JPH05299913A - Resonator and filter - Google Patents

Abstract

PURPOSE:To make the size of the resonator and the filter small, the weight light without deteriorating the Q and to realize the resonator and the filter easily manufactured with respect to the resonator and the filter. CONSTITUTION:A resonance conductor 13 being a component of a lambda/4 resonator is made of a metallic foil such as a copper foil, both sides of the resonator 13 are inserted by resins group high dielectric layers 12-1, 12-2, both sides are inserted with low dielectric layers 11-1, 11-2 of a resin group to form a laminator, a GND electrode 14 is provided to the outside of the laminator to form the resonator. Furthermore, plural resonance conductors 13 are provided and their resonance frequencies are made different to form the filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator that can be used in various wireless devices or other communication devices, and a filter using the resonator.

[0002]

2. Description of the Related Art FIG. 7 is an explanatory view of a conventional example, FIG. 7A is an exploded perspective view of a dielectric filter, and FIG. 7B is a perspective view of the dielectric filter.

In FIG. 7, 1-1 to 1-4 are dielectric layers, 3 is a GND electrode, 4-1 to 4-4 are resonance conductors, 5 is an input terminal (1N), and 6 is an output terminal (OUT). , 7 indicate a margin (a portion where no conductor is formed).

Hitherto, as a dielectric filter using a resonator, a dielectric filter using a ceramic dielectric has been proposed. One example is shown in FIG. This dielectric filter is manufactured by using a lamination technique of ceramic multilayer substrates, and is an example in which first to fourth dielectric layers 1-1 to 1-4 are used as ceramic dielectrics.

As shown in FIG. 7A, the first dielectric layer 1
-1, the GND electrode 3 is formed, and the third dielectric layer 1 is formed.
-4, four resonance conductors (resonance electrodes of λ / 4 type resonator) 4-1 to 4-4 are formed, and on the lower side (outside) of the fourth dielectric layer 1-4. The GND electrode 3 is formed.

The first to fourth dielectric layers 1-1 to 1-1
After stacking -4, the GND electrode 3 is formed on all surfaces except one surface of the stacked body, as shown in FIG. 7B. Also, G
On one surface of the laminated body on which the ND electrode 3 is not provided, the input terminal (1
N) 5 and the output terminal (OUT) 6 are formed. in this case,
Since it is necessary to separate the input terminal 5 and the output terminal 6 from the GND electrode 3, a margin 7 is provided between them.

In this way, a dielectric filter using the ceramic laminate is obtained.

[0008]

SUMMARY OF THE INVENTION The above-mentioned conventional device has the following problems. (1) When manufacturing a dielectric resonator or a dielectric filter using a ceramic dielectric, a firing process is required.

Therefore, the resonance conductor formed inside the laminated body is also a sintered metal. By the way, the sintered metal has a higher conductor resistance than, for example, an ordinary metal foil. In particular, when the frequency of the signal becomes high, the conductor resistance of the sintered metal further increases due to the influence of the skin effect and the like, and the Q of the conductor decreases.

Therefore, in a dielectric resonator or a dielectric filter using a ceramic dielectric, Q of the resonator or the like is used.
It is difficult to raise. Especially when used in a high frequency region, it becomes more difficult to increase the above Q.

(2) A dielectric resonator or a dielectric filter using a ceramic dielectric requires a firing process, which complicates the manufacturing process and takes time. (3) Dielectric resonators or filters that use ceramic dielectrics are heavier than other circuit components.

In the case of SMD, when a component is mounted on a mother board, it has a large heat capacity, so that it is difficult to keep a thermal balance with other components, which makes it difficult to cope with a reflow furnace. However, the manufacturing time becomes long.

An object of the present invention is to solve the conventional problems described above, to reduce the size of the resonator and the filter without lowering the Q, and to realize a light-weight and easily manufactured resonator and filter. To do.

[0014]

FIG. 1 is a principle view of the present invention. In FIG. 1, 11-1 and 11-2 are low dielectric layers, and 12 is a low dielectric layer.
-1, 12-2 are high dielectric layers, 13 is a resonance conductor (resonance electrode), and 14 is a GND electrode.

In order to solve the above problems, the present invention has the following configuration. (1) A plurality of dielectric layers 11-1, 11-2, 12-1, 1
A resonator in which a resonance conductor 13 is set in a laminated body in which 2-2 are laminated, and the resonance conductor 13 is formed of a metal foil, and the layers 11-1 and 1 are located at least outside the dielectric layer.
1-2 was composed of a resin-based dielectric layer.

