JPH1093312A - Dielectric resonator and resonance frequency adjustment method for the dielectric resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the dielectric resonator by which the resonance frequency is easily adjusted and fine-adjusted and to provide the resonance frequency adjustment method. SOLUTION: A dielectric filter 1 is configured with a dielectric board 2 on the major sides of which electrodes 2a each having three circular openings with a prescribed specific dielectric constant, an input slot line 5a and an output slot line 5b, and electrodes 2b each having three circular openings are arranged so that the respective openings are opposed to each other, and with conductor plates 4a, 4b arranged and fixed to have the dielectric board 2 in between spaced apart from the dielectric board 2 by a prescribed interval, and a dielectric film 6 for resonance frequency adjustment is formed onto the dielectric material exposed through the circular openings of the electrodes 2a. Moreover, the resonance frequency of the resonance areas 3 specified by the openings of the electrodes is adjusted by selecting the shape, the dielectric constant and the amount of the dielectric film 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator used in a microwave band or a millimeter wave band and a method of adjusting the resonance frequency of the dielectric resonator.

[0002]

2. Description of the Related Art In recent years, a large-capacity and high-speed communication system has been demanded in response to a rapid increase in demand for a mobile communication system and multimedia. With such an increase in the amount of information to be communicated, the used resonance frequency band is being expanded from the microwave band to the millimeter wave band. Even in such a millimeter wave band, a conventionally known TE _01δ mode dielectric resonator made of a cylindrical dielectric can be used in the same manner as the microwave band. At this time,
Since the resonance frequency of the TE _01δ mode dielectric resonator is determined by the outer dimensions of the cylindrical dielectric, strict processing accuracy is required.

[0003] When a dielectric filter is constructed by arranging a plurality of TE _01δ mode dielectric resonators in a metal case at predetermined intervals, an input / output means such as a metal loop, a dielectric resonator, Alternatively, since the coupling between the dielectric resonators is determined by the distance between them, it is necessary to arrange them with high positional accuracy. In view of this, the applicant of the present application has proposed in Japanese Patent Application No. 7-62625 a dielectric resonator excellent in processing accuracy and a dielectric filter excellent in positional accuracy, which solves these problems.

FIGS. 5 and 6 show a basic configuration of the dielectric resonator according to the above application. FIG. 5 is a cross-sectional view of the dielectric resonator according to the above-mentioned application, and FIG. 6 is an enlarged perspective view of a dielectric substrate used for the dielectric resonator of the above-mentioned application.

As shown in FIGS. 5 and 6, the dielectric substrate 10
Reference numeral 2 denotes a substrate having a constant relative dielectric constant, and electrodes 102 are formed on both surfaces of the substrate except for a circular opening having a predetermined size.
a and 102b are formed, and the openings on both main surfaces are shown in FIG.
As shown in FIG. Conductor plates 104a, 104b
Are arranged at predetermined intervals from the dielectric substrate 2 so as to sandwich the dielectric substrate 2.

At this time, the electromagnetic field energy is confined in the vicinity of a portion sandwiched between the opposed openings of the electrodes 102a and 102b, so that a resonance region 103 is formed and can be used as a resonator. Therefore, the electrode 102 shown in FIGS.
A dielectric filter can be configured by arranging a plurality of openings a and 102b continuously.

With this structure, the resonance region can be defined by the size of the opening of the electrode, so that a method such as etching can be used at the time of manufacturing, and the dielectric material that reproduces the dimensional accuracy of the resonator with respect to the resonance frequency very accurately A resonator can now be made.

The adjustment of the resonance frequency of such a dielectric resonator is performed by changing the size of the openings of the electrodes formed on both main surfaces of the dielectric substrate constituting the manufactured dielectric resonator. I was going.

[0009]

However, when the size of the opening of the electrode is changed, the electromagnetic field is disturbed depending on the shape of the opening, and unnecessary spurious may be generated.

In the case of a dielectric filter having a plurality of openings, when the size of the openings of the electrodes is changed, the distance between the openings changes, and the degree of coupling between the resonance regions changes. Therefore, the size of the opening of the electrode cannot be simply changed appropriately, and a complicated method of changing the size of the opening while checking the overall filter characteristics has been used.

Further, when the resonance frequency is changed by changing the size of the opening, the resonance frequency cannot be finely adjusted because the change width of the resonance frequency is large.

SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and has as its object to provide a dielectric resonator which can easily and finely adjust the resonance frequency and a method of adjusting the resonance frequency of the dielectric resonator. And

[0013]

Therefore, according to the present invention, an electrode having openings of substantially the same shape on both main surfaces of a dielectric substrate is formed so that the openings face each other. The dielectric substrate is disposed between the first and second conductor plates facing each other at a predetermined distance from the dielectric substrate, and a space between the opposed openings of the dielectric substrate is a resonance region, and A dielectric for adjusting the resonance frequency is attached to the dielectric substrate exposed from the opening.
Thus, the resonance frequency is changed by increasing or decreasing the dielectric for adjusting the resonance frequency, so that the resonance frequency can be easily adjusted.

In the invention according to claim 2, the dielectric for adjusting the resonance frequency is formed in a plurality of islands. Thus, the resonance frequency adjustment can be performed stepwise by removing one or several of the plurality of island-shaped dielectric films collectively.

Further, in the invention according to claim 3, electrodes having openings of substantially the same shape are formed on both main surfaces of the dielectric substrate so that the openings face each other. A method for adjusting the resonance frequency of a dielectric resonator which is disposed between a first and a second conductor plate facing each other at a predetermined distance from a dielectric substrate and has a resonance region between the opposed openings of the dielectric substrate. The resonance frequency is changed by partially attaching a dielectric to the dielectric substrate exposed from the opening of the electrode. Thereby, a predetermined resonance frequency can be adjusted by adjusting the amount or the dielectric constant of the dielectric formed on the dielectric substrate exposed from the opening of the electrode.

Next, in the invention according to claim 4, the resonance frequency is changed by partially removing the dielectric for adjusting the resonance frequency formed on the dielectric substrate exposed from the opening. . Thereby, even when the amount of the dielectric substance is too large or the dielectric constant is too high, the predetermined filter characteristic can be obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described. In the present embodiment, a dielectric filter is used in which a plurality of dielectric resonators described with reference to FIG. 5 are arranged, that is, a plurality of resonance regions are arranged by arranging a plurality of openings of electrodes of a dielectric substrate. Will be explained.

As shown in FIG. 1, the dielectric filter 1 comprises:
Dielectric substrate 2 having electrodes formed on both main surfaces and conductive plates 4a, 4
b.

The dielectric substrate 2 is a substrate having a constant relative dielectric constant. The electrodes 2a and 2b having three circular openings on both main surfaces thereof are arranged such that the openings on both main surfaces face each other. It is arranged and formed. On one main surface side (upper side in FIG. 4) of the dielectric substrate 2, the input slot line 5a is located close to the openings at both ends of the three openings.
And an output slot line 5b.

The conductor plates 4a and 4b are arranged and fixed so as to sandwich the dielectric substrate 2 at a predetermined distance from the dielectric substrate 2 in the vicinity of the opening, and the input slot line 5a and the output slot line 5b Project from the conductor plates 4a and 4b.

A dielectric film 6 for adjusting the resonance frequency is formed on the dielectric substrate exposed from the openings of the electrodes 2a and 2b on one main surface side (upper side in FIG. 4) of the dielectric substrate 2.

The dielectric substrate 2 used for such a dielectric filter 1 is manufactured by the following manufacturing process.

First, as shown in FIG. 2A, a dielectric mother substrate 10 having a predetermined relative permittivity is prepared.

Next, as shown in FIG. 2B, electrodes 10a are formed on both main surfaces of the dielectric mother substrate 10 by a technique such as vapor deposition.
Form 10b.

Further, as shown in FIG. 2C, etching is performed so that a plurality of filter patterns 1a each having two slot lines and three openings are arranged on one main surface side. Then, although not shown, three openings are formed on the other main surface side at positions facing the openings on the one main surface side.

Then, as shown in FIG. 2D, the dielectric substrate 2 is obtained by cutting two slot lines and three openings for each filter pattern 1a.

The dielectric film 6 has a resonance frequency at which, for example, a polyimide resin is changed by spinning on the dielectric exposed from the opening at the stage of FIG. 2C or 2D. It is formed by making a selection according to a predetermined amount and adhering it in a film form. Of course, the deposition method is not limited to spinning, and for example, silicon nitride, silicon oxide, or the like may be deposited by plasma CVD or the like.

Since the dielectric film 6 is formed as described above, the electric field in each resonance region near the opening of the dielectric filter 1 is affected, so that the resonance frequency can be changed for each resonance region. The resonance frequency can be adjusted by adjusting the dielectric constant, thickness, and size of the dielectric film 6.

Next, a second embodiment will be described with reference to FIG. FIG. 3 is an enlarged perspective view of the vicinity of one opening of the electrodes 2a and 2b of the dielectric substrate 2 shown in FIG.

In this embodiment, the dielectric film 6 provided on the dielectric substrate exposed from the opening is burned off by the laser 8. Therefore, even if the dielectric film 6 adheres to a predetermined amount or more, it can be adjusted to a predetermined resonance frequency.

