JPWO2005051861A1 - High frequency dielectric ceramic composition, dielectric resonator, dielectric filter, dielectric duplexer, and communication device - Google Patents

Abstract

An object of the present invention is to provide a dielectric ceramic composition for high frequency, which has a high relative dielectric constant εr and a high Q value, and the temperature coefficient τf of the resonance frequency can be arbitrarily controlled around 0 ppm / ° C. Composition formula: xCaTiaO1 + 2a-yCa (Alb / 2Nbc / 2) O1 + (3b + 5c) / 4-zCa (Mgd / 2We / 2) O1 + (d + 3e) / 2 In the formula, x, y, z, a, b, c, d, and e (where x, y, and z are molar ratios) are 0.475 ≦ x ≦ 0.58, 0.21 ≦ y ≦ 0. .505, 0.018 ≦ z ≦ 0.25, x + y + z = 1.000, 0.9 ≦ a ≦ 1.05, 0.9 ≦ b ≦ 1.1, 0.9 ≦ c ≦ 1.1, 0 .9 ≦ d ≦ 1.1 and 0.9 ≦ e ≦ 1.05.

Description

  The present invention relates to a high-frequency dielectric ceramic composition used in a high-frequency region such as a microwave and a millimeter wave, and a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device configured using the same About.

  In high frequency regions such as microwaves and millimeter waves, dielectric ceramics are widely used as materials constituting dielectric resonators and circuit boards.

When such a high-frequency dielectric ceramic is particularly intended for applications such as dielectric resonators and dielectric filters, the required dielectric characteristics are as follows: (1) the wavelength of electromagnetic waves in the dielectric is 1 / (ε _r ) is reduced to ^1/2 , so that the dielectric constant (ε _r ) is high as a response to the demand for miniaturization, (2) the dielectric loss is small, that is, the Q value is high, (3) the resonance frequency In that the temperature coefficient of resonance frequency (τ _f ) is around 0 ppm / ° C.

Here, τ _f is the slope (first derivative) when the resonance frequency temperature curve is linearly approximated using the resonance frequency (f ₂₅ ) at 25 ° C. and the value of the resonance frequency (f ₅₅ ) at 55 ° C. The value is obtained by the equation of τ _f = (f ₅₅ −f ₂₅ ) / (f ₂₅ · (55 ° C.−25 ° C.)).

Conventionally, as a high frequency dielectric ceramic composition that can satisfy the above-described requirements, for example, CaO—TiO ₂ —Al ₂ O ₃ — (Nb, Ta) ₂ O ₅ (see Patent Documents 1 to 7), Ca ( Many porcelain compositions such as Mg _1/2 W _1/2 ) O ₃ have already been proposed.
JP-A-10-95663 JP 2001-302331 A JP 2001-302332 A JP 2001-302333 A JP 2001-302334 A JP 2002-255640 A JP 2002-308670 A Japanese Patent Laid-Open No. 9-2441073

In recent years, there has been an increasing demand for low loss and downsizing of electronic devices, and more excellent dielectric properties required for high frequency dielectric ceramics for applications such as dielectric resonators and dielectric filters are required. It is supposed to be. In particular, even when used in a high frequency region, there is an increasing demand for materials having both high ε _r , high Q value, and high temperature stability (τ _f is around 0 ppm / ° C.).

However, although the dielectric ceramic composition having the composition system described in Patent Document 1 has a high ε _r of 41 to 66, the Q value (1 GHz) is 12000 to 27300 and cannot be said to be sufficiently high.

Moreover, the dielectric ceramic composition having the composition system described in Patent Documents 2 to 7 has a high ε _r of 35 or more and τ _f can be controlled around 0 ppm / ° C. However, when ε _r is increased, τ _f There was a problem that the Q value (1 GHz) deteriorated.

The dielectric ceramic composition having the composition system described in Patent Document 8 has a high Q value (1 GHz) of 45000 or more, but has a low ε _r of 17 to 19 and an absolute value of τ _f of 70. It was more than that.

Therefore, an object of the present invention is to solve the above-described problem, that is, even when used in a high frequency region such as a microwave or a millimeter wave, it has a high ε _r and a high Q value, and the absolute value of τ _f An object is to provide a dielectric ceramic composition for high frequency with a small value.

In order to solve the above technical problem, the dielectric ceramic composition for high frequency of the present invention has a composition formula: xCaTi _a O _{1 + 2a} -yCa (Al _{b / 2} Nb _{c / 2} ) O _{1+ (3b + 5c ) / 4-} zCa (Mg _{d / 2} W _{e / 2} ) O _{1+ (d + 3e) / 2} , and x, y, z, a, b, c, d in the above composition formula , And e (where x, y and z are molar ratios) are 0.475 ≦ x ≦ 0.58, 0.21 ≦ y ≦ 0.505, 0.018 ≦ z ≦ 0.25, x + y + z = 1.000, 0.9 ≦ a ≦ 1.05, 0.9 ≦ b ≦ 1.1, 0.9 ≦ c ≦ 1.1, 0.9 ≦ d ≦ 1.1, 0.9 ≦ e ≦ It is in the range of 1.05.

