface of the dielectric substrate 2.
In such a resonator 1, when the wavelength is λ and the effective permittivity of the dielectric substrate 2 is ε, the length L ₁ of the line electrode 3 is given by the following equation (1).

[0003]

(Equation 1)

As shown in FIG. 8 , there is a quarter-wave resonator in which one end of a line electrode 3 is connected to an earth electrode so as to extend from the end of a dielectric substrate 2. The length L ₂ of the line electrode 3 of the resonator 1 is given by the following equation (2).

[0005]

(Equation 2)

[0009] As shown in FIG. 9 , there is a resonator in which a spiral coil electrode 4 is formed on one main surface of a dielectric substrate 2. In this resonator 1, a ground electrode 5 is formed on the other main surface of the dielectric layer 2 so as to face the coil electrode 4. Further, an earth extraction electrode 6 connected to the earth electrode 5 is extracted from one end of the coil electrode 4, and an extraction electrode 7 is formed at an interval from the earth extraction electrode 6. In this resonator 1, since the coil electrode 4 is formed in a spiral shape, even if the coil electrode 4 is made longer, it is possible to reduce the size.

[0007]

SUMMARY OF THE INVENTION However, 1/2
For a wavelength resonator or a quarter wavelength resonator, for example,
In a 3 GHz resonator, the length of the line electrode is increased, and the size of the resonator is increased. In a resonator using a coil electrode, since the coil electrode has a spiral shape, a magnetic flux influences between adjacent lines, making it difficult for a current to flow through the coil electrode. Therefore, substantial resistance increases and Q decreases. When the size of the resonator is reduced, the distance between adjacent lines of the coil electrode is reduced, and the influence of magnetic flux between the lines is increased.

[0008] Therefore, a main object of the present invention is to provide a resonator that can be miniaturized and that has a small decrease in Q even when miniaturized.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a plurality of coil electrodes which are formed on a plurality of dielectric layers and are connected to each other to form a spiral electrode. A ground extraction electrode that is drawn to the end of the layer; a extraction electrode that is drawn from one of the coil electrodes to the end of the dielectric layer at a distance from the ground extraction electrode; and a coil on both sides of the plurality of coil electrodes. A shield electrode , a coil electrode, and a shield electrode that face each other at an interval from the electrode
Is formed so as to face the shield electrode between
Through the through hole formed in the dielectric layer.
A capacitor electrode electrically connected to the end of the
, And each coil electrode is a resonator in which the number of turns is one turn or less on the dielectric layer, and the ground extraction electrode is connected to the shield electrode.

[0010]

The dielectric layer on which the coil electrode is formed is laminated,
A spiral electrode is formed by connecting these coil electrodes. An inductance is formed in the spiral electrode portion, and a distributed capacitance is formed between each coil electrode and the shield electrode. When the spiral electrode and the shield electrode are connected via the ground extraction electrode, 1 /
A four-wavelength resonator is formed. In this case, a dielectric layer exists between adjacent lines. Further, by forming a capacitor electrode between the coil electrode and the shield electrode, a capacitance is formed between the capacitor electrode and the shield electrode.

[0011]

According to the present invention, since a spiral electrode is formed by a plurality of coil electrodes, the length of the spiral electrode is adjusted by adjusting the number of dielectric layers on which the coil electrodes are formed. can do. In this case, even if the spiral electrode is lengthened, the resonator does not become large unlike the case where the electrode is formed on one plane. Moreover, since the dielectric layer exists between the adjacent coil electrodes, a distance corresponding to the thickness of the dielectric layer can be secured, and the influence of the magnetic flux between the coil electrodes can be reduced. Therefore, the size of the resonator can be reduced without lowering the Q of the resonator. Further, by forming a capacitance between the capacitor electrode and the shield electrode, the resonance frequency can be reduced, and the resonance frequency can be adjusted.

Further, the shielding property in a high frequency region can be improved by the shield electrode. Further, the impedance of the resonator can be adjusted by changing the distance between the ground extraction electrode and the extraction electrode. Therefore, the resonator can be manufactured in consideration of impedance matching with an external circuit.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0014]

FIG. 1 is a perspective view showing an embodiment of the present invention. The resonator 10 includes a laminate 12. The stacked body 12 includes a first dielectric layer 14, as shown in FIG. On the first dielectric layer 14, a first shield electrode 16 is formed. The first shield electrode 16 is formed on almost the entire surface of the first dielectric layer 14,
Pulled out at one end.

On the first shield electrode 16, a second dielectric layer 18 is disposed. On the second dielectric layer 18,
A first coil electrode 20 is formed. The first coil electrode 20 is formed in a U-shape so that the number of turns is one turn or less in a substantially half area of one main surface of the second dielectric layer 18. A ground extraction electrode 22 is formed from one end of the first coil electrode 20 toward the end of the second dielectric layer 18. Further, the first coil electrode 2
The extraction electrode 24 is drawn out from the middle part of the second dielectric layer 18 toward the end of the second dielectric layer 18. In this embodiment, the extraction electrode 24 is extracted to the end of the second dielectric layer 18 adjacent to the end from which the ground extraction electrode 22 is extracted. The first coil electrode 20 and the ground extraction electrode 22 are formed so as to face the first shield electrode 16, and the extraction electrode 24 corresponds to a portion where the first shield electrode 16 is not formed. Pulled out to the end.

