JPH04803A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To miniaturize the dielectric resonator and to improve its air tightness by providing a deformable bend part at one part of a metal shield case at least and fixing the deformation of the said bend part by charging a prescribed material to the said bend part after deforming the bend part by impressing external force to a case in order to control a resonance frequency while changing a distance between the case and a dielectric in the said case. CONSTITUTION:First of all, the external force is applied to a shield case 7 in an arrow direction so as to deform a bend part 16, and the resonance frequency of the dielectric resonator or the oscillation frequency of a dielectric oscillator is matched to a target value while controlling the distance between a dielectric 3 and the upper surface part of the shield case 7. Next, a soldering or adhesive material 17 is charged into the bend part 16 so as to fix the deformation. At such a time, the distance between the dielectric 3 and the upper surface part of the case 7 is kept constant. When excluding the external force after fixing the soldering or adhesive material 17, the frequency control work is completed. Thus, since the deformation of the bend part 16 is fixed by the soldering or adhesive material 17, the frequency can be prevented from being deviated by the elasticity when the external force is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dielectric resonator, and particularly to an improvement in a means for adjusting the resonant frequency thereof.

[Summary of the Invention] In a dielectric resonator, the bent portion provided in the metal shield case is deformed by applying an external force to adjust the resonance frequency, and then the bent portion is filled with solder or adhesive to deform the bent portion. By fixing it, it is possible to reduce the size and simplify the adjustment.

[Prior Art] Adjustment of the resonant frequency of a dielectric resonator is usually performed by utilizing the property that the resonant frequency increases when a metal member is brought closer to the dielectric. FIGS. 11 to 14 show a conventional method for adjusting the resonant frequency of a dielectric resonator.

In these drawings, 1 is a screw, 2 is a nut, 3 is a dielectric, 4 is a spacer, 5 is a substrate, 6 is a strip line,
7 is a metal shield case, 8 is a metal bottom plate, 9 is a recess, 1
0 is a groove, 11 is a presser, 12 is an adjustment jig, 13 is an outer metal case, 14 is an inner metal case, and 15 is a spring portion.

In the dielectric resonator shown in FIG.
is attached via a spacer 4, and a strip line 6 magnetically coupled to the dielectric 3 is formed in the vicinity thereof. A screw hole is drilled on the top of the case 7.
The screw 1 inserted into this hole via the nut 2 has a dielectric material 3
The resonant frequency can be adjusted according to the insertion amount of the screw 1. After adjustment, screw 1 is fixed by tightening nut 2 so that screw 1 does not rotate.

The dielectric resonator shown in FIG. 11 has a relatively simple structure and is currently in wide use.

In FIGS. 12 and 13, the portion of the upper surface of the metal shield case 7 facing the dielectric 3 is recessed to form a recess 9.
This is a dielectric resonator that adjusts the resonance frequency by changing the distance between the dielectric 3 and the top surface of the case 7. As a method of forming the recess 9, there is a method of recessing the case 7 by tightening the presser 11 of the adjustment jig 12, as shown in FIG. In this case, a groove 10 is formed inside the upper surface of the case 7 to facilitate deformation.

Figure 14 shows the metal shield case and the inner metal case 14.
It has a double structure of a metal case 13 and an outer metal case 13, and a spring part 15 is formed on the side wall of the inner metal case 14. By inserting the screw 1 into the screw hole on the top surface of the outer metal case 13 and pressing the top surface of the inner metal case 14, the spring portion 15 brings the top surface close to the dielectric 3, thereby increasing the resonance frequency. can be adjusted.

[Problems to be Solved by the Invention] However, the above-described conventional dielectric resonator has the following problems.

