JPH0136328Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a structure for fixing a dielectric coaxial resonator to a case.

Although the dielectric coaxial resonator itself is well known,
Just to be sure, this will be explained with reference to FIG.

1 is a 1/4 wavelength dielectric coaxial resonator, which has an inner conductor 12 on the inner wall surface and outer peripheral surface of a cylindrical (cylindrical, rectangular cylinder, etc.) body 11 made of a titanium oxide based ceramic dielectric, etc.
An electrode 14 for short-circuiting the outer conductor 13 and the inner conductor 12 and the outer conductor 13 is provided on the entire bottom surface in the figure.
It is formed by baking silver paste or by electroless copper plating. Dielectric coaxial resonators with such a configuration are used, for example, in UHF band filters, antenna duplexers, oscillators, and the like. FIG. 2 shows an example of the arrangement of dielectric coaxial resonators in a filter. That is, dielectric coaxial resonators 1 that utilize coaxial TEM mode resonance are distributed on both sides of the signal propagation direction T and arranged so that their open ends face each other. By sharing one cutoff space 3 and coupling the stages with a capacitor that is more advantageous than inductive coupling, an extremely rational arrangement can be obtained, and a filter that is small, free of unnecessary coupling, and has a simple structure suitable for mass production can be obtained.

Normally, a dielectric coaxial resonator is housed and fixed in a case, but conventionally, the outer conductor and the case are fixed by soldering, as disclosed in Japanese Utility Model Application Publication No. 56-163303, or conductive It was fixed using paste. When soldering, the strength of the resonator electrodes weakens due to the heat during soldering. If impurities are added to the electrode material to increase its strength, Q decreases. In the case of silver electrodes, so-called "silver eating" occurs.
It has drawbacks such as being susceptible to thermal expansion strain, and electrode peeling may occur. When using conductive paste, it is difficult to handle,
It requires heating and curing, which takes time; conductive paste has poor electrical conductivity and is unstable;
There are drawbacks such as. Therefore, as shown in FIG. , 1, and the case lid 31 and the outer conductor 13, 13, 13, 13 of the dielectric coaxial resonator 1, 1, 1, 1.
However, as shown in the figure, the more stages there are, the more the case lid 31 deforms into a convex shape, and the force that holds down the resonator in the center becomes weaker. Furthermore, if there are manufacturing errors in each resonator, some resonators will not come into contact.

The main purpose of this invention is to provide a fixing structure for dielectric coaxial resonators that provides reliable fixing and continuity, is easy to work with, does not require special jigs, and requires short work time. be.

The gist of this idea is to place a dielectric coaxial resonator on the case body, place a thin grounding plate on top of the dielectric coaxial resonator, and place a thin ground plate on top of the dielectric coaxial resonator, which has grooves between adjacent dielectric coaxial resonators. It is fixed to the case body using a presser plate. Here, the groove in the present invention is groove-shaped when viewed from the side opposite to the dielectric coaxial resonator across the presser plate, and has a convex shape when viewed from the dielectric coaxial resonator side. The board has a corrugated shape when viewed as a whole.

The above-mentioned and other objects of this invention will become clear from the examples described below.

4 and 5 show a first embodiment. The case body 21 includes a plurality of resonators 1, 1,
recesses 22, 22, 22, into which 1, 1 partially fits;
22 are provided. A thin ground plate 41 is placed on the top surface of the resonators 1, 1, 1, 1. Furthermore, a rubber sheet 51 is placed on the ground plate 41 as required. A press plate 61 is placed on top of the rubber sheet 51. The holding plate 61 is formed with a groove 62 that extends in the axial direction of the resonator 1 and has a substantially U-shaped cross section. The grooves 62 are located between the resonators, and when the holding plate is attached to the case body 21 with screws (not shown), the resonators 1, 1, 1, 1
outer conductor 13, 13, 13, 13 and ground plate 41
The resonators 1, 1,
1, 1 is the recessed part 22, 22 of the lower case body 21,
22, 22, and the fixation is also ensured. To be more specific, as shown in an enlarged view in FIG.
The ground plate 41,
The rubber sheet 51 is deformed along the outer peripheral surface of the resonator 1, and the ground plate 41 and the outer conductor 13 come into surface contact. Therefore, the resonator 1 can be stably and reliably fixed and electrical continuity between the ground plate 31 and the outer conductor 13 can be achieved. Note that the rubber sheet 51 and the recess 22 of the case body 21 are not essential.
The center portion 64 between the grooves 62, 62 does not necessarily need to be in pressure contact with the rubber sheet 41 or the ground plate 31.

