JPS6156641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coaxial resonator for quarter-wave ultra-high frequencies with one end short-circuited and the other end open.

A quarter-wavelength ultra-high frequency coaxial resonator with one end short-circuited and the other end open is a resonator in which one end of a rod-shaped inner conductor is fixed in a cylindrical outer conductor, and it is small, has a high Q, and is easy to design and manufacture. Although this type of resonator is often used in high-frequency bands, it has the disadvantage that its characteristics tend to deteriorate due to vibration because the central conductor is cantilevered due to its structure.

For this reason, in the past, a dielectric disk was inserted into the tip of the center conductor to mechanically support the tip with respect to the outer conductor to provide vibration resistance.

Figures 1a and 1b show a conventional method of supporting the center conductor. 101 is a resonator outer conductor, 102 is a center conductor, and 103 is a dielectric support disk. Second
The figure shows the structure of the dielectric disk 103, and 201 is a hole for inserting into the center conductor 102.

When supporting the center conductor using this method, there is no problem with the support itself, but when inserting the disk 103 into the resonator, the entire outer periphery of the disk 103 touches the inner periphery of the outer conductor 101, resulting in large friction. In addition, since the dielectric disk 103 forms a capacitance between the center conductor 102 and the outer conductor 101, the no-load Q of the resonator deteriorates due to dielectric loss. I had a problem.

The present invention seeks to eliminate these drawbacks. FIGS. 3 and 4 show the structure of a dielectric support plate according to the present invention. In FIG. 3, 301 is a dielectric substrate, and its shape consists of three parts 302 to 304 surrounded by arcs and chords from a disc-shaped dielectric.
is cut, and the remaining circumferential portion 306, 3
It contacts the outer conductor at 07,308. 305 indicates a hole through which the center conductor passes. FIG. 4 shows another embodiment of the present invention, and shows a dielectric plate 401 having a shape obtained by cutting four parts 402 to 405 surrounded by arcs and chords from a disc-shaped dielectric. The center conductor is passed through 406, and the four circumferential parts remaining after cutting are used to contact the outer conductor and support the center conductor.

Figures 5a and 5b show the center conductor support plate 30 of Figure 3.
1 is used to illustrate the structure of a resonator in an embodiment of the present invention in which a center conductor 102 is supported.

As can be easily understood by comparing with Figure 1,
Since the portion of the support plate 301 in contact with the coaxial outer conductor 101 is extremely small, friction is reduced when inserting it into the resonator, and it can be easily mounted and fixed. In addition, the center conductor 102 and the ground conductor 1 are connected via a dielectric.
Since the capacitance formed between 01 and 01 can be significantly reduced compared to the case of FIG. 1, loss accompanying dielectric loss is also improved, and deterioration of no-load Q can be almost ignored. On the other hand, the vibration resistance characteristics are also as good as in the case shown in FIG.

As shown in FIG. 5, if the diameter w ₁ of the tip of the center conductor 102 is made smaller than the diameter w ₂ of the other parts, the insertion position of the dielectric plate 301 can be easily determined and the work can be done easily. You can increase your sexuality.

In the embodiment shown in FIG. 5, the dielectric plate 301 having the approximately triangular shape shown in FIG. It is possible to achieve the same effect by using In addition, this dielectric plate 301
The shape is not limited to the above examples, but may be pentagonal,
Although polygons such as hexagons exhibit similar effects, the effect becomes smaller as the number of corners increases, as the area for cutting the peripheral portion of the dielectric becomes smaller and the shape approaches a circle. Generally, a triangle to a hexagon is suitable.

Furthermore, although the symmetry of the shape of the dielectric plate 301 does not pose any particular problem in terms of characteristics, in consideration of ease of processing, uniformity of stress, etc., it is desirable to have a symmetrical structure with respect to the center, so that it is not cut. It is preferable that the remaining outer peripheral portion corresponds to the corners of a substantially regular polygon.

As described above, in order to mechanically support the center conductor of a quarter-wavelength coaxial resonator with one end short-circuited and one end open, a portion of the peripheral portion of the disc-shaped dielectric material is cut off. This is a coaxial resonator in which a polygonal support plate is inserted into the tip of the center conductor. Since this support plate has a small area in contact with the coaxial outer conductor, there is little friction and the workability of installation is significantly improved. Moreover, the deterioration of the no-load Q can be almost ignored, and a coaxial resonator with excellent vibration resistance characteristics for ultra-high frequencies can be obtained.

[Brief explanation of the drawing]

Figures 1a and b are a cross-sectional side view and a cross-sectional view taken along the line A-A' of an example of a conventional coaxial resonator for ultra-high frequencies, and Figure 2 is a coaxial resonator used for the ultra-high frequency coaxial resonator in Figure 1. A plan view of a dielectric disk for supporting a center conductor, and FIGS. 3 and 4 are plan views showing examples of a dielectric plate for supporting a center conductor used in an ultra-high frequency coaxial resonator according to the present invention, respectively. , FIGS. 5a and 5b are a cross-sectional side view and a cross-sectional view taken along the line A-A' of the embodiment of the ultra-high frequency coaxial resonator according to the present invention. 101...Outer conductor, 102...Center conductor, 3
01,401...Dielectric substrate.

Claims (1)

[Scope of Claims] 1. One end of a rod-shaped internal conductor is fixed substantially coaxially within a cylindrical external conductor, and at the other end of the internal conductor, a part of the outer peripheral portion of a dielectric disk having a diameter equal to the internal diameter of the external conductor is attached. A coaxial resonator for ultra-high frequencies, characterized in that a supporting plate is inserted with parts left in three or more places. 2. The ultra-high frequency coaxial resonator according to claim 1, wherein the outer peripheral portion of the support plate that remains uncut is formed so as to correspond to the corners of a substantially regular polygon. 3. The ultra-high frequency coaxial resonator according to claim 2, wherein the regular polygon is a regular triangle or a regular hexagon.