JP2004091266A - Gallium-added dielectric porcelain composition, dielectric resonator, and microwave communication apparatus - Google Patents

Abstract

An object of the present invention is to provide a dielectric ceramic composition capable of lowering a firing temperature than before, and to develop a dielectric resonator and a microwave communication device which are inexpensive and have high performance.
The gallium-doped dielectric ceramic composition according to the present invention has a composition formula of [(Ln) _{1 + x} (Al _1-y G _ay ) _1-x O ₃ ] with m (wt%) and [(M _{1 + z} Ti _1-z O ₃ ] is a dielectric porcelain composition comprising n (wt%), -0.5 ≦ x ≦ 0.5, 0 <y ≦ 1, -0.5 ≦ z ≦ 0 A gallium-doped dielectric ceramic composition satisfying 0.5 and m + n = 100. By partially adding Ga to Al or completely adding Ga (completely replacing Al), the sintering temperature of the dielectric porcelain composition can be lowered, and the price of the heater, heat-resistant furnace, and energy consumption can be reduced. It becomes possible to realize a reduction in price and mass productivity. Further, a dielectric resonator 4 in which the dielectric ceramic 2 is formed from the dielectric ceramic composition and arranged between the input / output terminals 8 and 10 is provided.
[Selection] Figure 2

Description

【０１１８】
【表２】

【０１１９】
【表３】

【０１２０】
【表４】

【０１２１】
【表５】

【０１２２】
【表６】

【０１２３】
【表７】

【０１２４】
【発明の効果】
第１の発明によれば、誘電体磁器組成物の組成式を［（Ｌｎ）_１＋ｘ（Ａｌ_１−ｙＧａ_ｙ）_１−ｘＯ_３］［（Ｍ）_１＋ｚＴｉ_１−ｚＯ_３］で構成し、Ｇａ添加率ｙの範囲を０＜ｙ≦１とたから、ＡｌにＧａを添加することにより、誘電体磁器組成物の焼結温度を低下させることに初めて成功した。Ｇａの添加量を次第に増大させてゆくと、焼成温度は逆に次第に低下し、Ｇａの添加量を最大にすること、つまりＡｌをＧａで完全に置換すると、焼結温度を最低温度にまで低下させることができる。従って、Ｇａを添加することによって、焼成温度を低下することに成功し、発熱ヒーターや耐熱炉や消費エネルギーの価格を低下させて製品価格の低下を実現し、同時に冷却時間の短縮により量産性を向上できる。
【０１２５】
第２の発明によれば、ガリウム添加形誘電体磁器組成物に種々の酸化物を添加すると、比誘電率（εｒ）、品質係数（Ｑ・ｆ）及び温度係数（τｆ）からなるマイクロ波誘電体特性を自在に可変することができ、所望特性のガリウム添加形誘電体磁器組成物を実現できる。これらの酸化物を添加しない場合には、誘電体特性を可変するには成分のモル比又はｗｔ％を調整する以外にないが、組成比の変更は複雑な作業手順の変更を必要とする。これに対し、酸化物の添加だけマイクロ波誘電体特性を調整できる簡便性がある。同時に、この酸化物の添加により、焼成温度を微調整することも可能になる。
【０１２６】
第３の発明によれば、希土類元素Ｌｎは単一の希土類元素であるだけでなく、２種の希土類元素を適当な比率で混合して構成することもできる。２種の希土類元素を混合することによって、誘電体磁器組成物に多様性を導入でき、しかもマイクロ波誘電体特性と焼成温度を調整することが可能になる。
【０１２７】
第４の発明によれば、アルカリ土類元素Ｍは単一のアルカリ土類元素であるだけでなく、２種のアルカリ土類元素を適当な比率で混合して構成することもできる。希土類元素と同様に、２種のアルカリ土類元素を混合することによって、誘電体磁器組成物に多様性を導入でき、しかもマイクロ波誘電体特性と焼成温度を調整することが可能になる。
【０１２８】
第５の発明によれば、ガリウム添加形誘電体磁器組成物を適当な形状に成形して焼成すると、所望形状の誘電体磁器を提供できる。この誘電体磁器を入出力端子間に配置すると、誘電体磁器の形状に応じて特定振動数領域のマイクロ波と共振する安価な誘電体共振器を実現できる。
【０１２９】
第６の発明によれば、安価な前記誘電体共振器を送信装置や受信装置に配置することによって、マイクロ波通信装置の価格低下に貢献でき、携帯電話や自動車電話等に代表されるマイクロ波通信システムの更なる普及に貢献することができる。
【図面の簡単な説明】
【図１】本発明に係る誘電体磁器の各種実施例の斜視図である。
【図２】本発明に係る誘電体共振器の一例を示すモデル図である。
【図３】本発明に係る誘電体共振器を組み込んだ基地局通信装置の概略構成図である。
【図４】本発明に係る誘電体共振器を組み込んだ移動体通信装置の概略構成図である。
【符号の説明】
２は誘電体磁器、４は誘電体共振器、６は基板、８は入力端子、１０は出力端子、１２は電磁界結合、１４は電磁界結合、１８は上位回線網、２０は基地局通信装置、２２は変調器、２４は送信装置、２６は送信用共振器、２８はアンテナ共用器、３０はアンテナ、３２は受信用共振器、３４は受信装置、３６は復調器、４０は移動体通信装置、４２はアンテナ、４４はバッテリー、４６は制御部、４８はシンクロナイザー、５０は操作部、５２はマイク、５４は送信装置、５６は送信用共振器、５８は受信用共振器、６０は受信装置、６２はスピーカー。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a dielectric porcelain composition used in a microwave communication device such as a mobile phone, a car phone, a microwave radio device, and a cordless phone, and more particularly, to reduce the firing temperature by adding gallium. The present invention relates to a gallium-doped dielectric porcelain composition, a dielectric resonator, and a microwave communication device using the same, which realize cost reduction.
[0002]
[Prior art]
2. Description of the Related Art In recent years, communication devices using microwaves as carrier waves, particularly mobile communication devices that move with a car or a person, have been rapidly spreading. These mobile communication devices include, for example, mobile phones, car phones, cordless telephones, personal radios, satellite broadcast receivers, and the like. In this mobile communication, there are a mobile communication device that moves with a person, a car, and the like, and a base station communication device that is a communication base of the mobile communication device. In the present invention, the mobile communication device and the base station communication device are referred to as a mobile communication device and a base station communication device. Inclusively, it is called a microwave communication device.
[0003]
The rapid development of such mobile communication systems depends on the development of dielectric ceramic compositions having high sensitivity to microwaves. A dielectric ceramic of a specific shape is formed by firing from the dielectric ceramic composition, and a microwave dielectric resonator is formed from the dielectric ceramic.
[0004]
The characteristics that such a microwave dielectric porcelain composition should satisfy include (1) relative permittivity (ε) for miniaturization._r) Is large, (2) the dielectric loss (tan δ) in the microwave region is small, and (3) the temperature coefficient of resonance frequency (τ_f) Is small.
[0005]
The Q value is defined by Q = 1 / tan δ, and when combined with the resonance frequency f, Q · f = constant, and the value of Q · f is called a quality factor. At present, the fact that the value of the quality factor Q · f is large is used instead of the condition (2). These three properties are also called microwave dielectric properties.
[0006]
[Problems to be solved by the invention]
As a dielectric ceramic composition satisfying the above three characteristics, a dielectric ceramic composition disclosed in JP-A-6-76633 (Japanese Patent No. 2625074) is known. This dielectric porcelain composition is Ln₂O_x(Ln is a rare earth element), Al₂O₃, CaO and TiO₂The four components are mixed and fired.
[0007]
More specifically, in this conventional dielectric ceramic composition, the above-mentioned four components are aLn using the molar ratios a, b, c, and d.₂O_x・ BAl₂O₃・ CCaO ・ dTiO₂When represented, the values of a, b, c, d and x are
a + b + c + d = 1
0.056 ≦ a ≦ 0.214
0.056 ≦ b ≦ 0.214
0.286 ≦ c ≦ 0.500
0.230 <d <0.470
3 ≦ x ≦ 4
It is characterized by satisfying.
[0008]
This publication describes that the molar ratios a, b, c, and d can be arbitrarily and independently varied. However, in practice, the most effective dielectric ceramic composition is the case where a = b and c = d. Has been found by the present inventors. x merely takes into account that the number of valence electrons may slightly increase from 3 depending on the type of rare earth element (lanthanide element), and it may be considered that x = 3 in practice.
[0009]
Therefore, this dielectric porcelain composition is [LnAlO₃] And [CaTiO₃] At an appropriate weight ratio. At this time, the composition formula of the obtained dielectric ceramic composition is [LnAlO₃] ・ [CaTiO₃] Can be written.
[0010]
The present inventors have actually manufactured this conventional dielectric porcelain composition and measured the microwave dielectric characteristics in detail, and as a result, have found that the relative dielectric constant is high, the Q value is high, and the temperature coefficient is small. confirmed. That is, this dielectric ceramic composition has excellent microwave dielectric properties, and it has been confirmed that the dielectric ceramic formed from this dielectric ceramic composition becomes an excellent microwave resonator.
[0011]
