JPS62209901A - Frequency variable mechanism for microwave oscillator - Google Patents

Abstract

PURPOSE:To maintain a high quality for a long period without worsening the environmental performance of an oscillator by providing a supporting frame supported at a base and an adjusting means to press the ceiling part of a cover supported by the supporting frame in the base direction or to draw it in the reverse direction. CONSTITUTION:By screwing a tuning screw 6 into the screw hole of an external cover 8, the ceiling part of a cover 5 can be pressed. When the tuning screw 6 is loosened, the screw is returned to the original position by the elasticity of the cover 5. For such a reason, when the condition that the tuning screw 6 is screwed to some extent beforehand is the reference condition, by screwing or loosening further the tuning screw 6, the oscillating frequency can be freely adjusted. In addition to it, since the internal part of the cover 5 is completely closed regardless of the adjusting means, the danger that the environmental performance of an oscillator will be worsened does not occur.

Description

Detailed Description of the Invention (a) Technical Field The present invention relates to a frequency variable mechanism for a microwave oscillator using a dielectric resonator.

(bl Prior Art and Its Disadvantages) A microwave oscillator using a dielectric resonator is equipped with a dielectric resonator 1 and a strip line 2 coupled to the dielectric resonator 1, as shown in FIG. A substrate 3 on which an oscillation circuit is formed is sealed and protected from the outside air within a plate-shaped base 4 and a container-shaped cover 5 joined to the base 4. Conventionally, there has been a mechanism in which a screw hole is provided in the ceiling of the cover 5, and a tuning screw 6 is screwed into this screw hole. This is intended to change the oscillation frequency by changing the distance between the dielectric resonator 1 and the dielectric resonator 1.

Such a conventional frequency variable mechanism, after adjusting the frequency,
In order to fix the tuning screw 6 and seal the gap between it and the screw hole, the protrusion of the tuning screw 6 was covered with resin.

However, with this method, complete sealing is impossible, and a small amount of outside air enters and exits through the resin through the gap with the screw hole, resulting in a disadvantage that the environmental performance of the oscillator deteriorates.

(C) Purpose of the Invention This invention was made in view of the above circumstances, and it is possible to change the oscillation frequency of the oscillator by directly pressing or pulling the ceiling without making a screw hole in the cover. The purpose of the present invention is to provide a frequency variable mechanism for a microwave oscillator that does not deteriorate environmental performance.

(d) Structure and effect of the invention The frequency variable mechanism of the microwave oscillator of the present invention has a dielectric resonator attached thereto, and a substrate on which an oscillation circuit coupled to the dielectric resonator is formed is mounted on a plate-shaped base. In a microwave oscillator sealed inside a container-shaped cover joined to the base, the cover has a certain degree of rigidity and elasticity and is sealed in advance except for the joint with the base,
The present invention is characterized in that it includes a support frame supported by the base, and an adjusting means supported by the support frame to press the ceiling portion of the cover toward the base or pull it in the opposite direction.

In the present invention configured as described above, the position of the ceiling part of the cover is changed by the adjustment means, as in the conventional case.
The oscillation frequency can be adjusted by changing the distance between the dielectric resonator and this ceiling. Moreover, since there are no screw holes in the ceiling of this cover, this adjustment can be made while the cover is in a sealed state, so that it is possible to completely block the entry and exit of outside air. Therefore, the variable frequency mechanism of the microwave oscillator of this invention can maintain high quality for a long time without deteriorating the environmental performance of the oscillator, even though the frequency can be adjusted in the same way as in the past. .

(e) Embodiment FIG. 1 is a longitudinal sectional view of an oscillator which is a first embodiment of the present invention.

The dielectric resonator 1 is mounted and fixed on a substrate 3 via a support 7. Further, an oscillation circuit is formed on this substrate 3 and coupled to the dielectric resonator l via the strip line 2. The cover 5 is a metal plate formed into the shape of a container with a flat bottom, and is completely sealed except for the opening surface. This cover 5 is placed face down so as to cover the substrate 3 mounted on the base 5, and its peripheral edges are sealed and joined by seam welding.

The frequency variable mechanism is constructed by providing this oscillator with adjustment means consisting of an outer cover 8 and a tuning screw 6. The outer cover 8 is in the shape of a container that is slightly larger than the cover 5 and has a similar shape, and is placed face down on the base 4 so as to cover the cover 5, and is attached with its peripheral edges fixed. However, this outer cover 8 is set to have sufficiently higher rigidity than the cover 5, and furthermore, a screw hole is provided in the center of the ceiling portion. The tuning screw 6 is screwed into the screw hole of the outer cover 8.

In the first embodiment configured as described above, the ceiling portion of the cover 5 can be pressed by screwing the tuning screw 6 into the screw hole of the outer cover 8. Also,
When the tuning screw 6 is loosened, it returns to its original position due to the elasticity of the cover 5. For this reason, if the state in which this tuning screw 6 is screwed in to a certain extent is set as the reference state, then this tuning screw 6
The oscillation frequency can be adjusted freely by further tightening or loosening the screw. Moreover, since the inside of the cover 5 is completely sealed regardless of the adjustment method,
There is no fear that the environmental performance of the oscillator will deteriorate.

FIG. 2 shows a longitudinal sectional view of an oscillator according to a second embodiment of the invention.

In this second embodiment, the tuning screw 6 constituting the adjustment means is fixedly attached to the ceiling of the cover 5 so as to protrude upward, and the tuning screw 6 on the ceiling of the outer cover 8 is fixed. It is constructed by forming a hole 9 slightly larger than the screw diameter at a corresponding position. In this embodiment, a nut 10 is screwed into the tuning screw 6 that protrudes further upward through a hole 9 in the outer cover 8, and by tightening the nut 10, the ceiling portion of the cover 5 can be pulled upward. For this reason,
By further tightening or loosening the nut 10 after it has been tightened to a certain degree, the distance between the ceiling of the cover 5 and the dielectric resonator 1 changes, so that the oscillation frequency can be adjusted freely. Therefore, in the case of this second embodiment as well, it is possible to obtain the effect that the environmental performance inside the cover 5 is not deteriorated, as in the first embodiment.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an oscillator according to a first embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of an oscillator according to a second embodiment of the present invention, and FIG. 3 is a vertical cross-sectional view of a conventional oscillator. show. 1-dielectric resonator, 3-substrate, 4-base, 5-cover, 6-tuning screw, 8-external force bar. Figure 1 Figure 2 Figure 3A

Claims (1)

[Claims] (1) A board on which a dielectric resonator is attached and an oscillation circuit coupled to the dielectric resonator is formed is sealed inside a plate-shaped base and a container-shaped cover joined to this base. In the microwave oscillator, the cover has a certain degree of rigidity and elasticity and is sealed in advance except for the joint with the base, and has a support frame supported by the base and a cover supported by the support frame. 1. A frequency variable mechanism for a microwave oscillator, characterized in that it is provided with an adjustment means for pressing the ceiling part of the oscillator toward the base or pulling it in the opposite direction.