JPH0661714A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To part an undesired adjacent mode from a TE018 mode by selecting a ratio of a height and an outer diameter of a resonator part to be within a specific range. CONSTITUTION:The resonator has a resonator section of a ring shape made of a dielectric ceramic material whose specific dielectric constant is 34 and a support base 2 made of the same material as that of the resonator section 1 and the resonator section 1 and the support base 2 are formed integrally. Then a ratio D/L of the height L to the outer of the resonator section 1 is set to be 0.9-2.3. When the ratio D/L is within the range of 0.9-2.3, a Q0 is 2200 or over, and when the ratio D/L is 0.9 or below or 3.2 or over, the Q0 of the dielectric resonator in the TE018 mode is substantially decreased. Thus, the resonator is operated in the TE018 mode without substantial deterioration in the Q0 without being affected of higher or lower adjacent modes by selecting the size of the resonator section 1 so that the ratio D/L is within the range of 0.9-2.3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a filter in a high frequency band,
The present invention relates to a dielectric resonator used for an oscillator or the like.

[0002]

2. Description of the Related Art Conventionally, as a dielectric resonator of this type, a resonator section made of a dielectric material is usually bonded to a supporting table made of a material different from that of the resonator section by using an adhesive or the like to separate the supporting table. Type, and an integrated type in which the resonator part and the support base are made of the same dielectric material are known, and in any case, the resonator part is connected to the closed casing or cavity bottom wall via the support base. Stuck on top. The former examples of the support-separated type are disclosed in JP-A-59-21101 and JP-A-59-21.
97201, JP 62-97405, and JP 61-
No. 258505, and as a conventional example of the latter dielectric resonator integrated with a support, the one disclosed in Japanese Patent Application No. 1-59573 can be cited. Then, TE in the support base separation type dielectric resonator that uses _01Deruta mode, the dielectric constant of the dielectric material constituting the resonator unit to distance unwanted adjacent mode from the TE _01Deruta mode epsilon is epsilon> When it is 10, the ratio D / L of the height (L) of the resonator part to the outer diameter (D) of the resonator part is about 2.5.
Is designed to be. In addition, the support base integrated dielectric resonator can be designed similarly depending on the size of the cavity.

[0003]

By the way, in the case of a support base integrated type dielectric resonator, since the support base also has a relatively large dielectric constant, the height (L) and the outer diameter (D) of the resonator are set. Even if the ratio D / L with) is designed to be about 2.5 as described above, an unnecessary adjacent mode may be adjacent to the TE _01δ mode, causing a problem in the resonator filter and oscillation function. Even if such an unnecessary adjacent mode is separated from the TE _01δ mode to some extent, if the frequency is adjusted with a metal frequency adjustment plate when adjusting the frequency of the resonator, the unnecessary adjacent mode becomes the TE _01δ mode. When approaching, problems may occur in the filter and oscillation function of the resonator.

Therefore, the present invention solves the problems associated with the conventional support-integrated dielectric resonator that operates in the TE _{01 δ} mode, so that an unnecessary adjacent mode can be moved away from the TE _{01 δ} mode. It is intended to provide a resonator.

[0005]

In order to achieve the above object, a dielectric resonator using the TE _{01 δ} mode according to the present invention has a resonator portion and a support base which are integrally formed. The ratio D / L between the height (L) and the outer diameter (D) is 0.9 to 2.
It is characterized by setting 3. The size of the resonator section is preferably in accordance with the size of the cavity that houses the resonator, and the ratio D / L of the height (L) of the resonator section to the outer diameter (D).
Can be determined within the range of 0.9 to 2.3.

[0006]

In the dielectric resonator according to the present invention, the ratio D / L of the height (L) of the resonator portion to the outer diameter (D) is 0.9 to 2.
By setting to 3, it becomes possible to keep away unnecessary modes adjacent to the TE _{01 δ} mode. When the ratio D / L of the height (L) of the resonator portion to the outer diameter (D) is 0.9 or less, the unnecessary mode on the higher order side approaches the TE _01δ mode, and the resonator Since the distance between the upper end of the cavity and the upper wall of the cavity is reduced, the unloaded Q of the resonator is reduced. On the other hand, when the ratio D / L of the height (L) of the resonator part to the outer diameter (D) is 2.3 or more, TE _01δ
Unnecessary mode on the low order side with respect to the mode comes close to TE _01δ mode, and the distance between the outer diameter of the resonator part and the side wall of the cavity becomes small. Will be reduced. Therefore, by constructing the resonator so that the ratio D / L of the height (L) of the resonator portion to the outer diameter (D) is 0.9 to 2.3, unnecessary resonance mode is achieved without lowering the Q value. _Does not affect the TE _{01 delta} mode.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention. The illustrated dielectric resonator has a ring-shaped resonator part 1 made of a dielectric ceramic material having a relative dielectric constant 34, and the same material as that of the resonator part 1. A support part 2 made of a material, and a resonator part 1
The support base 2 is integrally formed. The resonator portion 1 has an outer diameter (D) of 58 mm and a height (L) of 50 mm, and the support base portion 2 has an outer diameter of 36 mm and a height of 24 mm. An inner hole 3 having an inner diameter of 22.5 mm is formed in the resonator portion 1 and the support base portion 2 along the axis as shown in the drawing. Therefore, in this example, the ratio of the outer diameter (D) to the height (L) of the resonator portion 1 is 58 ÷ 50 = 1.16. The dielectric resonator constructed as described above is fixedly housed in a metal casing having a diameter of 150 mm and a height of 95 mm closed on all four sides, that is, on the bottom wall in the cavity 4 by a suitable fixing means. The resonator portion 1 of the resonator is arranged to be located in the center of the cavity 4. An input coupling conductor loop 5 and an output coupling conductor loop 6 extend from the side wall of the cavity 4 toward the outer side surface of the resonator unit 1, respectively.

