JP3562162B2 - Dielectric resonator and method of adjusting resonance frequency of dielectric resonator - Google Patents

Description

[0001]
TECHNICAL 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 a resonance frequency of the dielectric resonator.
[0002]
[Prior art]
In recent years, large-capacity and high-speed communication systems have been demanded in response to a rapid increase in demand for mobile communication systems and multimedia applications. With the 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, TE _{01 δ made of} a conventionally known cylindrical dielectric material is used. It is possible to use a mode dielectric resonator as in the microwave band. At this time, TE _{01 δ} Since the resonance frequency of the mode dielectric resonator was determined by the external dimensions of the cylindrical dielectric, strict processing accuracy was required.
[0003]
Also, TE _{01 δ} When a dielectric filter is configured by arranging a plurality of mode dielectric resonators in a metal case at predetermined intervals, an input / output unit such as a metal loop and a dielectric resonator, or a dielectric resonator Since the coupling with the dielectric resonator 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 that have solved these problems.
[0004]
The basic configuration of the dielectric resonator according to the above application is shown in FIGS. FIG. 5 is a 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.
[0005]
As shown in FIGS. 5 and 6, the dielectric substrate 102 is a substrate having a constant relative permittivity, and electrodes 102a and 102b are formed on both main surfaces except for a circular opening having a predetermined size. The openings on both main surfaces face each other as shown in FIG. The conductor plates 104a and 104b are arranged at a predetermined distance from the dielectric substrate 2 so as to sandwich the dielectric substrate 2.
[0006]
At this time, the electromagnetic field energy is confined in the vicinity of the portion sandwiched between the opposed openings of the electrodes 102a and 102b, so that the resonance region 103 is formed and can be used as a resonator. Therefore, a dielectric filter can be formed by continuously arranging a plurality of openings of the electrodes 102a and 102b shown in FIGS.
[0007]
With this configuration, 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 a dielectric resonator that reproduces the dimensional accuracy of the resonator with respect to the resonance frequency extremely accurately is provided. It can be made.
[0008]
Adjustment of the resonance frequency of such a dielectric resonator has been 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. .
[0009]
[Problems to be solved by the invention]
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.
[0010]
Also, in the case of a dielectric filter having a plurality of openings, if 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. However, 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.
[0011]
Furthermore, 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.
[0012]
The present invention has been made in view of these problems, and an object of the present invention is to provide a dielectric resonator that can easily and finely adjust the resonance frequency and a method of adjusting the resonance frequency of the dielectric resonator.
[0013]
[Means for Solving the Problems]
Therefore, in the invention according to claim 1, 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, and the dielectric substrate is connected to the dielectric substrate. The dielectric is disposed between the first and second conductor plates facing each other at a predetermined distance from each other, and a space between the opposed openings of the dielectric substrate is defined as a resonance region, and the dielectric exposed from the openings of the electrode is provided. A dielectric for adjusting the resonance frequency is attached to the substrate. 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.
[0014]
In the invention according to claim 2, the dielectric for adjusting the resonance frequency is formed in a plurality of island shapes. Thus, the resonance frequency adjustment can be performed stepwise by removing one or several of the plurality of island-shaped dielectric films collectively.
[0015]
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, and the dielectric substrate is connected to the dielectric substrate. A resonance frequency adjusting method for a dielectric resonator, wherein the resonance frequency is arranged between the first and second conductor plates facing each other at a predetermined distance from each other, and the gap between the opposed openings of the dielectric substrate is a resonance region. The resonance frequency is changed by partially depositing a dielectric on the dielectric substrate exposed from the opening of the electrode. Thereby, the resonance frequency can be adjusted to a predetermined value by adjusting the amount or the dielectric constant of the dielectric formed on the dielectric substrate exposed from the opening of the electrode.
[0016]
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]
BEST MODE FOR CARRYING OUT THE INVENTION
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 in 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.
[0018]
As shown in FIG. 1, the dielectric filter 1 includes a dielectric substrate 2 having electrodes formed on both main surfaces and conductor plates 4a and 4b.
[0019]
The dielectric substrate 2 is a substrate having a certain relative permittivity, and 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. Is formed. On one main surface side (upper side in FIG. 4) of the dielectric substrate 2, an input slot line 5a and an output slot line 5b are formed so as to be close to the openings at both ends of the three openings. I have.
[0020]
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 near the opening, and the input slot line 5a and the output slot line 5b 4a and 4b.
[0021]
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.
[0022]
The dielectric substrate 2 used for such a dielectric filter 1 is manufactured by the following manufacturing process.
[0023]
First, as shown in FIG. 2A, a dielectric mother substrate 10 having a predetermined relative permittivity is prepared.
[0024]
Next, as shown in FIG. 2B, electrodes 10a and 10b are formed on both main surfaces of the dielectric mother substrate 10 by a technique such as vapor deposition.
[0025]
Further, as shown in FIG. 2C, etching is performed so that a plurality of filter patterns 1a each including 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.
[0026]
Then, as shown in FIG. 2 (D), the dielectric substrate 2 is obtained by cutting two slot lines and three openings for each filter pattern 1a.
[0027]
The dielectric film 6 is selected according to the resonance frequency at which, for example, a polyimide resin or the like is changed by spinning on the dielectric exposed from the opening at the stage of FIG. 2C or 2D. Then, it is formed by attaching a predetermined amount 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.
[0028]
By forming the dielectric film 6 in this manner, 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 the dielectric constant, thickness, and size of the body film 6.
[0029]
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.
[0030]
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.
[0031]
In this embodiment, burn-out by the laser 8 is used. However, the present invention is not limited to this, and a technique of mechanically removing or scientifically removing by etching or the like may be used. Any method may be used as long as the 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.
[0032]
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.
[0033]
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 peripheral edge of the burned-out dielectric film from being carbonized, thereby preventing the Q of the resonator from being reduced. Moreover, fine adjustment of the resonance frequency can be performed stepwise.
[0034]
In the first, second, and third embodiments, the dielectric film is formed on the dielectric substrate exposed from the opening of the electrode on the one main surface side of the dielectric substrate, but is not limited to this. Instead, it 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]
【The invention's effect】
As described above, in 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 resonance frequency adjustment of the dielectric resonator excellent in processing accuracy and position accuracy is performed. Can be easily performed. 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 performed by the size and the dielectric constant of the dielectric film, the adjustment is easy.
[0036]
Further, according to the dielectric resonator of the second aspect, since a plurality of dielectric films for resonance frequency adjustment are formed in an island shape, a plurality of dielectric films are formed one by one or several together. By removing it, the resonance frequency can be adjusted stepwise. Furthermore, if the size of the island-shaped dielectric film is set to a size that can be completely burned off by a laser, the 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 describing 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