However, significant weaknesses in manufacturing conditions have been discovered in making this dielectric porcelain composition. The weak point is that when firing the dielectric ceramic composition in a predetermined shape, the firing temperature exceeds 1550 ° C. This firing temperature is disclosed in JP-A-6-76633 (Japanese Patent No. 2625074) as simply 1500 to 1700 ° C., but is described as if it can be fired even at 1500 ° C. It was found that the minimum firing temperature was 1550 ° C. This fact has been confirmed for the first time by additional tests by the present inventors.
[0012]
The present inventors produced the following four types of dielectric ceramic compositions in order to determine the firing temperature of the dielectric ceramic composition.
(1) LaAlO₃―CaTiO₃
(2) (Nd_0.5La_0.5) AlO₃-CaTiO₃
(3) LaAlO₃-Ca_0.7Sr_0.3TiO₃
(4) (Nd_0.5La_0.5) AlO₃-Ca_0.7Sr_0.3TiO₃
[0013]
In these dielectric ceramic compositions, La and Nd are selected as the rare earth elements Ln, and Ca and Sr are selected as the alkaline earth elements. The firing temperature and relative permittivity (ε) of these four types of dielectric ceramic compositions_r) And a quality factor (Q · f) are measured, and a temperature coefficient (τ_f) Was measured. The results are summarized in Table 1.
[0014]
As shown in Table 1, all the samples were found to be in a non-sintered state when the firing temperature was lower than 1550 ° C. The unsintered state of the sample means that the sample has numerous pores remaining inside, is not uniformly densified as crystals, and cannot be used as a dielectric ceramic composition and a dielectric resonator. Means
[0015]
It was found that when the firing temperature was 1550 ° C. or higher, all the samples were sintered by firing for 4 hours. This sintered state means that pores have disappeared inside the sample and the sample has been uniformly crystallized in a dense state. That is, it was proved that the conventional dielectric ceramic composition was obtained by firing at a temperature of 1550 ° C. or more for 4 hours or more.
[0016]
However, when the firing temperature is as high as 1550 ° C. or more, there is a problem in the firing equipment. In other words, when the firing temperature is 1550 ° C. or higher, the drawbacks that the heating heater becomes expensive, energy consumption increases, and the heat-resistant furnace becomes expensive start to occur.
[0017]
At a sintering temperature of 1550 ° C. or more, MoSi whose normal use temperature is 1600 ° C.₂An exothermic heater using is required. Compared with a heating heater using SiC whose normal use temperature is 1400 ° C., the price of an electric furnace of the same size soars about three times, and this soaring equipment price causes the soaring price of the dielectric ceramic composition. It becomes.
[0018]
On the other hand, if the firing temperature exceeds 1550 ° C., a special material is required for the heat-resistant furnace, which causes a rise in the temperature of the heat-resistant furnace. The rise in refractory furnaces will rebound to the price of dielectric porcelain compositions. Further, an increase in the firing temperature causes a rise in price due to an increase in energy consumption, and at the same time, it takes time to cool the dielectric porcelain, thereby lowering mass productivity.
[0019]
As described above, despite the fact that the above-described dielectric porcelain composition has excellent microwave dielectric properties, the high temperature property of the sintering temperature generally causes a rise in product price, and the disadvantage that mass productivity is reduced. Had. Therefore, it has been an important issue to lower the firing temperature while maintaining the excellent microwave dielectric properties.
[0020]
Accordingly, the present invention has discovered a novel dielectric composition capable of lowering the firing temperature compared to the conventional dielectric ceramic composition, and based on this, has provided a low-cost dielectric ceramic composition. An object of the present invention is to provide a high-performance microwave communication device using a dielectric resonator formed of a ceramic composition and using the dielectric resonator.
[0021]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and the first invention is directed to one or more rare earth elements (Ln), Al, Ga, one or more alkaline earth metal elements (M), and [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] Is m (wt%) and [(M)_{1 + z}Ti_1-zO₃] Is a dielectric porcelain composition consisting of n (wt%), and its composition formula is [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] ・ [(M)_{1 + z}Ti_1-zO₃],
-0.5 ≦ x ≦ 0.5
0 <y ≦ 1
−0.5 ≦ z ≦ 0.5
m + n = 100
Is a gallium-doped dielectric ceramic composition that satisfies the following.
The present inventors have found for the first time in the world that the addition of Ga to Al in a conventional dielectric porcelain composition lowers the firing temperature of the dielectric porcelain composition. The present invention has been completed based on this finding. As the additive amount of Ga is gradually increased, the firing temperature gradually decreases, and when the additive amount of Ga is maximized, that is, when Al is completely replaced with Ga, the firing temperature reaches the minimum temperature. Therefore, by adding Ga, the firing temperature can be successfully reduced, and the price of the heater, the heat-resistant furnace, and the energy consumption can be reduced. Becomes possible.
[0022]
According to a second aspect of the invention, the gallium-doped dielectric porcelain composition is a main component, and ZnO, NiO, SnO is added to 100 parts by weight of the main component.₂, Co₃O₄, MnCO₃, ZrO₂, WO₃, Li₂CO₃, Rb₂CO₃, Sc₂O₃, V₂O₃, CuO, SiO₂, MgCO₃, Cr₂O₃, B₂O₃, GeO₂, Sb₂O₅, Nb₂O₅And Ta₂O₅The gallium-doped dielectric porcelain composition contains at least 10 parts by weight of one or more additives selected from the group consisting of:
By adding these oxides, it becomes possible to variably adjust the microwave dielectric characteristics including the relative dielectric constant (εr), the quality coefficient (Q · f) and the temperature coefficient (τf). A gallium-doped dielectric ceramic composition can be provided. When these oxides are not added, the only way to change the dielectric properties is to adjust the molar ratio or wt% of the components, but to change the dielectric properties when the molar ratio is constant. However, there is the simplicity that only the addition of this oxide is sufficient. Further, by adding this oxide, the firing temperature can be finely adjusted.
[0023]
In the third invention, the rare earth element (Ln) is constituted by combining two kinds of rare earth elements LA and LB, and (Ln) is (LA) in the composition formula._1-sLB_sAnd gallium-added dielectric ceramic composition satisfying 0 <s <1.
The rare earth element Ln is not only a single rare earth element, but can also be constituted by mixing two kinds of rare earth elements at an appropriate ratio. By mixing two kinds of rare earth elements, diversity can be introduced into the dielectric ceramic composition, and the microwave dielectric characteristics and the firing temperature can be adjusted.
[0024]
In a fourth invention, an alkaline earth metal element (M) is constituted by combining two kinds of alkaline earth metal elements MA and MB, and (M) is (MA)._1-tMB_t), And 0 <t <1.
The alkaline earth element M is not only a single alkaline earth element, but also can be constituted by mixing two kinds of alkaline earth elements at an appropriate ratio. As with the rare earth elements, by mixing two alkaline earth elements, diversity can be introduced into the dielectric ceramic composition, and the microwave dielectric characteristics and the firing temperature can be adjusted.
