JPH0729415A - Dielectric porcelain serving also as antenna - Google Patents

Abstract

PURPOSE:To provide a dielectric porcelain having a high no-load Q value and capable of arbitralily changing the temp. coefficient of resonance frequency without reducing the dielectric constant by using a specified composition of Zr, Ti, Mn and Nb oxide. CONSTITUTION:This porcelain is made of a composition expressed by a formula: xZrO2-yTiO2-zMn1/3Nb2/3O2 where (x), (y), (z) is mol fraction, and (x), (y) and (z) is in the following range: x+y+z=1, 0.10<=x<=0.60, 0.10<=y<=0.60, 0.10<=z<=0.80. With the use of this porcelain a compact antenna having a high no-load Q value in the frequency range of 0.8-5GHz can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric porcelain and an antenna duplexer used particularly in a high frequency region such as a microwave and a millimeter wave band.

[0002]

2. Description of the Related Art In recent years, microwaves having a wavelength of several cm or less and
Area of millimeter waves (hereinafter collectively referred to as microwaves)
In, dielectric resonators, filters, etc.
Many are used. Dielectric used in such applications
As a body material, unloaded Q (Q _u) High value and relative permittivity
(Ε_r) Is large and the temperature coefficient of the resonance frequency
(Τ_f) Is required to be changed arbitrarily.

Conventionally, various materials have been reported as materials suitable for such applications. ZrO ₂ -SnO ₂ -T
One of them is an iO ₂ -based porcelain, which is disclosed in, for example, JP-A-62-1
ZrO ₂ -SnO proposed in Japanese Patent No. 132769
_2- TiO ₂ —MgO porcelain and ZrO ₂ —SnO ₂ —TiO ₂ — proposed in JP-A-2-192460.
CoO-Nb ₂ O ₅ porcelain, and the like are known. Further, as a material exhibiting a particularly high unloaded Q value, a composite perovskite-based porcelain containing Nb or Ta is known.

[0004]

However, conventionally used materials have various properties such as a small relative permittivity, a low unloaded Q value, and the inability to arbitrarily change the temperature coefficient of the resonance frequency. Have a problem.

Further, in general, the resonance circumference of the same material is
Wave number (f) and unloaded Q (Q_u) Value is constant
However, when f becomes low and the element becomes large,
fQ _uThe product deteriorates significantly. Therefore, for example,
Relatively like an antenna duplexer for mobile communication base stations
For microwave dielectric elements used in the low frequency range
On the other hand, it is desired to have a higher unloaded Q value.
There is. In addition, the antenna used in the relatively low frequency range
Because the Tena Duplexer becomes very large,
It is desired to reduce the size.

In order to solve the above-mentioned problems of the prior art, the present invention provides a dielectric ceramic having a high unloaded Q value and capable of arbitrarily changing the temperature coefficient of the resonance frequency without lowering the relative dielectric constant. The purpose is to provide. Also,
It is an object of the present invention to provide a small antenna duplexer that has a high unloaded Q value in the frequency range of 0.8 to 5 GHz.

[0007]

[Means for Solving the Problems]
Therefore, the first structure of the dielectric ceramic according to the present invention is xZrO
₂-YTiO₂-ZMn_1/3Nb_2/3O₂(However, x,
y and z represent mole fractions),
Dielectric porcelain in which x, y, and z are in the following ranges.

X + y + z = 1 0.10≤x≤0.60 0.10≤y≤0.60 0.01≤z≤0.80 The second structure of the dielectric ceramic according to the present invention is xZr.
_{O 2 -yTiO 2 -zMn (1 +} w) / 3 Nb (2-w) / 3 O
₂ A dielectric porcelain having a composition represented by ₂ (where x, y, and z are mole fractions and w is a coefficient), and x, y, z, and w are in the following ranges.