On the first coil electrode 20, a third dielectric layer 26 is formed. On the third dielectric layer 26, a second coil electrode 28 is formed. Second coil electrode 2
8 has a U-shape opposite to the first coil electrode 20 so that the number of turns is one turn or less in a half area on the opposite side to the area where the first coil electrode 20 is formed. Formed. A through hole 30 is formed at one end of the second coil electrode 28 so as to penetrate the third dielectric layer 26. The other end of the first coil electrode 20 and one end of the second coil electrode 28 are connected via the through hole 30.

On the second coil electrode 28, a fourth dielectric layer 32 is disposed. On the fourth dielectric layer 32, a third coil electrode 34 is formed. Third coil electrode 3
4 is formed so as to have a U-shape in the same direction as the first coil electrode 20 so that the number of turns is one turn or less in a half area on the same side as the first coil electrode 20.
At one end of the third coil electrode 34, the fourth dielectric layer 32
Through hole 36 is formed. The other end of the second coil electrode 28 and one end of the third coil electrode 34 are connected via the through hole 36. As described above, the spiral electrode is formed by connecting the first coil electrode 20, the second coil electrode 28, and the third coil electrode 34.

On the third coil electrode 34, a fifth dielectric layer 60 is arranged. On the fifth dielectric layer 60 , a surface
A capacitor electrode 62 is formed. Capacitor electrode
62 through the fifth dielectric layer 60,
A through hole 64 is formed. This through hole 64
Between the capacitor electrode 62 and the third coil electrode 34
The end is connected. Further, on the capacitor electrode 64
A dielectric layer 38 of the sixth is arranged. On the sixth dielectric layer 38, a second shield electrode 40 is formed. The second shield electrode 40 is formed in the same shape as the first shield electrode 16. On this second shield electrode 40, a seventh dielectric layer 42 is formed. Then, a laminate 12 is formed in a state where these dielectric layers are laminated.

The external terminals 44a,
44b, 44c, 44d, 44e and 44f are formed. The external terminals 44a, 44b, 44d, 44e
Of the shield electrode 16 and the second shield electrode 40 are formed at the drawn-out end. These external terminals 44a, 44b, 44d, 44e are connected to the first shield electrode 16 and the second shield electrode 40, and the external terminal 44e is also connected to the ground extraction electrode 22 at the same time. The external terminals 44c and 44f are formed at the ends where the first shield electrode 16 and the second shield electrode 40 are not drawn out. And the external terminal 44c is
It is connected to the extraction electrode 24.

To manufacture the resonator 10, a plurality of ceramic green sheets 50 made of a dielectric material, ie, an insulating material, are prepared as shown in FIG. Then, the first green sheets 50 are placed on the plurality of ceramic green sheets 50.
, Shield electrode 16, ground extraction electrode 22, extraction electrode 24, first coil electrode 20, second coil electrode 28,
The third coil electrode 34 , the capacitor electrode 62 and the second
A paste layer 52 is formed by printing, for example, a conductive paste on the shape of the shield electrode 40. Further, the second coil electrode 28 , the third coil electrode 34 and
Through holes 54 are formed at the ends of the paste layer 52 corresponding to the capacitor electrodes 62 so as to penetrate the ceramic green sheet 50. By putting a conductive paste or the like into the through holes 54, the paste layers 52 corresponding to the first coil electrode 20, the second coil electrode 28 , the third coil electrode 34, and the capacitor electrode 62 are connected. Then, a necessary number of ceramic green sheets 50 are formed so that the thickness of each dielectric layer is obtained.
Are sandwiched, and the respective ceramic green sheets 50 are laminated and pressed to obtain a molded body.

A conductive paste is applied to the molded body so as to have the shape of the external electrodes 44a to 44f. These conductive pastes are connected to necessary paste layers 52 inside the molded body. Then, by firing this molded body, the resonator 10 is obtained. The external electrode 4
Before applying the conductive paste corresponding to 4a to 44f, the molded body may be baked, and thereafter, the external electrodes 44a to 44f may be baked.

The resonator 10 includes a first coil electrode 20
And the two shield electrodes 16 and 40 are connected via the ground extraction electrode 22 and the external electrode 44e, and thus function as a quarter-wavelength resonator. In the resonator 10, an inductance is formed by a spiral electrode portion formed by each of the coil electrodes 20, 28, 34. Also, each of the coil electrodes 20, 28, 34 and the two shield electrodes 16, 4
A small capacitance is formed between the zero and zero. further,
The capacitor electrode 62 and the first shield electrode 16, the second
An electrostatic capacitance is formed between the shield electrode 40 and the shield electrode 40. Therefore, the resonator 10 has an equivalent circuit as shown in FIG. FIG. 5 shows an example of the frequency characteristics of the resonator 10. In this frequency characteristic, a resonance frequency exists at about 1.6 GHz .

