JPH058886B2 - - Google Patents

Description

Detailed Description of the Invention [Summary] The present invention relates to a support structure for a sub-reflector of a Cassegrain antenna. By attaching the reflector, the accuracy of the position and inclination of the sub-reflector with respect to the primary horn and the ease of assembling the sub-reflector are improved.

[Industrial application field]

The present invention relates to a sub-reflector support structure for a Cassegrain antenna.

[Conventional technology]

A Cassegrain antenna includes a main reflector with a primary horn or main radiator in the center, and a sub-reflector located closer to the main radiator than the focal point of the main radiator. When a Cassegrain antenna is used as a transmitter, radio waves radiated from the main radiator are reflected by the sub-reflector, then re-reflected by the main reflector, and radiated forward as parallel radio waves. on the other hand,. When a Cassegrain antenna is used in the receiver, the parallel radio waves are reflected by the main reflector, then re-reflected by the sub-reflector and enter the waveguide of the main radiator.

In the conventional Cassegrain antenna, as shown in FIG. 3, the sub-reflector 1 and the main radiator 2 are separated, and the sub-reflector 1 connects to the main reflector via three or four stays 3. It was supported by 4.

[Problem that the invention seeks to solve]

In the case of the conventional sub-reflector support structure described above, since the sub-reflector 1 and the primary horn 2 are separately assembled to the main reflector 4, the position and inclination of the sub-reflector 1 with respect to the primary horn 2 may be misaligned. It had the disadvantage of being easy. In particular, since the sub-reflector 1 is assembled to the main reflector 4 by a plurality of elongated stays 3, the accumulation of accuracy errors of the stays 3 may cause the sub-reflector 1 to
The disadvantages are that accuracy errors in the position and inclination of the sub-reflector 1 become large, and on the other hand, it takes time and effort to adjust the position of the sub-reflector 1 with respect to the horn 2.

In view of the above problems, an object of the present invention is to provide a sub-reflector support structure for a Cassegrain antenna that can improve the accuracy of the position and inclination of the sub-reflector with respect to the primary horn and the workability of assembling the sub-reflector. shall be.

[Means for solving problems]

As a means for achieving the above-mentioned object, the present invention includes fitting the proximal end of a cylindrical support to the distal end surface of a primary horn to be attached to a main reflector, and attaching the proximal end of a cylindrical support by pressing it in the axial direction. The auxiliary reflector is fitted around the circumference of the annular recess inside the tip of the shaped support and is attached in contact with the axial direction, and the primary horn and the auxiliary reflector are coaxial and at mutual positions in the axial direction. Provided is a sub-reflector support structure for a Cassegrain antenna, in which the sub-reflector is positioned by a cylindrical support.

[Effect]

According to the above means according to the present invention, the sub-reflector is assembled to the primary horn via a single cylindrical support, and the primary horn and the sub-reflector are coaxial and mutually axially arranged. Since the position is determined by the cylindrical support, the alignment accuracy of the sub-reflector with respect to the primary horn is improved, and the workability of assembling the sub-reflector is improved. Moreover, the length of the support is between the tip of the primary horn and the sub-reflector, which is shorter than the conventional stay that extends between the sub-reflector and the main reflector, so its mechanical accuracy is reduced. Therefore, the assembly accuracy of the sub-reflector is improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show one embodiment of the present invention. Referring to these figures, the Cassegrain antenna includes a main reflector 11, and a primary horn 12 connects to the main reflector 1 through a base flange 13.
It is designed to be installed in the center of 1. Here, a base flange 13 is fixed to the main reflector 11 by rivets 14, and a circular flange 12a formed at the base end of the primary horn 12 is fixed to the base flange 13 by screws 15.