  In addition, part or all of Nb in the composition formula is substituted with Ta and / or Sb, and the substitution amount l of Sb (where l is a Sb / (Nb + Ta + Sb) molar ratio) is 0 ≦ It is in the range of l ≦ 0.5.

  Furthermore, part or all of Mg in the composition formula is substituted with Zn.

  The dielectric resonator according to the present invention is a dielectric resonator in which a dielectric ceramic is operated by electromagnetic coupling to an input / output terminal, and the dielectric ceramic is used for the high frequency of the present invention described above. It consists of a dielectric ceramic composition.

  The dielectric filter of the present invention includes the above-described dielectric resonator and external coupling means connected to the input / output terminal of the dielectric resonator.

  The dielectric duplexer of the present invention includes 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 filter. A dielectric duplexer, wherein at least one of the dielectric filters is the above-described dielectric filter according to the present invention.

  Furthermore, the communication device of the present invention includes the above-described dielectric duplexer, a transmission circuit connected to at least one input / output connection means of the dielectric duplexer, and the input / output described above connected to the transmission circuit. A receiving circuit connected to at least one input / output connection means different from the means; and an antenna connected to the antenna connection means of the dielectric duplexer.

According to the present invention, the composition _{formula: xCaTi a O 1 + 2a -yCa} (Al b / 2 Nb c / 2) O 1+ (3b + 5c) / 4 -zCa (Mg d / 2 W e / 2) O _{1+ (d + 3e) / 2} , and x, y, z, a, b, c, d, and e in the above composition formula (where x, y, and z are molar ratios) 0.475 ≦ x ≦ 0.58, 0.21 ≦ y ≦ 0.505, 0.018 ≦ z ≦ 0.25, x + y + z = 1.000, 0.9 ≦ a ≦ 1.05,. Since 9 ≦ b ≦ 1.1, 0.9 ≦ c ≦ 1.1, 0.9 ≦ d ≦ 1.1, and 0.9 ≦ e ≦ 1.05, ε _r Is 45 or more, a high Q value of 38000 or more is exhibited at a Q value (1 GHz), and a high-frequency dielectric ceramic composition having a small absolute value of τ _f within 25 ppm / ° C. can be obtained.

In the high frequency dielectric ceramic composition of the present invention, part or all of Nb in the composition formula is replaced with Ta and / or Sb, and the replacement amount l of Sb (where l is Sb / (Nb + Ta + Sb) ) (Which is the molar ratio) can be made to be in the range of 0 ≦ l ≦ 0.5, so that the absolute value of τ _f can be made smaller than when not substituted with Ta or Sb.

Furthermore, in the high frequency dielectric ceramic composition of the present invention, by replacing a part or all of Mg in the above composition formula with Zn, ε _r can be made higher than when not substituted with Zn. Can do.

  Therefore, for example, a dielectric resonator mounted in a base station, a mobile phone, a personal radio, a satellite broadcast receiver, etc. is downsized, the dielectric loss is reduced, and the temperature stability of the resonance frequency is excellent. be able to. As a result, if such a dielectric resonator is used, a dielectric filter, a dielectric duplexer, and a communication device that are downsized and have excellent characteristics can be advantageously configured.

It is sectional drawing which shows the basic structure of the dielectric resonator 1 comprised using the dielectric ceramic composition for high frequencies of this invention schematically. It is a block diagram which shows an example of the communication apparatus comprised using the dielectric resonator 1 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dielectric resonator 2 Metal case 3 Support stand 4 Dielectric porcelain 5, 6 Coupling loop 7, 8 Coaxial cable 10 Communication apparatus 12 Dielectric duplexer 14 Transmission circuit 16 Reception circuit 18 Antenna 20 Input connection means 22 Output connection Means 24 Antenna connection means 26, 28 Dielectric filter 30 External coupling means

  First, a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device to which the high frequency dielectric ceramic composition of the present invention is applied will be described.

  FIG. 1 is a cross-sectional view schematically showing the basic structure of a dielectric resonator 1 constructed using the high frequency dielectric ceramic composition of the present invention.

  Referring to FIG. 1, a dielectric resonator 1 includes a metal case 2, and a columnar dielectric ceramic 4 supported by a support base 3 is disposed in a space inside the metal case 2. A coupling loop 5 is formed between the center conductor and the outer conductor of the coaxial cable 7 to serve as an input terminal. Further, a coupling loop 6 is formed between the central conductor and the outer conductor of the coaxial cable 8 to serve as an output terminal. Each terminal is held by the metal case 2 in a state where the outer conductor and the metal case 2 are electrically joined.

  The dielectric porcelain 4 operates by electromagnetic coupling to the input terminal and the output terminal, and only a signal having a predetermined frequency input from the input terminal is output from the output terminal.

  The dielectric ceramic 4 provided in such a dielectric resonator 1 is composed of the high frequency dielectric ceramic composition of the present invention.

  The dielectric resonator 1 shown in FIG. 1 is a TE01δ mode resonator used in a base station or the like, but the high-frequency dielectric ceramic composition of the present invention has other TE modes, TM modes, and TEMs. The same can be applied to a dielectric resonator using a mode or the like.