Claims (4)

An electrode having openings of substantially the same shape on both main surfaces of the dielectric substrate is formed so that the openings face each other, and a first electrode facing the dielectric substrate at a predetermined distance from the dielectric substrate. A dielectric region for adjusting a resonance frequency on the dielectric substrate exposed from the opening portion of the electrode, the resonance region being disposed between the second conductor plates and the opposing opening portion of the dielectric substrate serving as a resonance region. A dielectric resonator, characterized in that a dielectric resonator is attached. 2. The dielectric resonator according to claim 1, wherein the dielectric for adjusting the resonance frequency is formed in a plurality of island shapes. An electrode having openings of substantially the same shape on both main surfaces of the dielectric substrate is formed so that the openings face each other, and a first electrode facing the dielectric substrate at a predetermined distance from the dielectric substrate. A method of adjusting the resonance frequency of a dielectric resonator, wherein the resonance frequency is set between the opposing openings of the dielectric substrate by disposing between the second conductor plates, A method for adjusting the resonance frequency of a dielectric resonator, wherein the resonance frequency is changed by partially attaching a dielectric for adjusting the resonance frequency to a dielectric substrate. 4. The resonance of the dielectric resonator according to claim 3, wherein the resonance frequency is changed by partially removing the dielectric for adjusting the resonance frequency formed on the dielectric substrate exposed from the opening. Frequency adjustment method.

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