JPS63209303A - Nondirectional antenna within horizontal plane - Google Patents

Abstract

PURPOSE:To facilitate the control of the directivity within a perpendicular plane by reflecting a radiated radio wave from a primary radiator in a sub-reflecting mirror having an annular hyperboloid or ellipsoid of revolution and making the radio wave incident in a main reflecting mirror having a conical paraboloid of revolution. CONSTITUTION:In constituting the sub-reflecting mirror 2 by an ellipsoid of revolution, one focus 5 of two foci 4, 5 is made coincident with the center of phase of a primary radiator 3 and the other focus 4 is made coincident with a focus of a conical paraboloid of revolution main reflecting mirror 1, then a spherical wave radiated from the radiator 3 is reflected in the annular paraboloid of revolution subrelecting mirror plane 2 and made incident in the conical paraboloid of revolution main reflecting mirror 1, which is equivalent to the radiation of a radio wave from the focus of the main reflecting mirror 1, then the radio wave is radiated horizontally as a plane wave with an equal phase from the aperture of the antenna. Thus, the directivity in the horizontal plane is nondirectional in the horizontal plane, the directivity in the vertical plane is maximum in the horizontal direction and the direction is varied vartically with respect to the horizontal plane by varying the position (shape) of the main reflecting mirror 1.

Description

[Detailed Description of the Invention] [Summary] An omnidirectional antenna in a horizontal plane for communicating between a central station and a large number of stator stations scattered around the central station or mobile stations moving in a horizontal plane. The main reflector is a conical paraboloid of revolution, and the secondary reflector has a toric hyperboloid of revolution or ellipsoid of revolution as a reflection surface to reflect the radio waves uniformly radiated from the -order radiator in the horizontal plane. The beam is reflected by the beam and made incident on the main reflecting mirror, making it easy to control the directivity in the vertical plane.

[Industrial application field]

The present invention relates to a horizontal omnidirectional antenna for communicating between a central station and a large number of stator stations or mobile stations.

In a system that communicates between a central station and a large number of stator stations scattered around the central station or slave stations that move around the central station, instead of providing the central station with an antenna for the slave stations, one It is preferable to provide two non-directional antennas in the horizontal plane.

[Conventional technology]

As an omnidirectional antenna in the horizontal plane, for example,
It is shown in the publication No.-65045. The antenna shown in this publication has the configuration shown in FIGS. 7 and 8, and in FIG. Consisting of a -order radiator 32 and a circular waveguide 33 for power feeding, the -order radiator 3
It is explained that the radio waves radiated from 2 are reflected by the reflecting mirror 31 and radiated in the horizontal direction, and are non-directional in the horizontal plane.

Further, in FIG. 8, a main reflecting mirror 34 having a substantially conical shape having a hyperboloid of rotation, a sub-reflecting mirror 35 having a paraboloid of revolution, a conical-order radiator 36, and a circular waveguide for power feeding are shown. The radio waves emitted from the -order radiator 36 are reflected by the sub-reflector 35 and incident on the main reflector 34, and are radiated from the main reflector 34 in the horizontal direction. It is explained that it is non-directional.

Also, dipole antennas, biconical antennas, and the like are known as other non-directional antennas in the horizontal plane.

[Problems to be solved by the invention] Using frequencies of several GHz or more, communication between a central station and a large number of stator stations scattered around the central station, or between a central station and mobile stations moving around the central station. When communicating between Furthermore, since the biconical antenna is a radiating antenna that does not have a reflecting mirror, it is difficult to interface between the excitation source and the antenna system in high frequency bands, and it is difficult to control the directivity in the vertical plane. There are drawbacks.

Furthermore, since the conventional antenna shown in FIG. 7 has only one reflecting mirror, it is difficult to control the electromagnetic field distribution on the antenna aperture, and the conventional antenna shown in FIG. Although a main reflecting mirror and a sub-reflecting mirror are used, since the main reflecting mirror 34 is a hyperboloid of rotation, there is a drawback that it is difficult to control the directivity in a vertical plane.

An object of the present invention is to provide non-directivity in the horizontal plane and to facilitate control of directivity in the vertical plane.

[Means for solving problems]

The omnidirectional antenna in the horizontal plane of the present invention has a -order radiator, a sub-reflector, and a main reflector, and will be described with reference to FIG. 1.