  FIG. 2 is a block diagram illustrating an example of a communication device configured using the dielectric resonator 1 described above.

  The communication device 10 shown in FIG. 2 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.

  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 and 28. The dielectric filters 26 and 28 are configured by connecting an external coupling means to the dielectric resonator of the present invention. In the illustrated embodiment, for example, each of the dielectric filters 26 and 28 is configured by connecting external coupling means 30 to the input / output terminals of the dielectric resonator 1 shown in FIG. 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 to.

  Next, the dielectric ceramic composition for high frequency of the present invention that is advantageously used in the high frequency region, such as the dielectric ceramic 4 provided in the dielectric resonator 1 shown in FIG. 1, will be described.

High frequency dielectric ceramic composition of the present invention, the composition _{formula: xCaTi a O 1 + 2a -yCa} (Al b / 2 Nb c / 2) O 1+ (3b + 5c) / 4 -zCa (Mg d / 2 W _{e / 2} ) O _{1+ (d + 3e) / 2} Here, x, y, z, a, b, c, d, and e (where x, y, and z are molar ratios) in the above composition formula are 0.475 ≦ x ≦ 0.58, 0.21. ≦ y ≦ 0.505, 0.018 ≦ z ≦ 0.25, x + y + z = 1.000, 0.9 ≦ a ≦ 1.05, 0.9 ≦ b ≦ 1.1, 0.9 ≦ c ≦ 1 .1, 0.9 ≦ d ≦ 1.1 and 0.9 ≦ e ≦ 1.05.

In the high frequency dielectric ceramic composition of the present invention, in order to make the absolute value of τ _f smaller, a part or all of Nb in the composition formula is replaced with Ta and / or Sb, and The substitution amount l of Sb (where l is the molar ratio of Sb / (Nb + Ta + Sb)) is selected so as to be in the range of 0 ≦ l ≦ 0.5.

Furthermore, in the high frequency dielectric ceramic composition of the present invention, in order to make ε _r higher, a part or all of Mg in the composition formula is substituted with Zn.

  In the present invention, examples that serve as the basis for selecting a specific composition as described above will be described below.

As starting materials, high-purity calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), magnesium oxide (MgO), and tungsten oxide (WO ₃ ) Each powder was prepared.

Next, the composition formula: xCaTi _a O _{1 + 2a} -yCa (Al _{b / 2} Nb _{c /)} selected for x, y, z, a, b, c, d, and e shown in Tables 1 and 2, respectively. ₂ ) Each of the above starting material powders so as to obtain a composition represented by O _{1+ (3b + 5c) / 4} -zCa (Mg _{d / 2} W _{e / 2} ) O _{1+ (d + 3e) / 2} Was formulated.

  Next, the blended powder was wet-mixed for 16 hours using a ball mill and dispersed uniformly, and then subjected to dehydration and drying treatment to obtain an adjusted powder.

  Next, the adjusted powder is calcined at a temperature of 1000 to 1300 ° C. for 3 hours, an appropriate amount of binder is added to the obtained calcined powder, and wet milled again using a ball mill for 16 hours. A powder was obtained.

Then, the powder for burning, after press-molded into a disk shape at a pressure of ^{0.98 × 10 2 ~1.96 × 10 2} MPa, and calcined at 4 hours in air at a temperature of from 1,400 to 1,650 ° C., A disk-shaped sintered body having a diameter of 10 mm and a thickness of 5 mm was obtained.

With respect to the obtained sintered body of each sample, ε _r and Q value at a measurement frequency f of 6 to 8 GHz were measured by a double-end short-circuited dielectric resonator method using TE011 mode, and Q × f (frequency) = Based on a fixed formula, it was converted into a Q value (1 GHz). In addition, the resonance frequency was measured by the cavity method in the TE01δ mode, and τ _f in the temperature range of 25 to 55 ° C. was measured.

Tables 1 and 2 show ε _r , Q value (1 GHz), and τ _f corresponding to the sample composition, measured as described above.

  In Tables 1 and 2, the sample number with * is a sample outside the scope of the present invention.

As shown in Tables 1 and 2, samples 8-12, 16-20, 23-27, 30-34, 37-41, 45-48, 57, 58, 61, 62, 65 within the scope of the present invention. , 66, 69, 70, 73 and 74, ε _r is as large as about 45 to 54, Q value (1 GHz) is as high as 38000 or more, and the absolute value of τ _f is 25 ppm. It can be reduced within / ° C., and excellent microwave dielectric properties can be obtained.

  In contrast, samples that are outside the scope of this invention are considered.

First, when x <0.475, as shown in samples 53 and 54, ε _r is less than 45 and the absolute value of τ _f exceeds 25 ppm / ° C. On the other hand, when x> 0.58, as shown in Samples 3 and 4, the Q value (1 GHz) is less than 38000.

  Next, when y <0.21, as shown in the sample 13, the Q value (1 GHz) is less than 38000. On the other hand, when y> 0.505, as shown in the sample 44, the Q value (1 GHz) is less than 38000.

