JP2000228609A - Structure for supporting secondary reflecting mirror of cassegrain antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid high manufacturing cost due to a complicated manufacturing/ assembling process requiring precise processing for uniformizing the thickness of a side wall of a dielectric cylinder that is used to cover the reflecting face of a secondary reflecting mirror in the structure for supporting the conventional secondary reflecting mirror of this kind. SOLUTION: The structure consists of a primary reflecting mirror retaining ring 10, a plurality of support plates 11a-11c whose ends are fitted to notch grooves 112 provided on the inner circular wall of the ring 10 and extended in the direction of a waveguide and radially at equal intervals, a restriction ring 12 to restrict the support plates 11a-11c from moving to the off-axis direction by fitting the other ends of the support plates 11a-11c to the respective notch grooves provide the inner circular wall of the restriction ring, and a reinforcement ring 13 that restricts the support plates 11a-11c from moving toward the axis direction through the fitting to respective notch grooves provided on the outer circular wall of the ring 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a Cassegrain antenna sub-reflector support structure, and more particularly to a relatively small Cassegrain antenna sub-reflector support structure.

[0002]

2. Description of the Related Art FIG. 4 is a view for explaining a Cassegrain antenna, wherein 1 is a transmitter, 2 is a primary radiator, 3 is a main reflecting mirror, and 4 is a sub-reflecting mirror. As is well known, the Cassegrain antenna applies the Cassegrain telescope to radio waves. In the configuration shown in FIG. 1, an electromagnetic wave radiated from the primary radiator 2 is located at the focal point of the main reflecting mirror 3 The sub-reflector 4 is illuminated, scattered by the sub-reflector 4 to irradiate the main reflector 3, and the main reflector 3 forms secondary radiation directivity at a long distance. As an antenna to be used, it is widely used because cross-polarization is less likely to occur and support and rotation are relatively easy.

Accordingly, as shown in FIG. 4, in the Cassegrain antenna, it is necessary to dispose the main reflector 3 and the sub-reflector 4 at predetermined positions with respect to the primary radiator 2, so that the irradiation of electromagnetic waves is prevented as much as possible. A support structure having such a structure is used. 5 is a cross-sectional view for explaining a conventional support structure, and FIG. 6 is a perspective view of the same. The conventional support structure includes a main reflector pressing ring 20 and a dielectric cylinder 21 as shown in FIGS. , A dielectric cap 22, and a mounting screw 23.

The main reflector pressing ring 20 is screwed to the primary radiator 2 with the main reflector 3 interposed therebetween so that the main reflector 3 is held.
Is fixed, and a screw is cut on the outer periphery. The screw is used to screw the dielectric cylinder 21 to attach the dielectric cylinder 21 to the primary radiator 2. The dielectric cylinder 21 is threaded on one inner side of the cylindrical shape. The thread is screwed with the main reflecting mirror holding ring 20 to be vertically attached to the main reflecting mirror 3. The arrangement position is determined. Reference numeral 23 denotes a sub-reflector 4 and a dielectric cap 2 on the side wall of the dielectric cylinder 21.
2 is a mounting screw for screwing the second screw.

The conventional sub-reflector support structure is constructed as described above. First, the main reflector pressing ring 20 is attached to the primary radiator 2 with the main reflector 3 interposed therebetween, and then one of the dielectric cylinders 21 is mounted. The sub-reflector 4 and the dielectric cap 12 are attached to the ends using the mounting screws 13, and the dielectric cylinder 21 to which the sub-reflector 4 and the dielectric cap 22 are attached is screwed to the main reflector press ring 20 for assembly. ing.