[0025]
A fifth aspect of the present invention is a dielectric resonator comprising a dielectric porcelain formed from the above-described gallium-doped dielectric porcelain composition, and arranging the dielectric porcelain between input and output terminals so as to resonate. . When the gallium-added dielectric ceramic composition is formed into an appropriate shape and fired, a dielectric ceramic having a desired shape can be provided. By arranging this dielectric porcelain between the input and output terminals, it is possible to provide an inexpensive dielectric resonator that resonates with microwaves in a specific frequency region according to the shape of the dielectric porcelain.
[0026]
According to the sixth aspect, the above-described dielectric resonator is built in the transmission circuit and / or the reception circuit, and the base station communication device and the mobile unit are driven by microwaves in a specific frequency region selected by the dielectric resonator. A microwave communication device that performs two-way communication between communication devices can be provided. By incorporating the inexpensive dielectric resonator of the present invention, it is possible to contribute to a reduction in the price of a microwave communication device and to further spread a microwave communication system represented by a mobile phone, a car phone, and the like. .
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
The present inventors have proposed a dielectric porcelain composition described in JP-A-6-76633 (Japanese Patent No. 2625074), that is, [LnAlO₃] ・ [CaTiO₃As a result of intensive studies to lower the firing temperature, the inventors have found a new fact that adding Ga to Al lowers the firing temperature, and completed the present invention based on this finding. In that sense, the dielectric porcelain composition according to the present invention is referred to as a gallium-doped dielectric porcelain composition.
[0028]
That is, the composition formula of the gallium-doped dielectric ceramic composition according to the present invention is [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] ・ [(M)_{1 + z}Ti_1-zO₃]. The most characteristic part of this composition formula is that Al in the conventional composition (Al_1-yGa_y). By adding Ga to Al, the firing temperature of the dielectric ceramic composition was successfully reduced.
[0029]
The addition rate of Ga is given by y, and the range of the addition rate y is given by 0 <y ≦ 1. The addition rate y does not include zero, and the firing temperature tends to gradually decrease as it becomes larger than zero. The sintering temperature is reduced by about 50 ° C. only by adding Ga by y = 0.01, and the sintering temperature is further decreased as y is increased.
[0030]
y = 1 gives the maximum addition rate of Ga, and shows the case where Ga is replaced with Al. At this time, the composition formula of the present invention is represented by [(Ln)_{1 + x}Ga_1-xO₃] ・ [(M)_{1 + z}Ti_1-zO₃], And the firing temperature drops to 1320 to 1350 ° C. In addition, microwave dielectric properties such as relative permittivity, quality coefficient and temperature coefficient also show good values.
[0031]
The rare earth elements (Ln) include Sc, Y, and lanthanoids. The lanthanoids include La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. included. In terms of lowering the firing temperature, Nd is relatively good.
[0032]
The rare earth element (Ln) includes not only the case of one kind of rare earth element but also the case of mixing two or more kinds of rare earth elements. As an example of a mixture of two kinds of rare earth elements, when the two kinds of rare earth elements are LA and LB, (Ln) becomes (LA)_1-sLB_s). The mixing ratio s is selected from the range of 0 <s <1. The reason why s = 0 and s = 1 are excluded is that one type is excluded.
[0033]
Examples of the alkaline earth element (M) include Mg, Ca, Sr, and Ba. Among them, Ca is relatively good. The alkaline earth element (M) includes not only a case of one kind of alkaline earth element but also a case of mixing two or more kinds of alkaline earth elements.
[0034]
As an example of mixing two kinds of alkaline earth elements, when two kinds of alkaline earth elements are MA and MB, (M) is (MA)_1-tMB_t), And the mixing ratio t is given in the range of 0 <t <1. The reason why t = 0 and t = 1 are excluded is that one type of case is excluded. Since Ca has relatively good properties, other alkaline earth elements can be mixed with Ca.
[0035]
In the present invention, [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃[Ln) and (Al)_1-yGa_y) Is not only one-to-one but also (Ln) and (Al_1-yGa_y) Are mixed at different ratios. The range of the mixing ratio x is allowed up to -0.5 ≦ x ≦ 0.5. Therefore, when x = −0.5, [(Ln)_0.5(Al_1-yGa_y)_1.5O₃], And when x = 0.5, [(Ln)₁. 5 (Al_1-yGa_y)_0.5O₃]. This intermediate state is of course included in the present invention.
[0036]
In the present invention, [(M)_{1 + z}Ti_1-zO₃As shown in the composition formula, not only the case where (M) and Ti are mixed in a one-to-one ratio but also the case where (M) and Ti are mixed in different ratios are included. The range of the mixing ratio z is allowed up to -0.5 ≦ z ≦ 0.5. Therefore, when z = −0.5, [(M)_0.5Ti1.₅O₃], And when z = 0.5, [(M) 1.₅Ti_0.5O₃]. This intermediate state is of course included in the present invention.
[0037]
Further, the gallium-doped dielectric porcelain composition of the present invention has a composition of [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] Is m (wt%) and [(M)_{1 + z}Ti_1-zO₃] Is a dielectric ceramic composition consisting of n (wt%), and the parameters m and n are selected so as to satisfy m + n = 100.
[0038]
The simplest gallium-doped dielectric porcelain composition is the case where m = n = 50 (wt%), and [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] And [(M)_{1 + z}Ti_1-zO₃] Are mixed at the same mass ratio. The parameter m is in the range of 0 <m <100, and the corresponding parameter n is also in the range of 0 <n <100, and is always mixed to satisfy m + n = 100.
[0039]
The values of the parameters m and n giving wt% (wt%) are arbitrarily adjusted so that the gallium-doped dielectric porcelain composition has good microwave dielectric properties and has a good low firing temperature. You.
[0040]
[(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] Is Ln₂O_w(3 ≦ w ≦ 4, w varies depending on the type of rare earth element) and Al₂O₃And Ga₂O₃These raw materials are mixed at a volume ratio corresponding to the composition ratios x and y. Also, [(M)_{1 + z}Ti_1-zO₃] Are MO and TiO₂It is obtained by mixing these raw materials at a quantitative ratio according to the composition ratio z. Here, Ln means a rare earth element and M means an alkaline earth element.
[0041]
When the rare earth element (Ln) is composed of two kinds of elements LA and LB, (LA_1-sLB_s), LA such that 0 <s <1₂O_wAnd LB₂O_wAre mixed in an appropriate ratio. When the alkaline earth element (M) is composed of two types of alkaline earth elements, MA and MB, (MA_1-tMB_t), MAO and MBO are mixed at an appropriate ratio so that 0 <t <1.
[0042]
[(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] Is m (wt%), [(M)_{1 + z}Ti_1-zO₃] In the gallium-doped dielectric composition with n (wt%), [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] M (wt%), [(M)_{1 + z}Ti_1-zO₃Are prepared by n (wt%) and mixed with each other.
[0043]
