JP2003249803A - Dielectric resonator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric resonator having a new structure to be expected an improvement of the Q characteristics and the temperature characteristics, and capable of controlling spurious characteristics. <P>SOLUTION: The dielectric resonator using a dielectric as medium newly introduces an inner structure divided by prescribed distance in addition to a predetermined external structure being held as a whole. The prescribed distance is desirably one which is capable of strongly and mutually coupling between neighboring parts, constituting the internal structure by evanescent electromagnetic field, and the division is desirably one of planar division, annular division, or radial division. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator widely used in electric and electronic circuits, and more particularly to a novel dielectric resonator having an internal structure.

[0002]

2. Description of the Related Art Resonators are widely used in electric and electronic circuits, and are electric and electronic parts that help these circuits to fulfill a predetermined function. Generally, the characteristics required for a resonator are as follows: Although it depends on the application, the resonance mode is not excessively crowded and the desired mode can be selectively excited (good spurious characteristics), high temperature stability, low loss (high Q value), good nonlinear characteristics and distortion characteristics Inexpensive, small shape and weight,
And so on. In particular, the characteristics required for a dielectric resonator that uses a dielectric material that is often used in high-frequency circuits are common in spurious characteristics, temperature stability, and low loss.
Depending on the application, high permittivity is required for downsizing, and low distortion characteristics are required for handling high power. Various dielectric resonators with excellent characteristics have been developed to meet these requirements, but as a matter of course, no matter what characteristics are taken, the requirements from circuit engineers cannot be stopped, so they are said to be perfect. Is far from.

In view of such a situation, the present inventor can first freely control the temperature characteristics and the mode arrangement,
For the purpose of providing a resonator in which the resonator characteristics can be expected to be significantly improved, the wavelength of the target electromagnetic wave is approximately 1 /
A resonator using an artificial medium in which dielectric particles or the like having a size of 10 or less are used as unit particles and the unit particles are arranged homogeneously or nonhomogeneously in another matrix medium has been proposed (Japanese Patent Application No. 2001-1780).
No. 09). This invention provides a resonator using an artificial medium to which a macroscopic constitutive relation can be applied by arranging a large number of unit particles sufficiently smaller than the wavelength of the target electromagnetic wave so that they are sufficiently close to each other. It is a technology that allows you to freely control temperature characteristics and mode allocation, making the most of the characteristics of various selections and combinations.
It does not provide a resonator having an internal structure configured by dividing a medium to which a macroscopic constitutive relation can be applied.

As a prior art related to a resonator having an internal structure, the current distribution on the strip conductor of the strip resonator becomes very large at the end, and this current concentration increases the conductor loss and increases the conductor Q (Qc). It is known to lower the level, and a proposal to split the strip conductor has been made (RRMa
nsour, et al: Feasibility and commercial validity
issues for high-power output multiplexers for spac
e applications, IEEETrans. Microwave Theory Tech.,
Vol.48, pp.1199-1208, July 2000), it was expected that the deviation of the current distribution would be mitigated by dividing the strip conductor (RECollin: Foundation for microwave e.
ngineering, Mc.Graw Hill, p.165, 1992).

Further, Japanese Patent Laid-Open No. 2001-330572 discloses a cavity for an electron spin resonance device, which is provided with a spherical cavity narrowed in a nonmagnetic block and a microwave input / output hole from the cavity. In the resonator, a technique of dividing and / or joining the nonmagnetic block on a plane parallel to the microwave current flowing through the inner wall of the cavity is disclosed. This conventional technology uses a cavity resonator that is expected to have an extremely large Q value in theoretical calculation.
It is an object of the present invention to provide a technique that can be easily manufactured while preventing a decrease in the Q value by achieving a high degree of smoothness on the inner wall surface of the cavity and ensuring a smooth flow of the surface current of the microwave. Further, JP 2001-251110 A discloses that
A resonator in which an electrode is provided on a dielectric substrate and a slot-like opening is provided in the electrode for the purpose of improving the electromagnetic field confinement property in the opening of the electrode and suppressing the current concentration to reduce the conductor loss There is disclosed a resonator in which a pattern for dividing at least a part of the slot width of the slot-shaped opening is formed in the slot-shaped opening. This prior art is
By narrowing the slot width to improve the confinement of the electromagnetic field, and forming a structure in which a plurality of slot resonators divided into electrode patterns are arranged in parallel and making the currents in opposite directions close to each other, the electrode pattern part There is almost no conductor loss at, and only the conductor loss at the edge portions on both sides remains.