In Figure 1, it is rotationally symmetrical with respect to the axis 6, and the left side of the cross section is shown, and the outer side of the approximately conical paraboloid of revolution or a surface of revolution that has been corrected is the reflective surface. A conical paraboloid of revolution main reflecting mirror 1, a substantially toric hyperboloid of revolution or an ellipsoid of revolution, or a surface of revolution obtained by making corrections thereto is used as a reflecting surface, and the reflecting surface is a conical paraboloid of revolution main reflecting mirror. A sub-reflector 2 is placed opposite to the reflecting surface of the mirror 1, and radio waves are radiated to the reflecting surface of the sub-reflector 2 and radiated horizontally from the reflecting surface of the conical paraboloid of revolution main reflector 1. It is composed of a primary radiator 3.

[Effect]

The primary radiator 3 is composed of a biconical antenna, a dipole antenna, or the like, and radiates radio waves to the sub-reflector 2 nondirectionally in a horizontal plane.

This radio wave is reflected by the sub-reflector 2, enters the conical rotational speed object plane main reflector 1, and is emitted in the horizontal direction.

At this time, if the sub-reflector 2 is constructed of a spheroidal ellipsoid as shown in FIG. When the other focal point 4 is made to coincide with the focal point of the conical paraboloid of revolution main reflecting mirror 1, the spherical wave emitted from the -order radiator 3 forms an annular shape surrounding the -order radiator 3. The light is reflected by the sub-reflecting mirror 2 and is incident on the conical paraboloid of revolution main reflecting mirror 1, as if it were incident on the conical paraboloid of revolution main reflecting mirror 1 from the focal point 4. This is equivalent to a radio wave being radiated from the focal point of the main reflecting mirror 1, so that it is radiated horizontally from the aperture of the antenna as a plane wave with the same phase.

Therefore, the directivity in the horizontal plane becomes omnidirectional in the horizontal plane as shown in FIG. 2, and the directivity in the vertical plane becomes maximum in the horizontal direction as shown in FIG. This vertical plane directivity characteristic is
By changing the position and shape of the main reflecting mirror 1, it can be changed vertically with respect to the horizontal plane.

〔Example〕

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

FIG. 4 is an explanatory diagram of one embodiment of the present invention, and shows a schematic cross section. In the same figure, reference numeral 11 indicates a substantially conical paraboloid of revolution or a surface of revolution obtained by adding correction to the reflecting surface 11.
a is a conical paraboloid of revolution main reflecting mirror, 12 is a sub-reflecting mirror whose reflecting surface is a toric hyperboloid of revolution or an ellipsoid of revolution, or a surface of revolution obtained by correcting these surfaces, and 13 is a bi-directional mirror. A primary radiator such as a conical antenna, 14 a feeding waveguide,
15 is a support or cylinder made of metal or dielectric,
A case is shown in which the sub-reflector 12 uses a hyperboloid of rotation.

The conical paraboloid of revolution main reflecting mirror 11 has a parabola 1 indicated by a dotted line.
The reflecting surface 11a is a conical curved surface formed by rotating around an axis 17 at a predetermined position between the apex of 6 and the focal point.
In addition, the sub-reflector 12 has a part of a curved surface formed by rotating a hyperbola or an ellipse around an axis 17 as a -order radiator 13.
The main reflecting mirror 11 has a reflecting surface 12a having an annular shape surrounding the main reflecting mirror 11, and is arranged so that the focal point of the reflecting surface 12a and the focal point of the reflecting surface 11a of the main reflecting mirror 11 coincide with each other.

Therefore, it is fed through the waveguide 14 and the -order radiator 13
The spherical wave radiated from the reflection surface 12a of the sub-reflector 12
The radio wave is reflected by the main reflecting mirror 11 and is incident on the reflecting surface 11a of the main reflecting mirror 11, and since the focal points of the sub-reflecting mirror 12 and the main reflecting mirror 11 are at the same position, when the radio wave is incident on the main reflecting mirror 11 from that focal point. is equivalent to , and is radiated horizontally from the aperture surface as a plane wave with the same phase.