In the resonator 10, the length of the spiral electrode can be freely adjusted by adjusting the number of dielectric layers on which the coil electrodes are formed. Therefore, the resonance frequency can be freely designed. In the manufacturing process of the resonator, since the same pattern is alternately stacked, the processing process can be simplified. In addition,
In this embodiment, the line width is reduced to 0.3 mm or less to reduce the distributed capacitance of the coil electrodes 20, 28, and 34, and the thickness of the coil electrodes 20, 28, and 34 is set to 6 μm to prevent the deterioration of Q.
m or more, and the thickness of the third and fourth dielectric layers 26 and 32 is about 100 μm.

As described above, since the resonator 10 has a laminated structure, the resonator 10 can be downsized even if the spiral electrode becomes long. For example, in the case of a resonance frequency of 1.0 GHz and an effective permittivity of 25, a quarter-wave strip line resonator is 15 mm, and a resonator having a spiral electrode can be made smaller. On the other hand, in the resonator 10 of the present invention, the coil electrodes 20, 28, 34
As a result, the spiral electrode is formed, so that the adjacent line of the coil electrode is located in the laminating direction via the dielectric layer.
Therefore, even if the spiral electrode becomes long, it is not necessary to enlarge the dielectric layer on which the coil electrode is formed, and it is possible to further reduce the size of the resonator 10. At this time, since the distance between the adjacent coil electrodes is ensured by the dielectric layer, the decrease in Q due to the influence of the magnetic flux is small.

In the resonator 10, the impedance can be adjusted by adjusting the distance between the ground extraction electrode 22 and the extraction electrode 24. In the above-described embodiment, the ground extraction electrode 22 and the extraction electrode 24 are drawn toward the adjacent ends of the second dielectric layer 18, but these electrodes are drawn toward the same side end. It may be drawn to the end in any direction depending on the distance between these electrodes. Furthermore, the coil electrode 2
0, 28, and 34, the coil electrodes 20,
The impedance can also be adjusted by adjusting the distance between the shield electrodes 16 and 40 and the shield electrodes 16 and 40. As described above, since the adjustment of the impedance of the resonator 10 is simple, the resonator can be manufactured in consideration of impedance matching with an external circuit.

[0026] Also, the area of the capacitor electrode 62 was changed.
Between the capacitor electrode 62 and the second shield electrode 40.
By changing the thickness of the dielectric layer 38 between
Between the sensor electrode 62 and the shield electrodes 16 and 40.
Capacitance can be changed. In this way,
Electrostatic force between the densor electrode 62 and the shield electrodes 16 and 40
By changing the capacitance, the resonance frequency of the resonator 10 can be increased.
Can be adjusted.

Furthermore, since the shield electrode 16, 40 on both sides of the coil electrode 20,28,34 is formed, shielding performance is excellent in the high frequency range, it is possible to obtain stable characteristics.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a laminated body of the resonator shown in FIG.

FIG. 3 is an illustrative view showing one portion of a manufacturing process of the resonator shown in FIG. 1;

FIG. 4 is an equivalent circuit diagram of the resonator shown in FIG.

5 is a graph showing a frequency characteristic of the resonator shown in FIG.

FIG. 6 is a plan view showing an example of a conventional resonator as a background of the present invention.

FIG. 7 is a plan view showing a modification of the conventional resonator shown in FIG.

FIG. 8 is a plan view showing another example of the conventional resonator.

FIG. 9 is a plan view showing still another example of the conventional resonator.

[Explanation of symbols]

Reference Signs List 10 resonator 12 laminate 14 first dielectric layer 16 first shield electrode 18 second dielectric layer 20 first coil electrode 22 ground extraction electrode 24 extraction electrode 26 third dielectric layer 28 second Coil electrode 32 Fourth dielectric layer 34 Third coil electrode 38 Sixth dielectric layer 40 Second shield electrode 42 Seventh dielectric layer 60 Fifth dielectric layer 62 Capacitor electrode

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Tonegawa 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-3-254511 (JP, A) JP-A-63-102215 (JP, A) JP-A-58-145114 (JP, A) JP-A-3-39825 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01P 7 / 00 H03H 5/02 H03H 7/01-7/075

Claims (1)

(57) [Claims] 1. A plurality of coil electrodes formed on a plurality of dielectric layers and connected to each other to form a helical electrode, and are drawn out from one of the coil electrodes to an end of the dielectric layer. An extraction electrode for grounding; an extraction electrode that is extracted from one of the coil electrodes to an end of the dielectric layer at a distance from the grounding extraction electrode; and a gap between the coil electrode on both sides of the plurality of coil electrodes. A shield electrode facing away from the other , and the coil
Between the electrode and the shield electrode.
Formed to face the pole and formed on the dielectric layer
The end of the coil electrode is connected to the
Including a capacitor electrode that is electrically connected, each of the coil electrodes is formed on the dielectric layer so as to have a number of turns of one turn or less, and the ground extraction electrode is connected to the shield electrode, Resonator.