JP4303369B2 - Dielectric ceramic composition and dielectric resonator using the same - Google Patents

Description

【００３４】
実施例２
出発原料として高純度の酸化ランタン（Ｌａ₂ Ｏ₃ ）、酸化アルミニウム（Ａｌ₂ Ｏ₃ ）、炭酸ストロンチウム（ＳｒＣＯ₃ ）、酸化チタン（ＴｉＯ₂ ）の各粉末を用いて、それらを表２となるように秤量後、純水を加え、混合原料の平均粒径が２．０μｍ以下となるまで、ミルにより約２０時間湿式混合、粉砕を行った。
【００３５】
この混合物を乾燥後、１２００℃で２時間仮焼した。この仮焼粉１００重量部に対し、ＭｎＯ₂ 、ＷＯ₃ 、ＭｏＯ₃ を表２に示す量を添加後、純水を加え、混合原料の平均粒径が２．０μｍ以下となるまで、ミルにより約２０時間湿式混合、粉砕を行った。乾燥後、さらに約５重量％のバインダーを加えてから造粒した。
【００３６】
得られた粉末を約１ｔｏｎ／ｃｍ² の圧力で円板状に成形し、１５００〜１７００℃の温度で２時間大気中において焼成した。
【００３７】
得られた磁器の円板部を平面研磨し、アセトン中で超音波洗浄し、１５０℃で１時間乾燥した後、円柱共振器法により測定周波数３．５〜４．５ＧＨｚで比誘電率εｒ、Ｑ値、共振周波数の温度係数τｆを測定した。Ｑ値は、マイクロ波誘電体において一般に成立するＱ値×測定周波数ｆ＝一定の関係から１ＧＨｚでのＱ値に換算した。
【００３８】
共振周波数の温度係数τｆは、−４０〜８５℃の範囲で測定した。
【００３９】
【表２】

【００４０】
表１、２からも明らかなように、本発明の範囲外の誘電体では、比誘電率又はＱ値が低いか、あるいはτｆの絶対値が３０を超えていた。
【００４１】
これらに対し、本発明により得られた誘電体は、Ｑ値が７００００以上、τｆが±３０（ｐｐｍ／℃）以内の優れた誘電特性が得られることがわかった。
【００４２】
【発明の効果】
以上詳述した通り、本発明によれば、金属元素として少なくともＬａ，Ａｌ，Ｓｒ，Ｔｉを含有し、これらの金属元素のモル比による組成式をａＬａ₂ Ｏ₃ ・ｂＡｌ₂ Ｏ₃ ・ｃＳｒＯ・ｄＴｉＯ₂ と表した時、前記ａ、ｂ、ｃ、ｄが、
０．０９５４≦ａ≦０．１５９６
０．０９５４≦ｂ≦０．１５９６
０．３９０３≦ｃ≦０．５５１６
０．２１２９≦ｄ≦０．３５４６
０．８１８１≦ｂ／ａ≦１．２２２２
かつ０．４２８５≦ｄ／ｃ＜０．７５００
（ただし ａ＋ｂ＋ｃ＋ｄ＝１）
と表される組成範囲内に調整することによって、また、この主成分にＭｎ、Ｗ、Ｍｏを添加することで、高周波領域において比誘電率εｒが３０付近で高いＱ値を有するとともに、共振周波数の温度係数τｆを０付近に、安定して制御することができた。
【００４３】
また、Ｔａ、Ｎｂ等を構成元素とする従来の誘電体磁器組成物に比べてより安価な材料を提供することができる。さらに、Ｔａ、Ｎｂで構成されている既存材は、高温で、長時間焼成温度を保持しなければ、結晶の規則化が起こらない為、焼成コストがかかっていたが、本発明の材料であれば、焼成温度の保持時間も２〜１０時間ですみ、焼成コストが大幅に削減できる。
【００４４】
これにより、本発明の誘電体磁器組成物は、例えば、自動車電話、コードレステレホン、パーソナル無線機、衛星放送受信機等の装置において、マイクロ波やミリ波領域において使用される共振器用材料やＭＩＣ用誘電体基板材料、誘電体導波線路、誘電体アンテナ、その他の各種電子部品等に好適に適用することができる。
【図面の簡単な説明】
【図１】本発明の誘電体共振器を示す説明図である。
【符号の説明】
１．金属ケ−ス
２．入力端子
３．出力端子
４．誘電体磁器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dielectric ceramic composition having a high Q value in a high-frequency region such as microwaves and millimeter waves, and various resonator materials used in a high-frequency region such as microwaves and millimeter waves. The present invention relates to a dielectric ceramic composition that can be used for dielectric substrate materials for MIC (Monolithic IC), dielectric waveguide materials, multilayer ceramic capacitors, and the like.