6 and 7 show a second embodiment, in which a holding plate 71 is used which has a groove 72 with a substantially U-shaped cross section extending in the signal propagation direction T shown in FIG. With this structure, the grounding plate 41 and the outer conductors 13, 13 of the resonators 1, 1 are surely in contact with each other at the open ends of the resonators 1, 1, so an ideal grounding current path is formed. , it is also possible to prevent displacement of the resonator in the axial direction.

It is also conceivable to combine the first embodiment and the second embodiment as shown in FIG.

In either case, the presence of the grooves also has the effect of increasing the strength of the presser plate.

As is clear from the above embodiments, according to this invention, a plurality of dielectric coaxial resonators are fixed with a single holding plate. deformation is prevented and multiple resonators are pressed down with the same force. In addition, the grooves ensure that the ground plate is pressed against the outer conductor of the resonator, making contact on more surfaces, and depending on the direction in which the grooves are provided, the outer conductor closest to the open end of the resonator may This is preferable because the ground plate is securely pressed into contact with the ground plate. Furthermore, when fixing a dielectric coaxial resonator, the position of the unevenness on the holding plate and the relative arrangement between the resonators becomes clear from the worker's perspective, making it easier to fix the resonator in a short time. effective.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a dielectric coaxial resonator, FIG. 2 is a schematic layout of a filter, FIG. 3 is a sectional view of a conventional example, and FIG. 4 is a sectional view of a first embodiment of this invention. FIG. 5 is an enlarged sectional view of the first embodiment of this invention, and FIG. 6 is a sectional view of the second embodiment of this invention.
FIG. 7 is a plan view thereof, and FIG. 8 is a plan view of another embodiment. 1 is a dielectric coaxial resonator, 21 is a case body, 4
1 is a ground plate, 61, 71 are holding plates, 62, 72
is a groove.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of dielectric coaxial resonators are placed inside the case body, and a thin grounding plate is placed on the dielectric coaxial resonators, and the grounding plate is connected to the dielectric coaxial resonator. A fixing structure for a dielectric coaxial resonator, in which the outer conductor of the dielectric coaxial resonator is pressed with a presser plate so as to be in contact with the outer conductor of the body coaxial resonator, and the dielectric coaxial resonator is press-fitted to the case body. A waveform having a groove-like groove when viewed from the side opposite to the dielectric coaxial resonator across the presser plate and a convex groove when viewed from the dielectric coaxial resonator side is formed in the intervening part, and the groove is provided with a groove. Therefore, a fixing structure for a dielectric coaxial resonator is characterized in that the ground plate is pressed to contact the outer conductor and is fixed to the case body by pressure contact. (2) The groove is provided in the axial direction of the resonator between the dielectric coaxial resonators arranged in parallel on the holding plate, and the groove connects the ground plate to the dielectric coaxial resonator. A fixing structure for a dielectric coaxial resonator according to claim 1, characterized in that the outer conductor of the resonator is pressed so as to be in contact with a plurality of locations. (3) The groove is provided in a cut-off space of the holding plate in a direction intersecting the axial direction of the plurality of dielectric coaxial resonators arranged in parallel and connected to the open end of the dielectric coaxial resonator. dielectric coaxial resonance according to claim 1, wherein the groove presses the ground plate so that it comes into contact with a portion near the open end of the dielectric coaxial resonator. Fixed structure of the vessel.