The target composition and the dielectric porcelain can be manufactured by mixing and molding these raw material powders and firing the molded body. For the preparation of the raw material powder material, any of the known powder preparation methods (solid phase method, liquid phase method, gas phase method, spray pyrolysis method, etc.) usually employed in the field of ceramics can be applied.
[0044]
In the solid-phase method, first, each composition composed of the above-mentioned main raw material and sub-raw material is weighed and collected so as to have the above-mentioned predetermined composition ratio as a starting material. And dry / wet mixing using a known pulverizer. In this case, an organic binder and a sintering aid can be further added as necessary.
[0045]
Next, the pulverized mixture is calcined at a temperature lower than the calcining temperature to prepare a calcined body having a target phase, and the powdered material can be prepared by further pulverizing the calcined body as necessary. . In this case, the starting material is the oxide described above. However, any one that can be finally turned into an oxide by calcination, such as a hydroxide or a carbonate, can be used. In particular, a composition that is easy to control the particle size and has excellent mixing properties is more preferable.
[0046]
In the liquid phase method, a known method such as a coprecipitation method or a hydrothermal synthesis method is used to precipitate a desired composition from a solution raw material or to evaporate a solvent to obtain an evaporative solid to obtain a powder raw material. Can be obtained. As a solution raw material, for example, a solvent obtained by dissolving a composition such as an alkaline earth metal element, a rare earth element, an aluminum element, a titanium element, a chloride of other elements, a nitrate, an organic acid salt or the like, or Using a solvent other than water (an organic solvent such as methanol or ethanol), a solution of the above composition such as an alkoxide can also be used.
[0047]
Powder raw materials synthesized by the liquid phase method are excellent in that the raw material composition can be easily made uniform. In the liquid phase method, a solution raw material containing a predetermined amount of an alkaline earth metal element, a rare earth element, an aluminum element, a titanium element, and other elements is applied to an appropriate substrate, and the coating film is directly fired and sintered. By forming the body, the microwave dielectric composition in the form of a thin film can be manufactured in a state of being integrated with the base material.
[0048]
In the gas phase method, for example, a CVD (Chemical Vapor Deposition) method, a gas phase decomposition method using a liquid material, or the like can be applied. The vapor phase method is particularly advantageous when a thin-film microwave dielectric composition is directly formed on a substrate, or when a powder material having high crystallinity is prepared.
[0049]
The average particle size of these powder raw materials can be appropriately changed depending on the composition of the powder raw materials, the form of the final product, and the like, but is usually about 0.05 to 10 μm, preferably 0.1 to 8 μm, and more preferably 0.2 to 8 μm. The thickness may be up to 6 μm.
[0050]
Next, molding is performed by mixing powder raw materials. The molding method in this case is not particularly limited. For example, a pressure molding method using a mold, a cold isostatic pressing method (CIP molding (Cold Isostatic Pressing)), an extrusion molding method, a doctor blade tape molding method, and a casting method A molding method widely used in the field of ceramics and powder metallurgy such as a molding method can be used. The molding conditions may be adjusted within the molding conditions in each of the known molding methods, and it is particularly preferable to appropriately set the molding conditions so as to increase the uniform filling property of the powder.
[0051]
Subsequently, the obtained molded body is fired. The sintering method is not particularly limited, and a known sintering method such as a well-known Jojo sintering method and a pressure sintering method can be employed. The firing temperature of the present invention can be appropriately changed in the range of 1300 to 1500 ° C. according to the type and composition of the powder raw material as described above.
[0052]
The greatest feature of the present invention is that it can be fired at a temperature approximately 200 ° C. lower than the conventional firing temperature of 1500 to 1700 ° C. According to the inventors' detailed follow-up tests, the firing temperature of the conventional composition is actually 1550 ° C. or more, and the firing temperature of the present invention can be reduced by about 250 ° C. from the conventional firing temperature. In addition, the cost can be remarkably reduced in a heating heater, a heat-resistant furnace, energy consumption, and the like, and at the same time, the mass production performance can be improved by shortening the cooling time.
[0053]
However, even in the present invention, if the firing temperature is too low, the sintered body is in a non-sintered state, and the denseness as a dielectric cannot be obtained, and the excellent microwave dielectric properties that the sintered body should have cannot be obtained. If the firing temperature is too high, a change in the composition or a change in the microstructure due to grain growth occurs, so not only is it difficult to control the physical properties of the sintered body, but also the energy consumption increases or the production efficiency decreases. is there.
[0054]
The firing atmosphere is not particularly limited, and can be selected, for example, according to the necessity of the reduction treatment. For example, when a reduction treatment is required at the same time as firing, a reducing atmosphere may be used. In the case where the reduction treatment is not required, it may be fired at normal pressure in the atmosphere, for example. Firing in an oxygen atmosphere is effective in controlling the oxygen partial pressure when control of the composition, microstructure, and the like of the sintered body is particularly required. In the present invention, the oxygen partial pressure is not particularly limited as long as it is an oxidizing atmosphere.
[0055]
In the present invention, the molded body may be calcined, if necessary, prior to the above-mentioned firing (main firing), even with the powder raw material synthesized by any of the methods. The calcining temperature may be appropriately determined at a temperature lower than the firing temperature of the compact. The calcining atmosphere can also be set appropriately as in the case of the above-described firing.
[0056]
The crystal structure of the prepared microwave dielectric composition was analyzed by a powder X-ray diffraction method. The fired sample was pulverized with a mortar until the particle size became about 20 μm or less, and the powder sample was filled in a glass holder and measured. The measurement used Geigerflex @ RAD-B \ System made by Rigaku Denki. The result of the measurement was used to identify the phase using an ICDD card.
[0057]
Next, the lattice constant of the sample was refined by the WPPD method. In this case, data measured with X'pert System manufactured by Philips was used. WPPD is an abbreviation of Whole-Powder-Pattern Decomposition Method, which derives information on diffraction angle, integrated intensity, and half-width at once by pattern fitting the entire experimental powder diffraction data and the theoretical powder diffraction pattern at the same time. It is. Thus, the crystal structure of the prepared sample was analyzed.
