JP2001163665A - Dielectric porcelain composition for high frequency, dielectric resonator, dielectric filter, dielectric duplexer and communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dielectric porcelain composition for high frequencies having a relative dielectric constant as high as 40 to 60, Q value as high as >=30,000 (at 1 GHz) in which the temperature coefficient of the resonance frequency can be controlled to within 0±30 (ppm/ deg.C). SOLUTION: The porcelain composition has a composition expressed by formula of (1-y)xCaTiaO1+2a-(1-y)(1-x)Ca(Mg1/3M2/3)bO1+2b-yLnAlcO(3+3c)/2 and has a perovskite crystal phase as the main crystal. In formula, Ln is a rare earth element, M is Nb and/or Ta, and x, y, a, b and c range 0.550<=x<=0.800, 0.080<=y<=0.180, (1-y)x<=0.650, 0.910<=a<=1.100, 0.900<=b<=1.100 and 0.900<=c<=1.100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dielectric ceramic composition for high frequencies, and a dielectric resonator, a dielectric filter, a dielectric duplexer and a communication device using the same.

[0002]

2. Description of the Related Art For example, a dielectric resonator or a dielectric filter mounted on an electronic device used in a high frequency region such as a microwave or a millimeter wave, such as a cellular phone, a personal radio, and a satellite broadcast receiver. Dielectric porcelain is widely used as a material for circuit boards.

[0003] The dielectric properties required of such high-frequency dielectric porcelain are: (1) Since the wavelength of an electromagnetic wave is reduced to 1 / (ε _r ) ^1/2 in a dielectric, there is a demand for miniaturization. (2) the dielectric loss is small, that is, the Q value is large, and (3) the temperature stability of the resonance frequency is excellent, that is, the temperature coefficient of the resonance frequency (ε _r ) τf) is around 0 (ppm / ° C.)
And the like.

Conventionally, this type of dielectric porcelain composition
Is, for example, Ba (Zn, Ta) O _ThreeSystem (Special Publication 58
-25068), Ba (Sn, Mg, Ta) O_Three
(JP-B-3-34164), (Zr, Sn) T
iO_FourSystem (Japanese Patent Publication No. 4-59267), Ba_TwoTi₉
O₂₀(Japanese Unexamined Patent Publication No. 61-10806)
Instrument compositions are known.

[0005]

SUMMARY OF THE INVENTION However, Ba
(Zn, Ta) O ₃ or Ba (Sn, Mg, Ta) O ₃ material has a Q value of 150,000 to 300,000 (1 GHz).
z), but the relative permittivity (ε _r ) is 2
It is relatively small, 4 to 30.

On the other hand, (Zr, Sn) TiO ₄ and Ba ₂ T
The i ₉ O ₂₀ material has a relatively large relative dielectric constant (ε _r ) of 37 to 40 and a Q value of 50,000 to 60,000 (1 GHz).
), But it is difficult to realize a larger relative dielectric constant (ε _r ), for example, over 40.

In recent years, there has been a growing demand for lower loss and smaller size of electronic equipment. With this, dielectric materials have been further improved in dielectric properties, particularly large relative permittivity (ε _r ) and large Q value. There is an increasing demand for the development of materials that combine the above, but at present it has not been possible to adequately meet such demands.

Therefore, an object of the present invention is to provide a dielectric constant (ε _r ) as large as 40 to 60 and a Q value of 30000 (1
It is an object of the present invention to provide a high-frequency dielectric ceramic composition that has a temperature coefficient (.tau.f) of not less than 0. +-. 30 (ppm / .degree. C.). Another object of the present invention is to provide a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device using the same.

[0009]

In order to achieve the above object, the high frequency dielectric ceramic composition of the present invention comprises a rare earth element (Ln), Al, Ca, Mg, M (M: Nb and Ta). At least one) and Ti, and a composition formula: (1
_{-Y) xCaTi a O 1 + 2a} - (1-y) (1-x) Ca
_{(Mg 1/3 M 2/3) b O} 1 + 2b -yLnAl c O (3 + 3c) / 2 ( where, x, y is the molar ratio) having a composition represented by, alpha =
(1-y) x, x, y, α, a, b, and c
Is 0.550 ≦ x ≦ 0.800, 0.080 ≦ y ≦
0.180, α ≦ 0.650, 0.910 ≦ a ≦ 1.1
00, 0.900 ≦ b ≦ 1.100, 0.900 ≦ c ≦
It is within a range of 1.100, and is characterized by using a perovskite type crystal phase as a main crystal.

[0010] More preferably, α is in the range of α ≦ 0.600.