In the present embodiment, the burn-out by the laser 8 is used. However, the present invention is not limited to this, and a method of mechanically shaving or scientifically removing by etching or the like may be used. Any method may be used as long as the dielectric film can be removed. Of course, the removal of the dielectric film in this case also includes substantial removal from the viewpoint of changing the characteristics of the dielectric film.

Next, a third embodiment will be described with reference to FIG. FIG. 4 is an enlarged perspective view of the vicinity of one opening of the electrodes 2a and 2b of the dielectric substrate 3 shown in FIG. 1 as in FIG.

In this embodiment, the dielectric film for adjusting the resonance frequency is formed of a group of a plurality of island-shaped dielectric films 7. By forming such a dielectric film 7, it is possible to completely burn off each of the island-shaped dielectric films 7 when burning off with the laser 8 for adjusting the resonance frequency. Therefore, it is possible to prevent the dielectric film on the periphery of the burned-out dielectric film from being carbonized, thereby preventing the Q of the resonator from being reduced. Moreover, the resonance frequency can be finely adjusted stepwise.

In the first, second, and third embodiments, the dielectric film is formed on the dielectric substrate exposed from the opening of the electrode on one main surface of the dielectric substrate. The present invention is not limited to this, and may be formed on the dielectric substrate exposed from the opening on the other main surface side, or may be formed on both of them.

[0035]

As described above, according to the present invention, since the dielectric film is formed on the dielectric substrate exposed from the opening of the electrode of the dielectric substrate, the dielectric resonance having excellent processing accuracy and positional accuracy is achieved. The resonance frequency of the vessel can be easily adjusted. In a dielectric filter in which a plurality of dielectric resonators are arranged, the resonance frequency can be individually adjusted without affecting other resonators (resonance regions), so that the resonance frequency adjustment operation can be easily performed. In addition, since the adjustment can be made according to the size and the dielectric constant of the dielectric film, the adjustment is easy.

According to the dielectric resonator of the second aspect, since the dielectric film for adjusting the resonance frequency is formed in a plurality of islands, the dielectric films are formed one by one or several together. The resonance frequency can be adjusted in a stepwise manner by forming and removing. Furthermore, if the size of the island-shaped dielectric film is set to a size that can be completely burned off with a laser, deterioration of Q due to carbonization of the dielectric film on the periphery of the burned-out dielectric film is reduced. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a dielectric filter for explaining a first embodiment.

FIG. 2 is a perspective view showing a manufacturing process of a dielectric substrate constituting the dielectric filter of FIG.

FIG. 3 is a partially enlarged perspective view for explaining a second embodiment.

FIG. 4 is a partially enlarged perspective view for explaining a third embodiment.

FIG. 5 is a cross-sectional view of a dielectric resonator previously proposed by the present applicant.

FIG. 6 is a perspective view of a dielectric substrate constituting the dielectric resonator of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric filter 1a Filter pattern 2 Dielectric substrate 2a, 2b, electrode 3 Resonance area 4a, 4b Conductor plate 5a Input slot line 5b Output slot line 6, 7 Dielectric film 8 Laser 10 Dielectric mother substrate 10a, 10b , Electrode

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Sadao Yamashita 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Inside Murata Manufacturing Co., Ltd.

Claims (4)

[Claims] An electrode having openings of substantially the same shape is formed on both main surfaces of a dielectric substrate so that the openings face each other, and the dielectric substrate is separated from the dielectric substrate by a predetermined distance. It is arranged between the first and second conductor plates facing each other, and a resonance region is defined between the opposed openings of the dielectric substrate, and a resonance frequency is provided on the dielectric substrate exposed from the openings of the electrodes. A dielectric resonator having an adjusting dielectric attached thereto. 2. The dielectric resonator according to claim 1, wherein the dielectric for adjusting the resonance frequency is formed in a plurality of island shapes. 3. An electrode having openings of substantially the same shape on both main surfaces of the dielectric substrate so that the openings face each other, and the dielectric substrate is separated from the dielectric substrate by a predetermined distance. A method of adjusting a resonance frequency of a dielectric resonator which is disposed between first and second conductor plates facing each other and has a resonance region between the opposed openings of the dielectric substrate, wherein the opening of the electrode is A resonance frequency adjusting method for a dielectric resonator, characterized in that the resonance frequency is changed by partially attaching a dielectric material for adjusting the resonance frequency on a dielectric substrate exposed from a portion. 4. The resonance frequency according to claim 3, wherein the resonance frequency is changed by partially removing the dielectric material for adjusting the resonance frequency formed on the dielectric substrate exposed from the opening. A method for adjusting the resonance frequency of a body resonator.