Next, when z <0.018, as shown in Samples 7, 15, 22, 29, and 36, the Q value (1 GHz) is less than 38000. On the other hand, when z> 0.25, as shown in Samples 49 and 50, ε _r is less than 45, and the absolute value of τ _f exceeds 25 ppm / ° C.

  Next, when a <0.9 or a> 1.05, the Q value (1 GHz) is less than 38000, as shown in Samples 56 and 59, respectively.

  Next, when b <0.9 or b> 1.1, the Q value (1 GHz) is less than 38000, as shown in samples 60 and 63, respectively.

  Next, in the case of c <0.9 or c> 1.1, the Q value (1 GHz) is less than 38000 as shown in Samples 64 and 67, respectively.

  Next, when d <0.9 or d> 1.1, the Q value (1 GHz) is less than 38000, as shown in samples 68 and 71, respectively.

  Next, in the case of e <0.9 or e> 1.05, the Q value (1 GHz) is less than 38000 as shown in samples 72 and 75, respectively.

  Example 2 was carried out in order to investigate the influence exerted by substituting part or all of Nb with Ta or Sb.

As starting materials, high-purity calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), tantalum oxide (Ta ₂ O ₅ ), antimony oxide (Sb ₂ O ₃ ), magnesium oxide (MgO), and tungsten oxide (WO ₃ ) powders were prepared.

Next, the composition formulas: xCaTi _a O _{1 + 2a} -yCa {Al _{b / 2} (chosen for x, y, z, a, b, c, d, e, k, and l shown in Table 3, respectively. _{nb 1-kl Ta k Sb l} ) c / 2} O 1+ (3b + 5c) / 4 -zCa (Mg d / 2 W e / 2) O 1+ (d + 3e) / 2 composition represented by the Each of the above starting material powders was prepared so as to be obtained.

Thereafter, a disk-shaped sintered body to be a sample is obtained by the same method as in Example 1, and ε _r , Q value (1 GHz), and τ _f are obtained for the obtained sintered body according to each sample. Was measured respectively.

Table 3 shows the measurement results of ε _r , Q value (1 GHz), and τ _f corresponding to the sample composition.

  In Table 3, the sample number with * is a sample outside the scope of the present invention.

As shown in Table 3, according to the dielectric ceramic composition according to Samples 76, 77, 79 to 81, 83, 84, and 86 to 90 within the scope of the present invention, part or all of Nb is converted to Ta. And / or the absolute value of τ _f can be reduced without deteriorating the ε _r and the Q value (1 GHz) as compared with the case where no substitution is made with Sb, and excellent microwave dielectric characteristics can be obtained. it can.

  In contrast, samples that are outside the scope of this invention are considered.

  In the case of l> 0.5, the Q value (1 GHz) is less than 38000 as shown in samples 78, 82, and 85.

  Example 3 was carried out in order to investigate the influence exerted by substituting part or all of Mg with Zn.

As starting materials, high-purity calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), tantalum oxide (Ta ₂ O ₅ ), antimony oxide (Sb ₂ O ₃ ), magnesium oxide (MgO), zinc oxide (ZnO), and tungsten oxide (WO ₃ ) powders were prepared.

Next, the composition formula: xCaTi _a O _{1 + 2a} −yCa {Al _{b /} , which was selected for each of x, y, z, a, b, c, d, e, k, l, and m shown in Table 4. ₂ (Nb _1-kl Ta _k Sb _l ) _{c / 2} } O _{1+ (3b + 5c) / 4} −zCa {(Mg _1−m Zn _m ) _{d / 2} W _{e / 2} ) O _{1+ (d +} Each of the above starting material powders was prepared so as to obtain a composition represented by _{3e) / 2} .

Thereafter, a disk-shaped sintered body to be a sample is obtained by the same method as in Example 1, and ε _r , Q value (1 GHz), and τ _f are obtained for the obtained sintered body according to each sample. Was measured respectively.

Table 4 shows the measurement results of ε _r , Q value (1 GHz), and τ _f corresponding to the sample composition.

  In Table 4, the sample number with * is a sample outside the scope of the present invention.

As shown in Table 4, according to the dielectric ceramic composition according to Samples 91 to 110 and 116 to 120 within the scope of the present invention, compared to the case where part or all of Mg is not substituted with Zn. Thus, ε _r can be improved without deteriorating the Q value (1 GHz) and the absolute value of τ _f , and excellent microwave dielectric characteristics can be obtained.

  In contrast, samples that are outside the scope of this invention are considered.

  Even when part or all of Mg is replaced with Zn, when l> 0.5, the Q value (1 GHz) is less than 38000 as shown in Samples 111 to 115.

The high frequency dielectric ceramic composition of the present invention may be added with a slight amount of additives as long as the object of the present invention is not impaired. For example, ZrO ₂ , SiO ₂ , Li ₂ O, B ₂ O ₃ , PbO, Bi ₂ O ₃ , MnO ₂ , NiO, CuO, Fe ₂ O ₃ , Cr ₂ O ₃ , V ₂ O _5, etc. are 0.01. By adding ˜1.00 wt%, the firing temperature can be lowered by 20 to 30 ° C. without deteriorating the characteristics of the dielectric ceramic.