[0006]

Since the conventional Cassegrain antenna sub-reflector support structure is constructed as described above, the following problems arise. Since the conventional support structure has a configuration in which the dielectric cylinder covers the primary radiator, the electrical characteristics of the antenna greatly change due to a change in the thickness of the dielectric cylinder. Therefore, strict uniformity is required for the processing of the wall thickness. Further, since the dielectric cylinder is configured to be screwed to the main reflector pressing ring, the manufacturing / assembly process is complicated, for example, it is necessary to form a screw on the outer circumference of the pressing ring and the inner circumference of the dielectric cylinder. The manufacturing cost of the antenna becomes expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a sub-reflector support structure which can simplify a manufacturing / assembly process with a simple configuration and provide an inexpensive antenna. .

[0008]

According to the Cassegrain antenna sub-reflector support structure of the present invention, a main reflector is mounted on a primary radiator, and a sub-reflector is provided at a predetermined distance in front of an opening of a waveguide protruding from the primary radiator. In the Cassegrain antenna sub-reflecting mirror support structure in which the reflecting mirror is provided, at least the ends of the main reflecting mirror retaining ring and the respective notches provided in the inner circular wall of the main reflecting mirror retaining ring do not come off. And a plurality of (preferably three or four) radially-spaced support plates extending in the direction of the waveguide and fitted at the other end of the support plates. The notch grooves provided on the inner circular wall of the support plate are fitted to each other, and a restraining ring for restricting movement of these support plates in the off-axis direction; a main reflector holding ring of the support plate; Between the restraining ring and Each notch groove provided in the wall is fitted and attached, and is constituted by a reinforcing ring for restricting movement of the support plate in the axial direction, and the main reflector pressing ring holds the main reflector in between. The primary radiator has a structure in which it is mounted so as to surround the waveguide projection of the primary radiator, and a sub-reflector is mounted on the restraining ring.

When a plurality of reinforcing rings are used,
An outer diameter of the reinforcing ring located near the sub-reflector is made smaller. Further, the main reflector holding ring, the support plate, the restraining ring, and the reinforcing ring are all made of a non-metallic plate.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view for explaining a Cassegrain antenna sub-reflector support structure of the present invention;
FIG. 2 is a perspective view, and FIG. 6 is an exploded configuration view.
In these figures, 10 is a main reflector holding ring, 11
a to 11c are support plates, 12 is a restraining ring, 13
a and 13b are reinforcing rings, 14 is a cap, and 15 is a fixing screw.

As shown in FIG. 3, the main reflector pressing ring 10 is attached to one end of the support plate 11 with a screw hole 111 to be fixed to the primary radiator 2 with the main reflector 3 interposed therebetween. A notch groove 112 that fits with the projected portion 100 is provided. The support plate 11 is a plate which is vertically attached to the main reflector pressing ring 10 via the protrusion 100 to form a support, and a protrusion 103 which fits with the restraining ring 12 is provided at the other end. Notch grooves 101, which fit with the reinforcing rings 13a, 13b, respectively,
102 are provided.

The restraining ring 12 has a notch groove 115 which fits into the projection 103 provided on the support plate 11,
A screw hole 116 is provided for screwing and fixing together with the cap 14, and restricts the movement of the plurality of (preferably three or four) support plates 11 erected on the main reflector pressing ring 10 in the off-axis direction. Play a role. Further, the reinforcing rings 13a and 13b are fitted into the intermediate portions of the support plate 11 at predetermined intervals with the cutout grooves 113 and 114, respectively.
1 plays a role of restricting the movement in the axial direction. The reason why the outer shape of the reinforcing ring 13b is smaller than that of the reinforcing ring 13a is that as the closer to the sub-reflector 4, the larger the diameter, the more the electromagnetic wave irradiation is hindered.

The sub-reflector support structure of the present invention is constructed as described above. First, the notch grooves 101 and 113, 102 and 11 are provided.
4 are fitted, and a plurality of (three in this embodiment) support plates 11 are combined on the outer periphery of each of the reinforcing rings 13a and 13b.
Next, each support plate 11 is inserted into each notch groove 115 of the restraining ring 12.
And the restraining ring 12 is attached to one end of the support plate 11. Next, the support structure is assembled by fitting the projections 100 provided at the other end of each support plate 11 into the notch grooves 112 of the main reflector pressing ring 10. The main support mirror 3
The sub-reflector 4 and the cap 14 are screwed together with the cap 14 to the constraining ring 12 with the fixing screw 15 so that the Cassegrain antenna is manufactured. finish.

