JPH0653716A - Resonator - Google Patents

Abstract

PURPOSE:To obtain a resonator small in size in which the deterioration in the Q is less even in the case of miniaturization. CONSTITUTION:A 1st shield electrode 16 of facial shape is formed on a 1st dielectric layer 14. Channel-shaped 1st coil, 2nd coil and 3rd coil electrodes 20, 28, 34 are formed respectively on a 2nd dielectric layer 18, a 3rd dielectric layer 36 and a 4th dielectric layer 32 on a 1st shield electrode 16. The coil electrodes 20, 28, 34 are connected via throughholes 30, 36 to form a spiral electrode. An earth lead electrode 22 and an extraction electrode 24 are extracted from the 1st coil electrode toward the end of the 2nd dielectric layer. A 2nd shield electrode 40 is formed on a 5th dielectric layer 38 and a 6th dielectric layer 42 is formed on the electrode 40. The dielectric layers as above are laminated and plural external terminals are formed to the layers. The 1st shield electrode 16, the earth lead electrode 22, and the 2nd shield electrode 40 are connected at the external terminals and the extract electrode 24 connects to the other external terminal.

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 a resonator used in the several GHz band.

[0002]

2. Description of the Related Art As a conventional resonator, for example, there is a 1/2 wavelength stripline resonator as shown in FIGS. In this resonator 1, a line electrode 3 whose both ends are open is formed on one main surface of a dielectric substrate 2, and a ground electrode is formed on the entire other main surface of the dielectric substrate 2. In such a resonator 1, the wavelength is λ, the dielectric substrate 2 is
If the effective permittivity of is ε, the length L of the line electrode 3 is
₁ is given by the following equation (1).

[0003]

[Equation 1]

Further, as shown in FIG. 11, the dielectric substrate 2
There is a quarter-wave resonator in which one end of the line electrode 3 is connected to the ground electrode so as to wrap around from the end of the. The length L ₂ of the line electrode 3 of the resonator 1 is given by the following equation (2).

[0005]

[Equation 2]

Further, as shown in FIG. 12, the dielectric substrate 2
There is a resonator in which a spiral coil electrode 4 is formed on one main surface. 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, the ground extraction electrode 6 connected to the ground electrode 5 is extracted from one end of the coil electrode 4, and the extraction electrode 7 is formed at a distance from the ground extraction electrode 6. In this resonator 1, since the coil electrode 4 is formed in a spiral shape, the coil electrode 4 can be downsized even if the coil electrode 4 is lengthened.

[0007]

However, it is 1/2
For a wavelength resonator or a quarter wavelength resonator, for example, 2 to
In the 3 GHz resonator, the line electrode becomes long and the resonator becomes large. Further, in the resonator using the coil electrode, since the coil electrode has a spiral shape, the magnetic flux influences between adjacent lines, which makes it difficult for current to flow in the coil electrode. Therefore, the substantial resistance increases and the Q decreases. When the size of the resonator is reduced, the distance between the adjacent lines of the coil electrode is reduced, the influence of the magnetic flux between the lines is increased, and such an adverse effect is increased.

Therefore, a main object of the present invention is to provide a resonator which can be miniaturized, and whose Q is less lowered even when miniaturized.

[0009]

According to the present invention, a plurality of coil electrodes are formed on a plurality of dielectric layers and are connected to each other to form spiral electrodes, and one of the coil electrodes is used as a dielectric. A grounding extraction electrode that is drawn out to the end of the layer, an extraction electrode that is drawn out from one of the coil electrodes to the end of the dielectric layer at a distance from the grounding extraction electrode, and coils on both sides of the coil electrodes. A resonator including an electrode and a shield electrode facing each other with a space. Further, a capacitor electrode may be formed between the coil electrode and the shield electrode so as to face the shield electrode. In this case, the capacitor electrode and the coil electrode are electrically connected.

[0010]

[Function] The dielectric layers on which the coil electrodes are formed are laminated,
A spiral electrode is formed by connecting these coil electrodes. In this case, there is a dielectric layer between adjacent lines. Further, by forming the capacitor electrode between the coil electrode and the shield electrode, an electrostatic capacitance is formed between the capacitor electrode and the shield electrode.

[0011]

According to the present invention, since the 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 can be secured and the influence of the magnetic flux between the coil electrodes can be reduced. Therefore, the resonator can be downsized without lowering the Q of the resonator. Furthermore, by forming an electrostatic capacitance between the capacitor electrode and the shield electrode, the resonance frequency can be lowered and the resonance frequency can be adjusted.