First, in the structure shown in Fig. 11, the screw 1 protrudes from the upper part of the case 7, and in order to fix the screw 1 using the nut 2 and adjust the insertion length of the screw 1, when mounting it, the main resonance It is necessary to provide sufficient space in the height direction of the vessel. Currently, dielectric resonators are used as local oscillators, ie, dielectric oscillators, in down converters for home satellite broadcast reception, and therefore, there is a need for small-sized dielectric resonators. However, when the oscillation frequency is adjusted using a resonant frequency adjustment mechanism as shown in FIG. 11, it is difficult to reduce the size in the height direction, which causes the size of the converter to increase. Furthermore, drilling screw holes in the metal shield case 7 reduces airtightness, causing fluctuations in oscillation frequency and deterioration of semiconductor elements due to intrusion of water vapor and the like. Furthermore, even if the insertion length of the screw 1 is adjusted to match the oscillation frequency to a predetermined value, when the nut 2 is subsequently turned to fix the screw 1, the screw 1 moves slightly and the oscillation frequency shifts.

Therefore, adjusting the oscillation frequency takes time and effort, which causes an increase in costs.

Next, in the structure shown in FIGS. 12 and 13, since the metal case 7 always has some elasticity, the presser 11 is tightened to adjust the resonant frequency of the dielectric resonator or the oscillation frequency of the dielectric oscillator to a predetermined value. After alignment, when the presser 11 is loosened, the deformed recess 9 returns to its original state to some extent, resulting in a frequency shift. Moreover, if the recess 9 is recessed too much and the frequency exceeds the target value, the frequency cannot be lowered, so the adjustment work must be done carefully, which is very time-consuming. Furthermore, since the upper surface of the metal case 7 is made to be easily deformable, if an impact is applied from the outside after adjusting the frequency, the top surface of the metal case 7 will deform and the frequency will shift.

The structure shown in Fig. 14 has improved airtightness compared to the structure shown in Fig. 11, but because the metal case has a double structure, it becomes even larger, making it impractical. . Furthermore, the frequency shift caused by slight movement of the screw 1 when the nut 2 is tightened cannot be improved.

[Object of the Invention] Therefore, the object of the present invention is to provide a dielectric resonator which is small, has high airtightness, allows easy adjustment of the resonant frequency, and has no frequency shift after adjustment, in order to solve the above-mentioned drawbacks of the conventional device. This is to do so.

[Means for Solving the Problems] In order to achieve the above object, a dielectric resonator of the present invention is provided in at least one location of a metal shield case.

A deformable bent portion is provided, and the bent portion is deformed by applying an external force to the case in order to change the distance between the case and the dielectric in the case to adjust the resonant frequency. The gist is that the deformation of the bent portion is fixed by filling it with a predetermined material.

[Function] It is sufficient to simply apply an external force to deform the bent portion, and there is no need for adjustment screws on the top surface of the metal case, allowing for miniaturization. Also, since there are no screw holes, airtightness is improved. Since the deformation of the bent portion is fixed, even if the external force is removed after adjustment, there will be no deviation in frequency due to the elasticity of the metal, making the adjustment work easier. It is also structurally strong against external impacts.

[Example code] The present invention will be described below with reference to embodiments shown in the drawings.

1 to 4 show an embodiment of a dielectric resonator according to the present invention, and the same reference numerals as in FIG. 11 indicate the same or similar members or parts.

FIG. 1 shows a state before frequency adjustment, in which at least a portion of the metal shield case 7, for example, a side wall, is provided with a deformable bending portion 16, and a deformable bending portion 16 is provided on the upper surface of the case 7 in the direction of the arrow in the figure. When an external force is applied in an appropriate manner, the bent portion 16
is deformed so that the distance between the upper surface of the case 7 and the dielectric 3 changes. It is desirable that the bent portion 16 be formed thinner than the other portions of the case 7 so that it can be easily deformed.