[0002]
[Prior art]
Dielectric ceramics are widely used in dielectric resonators, dielectric substrates for MICs, waveguides, and the like in high frequency regions such as microwaves and millimeter waves. The required characteristics are as follows: (1) Since the wavelength is shortened to 1 / εr ^1/2 in the dielectric, the relative permittivity is large to meet the demand for miniaturization. (2) Dielectric loss at high frequency The above three characteristics are mainly cited as follows: small Q, that is, high Q value, (3) small change in resonance frequency with temperature, that is, low temperature dependence of relative permittivity and stability. It is done.
[0003]
Conventionally, as this kind of dielectric ceramic, for example, Ba (Mg _1/3 Ta _2/3 ) O ₃ -based material (Japanese Patent Publication No. 59-23048), Ba (Zn _1/3 Ta _2/3 ) O ₃ Material (Japanese Patent Publication No. 59-48484), Ba (Zn _1/3 Nb _2/3 ) O ₃ type material (Japanese Patent Publication No. 53-35453), Ba (Mg _1/3 Nb _2/3 ) O ₃ type material An oxide porcelain material such as JP-A-53-35345 is known.
[0004]
[Problems to be solved by the invention]
However, recently, the frequency range to be used has become higher, and a material having a higher Q value is required in response to this. In view of this, the conventional dielectric ceramic composition has a small unloaded Q and a low relative dielectric constant, so that the shape when the resonator is made large, and the temperature coefficient is large. There are some problems in using in the frequency band, and there are many inconveniences in actual use. In addition, these materials have high firing temperatures and high firing costs, and the materials themselves are expensive because they contain Ta and Nb, so there is a problem that they are expensive and difficult to reach the market. .
[0005]
The present invention has been devised in view of the above-described drawbacks, and is a dielectric ceramic made of a material having a large relative permittivity, a high Q value, a small and stable temperature dependence of the relative permittivity, and a low cost. A composition is provided.
[0006]
[Means for Solving the Problems]
As a result of repeated studies on the above problems, the present inventor contains at least La, Al, Sr, and Ti as metal elements, and by adjusting these to a specific range, the relative permittivity is large and the high Q value is high. Thus, it has been found that a dielectric ceramic composition having a low temperature dependence of the relative dielectric constant and being stable can be obtained.
[0007]
That is, the dielectric ceramic composition of the present invention contains at least La, Al, Sr, and Ti as metal elements, and the composition formula based on the molar ratio of these metal elements is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO. When expressed as dTiO ₂ , the a, b, c, d are
0.0954 ≦ a ≦ 0.1596
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c <0.7500
(However, a + b + c + d = 1)
It is in the composition range represented as follows.
[0008]
Further, at least La, Al, Sr and Ti are contained as metal elements, and the composition formula by the molar ratio of these metal elements is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO.dTiO _2.
Where a, b, c and d are 0.0954 ≦ a ≦ 0.1596.
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c ≦ 0.7500
(However, a + b + c + d = 1)
A main component which satisfies, with respect to the main component 100 parts by weight, Mn below 3.0 parts by weight MnO ₂ terms, or W and WO ₃ in terms of 5.0 parts by weight or less, or Mo and calculated as MoO ₃ And 5.0 parts by weight or less.