X + y + z = 1 0.10 ≦ x ≦ 0.60 0.10 ≦ y ≦ 0.60 0.01 ≦ z ≦ 0.80 0 <w ≦ 1.90 Further, the antenna duplexer according to the present invention is The first configuration is gold
Cylindrical or ring-shaped at the center of the metal-made cylindrical cavity
The dielectric porcelain of the
TE of the dielectric due to electromagnetic waves transmitted from the tenor₀₁δ mode
An antenna duplexer that utilizes the resonance of
Porcelain is xZrO₂-YTiO₂-ZMn _1/3Nb_2/3O
₂(However, x, y, and z represent mole fractions)
It has a composition and x, y, z are 0.10 ≦ x ≦ 0.6
0, 0.10 ≦ y ≦ 0.60, 0.01 ≦ z ≦ 0.80
(However, x + y + z = 1)
It

A second antenna duplexer according to the present invention is also provided.
The structure of is, if the center of the metal cylindrical cavity is cylindrical.
Arrange a ring-shaped dielectric porcelain on the side of the cavity.
T of the dielectric due to the electromagnetic wave transmitted from the antenna provided in
E₀₁It is an antenna duplexer that uses δ-mode resonance.
And the dielectric porcelain is xZrO₂-YTiO₂-ZMn
_{(1 + w) / 3}Nb_{(2-w) / 3}O₂(However, x, y, z are moles
Rate, w represents a coefficient), and
x, y, z, w are 0.10 ≦ x ≦ 0.60, 0.10 ≦
y ≦ 0.60, 0.01 ≦ z ≦ 0.80, 0 <w ≦ 1.
Characterized by being in the range of 90 (however, x + y + z = 1)
And

[0011]

According to the structure of the dielectric ceramic according to the present invention,
The unloaded Q value is high, and the temperature coefficient of the resonance frequency can be arbitrarily changed without lowering the relative dielectric constant.

Further, according to the configuration of the antenna duplexer according to the present invention, it is possible to realize a small antenna duplexer having a high unloaded Q value in the frequency range of 0.8 to 5 GHz. .

[0013]

EXAMPLES The present invention will be described in more detail below with reference to examples. As the starting material for the dielectric ceramics in the present invention, any of oxides, carbonates, hydroxides, alkoxides, etc. of the component elements may be used.

As a method of mixing the raw material powders, a wet mixing method of mixing with water or an organic solvent in a ball mill,
A dry mixing method or the like in which the materials are mixed with a mixer or the like and mixed in a ball mill without using a solvent is generally used, but any method may be used. Further, an alkoxide method or a coprecipitation method may be used depending on the starting material. The method of mixing in a ball mill using a solvent is preferable because the process is relatively complicated and it is easy to obtain a homogeneous mixture. Furthermore, a dispersant is used to adjust the dispersibility of the powder, and the pH is adjusted. Is preferably performed.

The mixture does not necessarily have to be calcined, but calcining is preferable because the calcining time can be shortened. As a method for pulverizing the calcined product or the mixture, there is a method using a ball mill, a high speed rotary pulverizer, a medium agitating mill, an air flow pulverizer or the like, but any method may be used.

The present invention will be described below with reference to specific examples.
Will be described in detail. (Example 1) Chemically high-purity Zr as a starting material
O₂, TiO₂, Nb₂O_Five, MnCO ₃Using this
And weigh them so that they have the desired composition, and use a ball mill.
Wet mixed with ethanol. Where powder and eta
The volume ratio with the nor is about 2: 3. Bo this mixture
90 minutes in air after removal from the rumill and drying
It was calcined at a temperature of 0 to 1250 ° C. for 2 to 8 hours. Calcined
Wet milled with ethanol in the ball mill. powder
Remove the crushed mud from the ball mill and dry it.
Polyvinyl alcohol with a concentration of 6% as a binder at the end
Solution was added at 8% by weight and mixed to homogeneity. That
Then, the particles were sized through a 32 mesh sieve. Sized powder
1.3 ton / cm using a mold and hydraulic press²Success
Formed into a disc shape with a diameter of 7 mm and a thickness of 3 mm.
It was Place the compact in a high-purity magnesia pod and empty.
Keep in the air at a temperature of 400 ℃ -700 ℃ for 4-8 hours.
Hold and hold out the binder, then in air 1
Hold at a temperature of 200 ℃ -1500 ℃ for 1-100 hours
Firing was performed to obtain a dielectric ceramic.

The resonance frequency f, the no-load Q (Q _u ) value, and the relative permittivity ε _r were obtained by the measurement using the conductor cavity type dielectric cylinder resonator method. Resonance frequency temperature coefficient τ _f is -25 ° C
To 85 ° C. Resonance frequency is 6-12GH
It was in the z range.