Further, by adding 1.00 to 3.00% by weight of BaCO ₃ , SrCO ₃ or the like, ε _r and τ _f can be finely adjusted, and excellent microwave dielectric characteristics can be obtained.

As described above, according to the present invention, it is possible to obtain a dielectric ceramic composition for high frequency with ε _r of 45 or more, Q value (1 GHz) of 38000 or more, and absolute value of τ _f within 25 ppm / ° C. By using this dielectric ceramic composition for high frequency, a dielectric filter, a dielectric duplexer, and a communication device that are downsized and have excellent characteristics can be advantageously configured.
Therefore, the present invention can be widely used in fields such as a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device.

  The present invention relates to a high-frequency dielectric ceramic composition used in a high-frequency region such as a microwave and a millimeter wave, and a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device configured using the same About.

  In high frequency regions such as microwaves and millimeter waves, dielectric ceramics are widely used as materials constituting dielectric resonators and circuit boards.

When such a high-frequency dielectric ceramic is particularly intended for applications such as dielectric resonators and dielectric filters, the required dielectric characteristics are as follows: (1) the wavelength of electromagnetic waves in the dielectric is 1 / (ε _r ) is reduced to ^1/2 , so that the dielectric constant (ε _r ) is high as a response to the demand for miniaturization, (2) the dielectric loss is small, that is, the Q value is high, (3) the resonance frequency In that the temperature coefficient of resonance frequency (τ _f ) is around 0 ppm / ° C.

Here, τ _f is the slope (first derivative) when the resonance frequency temperature curve is linearly approximated using the resonance frequency (f ₂₅ ) at 25 ° C. and the value of the resonance frequency (f ₅₅ ) at 55 ° C. The value is obtained by the equation of τ _f = (f ₅₅ −f ₂₅ ) / (f ₂₅ · (55 ° C.−25 ° C.)).

Conventionally, as a high frequency dielectric ceramic composition that can satisfy the above-described requirements, for example, CaO—TiO ₂ —Al ₂ O ₃ — (Nb, Ta) ₂ O ₅ (see Patent Documents 1 to 7), Ca ( Many porcelain compositions such as Mg _1/2 W _1/2 ) O ₃ have already been proposed.
JP-A-10-95663 JP 2001-302331 A JP 2001-302332 A JP 2001-302333 A JP 2001-302334 A JP 2002-255640 A JP 2002-308670 A Japanese Patent Laid-Open No. 9-2441073

In recent years, there has been an increasing demand for low loss and downsizing of electronic devices, and more excellent dielectric properties required for high frequency dielectric ceramics for applications such as dielectric resonators and dielectric filters are required. It is supposed to be. In particular, even when used in a high frequency region, there is an increasing demand for materials having both high ε _r , high Q value, and high temperature stability (τ _f is around 0 ppm / ° C.).

However, although the dielectric ceramic composition having the composition system described in Patent Document 1 has a high ε _r of 41 to 66, the Q value (1 GHz) is 12000 to 27300 and cannot be said to be sufficiently high.

Moreover, the dielectric ceramic composition having the composition system described in Patent Documents 2 to 7 has a high ε _r of 35 or more and τ _f can be controlled around 0 ppm / ° C. However, when ε _r is increased, τ _f There was a problem that the Q value (1 GHz) deteriorated.

The dielectric ceramic composition having the composition system described in Patent Document 8 has a high Q value (1 GHz) of 45000 or more, but has a low ε _r of 17 to 19 and an absolute value of τ _f of 70. It was more than that.

Therefore, an object of the present invention is to solve the above-described problem, that is, even when used in a high frequency region such as a microwave or a millimeter wave, it has a high ε _r and a high Q value, and the absolute value of τ _f An object is to provide a dielectric ceramic composition for high frequency with a small value.

In order to solve the above technical problem, the high frequency dielectric ceramic composition of the present invention has a composition formula: xCaTiO ₃ —yCa (Al _1/2 Nb _1/2 ) O ₃ —zCa (Mg _1/2 W _{1) /} 2) has a composition represented by O _3, x in the above composition formula, y, z (was however x, y, z are mole ratio), 0.5 ≦ x ≦ 0.58,0. 21 ≦ y ≦ 0.482, 0.018 ≦ z ≦ 0.213, in the range of x + y + z = 1.00 0 , and, epsilon _r is 45 or more, Q value (1 GHz) is 40,000 or more, the tau _f The absolute value is ± 15 ppm / ° C.

And a part or all of Nb in the composition formula is substituted with Ta .

  Furthermore, part or all of Mg in the composition formula is substituted with Zn.

  The dielectric resonator according to the present invention is a dielectric resonator in which a dielectric ceramic is operated by electromagnetic coupling to an input / output terminal, and the dielectric ceramic is used for the high frequency of the present invention described above. It consists of a dielectric ceramic composition.

  The dielectric filter of the present invention includes the above-described dielectric resonator and external coupling means connected to the input / output terminal of the dielectric resonator.

  The dielectric duplexer of the present invention includes 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 filter. A dielectric duplexer, wherein at least one of the dielectric filters is the above-described dielectric filter according to the present invention.