[0009]
Further, at least La, Al, Sr, and Ti are contained as metal elements, and a composition formula according to the molar ratio of these metal elements is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO.dTiO _2.
Where a, b, c, d are 0.0954 ≦ a ≦ 0.1596.
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c ≦ 0.7500
(However, a + b + c + d = 1)
Mn, W, and Mo are contained in an amount of 6.0 parts by weight or less in terms of MnO ₂ , WO ₃ , and MnO ₃ with respect to 100 parts by weight of the main component satisfying the above.
[0010]
The dielectric resonator according to the present invention includes a dielectric ceramic disposed between a pair of input / output terminals, wherein the dielectric ceramic is operated by electromagnetic field coupling. It consists of a porcelain composition.
[0011]
With the above configuration, the present invention has a large relative dielectric constant εr, a high Q value, a small absolute value of the temperature coefficient τf of the resonance frequency, and can stably control the values of εr, Q, τf, Without using a material containing expensive elements such as Ta and Nb, an inexpensive dielectric ceramic composition and dielectric resonator can be obtained.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The dielectric ceramic composition for high frequency according to the present invention is a material containing a composite oxide containing at least La, Al, Sr and Ti as metal components as a main component composition. The composition formula by the molar ratio of the metal element in the main component composition is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO.dTiO _2.
Where a, b, c and d are 0.0954 ≦ a ≦ 0.1596.
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c <0.7500
(However, a + b + c + d = 1)
It is important that The reason why a, b, c, and d are limited to the above range is as follows.
[0013]
That is, 0.0954 ≦ a ≦ 0.1596 is set. When a <0.0954, the temperature coefficient τf of the resonance frequency increases positively, and the absolute value of the temperature coefficient τf of the resonance frequency increases 30. This is because when a> 0.1596, τf becomes negatively large and its absolute value exceeds 30. In particular, the range of 0.1211 ≦ a ≦ 0.1369 is preferable.
[0014]
In addition, 0.0954 ≦ b ≦ 0.1596 is set. When b <0.0954, the temperature coefficient τf of the resonance frequency becomes positively large, the absolute value of τf greatly exceeds 30, and b> 0 In the case of .1596, the resonance frequency τf becomes negatively large and the absolute value of τf exceeds 30. b is particularly preferably in the range of 0.1211 ≦ b ≦ 0.1369.
[0015]
Further, 0.3903 ≦ c ≦ 0.5516 is set because, when c <0.3903, the temperature coefficient τf of the resonance frequency becomes negative and the absolute value of τf greatly exceeds 30. is there. This is because when c> 0.5516, the temperature coefficient τf of the resonance frequency becomes positive and its absolute value exceeds 30. In particular, the range of 0.4284 ≦ c ≦ 0.4698 is preferable.
[0016]
The reason why 0.2129 ≦ d ≦ 0.3546 is set is that when d <0.2129, the temperature coefficient τf of the resonance frequency becomes negatively large and the absolute value thereof exceeds 30. This is because when d> 0.3546, the temperature coefficient τf of the resonance frequency increases positively and its absolute value exceeds 30. In particular, 0.2759 ≦ d ≦ 0.3107 is preferable.
[0017]
Furthermore, 0.8181 ≦ b / a ≦ 1.2222 is set when Q / b is smaller than 40000 when b / a <0.8181 or when b / a> 1.2222. Because it does. In particular, 0.9602 ≦ b / a ≦ 1.1744 is preferable.
[0018]
In addition, 0.4285 ≦ d / c <0.7500 is set because the specific dielectric constant εr is small when d / c <0.4285, and when d / c ≧ 0.7500, This is because τf increases positively and its absolute value exceeds 30. In particular, 0.6129 ≦ d / c ≦ 0.6949 is preferable.