None of these prior arts provides a resonator having an internal structure formed by dividing a medium to which a macroscopic constitutive relational expression can be applied with a predetermined gap.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned situation, and has a novel structure in which the spurious characteristics can be controlled and the dielectric resonance having a novel structure in which the Q characteristics and the temperature characteristics can be expected to be improved. The purpose is to provide a container.

[0008]

In order to solve the above problems, the invention of claim 1 is a dielectric resonator using a dielectric as a medium, wherein the dielectric as a whole has a predetermined external structure. Is substantially held, and a dielectric resonator having an internal structure divided by a predetermined gap is provided.

A second aspect of the present invention is an invention according to a preferred embodiment of a predetermined gap constituting the internal structure, wherein the predetermined gap is defined by adjacent parts constituting the internal structure,
A dielectric resonator having a gap to the extent that they are strongly coupled to each other by an evanescent electromagnetic field. The invention according to claim 3 is further characterized in that the predetermined gap is approximately 10 minutes of the maximum outer dimension of the dielectric resonator. It is a dielectric resonator having a value of 1 or less.

A fourth aspect of the present invention is an invention relating to a mode of division constituting the internal structure, wherein the division is a division that does not substantially disturb an electric field distribution and / or a magnetic field distribution of a specific mode. On the contrary, the invention of claim 5 is a body resonator, and conversely, the division is performed by the electric field distribution of a specific mode and / or
Alternatively, the invention is a dielectric resonator in which the magnetic field distribution is disturbed, and the invention of claim 6 is a dielectric resonator in which the division is any one of plate-shaped division, annular division, and radial division.

A seventh aspect of the present invention relates to a form of a member of a component forming the internal structure, wherein the divided internal structure is provided with a plurality of components having different relative dielectric constants with a predetermined gap. Alternatively, the invention is a dielectric resonator having an internal structure arranged without providing the divided internal structure, wherein two kinds of parts having different relative dielectric constants are provided with a predetermined gap. Alternatively, it is a dielectric resonator having an internal structure which is alternately arranged without being provided.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Generally, a resonator has its characteristics determined by the material (element) used and its structure, and this is a fact common to all circuit elements, not limited to the resonator.
The structure referred to here is a concept that determines the interaction and relationship between elements, and in the resonator, electromagnetic boundary conditions are determined by determining the structure. For example, the resonance frequency, which is the most important attribute of a resonator, corresponds to a specific resonance mode (electromagnetic field distribution) determined by boundary conditions. This structure is usually a so-called “outer shape”, and is referred to as an external structure in the present invention. That is, the external structure referred to in the present invention is
It means the overall outline for obtaining the desired predetermined resonator characteristics.

On the other hand, the greatest feature of the present invention is that in a dielectric resonator using a dielectric as a medium, an internal structure divided by a predetermined gap while generally maintaining a predetermined external structure as a whole. The structure is newly introduced.
That is, the greatest feature of the present invention is the "outer shape" of the dielectric resonator.
That is, the multiplicity of the structure having the external structure and the internal structure obtained by dividing the external structure, more precisely, the multi-layered structure. It should be noted that the present invention can be implemented as a dielectric resonator having an internal structure in which it is further hierarchized and has a multi-tiered structure such as a fractal.