(2) In the configuration (1), the plurality of dielectric layers are low-dielectric layers (dielectric constant ε ₁ ) 11-1, 11-2,
A high dielectric layer (dielectric constants ε ₂ and ε ₁ <ε ₂ ), and the high dielectric layer 1 is provided on both sides (both sides in the stacking direction) of the resonance conductor 13.
It is sandwiched between 2-1 and 12-2, and the low dielectric layer 11 is provided on both sides thereof.
-1, 11-2 were laminated so as to be sandwiched therebetween, and the GND electrodes 14 were set on both sides thereof.

(3) High-dielectric layer 1 having the structure (1) or (2)
As 2-1 and 12-2, a high dielectric layer having a composite structure in which a high dielectric such as ceramic is dispersed in resin is used.

(4) High-dielectric layer 12 having configurations (1) to (3)
-1, 12-2 were ceramic dielectric layers, and the low dielectric layers 11-1, 11-2 were resin dielectric layers. (5) In the configurations (1) to (4), the resonance conductor 13 is composed of a plurality of resonance conductors having different resonance frequencies, and the resonator is used as a filter.

[0019]

The operation of the present invention based on the above construction will be described with reference to FIG. In a resonator such as a dielectric resonator, the unloaded Q (which is referred to as Qu) is generally defined by the following equation.

[0020]

[Equation 1]

However, Qc is Q and Qd due to the transmission line conductor.
Indicates Q due to a dielectric material, and Qr indicates Q due to radiation. By the way, in a coaxial type resonator, 1 / Qr is usually ignored, so the formula is

[0022]

[Equation 2]

[0023] Here, Qc is expressed by the following equation by the series resistance component γ _s of the transmission line conductor and the line impedance Zo of the transmission line.

[0024]

[Equation 3]

Further, Qd is _expressed by the following equation by the relative permittivity ε _r ′ of the dielectric and the relative permittivity loss ε _r ″.

[0026]

[Equation 4]

From the above equation, the unloaded Q of the resonator
To increase (Qu), (a) increase the line impedance Zo and the relative permittivity ε _r ′, and (b) decrease the series resistance component γ _s and the relative dielectric loss ε _r ″. Recognize.

Particularly, if the relative permittivity ε _r 'is increased, the wavelength shortening shown by the following equation naturally occurs.

[0029]

[Equation 5]

That is, the length of the resonance conductor of the λ / 4 type resonator is shortened by shortening the wavelength shown in the equation. Therefore,
The series resistance component γ _s also decreases, and both Qc and Qd increase. As a result, the no-load Q (Qu) also increases.

By the way, according to the resonator and the filter of the present invention, the resonance conductor 13 includes the high dielectric layers 12-1 and 12-.
It is sandwiched by 2 and the wavelength shown in the formula can be shortened. Moreover, since the low dielectric layers 11-1 and 11-2 are interposed between the high dielectric layers 12-1 and 12-2 and the GND electrode 14, even if the thickness in the stacking direction is reduced. , Capacity C
The ingredients do not grow. Therefore, a large line impedance Zo can be obtained.

Further, since the resonance conductor 13 is formed of a metal foil such as a copper foil, the series resistance component γ _s is smaller than that of the conventional sintered metal. Therefore, the Q (Qc) of the resonance conductor 13, which is the transmission line conductor, increases, and the unloaded Q (Qc
u) also becomes large.

That is, the resonator and the filter can be downsized without lowering Q. Further, since the dielectric layer is made of resin, the firing process is unnecessary, the manufacturing process is simple and easy, and a light resonator and filter can be obtained.

[0034]

Embodiments of the present invention will be described below with reference to the drawings. (Description of First Embodiment) FIGS. 2 to 4 are views showing a first embodiment of the present invention, FIG. 2A is a perspective view of a dielectric resonator (without external terminals), and FIG. 2A is a sectional view taken along line XY, FIG. 3A is a perspective view of a dielectric resonator (with external electrodes),
3B is a sectional view taken along line XY of FIG. 3A, and FIG. 4 is a manufacturing process explanatory diagram.

2 to 4, 11-1 and 11-2 are low dielectric layers, 12-1 and 12-2 are high dielectric layers, 13 is a resonance conductor (resonance electrode), 14 is a GND electrode, and 15 Is an external terminal (side electrode), and 16 is a margin.

In the first embodiment, a resin dielectric layer and λ / 4 are used.
This is an example in which a dielectric resonator is formed by using a type resonator (λ: signal wavelength) and laminating the dielectric layers. The dielectric layer includes a low dielectric layer (dielectric constant ε ₁ ) made of a low dielectric constant material and a high dielectric layer (dielectric constant ε _{1 made} of a high dielectric constant material.
₂ and ε ₁ <ε ₂ ) were used.

As shown in the figure, this dielectric resonator has a prismatic appearance, and has λ / 4 at the center in the longitudinal direction.
A resonance conductor (resonance electrode) 13 that constitutes a type resonator is provided.