[0019]
Furthermore, 0.8181 ≦ b / a ≦ 1.2222 and 0.4285 ≦ d / c <0.7500 are set because τf can be adjusted in the vicinity of 0 in this range.
[0020]
Further, the present invention can improve only the Q value without changing εr and τf by containing 3.0 parts by weight or less Mn in terms of MnO _{2 with} respect to 100 parts by weight of the main component. It can be done. The reason why the Mn content is 3.0 parts by weight or less in terms of MnO ₂ is that the Q value becomes extremely small when the content exceeds 3.0 parts by weight. Furthermore, in order to exhibit the above-described effects, the amount of Mn is preferably 0.01 to 3.0 parts by weight in terms of MnO ₂ , and particularly preferably 0.1 to 1.0 parts by weight.
[0021]
The present invention is also relative to the 100 parts by weight of the main component, by the inclusion of 5.0 parts by weight or less W in terms _of WO _3, it is possible to improve the Q value. The reason why the W content is 5.0 parts by weight in terms of WO ₃ is that the Q value becomes extremely small when the content exceeds 5.0 parts by weight. Further, in order to achieve the above-described effects, the amount of W is preferably 0.01 to 5.0 parts by weight in terms of WO ₃ , and particularly preferably 0.1 to 2.0 parts by weight.
[0022]
The present invention is also relative to the 100 parts by weight of the main component, by the inclusion of 5.0 parts by weight or less Mo calculated as MoO _3, it is possible to improve the Q value. The reason why the Mo content is 5.0 parts by weight or less in terms of MoO ₃ is that the Q value becomes extremely small when the content exceeds 5.0 parts by weight. Furthermore, in order to achieve the above-described effects, Mo is preferably 0.01 to 5.0 parts by weight in terms of MoO ₃ , and particularly preferably 0.1 to 2.0 parts by weight.
[0023]
In addition, each component of said Mn, W, and Mo can contain 1 type, or 2 or more types, respectively. When all of these components are contained, the Q value can be improved by containing a total of 6.0 parts by weight or less in terms of MnO ₂ , WO ₃ , and MoO _{3 with} respect to 100 parts by weight of the main component. . The reason why the content of Mn, W, and Mo is 6.0 parts by weight or less in terms of MnO ₂ , WO ₃ , and MnO ₃ is that the Q value becomes extremely small when the content exceeds 6.0 parts by weight. Furthermore, in order to achieve the above-described effects, it is desirable that the amount be 0.01 to 6.0 parts by weight, particularly 0.1 to 2.0 parts by weight in terms of MnO ₂ , WO ₃ , and MnO _3. desirable.
[0024]
The dielectric ceramic composition of the present invention is produced, for example, as follows. Using high-purity lanthanum oxide, aluminum oxide, strontium carbonate, and titanium oxide powders as starting materials, weighed to a desired ratio, added pure water, and the average particle size of the mixed materials was 2.0 μm Wet mixing and pulverization are performed in a mill using zirconia balls or the like for 10 to 30 hours until the following. This mixture is dried, calcined at 1000 to 1300 ° C. for 2 to 10 hours, further granulated after adding 5% by weight of a binder, and the resulting powder is subjected to desired molding means such as a mold press, It can be obtained by firing in the atmosphere at a temperature of 1500 to 1700 ° C. for 1 to 10 hours after molding into an arbitrary shape by an isostatic pressing, extrusion molding or the like.
[0025]
In the dielectric ceramic composition of the present invention, the starting materials for La, Al, Sr, and Ti are heat treatments in an oxidizing atmosphere such as carbonates, acetates, nitrates and hydroxides in addition to oxides. A compound capable of generating an oxide may be used.
[0026]
In the present invention, Ca, Zr, Si, Ba, etc. may be mixed as inevitable impurities in the porcelain, but these may be mixed in about 0.1% by weight in terms of oxides, respectively or in total. There is no problem in characteristics.