By providing the internal structure, it becomes possible to improve the other predetermined characteristics while maintaining the desired predetermined characteristics of the dielectric resonator, or to improve the desired predetermined characteristics. For example, when a dielectric resonator that resonates at a predetermined frequency is divided so as not to disturb the electromagnetic field distribution (and also the electric field distribution) of that mode, the difference in mode is almost synonymous with the difference in electromagnetic field distribution. Yes, the division means to disturb the electromagnetic field distribution of other modes without fail. In other words, such division ideally makes it possible to fabricate a dielectric resonator having extremely excellent spurious characteristics that resonates only in a specific mode. On the contrary, it is possible to utilize other characteristics obtained by performing the division that actively disturbs the electromagnetic field distribution of a specific mode. The term "division that does not disturb the electromagnetic field distribution" as used in the present invention means that the electric field distribution and / or the magnetic field distribution of a specific mode should not be disturbed as much as possible among the electromagnetic field distribution that has an internal structure and an external structure. For example, the division is performed along a plane that is substantially parallel to the lines of electric force of a specific mode. In addition, the term “disturbing the electromagnetic field distribution” as used in the present invention is performed by disturbing the electric field distribution and / or the magnetic field distribution of a specific mode as much as possible, of the electromagnetic field distribution having an internal structure and having an external structure. For example, the division is performed along a plane that is substantially perpendicular to the lines of electric force of a specific mode.

Further, by such division, as shown in the above-mentioned prior art, it becomes possible to reduce the concentration of the current distribution on the conductor at the end portion and reduce the conductor loss.
The Q characteristic can be improved. Furthermore, various internal structures are possible, and improvement in temperature characteristics can be expected.

The predetermined intervals forming the internal structure generally hold a predetermined external structure as a whole, and one dielectric resonator is formed as a whole, and for the purpose of the present invention, adjacent parts forming the internal structure are formed. However, the gap is preferably such that they are strongly coupled to each other by the evanescent electromagnetic field, and further, the gap is preferably about 1/10 or less of the maximum outer dimension of the dielectric resonator.

The form of division which constitutes the internal structure of the present invention is not particularly limited to the present invention, but it is preferably any of plate division, annular division or radial division. Although it is possible to use a plate-like, annular or radial shape and an internal structure in which these are laminated, there is a drawback that the manufacturing cost increases.

Next, the form of the members of the parts constituting the internal structure will be described. In the dielectric resonator of the present invention, the divided internal structure may be composed of all parts of the same member, but for example, a plurality of parts having different relative dielectric constants may be provided with or without a predetermined gap. It can be implemented as an arranged internal structure, or can be implemented as an internal structure in which two types of components having different relative dielectric constants are alternately arranged with or without a predetermined gap. By having an internal structure in which two types of parts having different relative permittivities are alternately arranged with or without a predetermined gap, mechanical stability can be achieved, and the permittivity is small and the Q value is high. In addition to lowering the loss by utilizing the energy concentration in the component parts, it is possible to realize the improvement of the overall temperature characteristic by utilizing the difference in the dielectric constant temperature characteristic.

As will be apparent from the above description, the present invention does not require any limitation or restriction on a specific member to be used or a specific method for producing a dielectric resonator. A member of a known technique, a method of manufacturing a dielectric resonator, or the like can be applied, and a newly developed member, a method of manufacturing a dielectric resonator, or the like can also be applied.

As described above, the dielectric resonator of the present invention is a dielectric resonator in which a predetermined external structure is generally held as a whole and a divided internal structure is provided with a predetermined gap. , The present invention, by providing an internal structure, it is possible to improve other characteristics while securing the desired predetermined characteristics, or it is possible to improve the desired predetermined characteristics, spurious characteristics of It is possible to provide a dielectric resonator having a novel structure that can be controlled and can be expected to improve Q characteristics and temperature characteristics. Such a dielectric resonator can provide electric / electronic parts that can effectively respond to the social demand for radio wave service that is rapidly increasing in the fields of satellite communication, mobile communication, etc., and its social significance is large.

[0021]

Embodiments of the present invention will be described in detail below with reference to the drawings. It should be noted that the dielectric resonator is of course configured to include input / output terminals, electrodes, etc., but in the following examples, explanation will be given centering on the dielectric having the internal structure, which is the greatest feature of the invention Illustrations and explanations of attached input / output terminals, electrodes, etc. are omitted.