  Furthermore, the communication device of the present invention includes the above-described dielectric duplexer, a transmission circuit connected to at least one input / output connection means of the dielectric duplexer, and the input / output described above connected to the transmission circuit. A receiving circuit connected to at least one input / output connection means different from the means; and an antenna connected to the antenna connection means of the dielectric duplexer.

According to this invention, it has a composition represented by the composition formula: xCaTiO ₃ —yCa (Al _1/2 Nb _1/2 ) O ₃ —zCa (Mg _1/2 W _1/2 ) O ₃ , x, y, z (was however x, y, z are molar ratios) in the, 0.5 ≦ x ≦ 0.58,0.21 ≦ y ≦ 0.482, 0.018 ≦ z ≦ 0. 213, x + y + z = 1.00 and as in the range of 0, and, epsilon _r is not more 45 or more and to 40,000 or more high Q value in the Q value (1 GHz), also the absolute value of tau _f Is required to be as small as 15 ppm / ° C. or less, and therefore a high frequency dielectric ceramic composition having good characteristics that cannot be obtained by conventional techniques can be obtained.

In the dielectric ceramic composition for high frequency according to the present invention, by replacing part or all of Nb in the composition formula with Ta, the absolute value of τ _f can be made larger than when not substituted with Ta. Can be small.

Furthermore, in the high frequency dielectric ceramic composition of the present invention, by replacing a part or all of Mg in the above composition formula with Zn, ε _r can be made higher than when not substituted with Zn. Can do.

  Therefore, for example, a dielectric resonator mounted in a base station, a mobile phone, a personal radio, a satellite broadcast receiver, etc. is downsized, the dielectric loss is reduced, and the temperature stability of the resonance frequency is excellent. be able to. As a result, if such a dielectric resonator is used, a dielectric filter, a dielectric duplexer, and a communication device that are downsized and have excellent characteristics can be advantageously configured.

It is sectional drawing which shows the basic structure of the dielectric resonator 1 comprised using the dielectric ceramic composition for high frequencies of this invention schematically. It is a block diagram which shows an example of the communication apparatus comprised using the dielectric resonator 1 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dielectric resonator 2 Metal case 3 Support stand 4 Dielectric porcelain 5, 6 Coupling loop 7, 8 Coaxial cable 10 Communication apparatus 12 Dielectric duplexer 14 Transmission circuit 16 Reception circuit 18 Antenna 20 Input connection means 22 Output connection Means 24 Antenna connection means 26, 28 Dielectric filter 30 External coupling means

  First, a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device to which the high frequency dielectric ceramic composition of the present invention is applied will be described.

  FIG. 1 is a cross-sectional view schematically showing the basic structure of a dielectric resonator 1 constructed using the high frequency dielectric ceramic composition of the present invention.

  Referring to FIG. 1, a dielectric resonator 1 includes a metal case 2, and a columnar dielectric ceramic 4 supported by a support base 3 is disposed in a space inside the metal case 2. A coupling loop 5 is formed between the center conductor and the outer conductor of the coaxial cable 7 to serve as an input terminal. Further, a coupling loop 6 is formed between the central conductor and the outer conductor of the coaxial cable 8 to serve as an output terminal. Each terminal is held by the metal case 2 in a state where the outer conductor and the metal case 2 are electrically joined.

  The dielectric porcelain 4 operates by electromagnetic coupling to the input terminal and the output terminal, and only a signal having a predetermined frequency input from the input terminal is output from the output terminal.

  The dielectric ceramic 4 provided in such a dielectric resonator 1 is composed of the high frequency dielectric ceramic composition of the present invention.

  The dielectric resonator 1 shown in FIG. 1 is a TE01δ mode resonator used in a base station or the like, but the high-frequency dielectric ceramic composition of the present invention has other TE modes, TM modes, and TEMs. The same can be applied to a dielectric resonator using a mode or the like.

  FIG. 2 is a block diagram illustrating an example of a communication device configured using the dielectric resonator 1 described above.

  The communication device 10 shown in FIG. 2 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.

  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 and 28. The dielectric filters 26 and 28 are configured by connecting an external coupling means to the dielectric resonator of the present invention. In the illustrated embodiment, for example, each of the dielectric filters 26 and 28 is configured by connecting external coupling means 30 to the input / output terminals of the dielectric resonator 1 shown in FIG. 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 to.

  Next, the dielectric ceramic composition for high frequency of the present invention that is advantageously used in the high frequency region, such as the dielectric ceramic 4 provided in the dielectric resonator 1 shown in FIG. 1, will be described.

The dielectric ceramic composition for high frequency according to the present invention has a composition represented by the composition formula: xCaTiO ₃ —yCa (Al _1/2 Nb _1/2 ) O ₃ —zCa (Mg _1/2 W _1/2 ) O _3. Have. Where x in the above composition formula, y, z (was however x, y, z are mole ratio), 0.5 ≦ x ≦ 0.58,0.21 ≦ y ≦ 0.482, 0.018 ≦ z ≦ 0.213, chosen to be within the range of x + y + z = 1.00 0 . A dielectric ceramic composition for high frequency within the scope of the present invention has the characteristics that ε _r is 45 or more, Q value (1 GHz) is 40000 or more, and the absolute value of τ _f is ± 15 ppm / ° C.