[0027]
The dielectric ceramic composition of the present invention is most useful for a dielectric resonator. As a dielectric resonator of the present invention, a schematic diagram of the TE mode type dielectric resonator of FIG. 1 is shown. In the resonator shown in FIG. 1, an input terminal 2 and an output terminal 3 are formed on both sides of a metal case 1, and a dielectric ceramic 4 having the above-described composition is disposed between the terminals 2 and 3. Composed. As described above, the TE mode type dielectric resonator receives microwaves from the input terminal 2, and the microwaves are confined in the dielectric ceramic 4 by reflection at the boundary between the dielectric ceramic 4 and the free space. Resonance occurs at a specific frequency.
[0028]
This signal is electromagnetically coupled to the output terminal 3 and output. Although not shown, the present invention is applied to coaxial resonators, stripline resonators, TM mode dielectric ceramic resonators, and other resonators using the dielectric ceramic composition TEM mode of the present invention. Of course, it is also good.
[0029]
【Example】
Example 1
Table 1 shows powders of high purity lanthanum oxide (La ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), strontium carbonate (SrCO ₃ ), and titanium oxide (TiO ₂ ) as starting materials. Thus, after weighing, pure water was added, and wet mixing and pulverization were performed for about 20 hours with a mill until the average particle size of the mixed raw material became 2.0 μm or less. Depending on the type of ball of the mill and various other conditions, ZrO ₂ , SiO ₂ , and other rare earth element impurities may be contained in total of 1% by weight or less.
[0030]
This mixture is dried, calcined at 1200 ° C. for 2 hours, further granulated after adding about 5% by weight of binder, and the resulting powder is formed into a disk shape at a pressure of about 1 ton / cm ² , Firing was performed in the air at a temperature of 1500 to 1700 ° C. for 2 hours.
[0031]
The obtained porcelain disk portion was flat-polished, ultrasonically cleaned in acetone, dried at 150 ° C. for 1 hour, and then measured by a cylindrical resonator method at a measurement frequency of 3.5 to 4.5 GHz and a relative dielectric constant εr, The Q value and the temperature coefficient τf of the resonance frequency were measured. The Q value was converted to a Q value at 1 GHz from the relationship of Q value x measurement frequency f = generally established in microwave dielectrics.
[0032]
The temperature coefficient τf of the resonance frequency was measured in the range of −40 to 85 ° C.
[0033]
[Table 1]

[0034]
Example 2
Using each powder of high purity lanthanum oxide (La ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), strontium carbonate (SrCO ₃ ) and titanium oxide (TiO ₂ ) as starting materials, they are shown in Table 2. Thus, after weighing, pure water was added, and wet mixing and pulverization were performed for about 20 hours with a mill until the average particle size of the mixed raw material became 2.0 μm or less.
[0035]
The mixture was dried and calcined at 1200 ° C. for 2 hours. To this calcined powder 100 parts by weight, after the addition amount indicating the MnO _2, WO _3, MoO ₃ in Table 2, the pure water added, until the average particle diameter of the mixed raw material is 2.0μm or less, the mill Wet mixing and pulverization were performed for about 20 hours. After drying, the mixture was further granulated after adding about 5% by weight of a binder.
[0036]
The obtained powder was formed into a disk shape at a pressure of about 1 ton / cm ² and baked in the atmosphere at a temperature of 1500 to 1700 ° C. for 2 hours.
[0037]
The obtained porcelain disk portion was flat-polished, ultrasonically cleaned in acetone, dried at 150 ° C. for 1 hour, and then measured by a cylindrical resonator method at a measurement frequency of 3.5 to 4.5 GHz and a relative dielectric constant εr, The Q value and the temperature coefficient τf of the resonance frequency were measured. The Q value was converted to a Q value at 1 GHz from the relationship of Q value x measurement frequency f = generally established in microwave dielectrics.
[0038]
The temperature coefficient τf of the resonance frequency was measured in the range of −40 to 85 ° C.