A dielectric resonator using high dielectric constant ceramics is a general-purpose resonator that plays an important role as a constituent element of a low-loss small microwave BPF. In this embodiment, the external structure of the dielectric is used. Will be described by taking a cylindrical dielectric resonator as an example. Figure 1 is a conceptual diagram showing the electromagnetic field distribution of this dielectric resonator. (A) is the lowest order mode (TE ₀₁ δ)
(B) to (d) are the electromagnetic field distributions of the subsequent higher modes.

The dividing method for forming the internal structure of the present invention on the dielectric of the cylindrical dielectric resonator having the electromagnetic field distribution as shown in FIG. 1 differs depending on the purpose, but in the present embodiment, The division that does not substantially disturb the electric field distribution and / or magnetic field distribution of a specific mode will be described. That is,
For example, when this specific mode is the lowest order mode in FIG. 1 (a), by performing division so as to keep the equivalent permittivity or permeability high only in the direction of the electric force line or magnetic force line of the lowest order mode, , TE ₀₁ δ mode can be selectively survived, and other unnecessary modes can be suppressed. However, since the dielectric does not have a magnetic effect and the magnetic permeability cannot be controlled, specifically, division is performed in consideration of equivalent dielectric constant control. In the structure in which the dielectric sheets are stacked, the equivalent dielectric constant decreases in the thickness direction, which is similar to the decrease in the overall capacitance when capacitors are connected in series. On the contrary, the fact that the permittivity is kept high in the direction parallel to the thickness corresponds to the parallel connection of capacitors.

As a preferred division method of the dielectric division parallel to the electric flux lines of FIG. 1A, there are, for example, (a) flat division and (b) annular division of FIG. In addition, in FIG.
Another typical division method, (c) fan division (radial division) is also shown.

Next, the results of the flat plate-shaped division and the ring-shaped division calculated using commercially available high-frequency electromagnetic field analysis software HFSS (manufactured by Ansoft) will be described. The dielectric material assumed in the calculation is a high-dielectric-constant ceramic having an outer structure of a cylindrical shape having a diameter of 6.0 mm and a height of 1.8 mm and a relative dielectric constant of 38. Regarding the division, the flat plate-shaped division is equal division in which the plate thickness and the gap (0.4 mm) are the same, and the annular division is the ring thickness and gap (0.4 mm) are the same. It is a division.

FIG. 3 relates to flat plate division and annular division,
It is a diagram showing an example of the relationship between the number of divisions and the resonance frequency,
The frequency of the TE ₀₁ δ mode is almost unchanged, and the other higher-order modes are shown to shift to the high frequency side with division.
That is, FIG. 3 shows that according to the present embodiment, it is possible to fabricate a dielectric resonator having an excellent spurious characteristic that suppresses higher-order modes and resonates only in the lowest-order mode TE ₀₁ δ. Is.

FIG. 4 shows the two modes shown in FIG. 1, that is, the lowest order mode (a) TE in the case of flat plate-shaped two divisions.
FIG. 3 is a diagram showing an electromagnetic field distribution of ₀₁ δ mode and (b) HE ₁₁ δ mode which is a typical higher order mode. Figure 4 shows the lowest TE ₀₁ δ
The electromagnetic field distribution of the mode is the same as the distribution without division (Fig. 1 (a)), whereas the distribution of the HE ₁₁ δ mode, which is a higher order mode, is significantly different from the distribution without division (Fig. 1 (b)). , Which is the cause of the higher-order mode frequency shift due to the division.

Table 1 relates to flat plate division and annular division,
It is shown by comparing Qc without division and with four divisions.

[0029]

[Table 1]

Table 1 compares Qc in the case of no division and in the case of division, and shows the modes in which the lines of electric force are perpendicular to the plane of division (HE ₁₁ δ and TM ₀₁ δ of flat plate division, EH of annular division). ₁₁ δ and TM
_{In 01} δ), it is shown that Qc greatly increases due to the division. This is because, for example, as shown in the electric field distribution of the HE ₁₁ δ mode of FIG. 4 (b) (lower part of FIG. 4 (b)), the electric field is concentrated in the gap which is almost a lossless region, and as a result, , Qc
Is the one that has risen. According to the present invention, this result also utilizes other characteristics (in this embodiment, the increase of Qc in the higher order mode) obtained by positively dividing the electric field distribution and / or the magnetic field distribution. It shows that you can also do.