The high frequency dielectric ceramic composition of the present invention is selected so that part or all of Nb in the composition formula is replaced with Ta in order to make the absolute value of τ _f smaller.

Furthermore, in the high frequency dielectric ceramic composition of the present invention, in order to make ε _r higher, a part or all of Mg in the composition formula is substituted with Zn.

  In the present invention, examples that serve as the basis for selecting a specific composition as described above will be described below.

As starting materials, high-purity calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), magnesium oxide (MgO), and tungsten oxide (WO ₃ ) Each powder was prepared.

Next, the composition formula: xCaTi _a O _{1 + 2a} -yCa (Al _{b / 2} Nb _{c /)} selected for x, y, z, a, b, c, d, and e shown in Tables 1 and 2, respectively. ₂ ) Each of the above starting material powders so as to obtain a composition represented by O _{1+ (3b + 5c) / 4} -zCa (Mg _{d / 2} W _{e / 2} ) O _{1+ (d + 3e) / 2} Was formulated.

  Next, the blended powder was wet-mixed for 16 hours using a ball mill and dispersed uniformly, and then subjected to dehydration and drying treatment to obtain an adjusted powder.

  Next, the adjusted powder is calcined at a temperature of 1000 to 1300 ° C. for 3 hours, an appropriate amount of binder is added to the obtained calcined powder, and wet milled again using a ball mill for 16 hours. A powder was obtained.

Then, the powder for burning, after press-molded into a disk shape at a pressure of ^{0.98 × 10 2 ~1.96 × 10 2} MPa, and calcined at 4 hours in air at a temperature of from 1,400 to 1,650 ° C., A disk-shaped sintered body having a diameter of 10 mm and a thickness of 5 mm was obtained.

With respect to the obtained sintered body of each sample, ε _r and Q value at a measurement frequency f of 6 to 8 GHz were measured by a double-end short-circuited dielectric resonator method using TE011 mode, and Q × f (frequency) = Based on a fixed formula, it was converted into a Q value (1 GHz). In addition, the resonance frequency was measured by the cavity method in the TE01δ mode, and τ _f in the temperature range of 25 to 55 ° C. was measured.

Tables 1 and 2 show ε _r , Q value (1 GHz), and τ _f corresponding to the sample composition, measured as described above.

  In Tables 1 and 2, the sample number with * is a sample outside the scope of the present invention.

As shown in Tables 1 and 2, according to the dielectric ceramic composition according to Samples 18, 24 to 26, 31 to 33, and 38 within the scope of the present invention, ε _r is as large as 45 or more, and the Q value is (1 GHz) is as high as 40000 or more, the absolute value of τ _f can be reduced within 15 ppm / ° C., and excellent microwave dielectric characteristics can be obtained.

  In contrast, samples that are outside the scope of this invention are considered.

First, in the case of x <0.5, as shown in sample 43 to 50, the absolute value of tau _f is more than 15 ppm / ° C.. On the other hand, in the case of x> 0.58, as shown in Sample 1-3, the absolute value of tau _f is more than 15 ppm / ° C..

Next, when y <0.21, the absolute value of τ _f exceeds 15 ppm / ° C. as shown in samples 28 , 35, and 42 . On the other hand, when y> 0.482 , as shown in Samples 44 , 45, 53 , the absolute value of τ _f exceeds 15 ppm / ° C.

Then, in the case of z <0.018, as shown in the sample 1, 2, 7, the absolute value of tau _f is more than 15 ppm / ° C.. On the other hand, when z> 0.213 , as shown in samples 27 , 34, and 41 , the absolute value of τ _f exceeds 15 ppm / ° C.

  Example 2 was carried out in order to investigate the influence exerted by substituting part or all of Nb with Ta or Sb.

As starting materials, high-purity calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), tantalum oxide (Ta ₂ O ₅ ), antimony oxide (Sb ₂ O ₃ ), magnesium oxide (MgO), and tungsten oxide (WO ₃ ) powders were prepared.

Next, the composition formulas: xCaTi _a O _{1 + 2a} -yCa {Al _{b / 2} (chosen for x, y, z, a, b, c, d, e, k, and l shown in Table 3, respectively. _{nb 1-kl Ta k Sb l} ) c / 2} O 1+ (3b + 5c) / 4 -zCa (Mg d / 2 W e / 2) O 1+ (d + 3e) / 2 composition represented by the Each of the above starting material powders was prepared so as to be obtained.

Thereafter, a disk-shaped sintered body to be a sample is obtained by the same method as in Example 1, and ε _r , Q value (1 GHz), and τ _f are obtained for the obtained sintered body according to each sample. Was measured respectively.

Table 3 shows the measurement results of ε _r , Q value (1 GHz), and τ _f corresponding to the sample composition.

  In Table 3, the sample number with * is a sample outside the scope of the present invention.