[0058]
Further, the relative dielectric constant ε of the produced gallium-doped dielectric ceramic composition_r, Quality factor Q · f and temperature coefficient τ_fWas measured by the Hakki & Coleman method (referred to as “Research Report on Standardization of Performance Evaluation of New Ceramic Materials”, published by Japan Fine Ceramics Association in March 1992). The measurement was performed at a frequency of 4 to 5 GHz. Temperature coefficient τ_fWas determined from a change in resonance frequency in a temperature range of 20 to 80 ° C.
[0059]
The gallium-doped dielectric porcelain composition according to the present invention contains ZnO, NiO, SnO as a main component and 100 parts by weight of the main component.₂, Co₃O₄, MnCO₃, ZrO₂, WO₃, Li₂CO₃, Rb₂CO₃, Sc₂O₃, V₂O₃, CuO, SiO₂, MgCO₃, Cr₂O₃, B₂O₃, GeO₂, Sb₂O₅, Nb₂O₅, Ta₂O₅And the like may be added.
[0060]
Although the amount of addition depends on the added component, it can be added at a ratio of 10 parts by weight or less based on 100 parts by weight of the main component. By adding these oxides, the microwave dielectric characteristics can be freely changed, and a gallium-doped dielectric ceramic composition having desired characteristics can be obtained.
[0061]
The shape or size of the gallium-doped dielectric ceramic composition of the present invention is not particularly limited, and may be appropriately set according to the shape of the final product. For example, it can be used in the form of a granular material, a pellet, a film, a film, a sheet, a bar, a tube, a cone, or any other shape.
[0062]
The gallium-doped dielectric porcelain composition according to the present invention sintered in a specific shape suitable for a resonator is called a dielectric porcelain. The shape of the dielectric porcelain may be any shape as long as it is easy to resonate according to the purpose. For example, there are various shapes such as a cylinder, a prism, and a cylinder.
[0063]
This dielectric porcelain is arranged between the input and output terminals to form a dielectric resonator. Electromagnetic field coupling occurs between the input terminal and the dielectric porcelain and between the dielectric porcelain and the output terminal, and only microwaves having a specific frequency resonate due to the standing wave characteristics formed in the dielectric porcelain.
[0064]
By arranging this dielectric resonator in a receiving device, it is possible to selectively receive only microwaves having a specific frequency from electromagnetic waves having many frequencies, and by arranging this dielectric resonator in a transmitting device, noise is reduced. It becomes possible to remove noise from the contained signal and transmit only microwaves having a specific frequency from the antenna. By arranging the dielectric resonator of the present invention in the transmitting device and the receiving device as described above, it is possible to provide a microwave communication device having excellent resonance characteristics. This microwave communication device is a concept including both a mobile communication device and a base station device.
[0065]
【Example】
<Example 1: [Nd (Al_1-yGa_y) O₃] ・ [CaTiO₃]>
A feature of the first embodiment is that Nd is used as a rare earth element. As a starting material, a high purity rare earth oxide (Nd₂O₃), Aluminum oxide (Al₂O₃), Gallium oxide (Ga₂O₃), Titanium oxide (TiO)₂) And calcium carbonate (CaCO₃) Was weighed so as to have the composition shown in Table 2. Ethanol is added to the weighed raw materials in an alumina mortar and wet-mixed for 2 hours. The mixed raw material is calcined at 1000 ° C. for 2 hours to form a composition.
[0066]
To the calcined sample, 1 to 2 mL of a 1 to 3 wt% aqueous solution of PVA (polyvinyl alcohol) is added as a binder and mixed in an alumina mortar. This was passed through a 300 μm sieve and granulated. 2.35 g of the granulated sample was packed in a 12 mmφ mold, and uniaxially pressed at a pressure of 10 MPa for 1 minute to prepare a columnar pellet. The pellets were vacuum-packed and subjected to CIP (cold isostatic pressing, cold isostatic pressing) at a hydrostatic pressure of 100 MPa. The sample was molded by the CIP.
[0067]
The sample after CIP was degreased at 300 ° C. for 2 hours in a Kanthal furnace under an air atmosphere. Thereafter, each sample was baked stepwise at a temperature in the range of 1300 to 1600 ° C for 4 hours. The pellets were molded such that the ratio of the diameter d to the height h was d: h = 2: 1 due to restrictions from the Hakki and Coleman method.
[0068]
When measuring microwave dielectric properties, the surface of the pellet was mirror polished to reduce microwave loss. The pellets were coated with electron wax, adhered to the device, and polished using a # 800 SiC abrasive. Finishing was done with No. 2000 emery paper.
[0069]
The polished sample was ultrasonically cleaned with acetone. Finally, a heat treatment was performed at 900 ° C. for 2 hours in a Kanthal furnace under an atmospheric pressure atmosphere in order to remove electron wax and fat for bonding. At the time of measuring the microwave dielectric characteristics, a cotton swab was used to prevent the attachment of fat and dirt.
[0070]
The composition formulas of the sample molded in this way are the following three types.
(1) NdGaO₃・ CaTiO₃
(2) Nd (Al_0.95Ga_0.05) O₃・ CaTiO₃
(3) Nd (Al_0.99Ga_0.01) O₃・ CaTiO₃
[0071]
The sinterability of these samples was checked, and if the sinterability was good, the microwave dielectric properties were measured. That is, the relative dielectric constant ε_r, Quality factor Q · f and temperature coefficient τ_fWas measured for the three samples. The measuring method is the above-mentioned Hakki and Coleman method. The data is summarized in Table 2.
[0072]
As shown in Table 2, when the added amount y of Ga is 0.01, the minimum temperature at which the sintering is successfully performed is 1500 ° C., but when y = 0.05, the sintering temperature is reduced to 1450 ° C. However, it was found that the minimum temperature of sintering dropped to 1320 ° C. when y = 1 (all the amount of Al was replaced by Ga). Moreover, it was proved that the microwave dielectric properties were good even at the sintering temperature. Thus, it was proved that the addition of Ga reduced the firing temperature. Here, the sintering temperature at which good sintering was obtained is called the sintering temperature, and the sintering temperature is used in the same meaning hereinafter.
[0073]
In Table 2, the over-sintered state refers to a state in which the firing temperature is too high, the shape of the molded body changes and the components evaporate, pores are generated inside the molded body, and the molded body is not densified. Means The unsintered state and the sintered state are as described above, and together with the oversintered state, the same meaning will be used hereinafter.
[0074]
<Example 2: [La (Al_1-yGa_y) O₃] ・ [CaTiO₃]>
The feature of the second embodiment is that La is used as a rare earth element. As a starting material, a high-purity rare earth oxide (La₂O₃), Aluminum oxide (Al₂O₃), Gallium oxide (Ga₂O₃), Titanium oxide (TiO)₂) And calcium carbonate (CaCO₃) Was weighed so as to have the composition shown in Table 3.
[0075]
The weighed raw materials are calcined at 1000 ° C. for 2 hours to form a composition. Thereafter, granulation was performed in the same procedure as in Example 1, and molding was performed by applying CIP (low-temperature hydrostatic pressure). Finally, each sample was fired stepwise at 1300 to 1600 ° C. for 4 hours.