The relative permittivity ε _r thus obtained, the temperature coefficient τ _f (ppm / ° C.) of the resonance frequency, and the unloaded Q
The (Q _u ) values are shown in the following (Table 1) and (Table 2) [x, y,
z and w are xZrO ₂ —yTiO ₂ —zMn _{(1 + w) / 3} Nb
_{(2-w) / 3} O ₂ (however, x, y, and z are molar fractions, and w is a coefficient). In addition, (Table 1),
In Table 2, those marked with * are comparative examples outside the scope of the present invention.

[0019]

[Table 1]

[0020]

[Table 2]

As shown in (Table 1) and (Table 2), dielectric ceramics within the composition range of the present invention (those not marked with *)
Has a high unloaded Q value while maintaining a large relative dielectric constant in the microwave frequency band. That is, no load Q
The value is as high as about 3000-7000, and the relative dielectric constant is about 24-
It is as large as 60. Further, the temperature coefficient of the resonance frequency can be changed in a wide range of about −50 to 50 ppm / ° C. according to the composition.

On the other hand, when x is larger than 0.60, the no-load Q (Q _u ) value becomes extremely low as in Sample 14, and the object of the present invention cannot be achieved. Further, even when x is smaller than 0. 10, the unloaded Q value becomes low as in Sample 17, and the object of the present invention cannot be achieved.

When y is larger than 0.60,
As in Sample 5, the unloaded Q value was significantly reduced, and y was 0.
Even when it becomes smaller than 10, no load Q as in sample 1
The values are too low to achieve the object of the invention.

When z becomes larger than 0.80,
As in sample 6, the unloaded Q value is low and z is 0.01.
If it is smaller than the
Number τ _fIs extremely large and the unloaded Q value is remarkable
It is not possible to achieve the object of the present invention because it becomes low.
Yes.

Further, if w is larger than 0, the no-load Q value can be improved, but if w is larger than 1.90, the no-load Q value is deteriorated as in sample 25. . However, the characteristics of sample 25 were also better than those of the conventional dielectric ceramics.

(Example 2) Chemically pure as a starting material
Degree of ZrO₂, TiO₂, Nb₂O_Five, MnCO ₃For
Weigh these to the specified composition and
Wet mixed with ethanol. Where the powder
The volume ratio of body to ethanol is about 2: 3. This mix
Remove the item from the ball mill, dry it, and place it in the air.
And calcined at a temperature of 900 to 1250 ° C. for 2 to 8 hours.
The calcined product is wet powdered with ethanol in the above ball mill.
Crushed. Remove crushed mud from ball mill and dry
After that, the powder is used as a binder to make a polybiny with a concentration of 6%.
Add 10% by weight of alcohol solution and mix to homogeneity
did. After that, pass through a 32 mesh sieve and
It was 1ton / c of sized powder using a die and hydraulic press
m²With a molding pressure of 16 mm, 35 mm, 70 mm
It was formed into a cylindrical shape. The ratio of diameter to thickness of the compact is about 2: 1
So that Molded body with high purity magnesia pods
Put in the air, the temperature of 400 ℃ ~ 700 ℃ in the air
Held for 2 to 100 hours for binder out
Then, at a temperature of 1300 ° C to 1650 ° C in air, 1
It was held for about 100 hours and fired to obtain a dielectric ceramic.

Next, this dielectric ceramic was placed in the center of a copper-made cylindrical cavity plated with silver having a thickness of 10 μm, and the dielectric TE ₀₁ δ mode of the dielectric was generated by the electromagnetic wave emitted from the antenna provided on the side of the cavity. We constructed an antenna duplexer that utilizes resonance. Here, the inner size of the cavity is about 4 times the diameter and the thickness of the dielectric ceramic, and the thickness of the cavity is 5 mm.

The resonance frequency f and the no-load Q (Q _u ) value were obtained by measurement using a vector network analyzer. In the case of a molded product having a diameter of 16 mm, the resonance frequency is 2 to 5 GHz, and in the case of a diameter of 35 mm, 1 to 2.
0.6 to 1.5 GH in case of 5 GHz and diameter of 70 mm
It was z.

