JPH05114816A - Antenna system - Google Patents

Abstract

PURPOSE:To provide cosecant square characteristics in a vertical plane and nondirectivity in a horizontal plane by providing a main reflector in a nearly comic or frustum-of-circular-cone shape and a primary radiator which excites this main reflector for communications between a center station and many peripheral slave stations. CONSTITUTION:A necessary mode is generated by a mode generator 14 with an electromagnetic wave sent out of a transmitter receiver 16 through a waveguide 15 and the primary radiator 13 is excited, so that the radio wave is reflected by the reflecting surface 12 of a conic rotary double curve reflector (main reflector) 11 and radiated in a horizontal plane. For reception, this system operates reversibly to the transmission. The mirror surface shape of the antenna which has almost cosecant double characteristics in the vertical plane and pencil beam characteristics in the horizontal plane is known as the double curve reflecting mirror, whose center sectional shape 17 consists of two curves a1 and a2 differing in directivity direction. This main reflector 11 is formed by rotating this sectional shape 17 around an axis 18 of rotation and the primary radiator 13 is installed at the focus of the main reflector 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device for communicating between a central office and a large number of slave stations scattered around the central office.

As an example of a communication system for performing communication between a central station and a large number of fixed slave stations scattered around the central office or a large number of mobile slave stations moving around the central office, for example, a wireless LAN in a room, There is an aircraft relay radio system.

A wireless LAN in a room is provided for a trunk line formed in a loop between each room or each building.
Each room has a central station that forms a node, and wirelessly connects between the central station and each slave station that forms a terminal station that is placed on a table in the room where the central station is installed or is carried by an individual. By connecting, a large number of slave stations in each room or building communicate with each other via the backbone line.

The aircraft relay radio system is a system in which a large number of fixed or mobile slave stations scattered on the ground communicate with each other by relaying by a central station mounted on an aircraft (airplane, airship). When an aircraft flies at an altitude of 20 to 25 km, for example, the entire Kanto area can be used as a service area, which can be realized at a lower cost than a satellite relay system.

In the case of such a system in which the central station and a large number of fixed slave stations or mobile slave stations scattered around the central station are communicated by radio, the antenna device provided in the central station is the central station. Regardless of the distance of the slave station from the station, it is desired that they can always obtain a constant incoming electric field strength.

[0006]

2. Description of the Related Art An antenna device provided in a central station for performing communication between the central station and a large number of stationary stations or mobile stations scattered around the central station as described above has heretofore been known, for example. Japanese Patent Application No. 61-276981 (JP-A-63-1)
31602), Japanese Patent Application No. 61-291434 (Japanese Patent Laid-Open No. 63-291434).
-144605), Japanese Patent Application No. 62-41463 (Japanese Patent Application Laid-Open No. 6-46356)
3-209303), Japanese Patent Application No. 62-41464 (Japanese Patent Application Laid-Open No. 63-209304), Japanese Patent Application No. 63-27862 (Japanese Patent Application Laid-Open No. 1-2202903), and the like.

All of these prior arts realize omnidirectionality in the horizontal plane around the antenna, whereby the same incoming electric field can be obtained for slave stations in any direction at the same distance. Strength can be obtained.

[0008]

However, when communication is performed between the central station and a large number of slave stations scattered around the central station as described above, the central station existing above and each of the ground stations (on the floor). The relationship with the distance to the slave station is not uniform.

The conventional antenna device having omnidirectionality in the horizontal plane has, for example, an 8-character characteristic in the vertical plane. Therefore, when the distance is the same, the same incoming electric field strength is given to each slave station. However, there is a problem that the incoming electric field strength also changes when the distance changes.

Even when the relationship between the distance and the depression angle changes,
As an antenna device capable of giving the same incoming electric field strength, an antenna having a cosecant square characteristic used in a radar device or the like is conventionally known. For example, Japanese Examined Patent Publication No. Sho 61-30441 discloses a cosecant beam horn antenna in which a reflected wave from an aircraft having the same altitude has a constant value regardless of the distance.

However, the conventional cosecant square characteristic antenna can obtain the cosecant square characteristic in the vertical plane, but has narrow directivity in the horizontal plane, and therefore such an antenna is used. However, there is a problem that the same incoming electric field strength cannot be given from the central station to a large number of slave stations scattered around the central station.