[0076]
The composition formulas of the sample thus formed are the following five types.
(1) LaGaO₃・ CaTiO₃
(2) La (Al_0.50Ga_0.50) O₃・ CaTiO₃
(3) La (Al_0.90Ga_0.10) O₃・ CaTiO₃
(4) La (Al_0.95Ga_0.05) O₃・ CaTiO₃
(5) La (Al_0.99Ga_0.01) O₃・ CaTiO₃
[0077]
The sinterability of these samples was checked, and if the sinterability was good, the microwave dielectric properties were measured. Relative permittivity ε_r, Quality factor Q · f and temperature coefficient τ_fWas measured for the five samples. Temperature coefficient τ_fIs measured only for some samples. The measured microwave dielectric properties were found to be good. The data is summarized in Table 3.
[0078]
As is clear from Table 3, when the amount y of Ga added is 0.01, the minimum sintering temperature is 1500 ° C., but when y = 0.05, the sintering temperature drops to 1450 ° C. At y = 0.10, the temperature dropped to 1350 ° C. However, it was found that when y = 0.50 and y = 1 (all the amount of Al was replaced by Ga), the minimum temperature of sintering was 1350 ° C., which gave the same result as y = 0.10.
[0079]
The reason why the sintering temperature did not decrease even when y became larger than 0.10 is unknown at present. However, the sintering temperature decreases as y decreases, and the sintering temperature may have a saturation characteristic. What is important is that the sintering temperature never changes to an increasing trend as the addition rate y increases.
[0080]
<Example 3: [Sm (Al_1-yGa_y) O₃] ・ [CaTiO₃]>
A feature of the third embodiment is that Sm is used as a rare earth element. As a starting material, a high-purity rare earth oxide (Sm₂O₃), Aluminum oxide (Al₂O₃), Gallium oxide (Ga₂O₃), Titanium oxide (TiO)₂) And calcium carbonate (CaCO₃) Was weighed so as to have the composition shown in Table 4.
[0081]
The raw materials are calcined at 1000 ° C. for 2 hours to form a composition. Thereafter, granulation was performed in the same procedure as in Example 1, and molding was performed by applying CIP (low-temperature hydrostatic pressure). Finally, each sample was fired stepwise at 1300 to 1600 ° C. for 4 hours.
[0082]
The composition formula of the sample molded in this way is the following two types.
(1) Sm (Al_0.95Ga_0.05) O₃・ CaTiO₃
(2) Sm (Al_0.99Ga_0.01) O₃・ CaTiO₃
[0083]
The sinterability of these samples was checked, and if the sinterability was good, the microwave dielectric properties were measured. Relative permittivity ε_rAnd the quality factor Q · f were measured for the two types of samples. Temperature coefficient τ_fWas not measured. The data is summarized in Table 4.
[0084]
As is clear from Table 4, when the amount y of Ga added is 0.01, the minimum sintering temperature is 1500 ° C., but when y = 0.05, the sintering temperature drops to 1450 ° C. This tendency is exactly the same as when Nd (Example 1) and La (Example 2) are used as the rare earth elements. In addition, it was found that the sintered dielectric exhibited good microwave dielectric properties.
[0085]
<Example 4: [(Nd_0.5La_0.5) (Al_1-yGa_y) O₃] ・ [CaTiO₃]>
The feature of Example 4 is that two kinds of rare earth elements are added. As raw materials, two kinds of high-purity rare earth oxides (Nd₂O₃, La₂O₃), Aluminum oxide (Al₂O₃), Gallium oxide (Ga₂O₃), Titanium oxide (TiO)₂) And calcium carbonate (CaCO₃) Was weighed so as to have the composition shown in Table 5.
[0086]
The raw materials are calcined at 1000 ° C. for 2 hours to form a composition. Thereafter, granulation was performed in the same procedure as in Example 1, and molding was performed by applying CIP (low-temperature hydrostatic pressure). Finally, each sample was fired stepwise at 1300 to 1600 ° C. for 4 hours.
[0087]
The composition formula of the sample molded in this way is the following two types.
(1) (Nd_0.5La_0.5) (Al_0.95Ga_0.05) O₃・ CaTiO₃
(2) (Nd_0.5La_0.5) (Al_0.99Ga_0.01) O₃・ CaTiO₃
[0088]
The sinterability of these samples was checked, and if the sinterability was good, the microwave dielectric properties were measured. Relative permittivity ε_rAnd the quality factor Q · f were measured for the two types of samples. Temperature coefficient τ_fWas not measured. The data is summarized in Table 5. The measured microwave dielectric properties were found to be good.
[0089]
As is clear from Table 5, when the added amount y of Ga is 0.01, the minimum sintering temperature is 1500 ° C., and the minimum sintering temperature at y = 0.05 is also 1500 ° C. As can be seen from Table 1, when no Ga was added, the minimum sintering temperature was 1550 ° C. On the other hand, when Ga is added, the minimum sintering temperature decreases by 50 ° C. to 1500 ° C.
[0090]
Although the sintering temperature decreases when Ga is added, the amount of temperature decrease (in this case, 50 ° C.) is substantially the same at y = 0.01 and y = 0.05. Whether this result is general for binary systems of rare earth elements is unknown at this stage.
[0091]
<Example 5: [La_{1 + x}(Al_0.99Ga_0.01)_1-xO₃] ・ CaTiO₃]
[La (Al_0.99Ga_0.01) O₃] [Ca_{1 + z}Ti_1-zO₃]>
The feature of Example 5 is that the composition of the present invention is directed to a composition in which the amount of the rare earth element and Al / Ga is different, and a composition in which the amount of Ca and Ti are different. As a raw material, a high-purity rare earth oxide (La₂O₃), Aluminum oxide (Al₂O₃), Gallium oxide (Ga₂O₃), Titanium oxide (TiO)₂) And calcium carbonate (CaCO₃) Was weighed so as to have the composition shown in Table 6.
[0092]
The raw materials are calcined at 1000 ° C. for 2 hours to form a composition. Thereafter, granulation was performed in the same procedure as in Example 1, and molding was performed by applying CIP (low-temperature hydrostatic pressure). Finally, each sample was fired stepwise at 1300 to 1600 ° C. for 4 hours.
[0093]
The composition formulas of the samples molded in this way are the following four types.
(1) La_1.02(Al_0.99Ga_0.01)_0.98O₃・ CaTiO₃
(2) La_0.98(Al_0.99Ga_0.01)_1.02O₃・ CaTiO₃
(3) La (Al_0.99Ga_0.01) O₃・ Ca_1.02Ti_0.98O₃
(4) La (Al_0.99Ga_0.01) O₃・ Ca_0.98Ti_1.02O₃
[0094]
The sinterability of these samples was checked, and if the sinterability was good, the microwave dielectric properties were measured. Relative permittivity ε_rAnd the quality factor Q · f were measured for the four types of samples. Temperature coefficient τ_fWas not measured. The data is summarized in Table 6. The obtained microwave dielectric properties were good.
[0095]
As is clear from Table 6, the amount y of Ga added was 0.01 for all four types of compositions, and the lowest sintering temperature was common to 1500 ° C. The difference in the amount of addition was represented by x and z. In these four compositions, x = z = 0.02, which was extremely small. The reason why the minimum sintering temperature is in common with 1500 ° C. is whether the Ga addition amount y in the four compositions is in common with 0.01 or because of the very small amount of x = z = 0.02. No conclusions can be drawn at this stage.
[0096]
<Example 6: [La (Al_0.99Ga_0.01) O₃]: [CaTiO₃] = M: n>
The feature of the sixth embodiment is that La (Al_0.99Ga_0.01) O₃And CaTiO₃Is shifted from 50:50 by weight. As a raw material, a high-purity rare earth oxide (La₂O₃), Aluminum oxide (Al₂O₃), Gallium oxide (Ga₂O₃), Titanium oxide (TiO)₂) And calcium carbonate (CaCO₃) Was weighed so as to have the composition shown in Table 7.
[0097]
