JPH0263203A - Circular waveguide line - Google Patents

Abstract

PURPOSE:To increase the degree of freedom of the design of other part of a circular waveguide path by using a conductor torus fitted to a lower conductor so as to match the connection part. CONSTITUTION:The torus matching body 7 has nearly the same diameter as the diameter of the bottom face of a conical matching body 6 and matches the impedance of a coaxial cable 8 and the impedance of a guide space 9 made of a slit plate 1, a bottom plate 2 and an outer peripheral plate 3 with the synergistic effect with the conical matching body 6. The impedance of the coaxial cable 8 and the impedance of the guide space 9 are matched by the synergistic action between the torus matching body 7 and the conical matching body 6 in this way. Thus, the reflection caused at the connecting point between the coaxial cable 8 and the impedance of the guide space 9 is reduced. Thus, the coaxial cable with a free size is connected without being limited by the interval of the circular guide lines.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a circular waveguide such as a radial line slot antenna used in SHF, EHF bands, etc.

<Prior Art> In general, the one shown in FIG. 6 is known as a radial line slot antenna using a circular waveguide.

The radial line slot antenna shown in this figure includes a conductive slot plate 101 in which a plurality of slots are formed,
A conductive bottom plate 102 is arranged to face the slot plate 101 at a predetermined distance, and a conductive outer peripheral plate 1 connects the periphery of the slot plate 101 and the bottom plate 102.
03, a terminating resistor 104 attached to the inner circumferential surface of this outer peripheral plate 103, and its center conductor connected to the slot plate 101.
and a coaxial cable 105 whose outer conductor is connected to the bottom plate 102.

Then, when power is supplied via the coaxial cable 105, radio waves are emitted from each slot of the slot board 101.

Furthermore, as a radial line slot antenna using a circular waveguide, the antenna shown in FIG. 7 is also known. In this figure, the same parts as those shown in FIG. 6 are given the same reference numerals.

The radial line slot antenna shown in this figure has the sixth
A conical matching body 106 made of a conductor is added to the connecting portion between the slot plate 101 of the circular waveguide shown in the figure and the center conductor of the coaxial cable 105, and this conical matching body 106 allows the coaxial cable 105 to Reflection occurring at the connection portion between the center conductor and the slot plate 101 is reduced.

<Problems to be Solved by the Invention> The conventional circular waveguide as described above has the following problems.

First, in the one shown in FIG. 6, the coaxial cable 105
Since the impedance of the slot plate 101 and the impedance of the waveguide space 107 formed by the slot plate 101, the bottom plate 102, etc. do not match, power is reflected at these connections and the supplied power cannot be extracted effectively. There's a problem.

In addition, in the case shown in Fig. 7, if an optimal design is performed to prevent power reflection at the connection part, the shape of the conical matching body and the outer diameter of the coaxial feeder are determined by the spacing between the circular waveguides. Unfortunately, there was no freedom in design.

In the SHF, EHF bands, etc., if the spacing between the circular waveguides is determined based on a design that takes into account manufacturing accuracy, the outer diameter of the coaxial cable 105 for connection becomes large, and the basics of the coaxial cable 105 are In some cases, the circular waveguide cannot be normally excited because power is transmitted in the TE or TM mode rather than in the TEM mode.

The present invention has been made in order to eliminate the drawbacks of the prior art, and in particular reduces the reflection of power at the connection part,
It is an object of the present invention to provide a circular waveguide line to which a coaxial feeder line having a sufficiently small outer diameter can be connected to transmit only the TEM mode, which is the basic mode of a coaxial cable.

Means for Solving the Problems> In order to solve the above problems, the circular waveguide according to the present invention has an upper conductor surface and a lower conductor surface for emitting radio waves, and an upper conductor surface and a lower conductor surface. a waveguide space surrounded by a conductor wall having a connecting side conductor surface;
a conical matching body disposed within the waveguide space such that the top faces the power feeding opening hole formed in the lower conductor surface; and a conical matching body having a diameter comparable to the diameter of the bottom surface of the matching body. and a conductor ring disposed on the lower conductor surface so as to be concentric with the matching body, and a coaxial cable connected to the power feeding opening and having an outer diameter sufficiently smaller than the wavelength of the frequency used. It is characterized by

<Operation> With the above configuration, the connection portion can be matched by the conductor ring attached to the lower conductor, thereby increasing the degree of freedom in designing other parts of the circular waveguide.

<Embodiment> FIG. 1 is a partially cutaway perspective view showing an example of a radial line slot antenna using an embodiment of the circular waveguide according to the present invention.