In order to determine a preferable range of the ratio of the outer diameter (D) and the height (L) of the resonator portion 1, the cavity 4 having the above dimensions is used, and the outer diameter (D) and the height of the resonator portion 1 are increased. Of three dielectric resonators with different ratios to the height (L), that is, the resonator outer diameter (D) is 62 mm and the height (L) is 37 mm, the D / L is 1.68.
The outer diameter (D) of the resonator part is 65
mm, height (L) 31 mm and D / L of 2.10, and resonator outer diameter (D) 70 mm, height (L)
And a D / L of 2.70 was prepared. The other parts of these three dielectric resonators have the same structure and size as those shown in FIG. The results of measuring the electrical characteristics and unnecessary modes (spurious modes) of these dielectric resonators are shown in FIGS. Note that T
The resonance frequency f ₀ in the E _{01 δ} mode was constant at 849 MHz. FIG. 2 shows the relationship between the spurious mode and the ratio of the outer diameter (D) to the height (L) of the resonator section 1, and f _s represents the resonance frequency in the spurious mode. As can be seen from the graph shown, the D / L ratio is 0.9 to 2.3.
Within the range of, both the high-order side and low-order side adjacent modes are relatively far from the TE _01δ mode, and therefore TE
The substantial effect on _01δ mode is avoided. On the other hand, when the D / L ratio is 0.9 or less, the higher-order side adjacent mode is approaching, and when the D / L ratio is 2.3 or more, the lower-order side adjacent mode is approaching. ₀₁ The influence on the _δ mode occurs. FIG. 3 shows the relationship between the outer diameter (D) and the height (L) of the resonator section 1 and Q ₀ .
When the D / L ratio is in the range of 0.9 to 2.3, Q ₀ is 2200 or more, but when the D / L ratio is 0.9 or less or the D / L ratio is 2.3 or more, TE _{01 δ} mode dielectric The Q _{0 of the} body resonator is substantially reduced. Therefore, from these measurement results, by selecting the dimensions of the resonator part 1 such that the ratio of the outer diameter (D) to the height (L) of the resonator part 1 is within the range of 0.9 to 2.3, TE _{01 δ-} mode dielectric resonator is not affected by adjacent modes on the high-order side or low-order side,
Moreover, it is recognized that the device can be operated without substantially reducing Q ₀ .

By the way, in the illustrated embodiment, the resonator has a structure having an inner hole, but naturally the present invention can be implemented as a solid structure resonator having no inner hole. Further, the dimensions of each part of the resonator portion and the support base and the dimensions of the cavity are not limited to the values shown in the figure, and can be set arbitrarily according to the size of the cavity to be used. Further, although the resonator of the illustrated embodiment is not provided with a hole or member for frequency adjustment in the resonator portion, it is naturally applicable to a resonator provided with such frequency adjusting means.

[0010]

As described above, in the dielectric resonator according to the present invention, the dimensions of the resonator portion of the dielectric resonator are set so that the ratio of the outside diameter to the height is within the range of 0.9 to 2.3. Since it has been decided, even if the resonance frequency adjustment plate made of metal is adjusted to the desired frequency, it is possible to separate the unnecessary mode from the TE _01δ mode so as not to affect it, and as a result,
It is possible to provide a dielectric resonator having good filter and oscillator performance. Further, by dimensioning the resonator portion within the range of the above ratio according to the dimension of the cavity used, it is possible to suppress a substantial decrease in Q ₀ of the resonator.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part showing a support base integrated dielectric resonator according to an embodiment of the present invention.

FIG. 2 is a graph showing a comparative example of changes in the distance between the TE _01δ mode and the adjacent mode with respect to the height / outer diameter ratio of the resonator portion in the dielectric resonator.

FIG. 3 is a graph showing a comparative example of changes in Q ₀ with respect to the height / outer diameter ratio of the resonator section in the dielectric resonator.

[Explanation of symbols]

 1: Resonator part 2: Support part 3: Inner hole 4: Cavity

Claims (2)

[Claims] 1. A resonator portion and a support base portion are integrally formed, and T
In the dielectric resonator using the E _{01 δ} mode, the ratio D / L of the height (L) of the resonator portion to the outer diameter (D) is 0.9 to 2.
3. A dielectric resonator characterized in that the resonator section is configured as 3. 2. The height (L) of the resonator portion and the outer diameter (D) of the resonator portion according to the size of the cavity for housing the resonator.
The dielectric resonator according to claim 1, wherein the resonator portion is dimensioned within a ratio D / L 0.9 to 2.3.