A cylindrical support 1 is attached to the tip of the primary horn 12.
A sub-reflector 17 and a lid 18 having a larger diameter than the sub-reflector 17 are attached to the tip of the support 16. To explain in more detail, a flange 12b coaxial with the inner diameter of the primary horn 12 is formed at the tip of the primary horn 12, and a cylindrical support 16 is formed.
A circular recess 16a formed coaxially with the inner diameter of the base end of the support body 16 fits into the flange 12b of the primary horn 12, and the base end of the support body 16 is fitted with the screw 1.
9 is fixed to the flange 12b of the primary horn 12.

On the other hand, a sub-reflector 1 is provided on the inner surface of the tip of the support 16.
An inner annular recess 16b into which the lid 18 is fitted and an outer annular recess 16c into which the lid 18 is fitted are formed coaxially with the inner surface of the support body 16. The lid 18 is fixed to the support 16 with adhesive, and the sub-reflector 17 is clamped and fixed by the lid 18 and the support 16.

The support 16 is made of a material with a low dielectric constant and good radio wave transmittance, such as polytetrafluoroethylene or fiber reinforced plastic (FRP).

In the sub-reflector support structure having the above configuration, since the sub-reflector 17 is assembled to the primary horn 12 via the single cylindrical support 16, the position of the sub-reflector 17 with respect to the primary horn 12 is The alignment becomes easy, and the sub-reflector 17 also becomes easy to assemble. In particular, in this embodiment, the sub-reflector 17 and the lid 18 are fitted into the tip recesses 16b and 16c of the support 16, respectively, and the lid 18 is attached to the support 16 with adhesive.
By fixing the sub-reflector 17 to the support 16
Therefore, the assembly work of the sub-reflector 17 becomes very easy.

In addition, the support body 16 has a length between the tip of the primary horn 12 and the sub-reflector 17, and is shorter than a conventional stay extending between the sub-reflector and the main reflector, so that Therefore, the accuracy of assembling the sub-reflector 16 is improved. Furthermore, in the case of this embodiment, the base end of the support 16 is coaxially fitted to the tip of the primary horn 12, and the sub-reflector 17 is coaxially fitted to the tip of the support 16. Therefore, very high accuracy can be easily obtained regarding the position and inclination of the sub-reflector 17 with respect to the primary horn 12.

Although the illustrated embodiments have been described above, the present invention is not limited to the aspects of the above embodiments. Various changes can be made to the form, etc.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, the sub-reflector is assembled to the primary horn via a single cylindrical support, and furthermore, the primary horn and the sub-reflector are coaxial. Moreover, since the mutual positions in the axial direction are determined by the cylindrical support, the alignment accuracy of the sub-reflector with respect to the primary horn is improved, and the workability of assembling the sub-reflector is improved. Moreover, the length of the support is between the tip of the primary hoe and the sub-reflector, which is shorter than the conventional stay that extends between the sub-reflector and the main reflector, improving its mechanical precision. This improves the assembly accuracy of the sub-reflector. Therefore, it is possible to provide a sub-reflector support structure for a Cassegrain antenna that can improve the accuracy of the position and inclination of the sub-reflector with respect to the primary horn and the ease of assembling the sub-reflector.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a sub-reflector support structure of a Cassegrain antenna showing an embodiment of the present invention, Fig. 2 is an enlarged view of the main part of the support structure shown in Fig. 1, and Fig. 3 is a conventional Cassegrain antenna. FIG. 3 is a perspective view showing the sub-reflector support structure of FIG. In the figure, 11 is a main reflector, 12 is a primary horn, 16 is a support, 17 is a sub-reflector, and 18 is a lid.

Claims (1)

[Claims] 1 Primary horn 1 attached to main reflector 11
The proximal end of the cylindrical support 16 is fitted onto the distal end surface of the cylindrical support 16 and attached by pressure contact in the axial direction. A Cassegrain antenna in which the primary horn 12 and the sub-reflector 17 are fitted together and attached in contact with each other in the axial direction, and the primary horn 12 and the sub-reflector 17 are coaxially positioned with respect to each other in the axial direction by a cylindrical support 16. secondary reflector support structure.