The dielectric resonator of this embodiment has the same structure as the conventional dielectric resonator, except that the dielectric has an internal structure in which the dielectric is divided with a predetermined gap. A member similar to that of the dielectric resonator can be used and manufactured by the same manufacturing method. Although the embodiments of the present invention have been described above, it is obvious that various changes may be made in the form and details without departing from the spirit and scope of the present invention defined in the claims.

For example, in the present embodiment, the dielectric resonator having a cylindrical external structure has been described as an example, but it is also possible to implement it in the form of, for example, a rectangle or an elliptic cylinder. It does not limit the invention in any way. In addition, in the present embodiment, regarding the flat plate-shaped division and the circular ring-shaped division, the flat plate-shaped division is an equal division in which the plate thickness and the gap are the same, and the circular ring-shaped division is the division in which the ring thickness and the gap are the same. Although described, the thickness and / or the gap may be made uneven.

Furthermore, the number of divisions, the shape of the divided parts, the interval between adjacent divided parts, and the shape thereof are parameters to be optimized in accordance with the characteristics of the target dielectric resonator, and are appropriately selected. It goes without saying that it can be carried out.

[0034]

Industrial Applicability The dielectric resonator of the present invention is a dielectric resonator in which a predetermined external structure is generally held as a whole and a divided internal structure is provided with a predetermined gap provided between the dielectric resonator and the present invention. By providing the internal structure, it is possible to improve the other predetermined characteristics while securing the desired predetermined characteristics, or to improve the desired predetermined characteristics, so that the spurious characteristics can be controlled. Therefore, there is an effect that it is possible to provide a dielectric resonator having a novel structure that can be expected to improve Q characteristics and temperature characteristics.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a general electromagnetic field distribution of a dielectric resonator using a cylindrical dielectric, in which (a) is the electromagnetic field distribution of the lowest order mode (TE ₀₁ δ), (b) to (d) are the electromagnetic field distributions of the subsequent higher modes.

FIG. 2 is a conceptual diagram showing a typical dividing method for forming the internal structure of the present invention on a cylindrical dielectric body, in which (a) is flat plate division, (b) is annular division, (c) is a fan-shaped division.

FIG. 3 is a diagram showing a result of calculation using a high frequency electromagnetic field analysis software HFSS regarding a flat plate-shaped division and an annular division, showing an example of a relationship between the number of divisions and a resonance frequency.

FIG. 4 is a result of calculation using a high-frequency electromagnetic field analysis software HFSS in the case of a plate-shaped two-division, and the two modes shown in FIG. 1, that is, the lowest order mode (a) TE ₀₁ δ mode. FIG. 7 is a diagram showing an electromagnetic field distribution of (b) HE ₁₁ δ mode, which is a typical higher-order mode.

Claims (8)

[Claims] 1. A dielectric resonator using a dielectric as a medium, wherein the dielectric generally holds a predetermined external structure as a whole and has an internal structure divided by a predetermined gap. A dielectric resonator characterized by. 2. The dielectric resonator according to claim 1, wherein the predetermined gap is a gap to such a degree that adjacent components forming the internal structure are strongly coupled to each other by an evanescent electromagnetic field. . 3. The dielectric resonator according to claim 1, wherein the predetermined gap is approximately one-tenth or less of the maximum outer dimension of the dielectric resonator. 4. The dielectric resonance according to claim 1, wherein the division is such that the electric field distribution and / or the magnetic field distribution of a specific mode is not substantially disturbed. vessel. 5. The dielectric resonator according to claim 1, wherein the division is a division that disturbs an electric field distribution and / or a magnetic field distribution of a specific mode. 6. The dielectric resonator according to claim 1, wherein the division is any one of plate division, annular division and radial division. 7. The divided internal structure is an internal structure in which a plurality of parts having different relative dielectric constants are arranged with or without a predetermined gap. The dielectric resonator according to any one of 1. 8. The divided internal structure is an internal structure in which two types of components having different relative dielectric constants are alternately arranged with or without a predetermined gap. The dielectric resonator according to claim 7.