Further, the shield electrode can improve the shielding property in the high frequency region. Furthermore, 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-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0014]

1 is a perspective view showing an embodiment of the present invention. The resonator 10 includes a stack 12. The laminate 12 includes a first dielectric layer 14 as shown in FIG. A first shield electrode 16 is formed on the first dielectric layer 14. The first shield electrode 16 is formed on almost the entire surface of the first dielectric layer 14 and is formed on the first dielectric layer 14 so as to face each other.
Pulled out to one end.

A second dielectric layer 18 is arranged on the first shield electrode 16. On the second dielectric layer 18,
The first coil electrode 20 is formed. The first coil electrode 20 is formed in a U-shape in an approximately half area of one main surface of the second dielectric layer 18. A ground lead electrode 22 is formed from one end of the first coil electrode 20 toward the end of the second dielectric layer 18. Further, from the middle portion of the first coil electrode 20 to the second dielectric layer 18
The extraction electrode 24 is extracted toward the end of the. In this embodiment, the extraction electrode 24 is drawn out to the end of the second dielectric layer 18 adjacent to the end where the grounding extraction electrode 22 is drawn out. Then, 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 to the end.

A third dielectric layer 26 is formed on the first coil electrode 20. A second coil electrode 28 is formed on the third dielectric layer 26. Second coil electrode 2
8 is formed in a half area on the opposite side to the area where the first coil electrode 20 is formed so as to have a U shape opposite to the first coil electrode 20. 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.

A fourth dielectric layer 32 is disposed on the second coil electrode 28. A third coil electrode 34 is formed on the fourth dielectric layer 32. Third coil electrode 3
4 is formed in a half area on the same side as the first coil electrode 20 so as to have a U-shape in the same direction as the first coil electrode 20. At one end of the third coil electrode 34,
A through hole 36 is formed so as to penetrate the fourth dielectric layer 32. Through this through hole 36,
The other end of the second coil electrode 28 and one end of the third coil electrode 34 are connected. Thus, the first coil electrode 2
0, second coil electrode 28 and third coil electrode 34
A spiral electrode is formed by connecting the.

A fifth dielectric layer 38 is disposed on the third coil electrode 34. A second shield electrode 40 is formed on the fifth dielectric layer 38. The second shield electrode 40 is formed in the same shape as the first shield electrode 16. A sixth dielectric layer 42 is formed on the second shield electrode 40. Then, the laminated body 12 is formed in a state where these dielectric layers are laminated.

At the end of the laminate 12, external terminals 44a,
44b, 44c, 44d, 44e and 44f are formed. The external terminals 44a, 44b, 44d, 44e are the first
The shield electrode 16 and the second shield electrode 40 are formed on the extracted ends. The 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 simultaneously connected to the grounding lead electrode 22. Further, 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 make this resonator 10, as shown in FIG. 3, a plurality of ceramic green sheets 50 made of a dielectric material, that is, an insulating material are prepared. Then, on the plurality of ceramic green sheets 50, the first
Shield electrode 16, ground extraction electrode 22, extraction electrode 24, first coil electrode 20, second coil electrode 28,
A paste layer 52 is formed on the shapes of the third coil electrode 34 and the second shield electrode 40 by printing a conductive paste, for example. Further, through holes 54 are formed at the end portions of the paste layer 52 corresponding to the second coil electrode 28 and the third coil electrode 34 so as to penetrate the ceramic green sheet 50. By inserting a conductive paste or the like into the through hole 54, the paste layers 52 corresponding to the first coil electrode 20, the second coil electrode 28, and the third coil electrode 34 are connected. Then, a required number of ceramic green sheets 50 are sandwiched so that the thickness of each dielectric layer can be obtained, and the ceramic green sheets 50 are stacked and pressure-bonded to obtain a molded body.

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

This resonator 10 has a first coil electrode 20.
And the two shield electrodes 16 and 40 are connected via the grounding lead-out electrode 22 and the external electrode 44e, they function as a quarter-wavelength resonator. In this resonator 10, an inductance is formed in the spiral electrode portion formed by each coil electrode 20, 28, 34. Also, each coil electrode 20, 28, 34 and two shield electrodes 16, 4
A small capacitance is formed between 0 and 0. Therefore, the resonator 10 has an equivalent circuit as shown in FIG. Furthermore, an example of frequency characteristics of the resonator 10 is shown in FIG. In this frequency characteristic, the resonance frequency exists at about 2 GHz.