[0039]
[Table 2]

[0040]
As is clear from Tables 1 and 2, in dielectrics outside the scope of the present invention, the relative permittivity or Q value was low, or the absolute value of τf exceeded 30.
[0041]
On the other hand, it has been found that the dielectric obtained by the present invention can obtain excellent dielectric characteristics having a Q value of 70,000 or more and τf within ± 30 (ppm / ° C.).
[0042]
【The invention's effect】
As described above in detail, according to the present invention, at least La, Al, Sr, and Ti are contained as metal elements, and the composition formula based on the molar ratio of these metal elements is expressed as aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO. When expressed as dTiO ₂ , the a, b, c, d are
0.0954 ≦ a ≦ 0.1596
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
And 0.4285 ≦ d / c <0.7500
(However, a + b + c + d = 1)
And by adding Mn, W, and Mo to this main component, the relative permittivity εr has a high Q value near 30 in the high frequency region, and the resonance frequency. It was possible to stably control the temperature coefficient τf in the vicinity of 0.
[0043]
Moreover, a cheaper material can be provided compared with the conventional dielectric ceramic composition which uses Ta, Nb, etc. as a constituent element. Furthermore, the existing materials composed of Ta and Nb are high in temperature, and unless the firing temperature is maintained for a long time, crystal ordering does not occur. For example, the holding time of the baking temperature is only 2 to 10 hours, and the baking cost can be greatly reduced.
[0044]
As a result, the dielectric ceramic composition of the present invention can be used, for example, for resonator materials and MICs used in microwave and millimeter wave regions in devices such as automobile telephones, cordless telephones, personal radios, and satellite broadcast receivers. The present invention can be suitably applied to dielectric substrate materials, dielectric waveguide lines, dielectric antennas, and other various electronic components.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a dielectric resonator according to the present invention.
[Explanation of symbols]
1. Metal case 2. Input terminal 3. Output terminal 4. Dielectric porcelain

Claims (4)

It contains at least La, Al, Sr, and Ti as metal elements, and the composition formula according to the molar ratio of these metal elements is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO.dTiO _2.
Where a, b, c, and d are 0.0954 ≦ a ≦ 0.1596.
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c <0.7500
(However, a + b + c + d = 1)
A dielectric ceramic composition characterized by being in the range. It contains at least La, Al, Sr, and Ti as metal elements, and the composition formula according to the molar ratio of these metal elements is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO.dTiO _2.
Where a, b, c, and d are 0.0954 ≦ a ≦ 0.1596.
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c ≦ 0.7500
(However, a + b + c + d = 1)
Mn is 3.0 parts by weight or less in terms of MnO ₂ , or W is 5.0 parts by weight or less in terms of WO ₃ , or Mo is in terms of MoO ₃ with respect to 100 parts by weight of the main component satisfying A dielectric ceramic composition comprising 5.0 parts by weight or less. It contains at least La, Al, Sr, and Ti as metal elements, and the composition formula according to the molar ratio of these metal elements is aLa ₂ O ₃ .bAl ₂ O ₃ .cSrO.dTiO _2.
Where a, b, c and d are 0.0954 ≦ a ≦ 0.1596.
0.0954 ≦ b ≦ 0.1596
0.3903 ≦ c ≦ 0.5516
0.2129 ≦ d ≦ 0.3546
0.8181 ≦ b / a ≦ 1.2222
0.4285 ≦ d / c ≦ 0.7500
(However, a + b + c + d = 1)
A dielectric ceramic characterized by containing Mn, W and Mo in a total amount of 6.0 parts by weight or less in terms of MnO ₂ , WO ₃ and MoO ₃ with respect to 100 parts by weight of the main ingredient satisfying Composition. A resonant medium comprising the dielectric ceramic composition according to any one of claims 1 to 4 is disposed between a pair of input / output terminals, and a high frequency signal is applied between the input / output terminals to resonate at a desired frequency. A dielectric resonator characterized by the above.

Images