Further, the rare earth element (Ln) is Nd,
It is preferably at least one of Y, La, Sm and Pr.

The rare earth element (Ln) is more preferably at least one of Nd and La.

In the dielectric resonator according to the present invention, the dielectric resonator operates by coupling an electromagnetic field to an input / output terminal, wherein the dielectric ceramic has the above-described dielectric ceramic composition for high frequency. It is characterized by consisting of things.

Further, a dielectric filter according to the present invention is characterized in that the above-described dielectric resonator includes external coupling means.

Further, the dielectric duplexer of the present invention comprises at least two dielectric filters, input / output connection means connected to each of the dielectric filters, and antenna connection means commonly connected to the dielectric filters. And a dielectric duplexer, wherein at least one of the dielectric filters is the above-described dielectric filter.

Further, according to the communication apparatus of the present invention, a transmission circuit connected to the above-described dielectric duplexer, at least one input / output connection means of the dielectric duplexer, and a transmission circuit connected to the transmission circuit. It is characterized by comprising a receiving circuit connected to at least one input / output connecting means different from the writing output connecting means, and an antenna connected to an antenna connecting means of the dielectric duplexer.

[0017]

FIG. 1 is a sectional view schematically showing a basic structure of a dielectric resonator 1 according to one embodiment of the present invention.

Referring to FIG. 1, a dielectric resonator 1 includes a metal case 2, and a support base 3 is provided in a space in the metal case 2.
A pillar-shaped dielectric porcelain 4 supported by the above is arranged. The input terminal 5 and the output terminal 6 are held by the metal case 2 in a state where the input terminal 5 and the output terminal 6 are insulated from the metal case 2. The dielectric porcelain 4 operates by being electromagnetically coupled to the input terminal 5 and the output terminal 6, and only a signal of a predetermined frequency input from the input terminal 5 is output from the output terminal 6. The dielectric porcelain 4 in such a dielectric resonator 1 is composed of the high frequency dielectric porcelain composition according to the present invention.

Although the TE01δ mode dielectric resonator is shown in FIG. 1, the high frequency dielectric ceramic composition of the present invention can be applied to other TE mode, TM mode, and TEM mode dielectric resonators. It can be used similarly.

FIG. 2 is a block diagram showing an example of the communication device of the present invention. The communication device 10 includes a dielectric duplexer 12, a transmission circuit 14, a reception circuit 16, and an antenna 18. The transmission circuit 14 is connected to the input connection means 20 of the dielectric duplexer 12, and the reception circuit 16 is connected to the output connection means 22 of the dielectric duplexer 12. Further, the antenna 18 is connected to the antenna connection means 24 of the dielectric duplexer 12. The dielectric duplexer 12 includes two dielectric filters 26, 2
8 inclusive. The dielectric filters 26 and 28 are obtained by connecting external coupling means to the dielectric resonator of the present invention. In this embodiment, for example, it is formed by connecting the external coupling means 30 to the input / output terminals of the dielectric resonator 1, respectively. One dielectric filter 26 is connected between the input connection means 20 and the other dielectric filter 28, and the other dielectric filter 28 is connected between the one dielectric filter 26 and the output connection means 22. Connected.

As described above, the dielectric ceramic composition for high frequency according to the present invention comprises a rare earth element (Ln), Al, C
a, Mg, M (M: at least one of Nb and Ta) and Ti, and a composition formula: (1-y) xCaTi
_a O _{1 + 2a-} (1-y) (1-x) Ca (Mg _1/3 M _2/3 ) _b
O _{1 + 2b} -yLnAl _c O _{(3 + 3c) / 2} (where x and y are molar ratios), and when α = (1-y) x, x, y, α , A, b, and c are within the following ranges.

First, for x, 0.550 ≦ x ≦
It is in the range of 0.800. If x <0.550,
Q value is smaller than 30,000, and x> 0.80
In the case of 0, the temperature coefficient (τf) of the resonance frequency is +30.
(Ppm / ° C.).

As for y, 0.080 ≦ y ≦ 0.18
It is in the range of 0. If y <0.080 or y> 0.
In the case of 180, the Q value becomes smaller than 30,000.

For α = (1-y) x, α ≦ 0.6
It is in the range of 50. If α> 0.650, the temperature coefficient (τf) of the resonance frequency becomes larger than +30 (ppm / ° C.). By setting α ≦ 0.600, the temperature coefficient (τf) of the resonance frequency is +20 (p
pm / ° C.) or less.

For a, 0.910 ≦ a ≦ 1.10.
It is in the range of 0. a <0.910 and a> 1.100
In the case of, the Q value becomes smaller than 30,000.