In this resonator 10, the length of the spiral electrode can be freely adjusted by adjusting the number of dielectric layers forming the coil electrodes. Therefore, the resonance frequency can be freely designed. Further, in the manufacturing process of the resonator, the processing steps can be simplified because of the alternating stacked structure of the same pattern. In addition,
In this embodiment, the line width is set to 0.3 mm or less in order 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 in order to prevent deterioration of Q.
The thickness of the third and fourth dielectric layers 26, 32 is about 100 μm.

As described above, since the resonator 10 has the laminated structure, the resonator 10 can be downsized even if the spiral electrode becomes long. For example, when the resonance frequency is 1.0 GHz and the effective permittivity is 25, the quarter-wavelength stripline resonator is 15 mm, and the resonator having the spiral electrode can be made smaller than that. On the other hand, in the resonator 10 of the present invention, the coil electrodes 20, 28, 34
Since the spiral electrode is formed by, the adjacent lines of the coil electrode are located in the stacking direction with the dielectric layer interposed therebetween.
Therefore, even if the spiral electrode becomes long, it is not necessary to increase the size of the dielectric layer on which the coil electrode is formed, and the resonator 10 can be further downsized. At this time, since the distance between the adjacent coil electrodes is secured by the dielectric layer, the Q is less likely to decrease due to the influence of the magnetic flux.

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

Further, since the shield electrodes 16 and 40 are formed on both sides of the coil electrodes 20, 28 and 34, the shielding performance in the high frequency range is good and stable characteristics can be obtained.

Further, as shown in FIG. 6, a seventh dielectric layer 60 may be disposed on the third coil electrode 34, and a capacitor electrode 62 may be formed on the seventh dielectric layer 60. .
The capacitor electrode 62 is formed in a planar shape so as to face the second shield electrode 40. Then, a through hole 64 is formed so as to penetrate the seventh dielectric layer 60 from the capacitor electrode 62. The capacitor electrode 62 and the third coil electrode 34 are connected via the through hole 64. In this resonator 10, capacitance is formed between the capacitor electrode 62 and the first shield electrode 16 and the second shield electrode 40. Therefore, the equivalent circuit of the resonator 10 shown in FIG. 6 is a circuit having a capacitance connected in series with an inductance, as shown in FIG.

The dimensions of the electrodes other than the capacitor electrode 62 were made the same as those of the resonator shown in FIGS. 1 and 2, and the frequency characteristics of the resonator 10 shown in FIG. 6 were measured. The results are shown in FIG. In the resonators of FIGS. 1 and 2, the resonance frequency is 2 GHz.
On the other hand, in FIG. 8, the resonance frequency is about 1.6 GHz.
It is in the vicinity. By forming the capacitor electrode 62 in this way, the frequency characteristic of the resonator can be changed. In this resonator 10, for example, by changing the area of the capacitor electrode 62 or changing the thickness of the dielectric layer 38 between the capacitor electrode 62 and the second shield electrode 40, the capacitor electrode 62 and the shield electrode 1 can be changed.
Capacitance formed between 6 and 40 can be changed. In this way, the resonance frequency of the resonator 10 can be adjusted by changing the capacitance.

[Brief description of 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.

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

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

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

FIG. 6 is an exploded perspective view showing another embodiment of the present invention.

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

8 is a graph showing frequency characteristics of the resonator shown in FIG.

FIG. 9 is a plan view showing an example of a conventional resonator which is the background of the present invention.

FIG. 10 is a plan view showing a modified example of the conventional resonator shown in FIG.

FIG. 11 is a plan view showing another example of a conventional resonator.

FIG. 12 is a plan view showing still another example of a conventional resonator.

[Explanation of symbols]

 Reference Signs List 10 resonator 12 laminated body 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 fifth dielectric layer 40 second shield electrode 42 sixth dielectric layer 60 seventh dielectric layer 62 capacitor electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Tonegawa Ken 26, Tenjin, Nagaokakyo, Kyoto Prefecture Murata Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A plurality of coil electrodes, which are formed on a plurality of dielectric layers and become spiral electrodes by being connected to each other, and are drawn from one of the coil electrodes to an end of the dielectric layer. An extraction electrode for ground, an extraction electrode that is separated from the extraction electrode for ground and is extracted from one of the coil electrodes to an end portion of the dielectric layer, and a space between the coil electrode on both sides of the plurality of coil electrodes. Including shield electrodes facing each other,
Resonator. 2. The resonance according to claim 1, further comprising a capacitor electrode formed between the coil electrode and the shield electrode so as to face the shield electrode and electrically connected to the coil electrode. vessel.