The resonance frequency f and fQu product thus obtained are shown in the following (Table 3) [where x, y, z and w are the compositions of the dielectric porcelain xZrO ₂ -yTiO ₂ -zMn.
_{(1 + w) / 3} Nb _{(2-w) / 3} O ₂ (where x, y, and z are mole fractions and w is a coefficient) are values.

[0030]

[Table 3]

As can be seen from Table 3, the antenna duplexer of the present invention has a high Q _u value in the microwave frequency band, and a significantly high Q _u value particularly in a relatively low frequency band.
_{has u} value.

The volume of the dielectric porcelain at the resonance frequency of 0.8 GHz is, for example, ZrO ₂ --SnO ₂ --TiO _2.
Approximately 113 cc, Ba for the _2nd porcelain (ε _r = 37.0)
(Mg _1/3 Ta _2/3 ) O ₃ system porcelain (ε _r = 24.0)
Is about 200 cc, while sample 153 of the present invention is
Has a volume of about 77 cc. Since the volume of the antenna duplexer depends on the volume of the dielectric porcelain, the antenna duplexer of the present invention is extremely small in a relatively low frequency range. Further, since the dielectric porcelain is significantly smaller than the conventional one, it is possible to significantly reduce the raw material cost and the manufacturing cost of the antenna duplexer.

In the second embodiment, a cylindrical dielectric ceramic is used, but the dielectric ceramic is not limited to this. For example, even if a ring-shaped dielectric ceramic is used, it is equivalent. The present inventors have confirmed that an antenna duplexer having a higher unloaded Q (Q _u ) value can be constructed.

[0034]

As described above, according to the structure of the dielectric ceramics of the present invention, the unloaded Q value is high, and the temperature coefficient of the resonance frequency is arbitrarily changed without lowering the relative permittivity. be able to.

Further, according to the configuration of the antenna duplexer according to the present invention, it is possible to realize a small antenna duplexer having a high unloaded Q value in the frequency region of 0.8 to 5 GHz. .

Claims (4)

[Claims] 1. xZrO ₂ —yTiO ₂ —zMn _1/3 N
A dielectric porcelain having a composition represented by b _2/3 O ₂ (where x, y, and z represent mole fractions), and x, y, and z are in the following ranges. x + y + z = 1 0.10 ≦ x ≦ 0.60 0.10 ≦ y ≦ 0.60 0.01 ≦ z ≦ 0.80 2. xZrO ₂ —yTiO ₂ —zMn
_{(1 + w) / 3} Nb _{(2-w) / 3} O ₂ (where x, y, z are mole fractions, w is a coefficient), and x, y, z , W is a dielectric porcelain in the following range. x + y + z = 1 0.10 ≦ x ≦ 0.60 0.10 ≦ y ≦ 0.60 0.01 ≦ z ≦ 0.80 0 <w ≦ 1.90 3. A cylindrical or ring-shaped dielectric ceramic is arranged at the center of a metallic cylindrical cavity, and the TE ₀₁ δ mode resonance of the dielectric is utilized by an electromagnetic wave transmitted from an antenna provided on the side of the cavity. In the antenna duplexer, the dielectric porcelain is xZrO ₂ -yTiO ₂ -zM.
n _1/3 Nb _2/3 O ₂ (where x, y, and z represent mole fractions), and x, y, and z are 0.
10 ≦ x ≦ 0.60, 0.10 ≦ y ≦ 0.60, 0.0
An antenna duplexer having a range of 1 ≦ z ≦ 0.80 (where x + y + z = 1). 4. A cylindrical or ring-shaped dielectric ceramic is arranged at the center of a metallic cylindrical cavity, and the TE ₀₁ δ mode resonance of the dielectric is utilized by an electromagnetic wave transmitted from an antenna provided on the side of the cavity. In the antenna duplexer, the dielectric porcelain is xZrO ₂ -yTiO ₂ -zM.
n _{(1 + w) / 3} Nb _{(2-w) / 3} O ₂ (where x, y, z are mole fractions, w is a coefficient), and x, y, z, w are 0.10 ≦ x ≦ 0.60, 0.1
0 ≦ y ≦ 0.60, 0.01 ≦ z ≦ 0.80, 0 <w ≦
An antenna duplexer characterized by being in the range of 1.90 (where x + y + z = 1).