JPH07131216A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To provide the dielectric resonator which is reduced in size and weight and improved in the utilization efficiency of a mount space while enabling the resonance frequency of the dielectric resonator to finely be adjusted. CONSTITUTION:The dielectric resonator has the upper space of a dielectric substrate 4, having a dielectric resonance element 2 arranged on the top surface, put in a conductive shield case 1, and the dielectric resonance element 2 is covered with a rotatable cover 6 which is formed of a mesh type metallic conductor having electromagnetic shield effect to electromagnetic waves in an in-use frequency band and also has a gap at part of the metallic conductor and is rotatable on an axis in the normal direction of a plane containing the substrate surface. Then resonance characteristics are adjusted by rotating the cover 6. Consequently, the resonance characteristics of the dielectric resonator are finely adjusted to reduce the size and weight of the resonator and further improve the utilization efficiency of the mount space.

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 material to adjust it to a desired resonance frequency, it is considerably difficult to cut it because the ceramic mainly used as the dielectric material is a hard material, and the outer dimensions are also large. In order to adjust the resonance frequency to a desired value by machining, there is a limit in the adjustment range, and fine adjustment cannot be performed with high precision. 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. 2, 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 distance to is configured to be variable.

In order to operate the oscillator, it is necessary to increase the degree of coupling between the resonator and the coupling line to some extent. In the case of a dielectric resonator using the TE01δ mode,
Since the coupling line and the resonant element are magnetically coupled, the degree of coupling is proportional to the magnetic flux of the dielectric resonant element penetrating the region formed by the coupling line and its ground conductor. The adjustment is performed by changing the distance between the dielectric resonant element and the coupling line to change the magnetic flux penetrating the region or by changing the substrate thickness to change the size of the region penetrating the magnetic flux. It was realized by that.

[0007]

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 lowers the mounting efficiency.

Also, 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 the resonance frequency is higher than a desired resonance frequency due to excessive deformation of the shield case. It has been impossible to deal with the case where the value becomes a value or the value before the adjustment is already higher than the desired resonance frequency.

In the above-mentioned method of adjusting the coupling degree, in the conventional method based on the substrate thickness, the spatial distribution of the electromagnetic field in the dielectric resonator changes, so that the unnecessary resonance mode of the dielectric resonator is changed. It had the drawback of being easily combined with.

Further, as a problem common to the conventional methods,
For oscillators of different standards, the design itself of the dielectric resonator has to be changed, and there is a drawback that the versatility of the device is low.

In view of the above-mentioned conventional drawbacks, an object of the present invention is to reduce the size of the resonator while making it possible to adjust the resonance frequency of the above-described dielectric resonator by increasing and decreasing and the degree of coupling with a simple structure. It is an object of the present invention to provide a dielectric resonator that can be lightened, and can further improve the utilization rate of the mounting space.

[0013]

In order to solve the above-mentioned technical problems, the present invention has an effect of an electromagnetic shield against electromagnetic waves in a frequency band used, as shown in FIG. It is characterized in that the dielectric resonance element is covered with a mesh-shaped metal conductor having a gap in a part thereof, and a cover configured so as to be rotatable about the normal direction of the plane including the substrate surface is provided.

[0014]

According to this technical means, the cover 6 is provided before the dielectric resonant element 2 is sealed by the shield case 1.
Is physically deformed by, for example, pressing it to change the distance between the dielectric resonance element 2 arranged in the cover 6 and the cover 6, thereby changing the resonance frequency of the dielectric resonator. Can be adjusted. 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 the adjustment, the cover 6 is reticulated to utilize, for example, a thin key. It is also possible to lower the resonance frequency of the dielectric resonator by deforming the dielectric resonance element 2 and the cover 6 in a direction that increases the relative distance between them by using a tool or the like.