The radial line slot antenna shown in this figure consists of a conductive slot plate 1 in which a plurality of slots are formed, a conductive bottom plate 2 facing the slot plate 1 and a predetermined distance apart, and these slot plates 1. A conductive outer peripheral plate 3 connecting the peripheral edge of the base plate 2 to the peripheral edge of the bottom plate 2, a terminating resistor 4 attached to the inner peripheral surface of the outer peripheral plate 3, and a vertex facing the hole 5 formed in the bottom plate 2. A conductive conical matching body 6 is attached to the lower center of the slot plate 1 (lower center in this figure) in the direction as shown in FIG. The coaxial cable 8 has a central conductor end connected to the apex of the conical matching body 7 and an outer conductor end connected to the bottom plate 2. .

In this case, the annular matching body 7 is formed to have approximately the same diameter as the bottom diameter of the navigation conical matching body 6, and the conical matching body 6
This acts synergistically to match the impedance of the coaxial cable 8 and the impedance of the waveguide space 9 formed by the slot plate 1, the bottom plate 2, and the outer peripheral plate 3.

Thus, in this embodiment, the coaxial cable 8 is
Since the impedance of the coaxial cable 8 and the impedance of the waveguide space 9 are matched, reflections occurring at the connection points between the coaxial cables 8 and the waveguide space 9 can be significantly reduced as shown in FIG. Can be done.

In particular, even if a commonly used coaxial cable 8 is used, if the size of the conical matching body 6 and the size of the annular matching body 7 are adjusted appropriately.

As shown in FIG. 3, reflected power can be minimized.

Furthermore, even when an optimally designed coaxial cable 8 is used, by appropriately adjusting the size of the conical matching body 6 and the size of the annular matching body 7, the reflection as shown in FIG. characteristics can be obtained.

FIG. 5 is a partially cutaway perspective view showing an example of a radial line slot antenna using another embodiment of the circular waveguide according to the present invention. In this figure, the same parts as those in FIG. 1 are given the same reference numerals.

The radial line slot antenna shown in this figure is
The difference from what is shown in the figure is that a partition plate 10 is arranged between the slot plate 1 and the bottom plate 2, and the partition plate 10 and the slot plate 1 form an upper layer waveguide line 11. 10 and the bottom plate 2 form the lower waveguide line 1.
2, and a conductive folded part 13 is provided on the inner peripheral surface of the outer peripheral plate 3, and this folded part 13 prevents power reflection at the connection point between the upper layer waveguide line 11 and the lower layer waveguide line 12. This was done to prevent this from happening.

Even in the case of such a configuration, by appropriately adjusting the size of the conical matching body 6 and the size of the circular matching body 7, it is possible to prevent the problem from occurring at the connection point between the lower layer waveguide 12 and the coaxial cable 8. Reflection of power can be significantly reduced.

<Effects> As explained above, according to the present invention, it is possible to significantly reduce the reflection of power in the coaxial cable, the waveguide space, and the connection part, and also to freely operate the coaxial cable without being restricted by the spacing between the circular waveguides. Coaxial cables of various sizes can be connected.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an example of a radial line slot antenna using an embodiment of the circular waveguide according to the present invention, FIG. 2 is a characteristic diagram for explaining the effects of the embodiment, and FIG. Fig. 3 is a characteristic diagram for explaining the effects of the same embodiment, Fig. 4 is a characteristic diagram for explaining the effects of the same embodiment, and Fig. 5 is a characteristic diagram for explaining the effects of the same embodiment. FIG. 6 is a partially cutaway perspective view showing an example of a radial line slot antenna using a conventionally known circular waveguide; FIG. 7 is a partially cutaway perspective view showing an example of a radial line slot antenna using another example of a conventionally known circular waveguide. 1... Upper conductor surface (slot plate), 2... Lower conductor surface (bottom plate), 5... Opening hole for power supply (hole), 6...
Conical matching body (conical matching body), 7... conductor ring (
circular matching body), 9... waveguide space. Patent applicant: Anten Kogyo Co., Ltd. No. 1m No. 36 No. 7

Claims (1)

[Claims] (1) A waveguide space surrounded by a conductor wall having an upper conductor surface, a lower conductor surface, and a side conductor surface connecting the upper conductor surface and the lower conductor surface for radio wave emission; a conical matching body disposed in the waveguide space with its top facing the power feeding opening hole formed in the surface; and a conical matching body having a diameter comparable to the diameter of the bottom surface of the matching body. and a conductor ring disposed on the lower conductor surface so as to be concentric with the body.