JPH07131218A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To enable the resonance frequency of the dielectric resonator to be finely adjusted and to reduce the size and weight of the dielectric resonator and improve the utilization efficiency of its mount space. CONSTITUTION:The dielectric resonator has the upper space of a dielectric substrate 4, where a dielectric resonator 2 is arranged, put in a conductive shield case 1, part of the whole of the top surface of the conductive shield case 1 is formed of a metallic conductor which is relatively low in rigidity and composed of a mesh type member 6 having electromagnetic shield effect to electromagnetic waves in an in-use frequency band, and the mesh type member 6 is physically deformed to vary the relative distance between the dielectric resonance element and conductive shield case 1, thereby adjusting the resonance frequency. Consequently, while the resonance frequency of the dielectric resonator is finely adjusted by increasing and decreasing, the resonator is reduced in size and weight and the utilization efficiency of the mount space is improved.

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, and more particularly to a dielectric resonator having a resonance frequency adjusting mechanism.

[0002]

2. Description of the Related Art A dielectric resonator used as a resonator suitable for a microwave frequency band in satellite communication or mobile communication is formed of a ferroelectric material such as ceramics and combined with a coupling circuit to form a conductive metal. The resonator is housed in a case, and the resonance frequency of the resonator is determined by the permittivity of the dielectric and the external dimensions.

However, in order to properly process the outer dimensions of the dielectric to adjust it to a desired resonance frequency, it is considerably difficult to cut the outer dimensions because the ceramics mainly used as the dielectric are hard materials. There is a limit to the adjustment range for adjusting the resonance frequency to a desired value by machining, and it is impossible to perform fine adjustment with high accuracy. Therefore, it is necessary to provide the dielectric resonator with a structure that allows fine adjustment of the resonance frequency.

By the way, it is known that in a dielectric resonator, the resonance frequency fluctuates due to the influence of a change in external conditions when a conductive substance is brought closer to the outside. Using this property, conventionally, as a method of adjusting the resonance frequency of the dielectric resonator, adjustment of the resonance frequency has been realized by bringing a metal conductor into contact with and separating from above the dielectric resonance element (Japanese Patent Laid-Open No. Hei 3). 162109).

For example, as shown in FIG. 4, a dielectric substrate 14
A dielectric resonant element 12 is fixedly mounted on the upper surface of the dielectric substrate 14 via a spacer 13, and the back surface of the dielectric substrate 14 is bonded and fixed to a conductor bottom plate 15 serving as a ground conductor. An upper surface wall which is covered with a conductive shield case 11 and which is a canopy of the conductive shield case 11 facing directly above the dielectric resonant element 12,
The frequency adjusting screw 17 is rotatably screwed, and the screw 1
By rotating 7 the dielectric resonance element 12
The separation length with respect to is configured to be variable.

[0006]

However, in the conventional technique, the upper portion of the frequency adjusting screw 17 projects above the upper surface of the shield case 11. Also, adjust screw 1
In order to support 7 and to engrave its screw hole, the thickness of the shield case 11 is also limited to some extent, in other words, it is difficult to reduce the thickness. Therefore, there are obstacles such as reduction in size and weight of the dielectric resonator itself, and instability of the resonance frequency due to loosening of the screw 17 due to mechanical vibration.

Further, even at the time of mounting, a mounting space is required to rotate the adjusting screw 17, which substantially reduces the mounting efficiency.

Further, a method of adjusting the resonance frequency by deforming the conductive shield case has been conventionally performed (Japanese Patent Laid-Open No. 60-102), but it is difficult to deform the conventional shield case, and excessive deformation causes it. If the value becomes higher than the desired resonance frequency, or if the value before adjustment is already higher than the desired resonance frequency, it is impossible to deal with the situation.

In view of the above conventional drawbacks, an object of the present invention is to reduce the size and weight of the resonator while enabling the adjustment of the resonance frequency of the dielectric resonator as described above, and further to utilize the mounting space. Another object of the present invention is to provide a dielectric resonator capable of improving

[0010]

In order to solve the above-mentioned technical problems, according to the present invention, as shown in FIGS. 1 to 3, some or all of the upper part of the shield case 1 is pressed, for example. It is characterized in that a resonance frequency adjusting mechanism constituted by a mesh member 6 made of a metal conductor having an effect of an electromagnetic shield capable of being physically deformed is installed.