As for b, 0.900 ≦ b ≦ 1.10.
It is in the range of 0. b <0.900 or b> 1.100
In the case of, the Q value becomes smaller than 30,000.

As for c, 0.900 ≦ c ≦ 1.10.
It is in the range of 0. c <0.900 or c> 1.100
In the case of, the Q value becomes smaller than 30,000.

In the high frequency dielectric ceramic composition according to the present invention, the rare earth element (Ln) may be Nd,
It is preferable to use Y, La, Sm or Pr,
Among these, it is more preferable to use Nd or La.

[0029]

Next, the present invention will be described based on more specific examples.

Example 1 As starting materials, high-purity rare earth oxides (such as Nd ₂ O ₃ ) and aluminum oxide (Al
₂ O ₃ ), calcium carbonate (CaCO ₃ ), magnesium hydroxide (Mg (OH) ₂ ), niobium oxide (Nb ₂ O ₅ ),
Tantalum oxide (Ta ₂ O ₅ ) and titanium oxide (TiO ₂ ) were prepared.

Next, the composition formula shown in Table 1 is: (1-y) xC
aTi _a O _{1 +} 2a-(1-y) (1-x) Ca (Mg _1/3 M
_{2/3) b O 1 + 2b -yNdAl} c O (3 + 3c) / 2 ( provided that, x,
These raw materials were prepared so as to obtain a composition represented by (y is a molar ratio). The composition formula shown in Table 2 is 0.5
4CaTiO ₃ −0.36Ca (Mg _1/3 Nb _2/3 ) O ₃ −
These raw materials were prepared so as to obtain a composition represented by 0.10 LnAlO ₃ .

[0032]

[Table 1]

[0033]

[Table 2]

Samples 37 to 52 shown in Table 2 were obtained by replacing "Nd" in the composition formula in Table 1 with "Rare earth element" in Table 2.
, And has a composition corresponding to that of Sample 13 in Table 1.

Next, the powders of the prepared raw materials are wet-mixed using a ball mill for 16 hours, dehydrated and dried, and then calcined at 1100 to 1300 ° C. for 3 hours. A binder was added, and wet grinding was performed again using a ball mill for 16 hours to obtain a prepared powder.

Next, the prepared powder was mixed with 1000 to 2000
After press-molding into a disk at a pressure of kg / cm ² , 14
It was fired in the air at a temperature of 00 to 1600 ° C. for 4 to 24 hours to obtain a porcelain having a perovskite-type crystal phase having a diameter of 10 mm and a thickness of 5 mm as a main crystal.

With respect to the obtained porcelain, the measurement frequency was 6 to 8
The relative dielectric constant (ε _r ) and the Q value at GHz are measured by a double-ended short-circuit type dielectric resonator method, and according to Q × f = constant rule,
It was converted to a Q value of 1 GHz. Further, a temperature coefficient (τf) between 25 ° C. and 55 ° C. of the resonance frequency was measured from the TE01δ mode resonator frequency. The results are shown in Tables 1 and 2. In Table 1, samples with an asterisk (*) are out of the scope of the present invention.

As is clear from Tables 1 and 2, according to the samples within the scope of the present invention, it is possible to obtain a large Q value while maintaining a large relative dielectric constant (ε _r ) in the microwave band. it can.

[0039] Here, with reference to Table 1 mainly composition formula of the present _{invention: (1-y) xCaTi a} O 1 + 2a - (1-
y) (1-x) Ca (Mg _1/3 M _2/3 ) _b O _{1 + 2b} -yLn
The reason for limiting the range of the composition represented by Al _c O _{(3 + 3c) / 2} (where x and y are molar ratios) will be described below.

First, for x, 0.550 ≦ x ≦ 0.
The reason for setting the value to 800 is that when x <0.550, the Q value becomes smaller than 30,000 as in sample numbers 11 and 15. When x> 0.800, the temperature coefficient (τf) of the resonance frequency is +3 as in sample number 7.
This is because it becomes larger than 0 (ppm / ° C.).

For y, 0.080 ≦ y ≦ 0.180
The reason is that when y <0.080, sample number 1
This is because the Q value becomes smaller than 30,000 as in 7,18. Further, when y> 0.180, the Q value becomes smaller than 30,000 as in sample numbers 1, 2, and 3.

For α = (1-y) x, α ≦ 0.65
The reason why 0 was set is that when α> 0.650, sample number 1
4, the temperature coefficient (τf) of the resonance frequency is + 30p
It is because it becomes larger than pm / ° C. Note that α ≦ 0.6
00, the temperature coefficient of the resonance frequency (τf)
Is more preferable since characteristics of +20 (ppm / ° C.) or less can be obtained.