The raw materials are calcined at 1000 ° C. for 2 hours to form a composition. Thereafter, granulation was performed in the same procedure as in Example 1, and molding was performed by applying CIP (low-temperature hydrostatic pressure). Finally, each sample was fired stepwise at 1300 to 1600 ° C. for 4 hours.
[0098]
The composition formula of the sample molded in this way is the following two types.
(1) La (Al_0.99Ga_0.01) O₃: CaTiO₃= 55: 45
(2) La (Al_0.99Ga_0.01) O₃: CaTiO₃= 45: 55
[0099]
The sinterability of these samples was checked, and if the sinterability was good, the microwave dielectric properties were measured. Relative permittivity ε_rAnd the quality factor Q · f were measured for the two types of samples. Temperature coefficient τ_fWas not measured. The data is summarized in Table 7.
[0100]
As is clear from Table 7, the amount y of Ga added was 0.01 for both of the two types of compositions, and it was found that the minimum sintering temperature was common to 1500 ° C. The minimum sintering temperature was the same whether (m, n) giving (%, n) giving (%) was (55, 45) or (45, 55). The microwave dielectric characteristics at 1500 ° C. were good, and it was found that the sintering temperature could be lower than before.
[0101]
FIG. 1 is a perspective view of various embodiments of the dielectric porcelain according to the present invention. The gallium-doped dielectric porcelain composition obtained in the present invention, which is formed into a resonator, is called a dielectric porcelain. (1A) shows a cylindrical dielectric porcelain 2, (1B) shows a cylindrical dielectric porcelain 2, and (1C) shows a rectangular parallelepiped dielectric porcelain 2.
[0102]
FIG. 2 is a model diagram showing an example of the dielectric resonator according to the present invention. The dielectric resonator is formed by interposing the above-described dielectric porcelain between the input terminal and the output terminal, and can be sealed in a metal case to prevent noise from being mixed.
[0103]
As shown in (2A), the dielectric resonator 4 has the dielectric ceramic 2 disposed in the center of the substrate 6, and the input terminal 8 and the output terminal 10 arranged so as to sandwich the dielectric ceramic 2. An electromagnetic field couples between the input terminal 8 and the dielectric porcelain 2 and between the dielectric porcelain 2 and the output terminal 10. Further, due to the shape of the dielectric porcelain 2, the dielectric porcelain 2 is formed so as to resonate with microwaves in a specific frequency range.
[0104]
FIG. 2B is an equivalent circuit diagram of the dielectric resonator 4. Microwaves are input by the electromagnetic field coupling 12 between the coils, only microwaves having a specific frequency are selected by the dielectric ceramic 2, and the selected microwaves are output by the electromagnetic field coupling 14 between the coils.
[0105]
The dielectric resonator of the present invention is not limited to the above-described structure, and various dielectric resonators such as a TE mode dielectric resonator, a TM mode dielectric resonator, and a TEM mode dielectric resonator can be used. It can be expanded to.
[0106]
FIG. 3 is a schematic configuration diagram of a base station communication device incorporating the dielectric resonator according to the present invention. A base station communication device is a type of microwave communication device together with a mobile communication device. The base station communication device 20 is a device that wirelessly connects the upper line network 18 and one or more mobile communication devices 40 by microwave.
[0107]
The base station communication device 20 includes a modulator 22, a transmission device 24, and a transmission resonator 26 as a transmission circuit, and includes a reception resonator 32, a reception device 34, and a demodulator 36 as a reception circuit. I have. Further, it has an antenna duplexer 28 and an antenna 30 as a device for both transmission and reception.
[0108]
The above-described dielectric resonator 4 is disposed as a transmission resonator 26 and a reception resonator 32. The transmitting resonator 26 is provided in the transmitting device 24, and the receiving resonator 32 is provided in the receiving device 34.
[0109]
Upon receiving a base signal such as an audio signal from the upper line network 18, the modulator 22 modulates the microwave signal in order to load the base signal onto a microwave signal serving as a carrier. The modulated microwave signal is processed by the transmission device 24, and after removing unnecessary signals such as noise by the transmission resonator 26, the modulated microwave is transmitted from the antenna 30 through the antenna duplexer 28 in the direction of arrow a. Is done.
[0110]
The mobile communication device 40 receives the modulated microwave with the antenna 42, and performs two-way communication such as conversation. The modulated microwave from the mobile communication device 40 is transmitted from the antenna 42 in the direction of arrow b, and the modulated microwave is received by the antenna 30 of the base station communication device 20.
[0111]
The antenna 30 receives carrier waves of various frequencies propagating in space. Only microwaves in a specific frequency region are selected by the receiving resonator 32 and input to the receiving device 34. The demodulator 36 separates a base signal such as an audio signal from the selectively received microwave signal, and the base signal is transmitted to the higher-level network 18.
[0112]
FIG. 4 is a schematic configuration diagram of a mobile communication device incorporating the dielectric resonator according to the present invention. The mobile communication device 40 includes an antenna 42, a battery 44, a control unit 46, a synchronizer 48, an operation unit 50 such as an alphanumeric button, a microphone 52, a transmission device 54, a transmission resonator 56, a reception resonator 58, It comprises a receiving device 60 and a speaker 62.
[0113]
When the antenna 42 receives the modulated microwave coming from the direction of the arrow a, only the microwave signal in the specific frequency region is selected by the receiving resonator 58, and the selected microwave signal is sent to the receiving device 60. An audio signal (base signal) is extracted from the modulated microwave signal, and is uttered by the speaker 62 to have a conversation.
[0114]
When the owner of the mobile communication device 40 speaks to the microphone 52, the audio signal is sent to the transmission device 54, and a modulation process for putting the audio signal on the microwave signal is performed. The modulated microwave signal is sent to the transmitting resonator 56, where noise and the like are removed, and only the modulated microwave in the specific frequency region is transmitted from the antenna 42 in the direction of the arrow b.
[0115]
In the present invention, various unavoidable impurities may be present as long as the characteristics are not significantly deteriorated. In addition, various oxides may be added or the composition may deviate as long as the dielectric properties are not adversely affected. Further, similar effects may be exerted by low-temperature firing, but these cases are basically included in the technical scope of the present invention.
[0116]
As described above, the present invention is not limited to the above-described embodiment, and various modifications and design changes without departing from the technical idea of the present invention are included in the technical scope. Nor.
[0117]
[Table 1]