A high dielectric layer (for example, a dielectric layer made of a composite material of resin and ceramic) 12-is provided on both sides (both sides in the laminating direction of the laminated body) of the resonance conductor 13.
1, 12-2 are provided, and low dielectric layers (resin dielectric layers) 11-1, 11-2 are provided on both sides thereof.

In this case, the high dielectric layers 12-1 and 12-2
Is preferably formed thinner than the low dielectric layers 11-1 and 11-2. Further, the GND electrode 14 is formed on the outer side of the laminated body composed of the high dielectric layer and the low dielectric layer except for one surface on the signal input side.
An external terminal 15 is formed on one surface where is not formed and is connected to the internal resonance conductor 13 (see FIG. 3).

In this case, the external terminal 15 and the GND electrode 1
A margin 16 is provided between the external terminal 15 and the external terminal 15
Make sure that the ND electrode 14 does not come into contact. With such a configuration, the SMD (surface mount component) dielectric resonator is obtained. The manufacturing process will be described below with reference to FIG.

The step numbers in FIG. 4 are shown in parentheses. The manufacturing process of the dielectric resonator is as follows. First, 40 to 70% by volume of titanic acid-based ceramics is dispersed in a resin such as epoxy, and the coating material is impregnated into glass cloth to form a prepreg (S1).

This prepreg is used as the high dielectric layer 12-2. Therefore, in the next step, a copper foil is attached to the prepreg, a pattern is formed on the prepreg with a resist, and an etching process is performed to form a conductor pattern to be the resonance conductor 13 (S2).

After that, the required number of prepregs produced in the same manner as in the step S1 are laminated on the prepreg formed in the step S2 so as to cover the conductor pattern (resonant conductor 13), and the high dielectric layer. 12-1 is formed (S
3).

In this way, both sides of the resonant conductor 13 (both sides in the stacking direction of the stacked body) are connected to the high dielectric layers 12-1 and 12 respectively.
A laminate having a structure sandwiched by -2 is obtained. In the next step,
A low dielectric layer 11-is formed by laminating a required number of ordinary prepregs (using a resin such as epoxy) containing no ceramics on both sides of the laminated body so as to cover the laminated body.
1 and 11-2 are formed (S4).

In this case, the low dielectric layers 11-1 and 11-2
A copper foil (which becomes the outer GND electrode 14) is attached to the uppermost surface and the lowermost surface of the prepreg constituting the. Then, the above-mentioned laminated body is put into a mold and hot pressed to cure the resin (S5), and the cured laminated body is processed into a component shape (S6).

Next, in the step, the GND electrode 14 and the external terminal 15 on the side surface and the like are formed by plating (S7),
Further, a solder resist is printed while leaving the solder pad portion, and the solder pad is subjected to a treatment for improving the solderability to obtain a finished product (S8).

(Description of Second Embodiment) FIGS. 5 and 6 are views showing a second embodiment. FIG. 5 is an exploded perspective view of a dielectric filter, and FIG. 6 is a perspective view of the dielectric filter (A). Is a view seen from the front side, and B is a view seen from the back side).

5 and 6, the same parts as those in FIGS. 2 to 4 are designated by the same reference numerals. 15-1 is an input terminal, 15-2
Is an output terminal, and 13-1 to 13-4 are resonance conductors. The second embodiment is an example of a dielectric filter (band-pass filter) using four resonance conductors forming a λ / 4 type resonator.

As shown, the high dielectric layer (dielectric constant ε ₂ )
Four resonance conductors 13-1 to 13-4 are formed on 12-2, and a high dielectric layer (ε ₂ ) 12-1 is laminated thereon. On both sides of the high dielectric layers 12-1 and 12-2 (both sides in the laminating direction of the laminated body), the low dielectric layers 11-1 and 1-1 are formed.
1-2 are laminated, and the GND electrodes 14 are formed on both sides thereof.

In this case, the four resonance conductors 13-1 to 13-13
-4 has different lengths and different resonance frequencies. Further, one end of the resonance conductors 13-1 to 13-4 (the end having the wider portion in the drawing) is on the GND side, and the other end is on the signal input side.

In this way, the resonance conductors 13-1 to 13-13
-4 on both sides (both sides in the stacking direction) of the high dielectric layer 12-1,
12-2 and the low dielectric layers 11-1 and 11 on both sides thereof.
-2, and both sides thereof are sandwiched by the GND electrodes 14.

The GND electrode 14 is formed on the remaining surface of the laminated body except for one surface on the signal input side, and the signal input surface has an input terminal (1) as an external side surface electrode.
N) 15-1 and an output terminal (OUT) 15-2 are formed.

In this case, the input terminal 15-1 and the output terminal 1
Since 5-2 is formed of a conductor having the same length as the thickness of the laminated body, a part of the GND electrode 14 around the conductor is cut off to form a margin (a portion without a conductor) 16.