Alternatively, the cylinder 15 may be made of a dielectric material to fix the space between the main reflecting mirror 11 and the sub-reflecting mirror 12, and to have a sealed structure so that raindrops and the like do not enter into the interior through the opening surface.

FIG. 5 is an explanatory diagram of another embodiment of the present invention, and the same reference numerals as in FIG. 4 indicate the same parts. In this embodiment, the vertical positions of the main reflecting mirror 11 and the sub-reflecting mirror 12 are reversed with respect to the embodiment shown in FIG. This is similar to the embodiment.

FIG. 6 is an explanatory diagram of the control of the directivity in the vertical plane, and the shape is rotationally symmetrical about the axis 26 as in FIG. 1, and the left side of the cross section is shown. It shows. If one focus 25 of the focal points 24 and 25 of this sub-reflector 22 is made the phase center of the -order radiator 23, and the other focus 24 is made coincident with the focus of the main reflector 21, the -order A spherical wave is emitted from the phase center of the radiator 23 and is incident on the sub-reflector 22, reflected by the sub-reflector 22, and incident on the main reflector 21, where it is focused at the focal point 2, which is the phase center.
The radio waves radiated from the antenna 5 are equivalent to those radiated from the focal point 24 and incident on the main reflecting mirror 21, and since the reflecting surface of the main reflecting mirror 21 is a paraboloid of revolution, the radio waves are equal on the antenna aperture plane. It becomes a phase plane wave.

Then, the shape of the main reflecting mirror 21 is determined with the focal points 24 of the main reflecting mirror 21 and the sub-reflecting mirror 22 being aligned.

By changing the position, it is possible to obtain directivity in the vertical plane at an angle of θ downward with respect to the horizontal plane, as shown in the figure. Similarly, the shape of the main reflecting mirror 21.

By changing the position, it is possible to obtain directivity in the vertical plane at any angle upward with respect to the horizontal plane.

In addition to the biconical antenna, a non-directional dipole antenna in the horizontal plane can also be used as the second-order radiator. It is also possible to use a mirror surface modification technique in which the two reflecting mirrors are each deformed to control the aperture distribution.

〔Effect of the invention〕

As explained above, the present invention includes a conical paraboloid of revolution main reflecting mirror 1 whose reflecting surface is a conical paraboloid of revolution or a surface of revolution obtained by adding correction to the conical paraboloid of revolution, and a -order radiator 3. The position and shape of the main reflecting mirror 1 can be changed by combining the sub-reflecting mirror 2 whose reflecting surface is a toric-shaped hyperboloid of revolution or ellipsoid of revolution, or a surface of revolution obtained by correcting these. Since the amplitude 1-phase distribution, etc. in the aperture plane can be set arbitrarily, the directivity in the vertical plane can be easily controlled, and there are advantages in that high efficiency and low side lobes can be achieved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is an explanatory diagram of the directional characteristics in the horizontal plane, Fig. 3 is an explanatory diagram of the directional characteristics in the vertical plane, Fig. 4 is an explanatory diagram of an embodiment of the present invention, and Fig. 5 is an explanatory diagram of the directional characteristics in the vertical plane. FIG. 6 is an explanatory diagram of another embodiment of the present invention, FIG. 6 is an explanatory diagram of control of directivity in a vertical plane, and FIGS. 7 and 8 are explanatory diagrams of a conventional example. 1.11.21 is a conical paraboloid of revolution main reflector, 2.12
．． 22 is a sub-reflector, 3, 13.23 is a primary radiator, 4,
5, 24.25 is the focal point.

Claims (1)

[Claims] A conical paraboloid of revolution main reflecting mirror (1) whose reflecting surface is a substantially conical paraboloid of revolution or a surface of revolution obtained by adding correction to the paraboloid of revolution, and a substantially circular hyperboloid of revolution. Or a sub-reflector (2) in which the reflecting surface is an ellipsoid of revolution or a surface of rotation obtained by correcting these surfaces, and the reflecting surface is opposed to the reflecting surface of the conical paraboloid of revolution main reflecting mirror (1). and a primary radiator (3) for radiating radio waves onto the reflecting surface of the sub-reflector (2) and emitting radio waves from the reflecting surface of the conical paraboloid of revolution main reflector (1) in a substantially horizontal plane. ) An omnidirectional antenna in a horizontal plane.