[0118]
[Table 2]

[0119]
[Table 3]

[0120]
[Table 4]

[0121]
[Table 5]

[0122]
[Table 6]

[0123]
[Table 7]

[0124]
【The invention's effect】
According to the first invention, the composition formula of the dielectric ceramic composition is [(Ln)_{1 + x}(Al_1-yGa_y)_1-xO₃] [(M)_{1 + z}Ti_1-zO₃And the range of the Ga addition rate y is set to 0 <y ≦ 1, so that by adding Ga to Al, the sintering temperature of the dielectric ceramic composition was successfully reduced for the first time. As the additive amount of Ga is gradually increased, the sintering temperature gradually decreases, and when the additive amount of Ga is maximized, that is, when Al is completely replaced with Ga, the sintering temperature is reduced to the minimum temperature. Can be done. Therefore, by adding Ga, we succeeded in lowering the firing temperature, lowering the price of exothermic heaters, heat-resistant furnaces, and energy consumption, and realizing lower product prices. Can be improved.
[0125]
According to the second invention, when various oxides are added to the gallium-doped dielectric porcelain composition, a microwave dielectric having a relative dielectric constant (εr), a quality coefficient (Q · f) and a temperature coefficient (τf) is obtained. The body properties can be freely changed, and a gallium-doped dielectric ceramic composition having desired properties can be realized. When these oxides are not added, the only way to change the dielectric properties is to adjust the molar ratio or wt% of the components, but changing the composition ratio requires a complicated work procedure. On the other hand, there is the simplicity that the microwave dielectric characteristics can be adjusted only by adding the oxide. At the same time, the addition of this oxide makes it possible to finely adjust the firing temperature.
[0126]
According to the third aspect, the rare earth element Ln is not only a single rare earth element, but also can be formed by mixing two kinds of rare earth elements at an appropriate ratio. By mixing two kinds of rare earth elements, diversity can be introduced into the dielectric ceramic composition, and the microwave dielectric characteristics and the firing temperature can be adjusted.
[0127]
According to the fourth aspect, the alkaline earth element M is not only a single alkaline earth element, but also can be constituted by mixing two alkaline earth elements at an appropriate ratio. As with the rare earth elements, by mixing two alkaline earth elements, diversity can be introduced into the dielectric ceramic composition, and the microwave dielectric characteristics and the firing temperature can be adjusted.
[0128]
According to the fifth aspect, the gallium-doped dielectric porcelain composition is formed into an appropriate shape and fired to provide a dielectric porcelain having a desired shape. By arranging this dielectric porcelain between the input and output terminals, it is possible to realize an inexpensive dielectric resonator that resonates with microwaves in a specific frequency region according to the shape of the dielectric porcelain.
[0129]
According to the sixth aspect of the present invention, by arranging the inexpensive dielectric resonator in the transmitting device and the receiving device, it is possible to contribute to a reduction in the price of the microwave communication device. This can contribute to further spread of the communication system.
[Brief description of the drawings]
FIG. 1 is a perspective view of various embodiments of a dielectric porcelain according to the present invention.
FIG. 2 is a model diagram showing an example of a dielectric resonator according to the present invention.
FIG. 3 is a schematic configuration diagram of a base station communication device incorporating a dielectric resonator according to the present invention.
FIG. 4 is a schematic configuration diagram of a mobile communication device incorporating a dielectric resonator according to the present invention.
[Explanation of symbols]
2 is a dielectric ceramic, 4 is a dielectric resonator, 6 is a substrate, 8 is an input terminal, 10 is an output terminal, 12 is electromagnetic field coupling, 14 is electromagnetic field coupling, 18 is an upper line network, and 20 is base station communication. Device, 22 is a modulator, 24 is a transmitting device, 26 is a transmitting resonator, 28 is an antenna duplexer, 30 is an antenna, 32 is a receiving resonator, 34 is a receiving device, 36 is a demodulator, and 40 is a mobile unit. Communication device, 42, antenna, 44, battery, 46, control unit, 48, synchronizer, 50, operation unit, 52, microphone, 54, transmitting device, 56, transmitting resonator, 58, receiving resonator, 60 Is a receiving device, and 62 is a speaker.

Claims (6)

Including one or more rare earth elements (Ln), Al, Ga, one or more alkaline earth metal elements (M) and Ti, [(Ln) _{1 + x} (Al _1-y G _ay ) _1-x O ₃ ] Is a dielectric ceramic composition comprising m (wt%) and [(M) _{1 + z} Ti _1-z O ₃ ] being n (wt%), and the composition formula is [(Ln) _{1 + x} (Al _1-y) G _ay ) _1-x O ₃ ] · [(M) _{1 + z} Ti _1-z O ₃ ]
-0.5 ≦ x ≦ 0.5
0 <y ≦ 1
−0.5 ≦ z ≦ 0.5
m + n = 100
A gallium-doped dielectric porcelain composition, characterized by satisfying the following. The gallium-added dielectric ceramic composition according to claim 1 as a main component, and ZnO, NiO, SnO ₂ , Co ₃ O ₄ , MnCO ₃ , ZrO ₂ , WO ₃ , and Li based on 100 parts by weight of the main component. ₂ CO ₃ , Rb ₂ CO ₃ , Sc ₂ O ₃ , V ₂ O ₃ , CuO, SiO ₂ , MgCO ₃ , Cr ₂ O ₃ , B ₂ O ₃ , GeO ₂ , Sb ₂ O ₅ , Nb ₂ O ₅ and A gallium-doped dielectric porcelain composition characterized by adding at least 10 parts by weight of one or more additives selected from the group consisting of Ta ₂ O ₅ . The rare earth element (Ln) is composed of a combination of two kinds of rare earth elements LA and LB. In the composition formula, (Ln) is represented by (LA _1−s LB _s ), and 0 <s <1. The gallium-doped dielectric porcelain composition according to claim 1. The alkaline earth metal element (M) is constituted by combining two kinds of alkaline earth metal elements MA and MB, (M) is represented by (MA _1−t MB _t ), and 0 <t <1. The gallium-doped dielectric ceramic composition according to claim 1 or 2, wherein A dielectric porcelain is formed from the gallium-doped dielectric porcelain composition according to claim 1, 2, 3 or 4, and the dielectric porcelain is arranged between input and output terminals so as to perform resonance operation. Characteristic dielectric resonator. A transmission circuit and / or a reception circuit, wherein the dielectric resonator according to claim 5 is built in a transmission circuit and / or a reception circuit. A microwave communication device for performing two-way communication with a microwave.

Images