By doing so, it is possible to prevent the input terminal 15-1 and the output terminal 15-2 from coming into contact with the GND electrode 14. Also, by providing such an external terminal,
It is possible to realize an SMD (surface mount component) dielectric filter.

Like the dielectric resonator of the first embodiment, the above dielectric filter is made of a resin dielectric layer and a resonance conductor using copper foil. That is, the resonance conductor 13-1
13-4 are made of copper foil, and have high dielectric layers 12-1 and 12
-2 is formed by using a dielectric material having a composite structure in which titanate-based ceramics are dispersed in a resin such as epoxy, and further, the low dielectric layers 11-1 and 11-2 are formed by using a resin such as epoxy. To form.

Since the manufacturing process of the dielectric filter is the same as that of the first embodiment, its explanation is omitted. (Other Embodiments) The embodiments have been described above, but the present invention can be implemented as follows.

(1) The resonance conductor may be made of copper foil or other metal foil. (2) For the resin material of the dielectric layer, in addition to epoxy resin,
Other resins may be used.

(3) For example, glass epoxy resin, Teflon, or the like may be used for the low dielectric layer. (4) The high dielectric layer may have a composite structure in which titanate-based ceramics are dispersed in epoxy resin, but may be made of other material such as ceramics.

(5) The resonator and the filter are not limited to the configuration of the above embodiment, but can be applied to other configurations.

[0060]

As described above, the present invention has the following effects. (1) Since a metal foil (for example, copper foil) is used as the resonance conductor, the conductor resistance becomes smaller than that of the conventional sintered metal. In particular, in the high frequency region, the conductor resistance becomes much smaller than that of sintered metal.

Therefore, the Q of the resonance conductor which is the transmission line conductor can be made large, and as a result, the unloaded Q of the resonator can also be made large. That is, the resonator and the like can be downsized without reducing Q.

(2) Both sides of the resonance conductor are sandwiched by high dielectric layers,
The resonator and the filter can be miniaturized without lowering Q by the structure in which both sides thereof are sandwiched by the low dielectric layer and both sides thereof are sandwiched by the GND electrode.

(3) By virtue of the above (1) and (2), the size can be further reduced as compared with the conventional example, and the Q of the resonator and the like need not be lowered. (4) Since there is no firing process, the manufacturing process is simple and easy.

(5) Since the dielectric layer is made of a resin material, it is lighter than the conventional one using a ceramic dielectric. Therefore, handling becomes easy at the time of mounting components.

(6) When the resonator and the filter are made to be SMD, the heat capacity is small (compared to ceramics), so that it can be applied to a reflow furnace like a small component. Therefore, the steps for mounting the components are also simple and easy.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a diagram showing a dielectric resonator (without external terminals) according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a dielectric resonator (with external terminals) of the first embodiment.

FIG. 4 is an explanatory view of the manufacturing process of the first embodiment.

FIG. 5 is an exploded perspective view of a dielectric filter according to a second embodiment.

FIG. 6 is a perspective view of a dielectric filter according to a second embodiment.

FIG. 7 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 11-1, 11-2 Low-dielectric layer 12-1, 12-2 High-dielectric layer 13 Resonant conductor 14 GND electrode

Claims (5)

[Claims] 1. A plurality of dielectric layers (11-1, 11-2,
A resonator in which a resonance conductor (13) is set in a laminated body in which 12-1 and 12-2) are laminated, wherein the resonance conductor (13) is made of metal foil, and at least the dielectric layer is formed. Layers located outside (11-1, 11-
A resonator characterized in that 2) is composed of a resin-based dielectric layer. 2. The low dielectric layer (dielectric constant ε₁) (11-1, 11-2),
High dielectric layer (dielectric constant ε ₂, Ε₁<Ε₂) And both sides of the resonance conductor (13) (both sides in the stacking direction) with high dielectric constant.
It is sandwiched between body layers (12-1, 12-2) and both sides thereof are sandwiched by low dielectric layers (11-1, 11-2).
And stack the GND electrodes (14) on both sides.
The resonator according to claim 1, wherein the resonator is a resonator. 3. The high dielectric layer (12-1, 12-2)
3. The resonator according to claim 1, wherein is a high-dielectric layer having a composite structure in which a high-dielectric material such as ceramic is dispersed in resin. 4. The high dielectric layer (12-1, 12-2).
Is a ceramics dielectric layer, and the low dielectric layer (11-
The resonator according to any one of claims 1 to 3, wherein (11, 11-2) is a resin-based dielectric layer. 5. The resonator according to claim 1, wherein the resonance conductor (13) of the resonator comprises a plurality of resonance conductors having different resonance frequencies to form a filter. The filter used.