The frequency adjustment procedure in this embodiment is as follows: First, an external force is applied to the shield case 7 in the direction of the arrow to deform the bent portion 16, and the distance between the dielectric 3 and the upper surface of the shield case 7 is adjusted to cause dielectric resonance. Adjust the resonant frequency of the device or the oscillation frequency of the dielectric oscillator to the target value. Next, the bent portion 16 is filled with solder or adhesive 17 to fix the deformation. At this time, the distance between the dielectric 3 and the upper surface of the case 7 is kept constant. When the external force is removed after the solder or adhesive 17 has hardened, the frequency adjustment work is completed and the state as shown in FIG. 2 is obtained. Since the deformation of the bent portion 16 is fixed by the solder or adhesive 17 in this way, it is possible to prevent the frequency shift due to the elasticity of the case when the external force is removed, which was a problem with the conventional device, and it is possible to easily It can be tuned to the target frequency. Since there is no need to use screws as in the conventional method, it is advantageous in terms of airtightness and miniaturization.

Furthermore, as shown in FIG.
It is also possible to fill only a part of 6 instead of all of it.

Note that when adjusting the frequency, even if too much external force is applied and the frequency becomes higher than the target value, as long as the bent part has some elasticity before filling with solder or adhesive, the external force can be loosened. frequency can be lowered. If the bent part is accidentally deformed to the extent that the frequency exceeds the target value even when no external force is applied, insert a screwdriver etc. into the bent part 16 and move the bent part up and down as shown in Figure 4. If you push it wider, the frequency will drop and you can start adjusting again.

FIGS. 5 and 6 show other embodiments of the present invention, in which the bent portion 16
is provided at the connecting portion between the top surface and the side wall of the metal shield case 7, and FIG. 5 shows the state before adjustment, and FIG. 6 shows the state after adjustment.

7 and 8 show still another embodiment of the present invention, in which a bent portion 16 is provided near the connection portion between the lower side wall of the metal shield case 7 and the metal bottom plate 8, and FIG. 7 shows before adjustment. , FIG. 8 shows the state after adjustment.

The embodiments shown in FIGS. 5 to 8 have the advantage that the recessed portion of the bent portion 16 faces upward, making it easier to fill the solder or adhesive 16.

In the above description, only one bent portion 16 is provided around the shield case 7, but it goes without saying that similar frequency adjustment is possible even if a plurality of bent portions are provided.

Furthermore, the dielectric resonator of the present invention is not only a dielectric oscillator, but also
It can be applied to all devices using dielectric resonators such as various filters.

9 and 10 show an embodiment in which the present invention is applied to a bandpass filter using a plurality of dielectrics 3, in which all of the plurality of bends 16 of the metal shield case 7 are filled with solder or adhesive 17. has been done.

[Effects of the Invention] As explained above, according to the present invention, there is no need to use a screw as an external force applying means for adjusting one frequency, so miniaturization can be achieved and airtightness can be improved. In addition, since the deformation of the bent portion is fixed after adjustment, no frequency shift occurs even when external force is removed, making adjustment work easier.

Furthermore, since the bent portion is fixed against external shocks, frequency shifts are less likely to occur.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing one embodiment of the present invention, FIGS. 3 and 4 are perspective views showing the external appearance, and FIGS. 5 to 8 are respectively other embodiments of the present invention. FIG. 9 is a schematic diagram showing still another embodiment of the present invention, FIG. 10 is a perspective view showing its appearance, and FIGS. 11 to 14 are schematic diagrams showing a conventional dielectric resonator. It is a diagram. 3...Dielectric material, 7...Metal shield case, 8...Metal bottom plate, 16
......Bent part, 17...Solder or adhesive.

Claims (4)

[Claims] (1) A deformable bent portion is provided at at least one location of the metal shield case, and an external force is applied to the case in order to adjust the resonance frequency by changing the distance between the case and the dielectric within the case. A dielectric resonator characterized in that, after the bent portion is deformed, the bent portion is filled with a predetermined material to fix the deformation of the bent portion. (2) The dielectric resonator according to claim 1, wherein the bent portion is provided on a side wall portion of the case. (3) The dielectric resonator according to claim 1, wherein the bent portion is provided at a connection portion between the upper surface portion and the side wall portion of the case. (4) Dielectric resonance according to claim (1), characterized in that a plurality of dielectrics are installed in the case, and a plurality of bending parts are provided in the case corresponding to each dielectric. vessel.