That is, the supporting structure of the sub-reflector according to the present invention comprises a main reflector pressing ring 10, a support plate 11, a restraining ring 12,
The reinforcing rings 13a and 13b are both formed of plate-like members, and the plate-like members are combined in the horizontal and vertical directions.
In addition to restricting the movement of the reinforcing ring 1 in the off-axis direction,
Since the movement of the support plate 11 in the axial direction is restricted by 3a and 13b, a strong sub-reflector support structure can be formed only by the plate-like member. This means that the sub-reflector support structure can be formed only by a simple combination of plate-like members formed by using a mold, and an inexpensive and highly accurate Cassegrain antenna can be provided. Needless to say, it is desirable to use a plate made of a material other than metal, such as plastic or ceramic, so that the plate-like member does not obstruct the irradiation of electromagnetic waves as much as possible.

[0015]

As described above, in the Cassegrain antenna sub-reflector support structure of the present invention, a structure is formed by fitting a plurality of plate-like members, a sub-reflector is attached to one end of the structure, and the other end is provided. Need only be fixed to the primary radiator, and the manufacturing / assembly process is greatly simplified, and an inexpensive antenna can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a Cassegrain antenna sub-reflector support structure of the present invention.

FIG. 2 is a perspective view for explaining a Cassegrain antenna sub-reflector support structure of the present invention.

FIG. 3 is an exploded configuration diagram for explaining a Cassegrain antenna sub-reflector support structure of the present invention.

FIG. 4 is a diagram for explaining a Cassegrain antenna.

FIG. 5 is a cross-sectional view for explaining a conventional Cassegrain antenna sub-reflector support structure.

FIG. 6 is a perspective view for explaining a conventional Cassegrain antenna sub-reflector support structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transmitter 2 Primary radiator 3 Main reflecting mirror 4 Sub-reflecting mirror 10 Main-reflecting-mirror holding ring 11a-11c Each support plate 12 Restriction ring 13a, 13b Reinforcement ring 14 Cap 15 Fixing screw 100,103 Projection part 101,102,112 , 113, 114, 115 Notched groove

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J020 AA03 BA09 BC06 CA01 DA02 5J047 AA04 AA09 AA10 AA19 AB18 BA09 BB19 BB20 BB21 BB22 BG10

Claims (3)

[Claims] 1. A Cassegrain antenna sub-reflector support structure, comprising: a main reflector mounted on a primary radiator; and a sub-reflector disposed at a predetermined distance in front of an opening of a waveguide projecting from the primary radiator. A main reflector holding ring; and a notch groove provided in an inner circular wall of the main reflector holding ring such that its ends are not detached, and are radially spaced at the same wavelength with the waveguide as an axis. Multiple sheets (3 or 4
And a notch groove provided in the inner circular wall of the supporting plate is fitted to the other end of the supporting plate. A constraining ring for restricting movement in the off-axis direction, a notch groove provided in an outer circular wall of the supporting plate between the main reflector pressing ring and the constraining ring is fitted. And a reinforcing ring for restricting movement of the support plate in the axial direction, wherein the main reflector pressing ring is surrounded by the waveguide projection of the primary radiator with the main reflector interposed therebetween. A Cassegrain antenna sub-reflector support structure in which a sub-reflector is mounted on the restraining ring. 2. The Cassegrain antenna sub-reflector support structure according to claim 1, wherein when a plurality of the reinforcing rings are used, the outer diameter of the reinforcing ring located near the sub-reflector is made smaller. Cassegrain antenna auxiliary reflector support structure. 3. The Cassegrain antenna sub-reflector support structure according to claim 1, wherein the main reflector holding ring, support plate, restraining ring, and reinforcing ring are all made of non-metallic plates. Cassegrain antenna sub-reflector support structure.