For a, 0.910 ≦ a ≦ 1.100
The reason is that when a <0.910, the sample number 19
This is because the Q value becomes smaller than 30,000. Further, when a> 1.100, the Q value becomes smaller than 30,000 similarly as in the case of sample No. 22.

For b, 0.900 ≦ b ≦ 1.100
Is that when b <0.900, sample number 23
This is because the Q value becomes smaller than 30,000. Also, when b> 1.100, the Q value becomes smaller than 30,000 as in the case of sample No. 26.

For c, 0.900 ≦ c ≦ 1.100
The reason is that when c <0.900, sample number 27
This is because the Q value becomes smaller than 30,000. In addition, when c> 1.100, the Q value becomes smaller than 30,000 similarly as in sample number 30.

As is clear from the comparison between Sample No. 13 in Table 1 and Sample Nos. 37 to 52 in Table 2, by using at least one of Nd and La as the rare earth element (Ln), Larger relative permittivity (ε _r )
And the Q value.

The high frequency dielectric ceramic composition of the present invention
A small amount of additives within a range that does not impair the purpose of the present invention.
Can be added. For example, SiO_Two, MnC
O_Three, B _TwoO_Three, NiO, CuO, Li_TwoCO_Three, Pb
_ThreeO_Four, Bi_TwoO_Three, V_TwoO_Five, WO_Three0.01 to 1.
By adding 0 wt%, deterioration of characteristics is suppressed.
Accordingly, the firing temperature can be lowered by 20 to 30 ° C.
In addition, BaCO_Three, Sb_TwoO _Three1 to 3 wt%
The relative dielectric constant (ε_r) And fine adjustment of temperature characteristics
And excellent dielectric ceramics can be obtained.

[0048]

As apparent from the above description, according to the present invention, the relative dielectric constant (ε _r ) is as large as 40 to 60, the Q value is as large as 30000 (at 1 GHz), and the resonance frequency is increased. Temperature coefficient (τf) of 0 ± 30 (ppm
/ ° C) can be obtained.

Therefore, by using the dielectric ceramic having such a composition to manufacture a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device, good characteristics can be obtained. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a dielectric resonator according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a communication device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric resonator 2 Metal case 4 Dielectric porcelain 5 Input terminal 6 Output terminal 10 Communication apparatus 12 Dielectric duplexer 14 Transmission circuit 16 Receiving circuit 18 Antenna 20 Input connection means 22 Output connection means 24 Antenna connection means 26, 28 dielectric filter 30 external coupling means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 3/12 313 H01B 3/12 319 319 H01P 7/10 H01P 7/10 H03H 9/25 F H03H 9 / 25 C04B 35/00 J

Claims (8)

[Claims] 1. A rare earth element (Ln), Al, Ca, M
g, M: include and Ti (M at least one of Nb and Ta), composition _{formula: (1-y) xCaTi a} O 1 + 2a - (1-y)
(1-x) Ca (Mg _1/3 M _2/3 ) _b O _{1 + 2b} -yLnAl _c
It has a composition represented by O _{(3 + 3c) / 2} (where x and y are molar ratios), and when α = (1-y) x, x, y, α, a, b and c are , A high frequency dielectric ceramic composition characterized by having a perovskite-type crystal phase as a main crystal. 2. The high frequency dielectric ceramic composition according to claim 1, wherein the α is within a range of α ≦ 0.600. 3. The method according to claim 1, wherein the rare earth element (Ln) is Nd, Y,
The dielectric ceramic composition for high frequencies according to claim 1, wherein the composition is at least one of La, Sm, and Pr. 4. The rare earth element (Ln) comprises Nd and L
The high frequency dielectric ceramic composition according to claim 1, wherein the composition is at least one of a. 5. The high frequency dielectric ceramic composition according to claim 1, wherein said dielectric ceramic is operated by being electromagnetically coupled to an input / output terminal. A dielectric resonator, comprising a material. 6. A dielectric filter comprising the dielectric resonator according to claim 5 and external coupling means. 7. A dielectric duplexer comprising at least two dielectric filters, input / output connection means connected to each of the dielectric filters, and antenna connection means commonly connected to the dielectric filters. A dielectric duplexer, wherein at least one of the dielectric filters is the dielectric filter according to claim 6. 8. The dielectric duplexer according to claim 7, a transmission circuit connected to at least one input / output connection means of the dielectric duplexer, and the input / output connection means connected to the transmission circuit. A communication device, comprising: a receiving circuit connected to at least one input / output connection unit different from the above; and an antenna connected to an antenna connection unit of the dielectric duplexer.