The cover 6 has a gap,
As a result, it is coupled with the coupling line 8 existing in the vicinity of the dielectric resonance element 2, but is formed by the coupling line 8 and the conductor bottom plate 5 which is a ground conductor due to the rotational movement of the gap by rotating the cover 6. It is possible to change the amount of magnetic flux penetrating the region of the dielectric resonance element 2
It is also possible to adjust the degree of coupling between the coupling line 8 and the coupling line 8.

Further, as shown in FIG. 2, unlike the prior art, the frequency adjusting screw does not project above the shield case, and a conductor that moves in the vertical direction is also arranged in the space below the shield case ceiling. Things will disappear, so
Thinning of the shield 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.

In addition, since there is no upper protruding portion, it is possible to improve space utilization efficiency during mounting.

After the adjustment, the cover 6 is fixed to stabilize the electrical characteristics at a desired resonance frequency. Further, by sealing with the shield case 1 after fixing, an airtight structure can also be realized.

As a result, it is possible to perform the resonance characteristic adjusting work continuously and highly efficiently 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. I can.

[0020]

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.

FIG. 1 shows a dielectric resonator according to an embodiment of the present invention. In the figure, the dielectric resonant element 2 is fixedly mounted on a dielectric substrate 4, and the substrate 4 is
It is housed in a shield case 1 made of a metal conductor.

Inside the shield case 1, the dielectric resonance element 2 is constituted by a mesh-shaped metal conductor and has a function as an electromagnetic shield against electromagnetic waves corresponding to the frequency band used by the dielectric resonator. It is covered by the cover 6. A gap is provided on the side surface of the cover 6, and the dielectric resonant element 2 and the coupling line 8 are magnetically coupled through this gap.

In such a state, the resonator according to the present invention is incorporated into a jig, and the upper portion of the cover 6 is physically deformed, for example, pressed, so that the cover 6 is covered.
It is possible to adjust the resonance frequency of the dielectric resonator by changing the relative distance between the dielectric resonance element 2 installed inside and the cover 6. When pressed, the relative distance between the dielectric resonant element 2 and the upper portion of the cover 6 becomes short, so that the resonant frequency increases. It is also possible to deform the upper portion of the cover 6 in the direction of increasing the distance from the dielectric resonant element 2 by using, for example, a thin key-shaped tool or the like. Adjustment is also possible when resonating at a high frequency.

By rotating the cover 6, the amount of magnetic flux passing through the gap can be adjusted appropriately, and the coupling line 8 and the conductor bottom plate 5 serving as a ground conductor can be adjusted.
Since it is possible to change the magnetic flux penetrating the region formed by, it is possible to achieve a desired degree of coupling.

The resonance frequency can be stabilized by adhering the cover 6 to the shield case 1 after adjusting the resonance frequency of the dielectric resonator to a desired frequency. Furthermore, by the adjustment method described above,
By adjusting the resonance characteristic of the dielectric resonator to a desired value and then sealing with 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 prevent humidity and the like. It is also possible to stabilize the resonance characteristic under the physical condition of.

With the above structure and adjusting method, the assembling and adjusting the resonance characteristics can be smoothly and efficiently performed, and as a result, it is possible to provide a stable and high-quality dielectric resonator. I can.

[0027]

As described above, according to the structure and method of the present invention, it is possible to finely adjust the resonance characteristics of the dielectric resonator described above, reduce the size and weight of the resonator, and mount the resonator. It is possible to achieve various remarkable effects such as improvement of space utilization efficiency.

[Brief description of drawings]

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

FIG. 2 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 Conductive Net Cover 8 Coupling Line

Claims (1)

[Claims] 1. A dielectric resonator in which an upper space of a dielectric substrate having a dielectric resonant element arranged on an upper surface is surrounded by a conductive shield case, the dielectric resonator having a gap in part to cover the dielectric resonator and a substrate surface. A cover that can be rotated around the normal direction of the plane including is made of a mesh metal conductor that has an electromagnetic shield effect for electromagnetic waves in the frequency band used, and the resonance characteristics are adjusted by rotating the cover. A dielectric resonator having a structure as described above.