[0011]

According to such technical means, it is easy to physically deform the mesh member by, for example, pressing the mesh member, and by this deformation, the dielectric resonant element arranged in the shield case It is possible to adjust the resonance frequency of the dielectric resonator by changing the distance to the mesh member. Further, when the resonance frequency before adjustment is higher than the desired frequency, or when the resonance frequency becomes higher than the desired frequency during adjustment, the fact that the member is in a mesh shape is used, for example, a thin key shape. It is also possible to lower the resonance frequency of the dielectric resonator by deforming the dielectric resonance element and the mesh member in a direction of increasing the relative distance with the tool or the like.

After the adjustment, a hermetically sealed structure can be realized by bonding a cap made of a metal conductor so as to cover the upper surface of the shield case.

Further, unlike the prior art, the frequency adjusting screw does not project on the upper surface of the shield case, and a conductor that moves in the vertical direction is not provided in the space below the shield case ceiling. Thinning of the case is easily achieved. Furthermore, since it is not necessary to engrave a screw hole or the like for supporting the adjusting screw, the thickness of the shield case is not limited and the thickness can be easily reduced.

Further, in addition to this, since there is no upper protruding portion, it is possible to improve the space utilization efficiency at the time of mounting.

As a result, it is possible to continuously and efficiently perform the frequency adjustment work while assembling the respective constituent members in the manufacturing process as a product, and to obtain a compact and lightweight dielectric resonator of stable quality. .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, other relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless there is a specific description, and are merely illustrative examples. It is nothing more than a thing.

1 to 3 show a dielectric resonator according to an embodiment of the present invention, FIG. 1 is a schematic perspective view, and FIGS. 2 and 3 are vertical sectional views.

In the figure, the dielectric resonant element 2 is fixedly mounted on a dielectric substrate 4, and the substrate 4 is housed in a shield case 1 made of a metal conductor.

The shield case 1 is composed of a mesh member 6 whose upper surface is partially or wholly made of a metal conductor having a relatively low rigidity, and the mesh member 6 is in the frequency band used by the dielectric resonator. It has a function as an electromagnetic shield against corresponding electromagnetic waves. In this state, after incorporating the resonator according to the present invention into a jig,
By physically deforming the resonance frequency adjusting portion by the mesh member 6, for example, pressing the mesh member 6,
It is possible to adjust the resonance frequency of the dielectric resonator by changing the relative distance between the dielectric resonant element 2 installed in the shield case 1 and the mesh member 6. When pressed, the relative distance between the dielectric resonant element 2 and the mesh member 6 becomes short, so that the resonance frequency rises. Further, it is also possible to deform the mesh member 6 in the direction of increasing the separation length from the dielectric resonant element 2 by using a thin key-shaped tool or the like. Adjustment is also possible when resonating at a high frequency.

Further, after adjusting the resonance frequency of the dielectric resonator to a desired frequency by the adjusting method described above, the upper surface of the shield case 1, that is, the resonance frequency adjusting portion formed of the mesh member 6 is covered. By adhering the cap 7 made of a metal conductor to the shield case 1, it is possible to completely shield the internal space of the shield case 1 even in an airtight manner, and to improve the resonance characteristics under physical conditions such as humidity. It also becomes possible to stabilize.

With such a structure and adjustment method, the assembly and frequency adjustment work can be smoothly and efficiently performed, and as a result, a high-yield and stable high-quality dielectric resonator can be provided. .

[0022]

As described above, according to the configuration and method of the present invention, it is possible to finely adjust the resonance frequency of the dielectric resonator while reducing the size and weight of the resonator.
Further, it is possible to achieve various remarkable effects such as improvement of utilization efficiency of the mounting space.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a sectional view showing an embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Shield Case 2 Dielectric Resonant Element 3 Spacer 4 Dielectric Substrate 5 Conductor Bottom Plate 6 Frequency Adjusting Conductive Net Member 7 Conductive Cap

Claims (1)

[Claims] 1. A dielectric resonator in which an upper space of a dielectric substrate having a dielectric resonance element arranged on an upper surface thereof is accommodated in a conductive shield case, and a part or all of the upper surface of the conductive shield case has relatively low rigidity. It is composed of a mesh member made of a metal conductor and having an electromagnetic shield effect against electromagnetic waves in the frequency band used, and the dielectric resonator element and the conductive shield case are relatively arranged by physically deforming the mesh member. A dielectric resonator having a structure in which a resonance frequency is adjusted by changing a distance.