As shown in Table 3, according to the dielectric ceramic composition according to sample 79 within the scope of the present invention, ε _r and Q value (1 GHz) were compared with the case where Nb was not replaced with Ta. Without deteriorating, the absolute value of τ _f can be reduced, and excellent microwave dielectric characteristics can be obtained.

  Example 3 was carried out in order to investigate the influence exerted by substituting part or all of Mg with Zn.

As starting materials, high-purity calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), tantalum oxide (Ta ₂ O ₅ ), antimony oxide (Sb ₂ O ₃ ), magnesium oxide (MgO), zinc oxide (ZnO), and tungsten oxide (WO ₃ ) powders were prepared.

Next, the composition formula: xCaTi _a O _{1 + 2a} −yCa {Al _{b /} , which was selected for each of x, y, z, a, b, c, d, e, k, l, and m shown in Table 4. ₂ (Nb _1-kl Ta _k Sb _l ) _{c / 2} } O _{1+ (3b + 5c) / 4} −zCa {(Mg _1−m Zn _m ) _{d / 2} W _{e / 2} ) O _{1+ (d +} Each of the above starting material powders was prepared so as to obtain a composition represented by _{3e) / 2} .

Thereafter, a disk-shaped sintered body to be a sample is obtained by the same method as in Example 1, and ε _r , Q value (1 GHz), and τ _f are obtained for the obtained sintered body according to each sample. Was measured respectively.

Table 4 shows the measurement results of ε _r , Q value (1 GHz), and τ _f corresponding to the sample composition.

  In Table 4, the sample number with * is a sample outside the scope of the present invention.

As shown in Table 4, according to the dielectric ceramic composition according to Samples 96 to 105 within the scope of the present invention, the Q value was compared with the case where part or all of Mg was not substituted with Zn. Ε _r can be improved without deteriorating the absolute values of (1 GHz) and τ _f , and excellent microwave dielectric characteristics can be obtained.

The high frequency dielectric ceramic composition of the present invention may be added with a slight amount of additives as long as the object of the present invention is not impaired. For example, ZrO ₂ , SiO ₂ , Li ₂ O, B ₂ O ₃ , PbO, Bi ₂ O ₃ , MnO ₂ , NiO, CuO, Fe ₂ O ₃ , Cr ₂ O ₃ , V ₂ O _5, etc. are 0.01. By adding ˜1.00 wt%, the firing temperature can be lowered by 20 to 30 ° C. without deteriorating the characteristics of the dielectric ceramic.

Further, by adding 1.00 to 3.00% by weight of BaCO ₃ , SrCO ₃ or the like, ε _r and τ _f can be finely adjusted, and excellent microwave dielectric characteristics can be obtained.

As described above, according to the present invention, epsilon _r is 45 or more, Q value (1 GHz) is 40,000 or more, the absolute value of tau _f can be obtained high-frequency dielectric ceramic composition within 15 ppm / ° C. Thus, by using this high-frequency dielectric ceramic composition, a dielectric filter, a dielectric duplexer, and a communication device that are downsized and have excellent characteristics can be advantageously configured.
Therefore, the present invention can be widely used in fields such as a dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device.

Claims (7)

_{Formula: xCaTi a O 1 + 2a -yCa} (Al b / 2 Nb c / 2) O 1+ (3b + 5c) / 4 -zCa (Mg d / 2 W e / 2) O 1+ (d + 3e _{) / 2} , and x, y, z, a, b, c, d, and e (where x, y, and z are molar ratios) in the above composition formula are:
0.475 ≦ x ≦ 0.58,
0.21 ≦ y ≦ 0.505,
0.018 ≦ z ≦ 0.25,
x + y + z = 1.000,
0.9 ≦ a ≦ 1.05,
0.9 ≦ b ≦ 1.1,
0.9 ≦ c ≦ 1.1,
0.9 ≦ d ≦ 1.1,
0.9 ≦ e ≦ 1.05
A dielectric ceramic composition for high frequency within the range of A part or all of Nb in the composition formula is substituted with Ta and / or Sb, and the substitution amount l by Sb (where l is a molar ratio of Sb / (Nb + Ta + Sb)) is:
0 ≦ l ≦ 0.5
The dielectric ceramic composition for high frequency according to claim 1, which is within the range.   The dielectric ceramic composition for high frequency according to claim 1 or 2, wherein a part or all of Mg in the composition formula is substituted with Zn.   A high frequency dielectric according to any one of claims 1 to 3, wherein the dielectric ceramic is a dielectric resonator that operates by being electromagnetically coupled to an input / output terminal. A dielectric resonator comprising a body ceramic composition.   5. A dielectric filter comprising: the dielectric resonator according to claim 4; and external coupling means connected to an input / output terminal of the dielectric resonator.   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 filter, wherein the dielectric A dielectric duplexer, wherein at least one of the filters is a dielectric filter according to claim 5.   7. The dielectric duplexer according to claim 6, a transmission circuit connected to at least one input / output connection means of the dielectric duplexer, and at least one different from the input / output means connected to the transmission circuit A communication apparatus comprising: a receiving circuit connected to an input / output connection means; and an antenna connected to an antenna connection means of the dielectric duplexer.

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