The present invention is intended to solve the above problems of the prior art, is omnidirectional in the horizontal plane, and has a cosecant square characteristic in the vertical plane, and therefore, in the central office. When used, the incoming electric field strength from the central station can be made constant for all scattered slave stations regardless of the distance, and conversely all slave stations have the same EI.
It is an object of the present invention to provide an antenna device capable of obtaining the same incoming electric field strength at a central office by transmitting at RP (effective radiant power = antenna gain × antenna supplied power).

[0013]

An antenna device according to the present invention comprises a main reflecting mirror 11 having a substantially conical shape or a truncated cone shape.
And a primary radiator 13 for exciting the main reflecting mirror. The main reflecting mirror 11 is made up of two types of curved surfaces having different directing directions, and the central cross-sectional shape of the double curved reflecting mirror that realizes the directivity of approximately the cosecant square characteristic is rotated by rotating about the axis passing through its focal point. The reflective surface 12 is formed.

Further, the antenna device of the present invention comprises a main reflecting mirror 11 having a substantially conical shape or a truncated cone shape, and the main reflecting mirror 1.
1 is provided with a substantially conical or truncated conical sub-reflecting mirror 21 and a primary radiator 13 for exciting the sub-reflecting mirror 21. The main reflecting mirror 11 is formed by rotating a central cross-sectional shape of a double curved reflecting mirror, which is composed of two kinds of curved surfaces having different directing directions, and which realizes a directivity of approximately a cosecant square characteristic, about an axis passing through its focus. The sub-reflecting mirror 21 has a reflecting surface 22 formed of a rotating hyperboloid.

Further, the antenna device of the present invention comprises a main reflecting mirror 11 having a substantially conical shape or a truncated cone shape, and the main reflecting mirror 1.
1 and a substantially conical or frustoconical sub-reflecting mirror 23, and a primary radiator 13 for exciting the sub-reflecting mirror 23. The main reflecting mirror 11 is formed by rotating a central cross-sectional shape of a double curved reflecting mirror, which is composed of two kinds of curved surfaces having different directing directions, and which realizes a directivity of approximately a cosecant square characteristic, about an axis passing through its focus. The sub-reflecting mirror 23 has a reflecting surface 24 formed of a spheroidal surface.

Further, the antenna device of the present invention comprises a main reflecting mirror 31 having a substantially conical shape or a truncated cone shape, and the main reflecting mirror 3.
1 is provided with a sub-reflecting mirror 33 having a substantially circular truncated cone shape or an annular shape and coaxial with 1, and a primary radiator 13 for exciting the sub-reflecting mirror 33. The main reflecting mirror 31 and the sub-reflecting mirror 33 are provided.
However, the reflecting surfaces 32 and 34 are mirror-finished in accordance with the characteristics of the primary radiator 13 so as to realize the linear wave source distribution having the cosecant square characteristic.

Further, in the antenna device of the present invention, in these antenna devices, the primary radiator 13 is composed of a conical electromagnetic horn, and an axially symmetric mode of a circular waveguide is provided in front of the primary radiator 13. A mode generator 14 for generating is provided.

Further, the antenna device of the present invention comprises a main reflecting mirror 11 having a substantially conical shape or a truncated cone shape, and the main reflecting mirror 1.
1, a substantially conical or annular sub-reflecting mirror 51, and a biconical primary radiator 53 for exciting the sub-reflecting mirror 51. The main reflecting mirror 11 is formed by rotating a central cross-sectional shape of a double curved reflecting mirror, which is composed of two kinds of curved surfaces having different directing directions, and which realizes a directivity of approximately a cosecant square characteristic, about an axis passing through its focus. The sub-reflecting mirror 51 has a reflecting surface 52 which is a hyperboloid of revolution or a spheroid of revolution.

Further, the antenna device of the present invention, in these antenna devices, serves as a support member for the main reflecting mirror 11 or the sub-reflecting mirror 21 arranged in a portion through which electromagnetic waves pass.
It has cylindrical or frustoconical radomes 61 and 62 formed of a dielectric material.

In the antenna device of the present invention, in these antenna devices, a supporting member for the main reflecting mirror 11 or the sub-reflecting mirror, which is arranged in a portion through which electromagnetic waves pass, and the main reflecting mirror 11 and / or the sub-reflecting mirror. Is integrally formed by using a dielectric material, and the reflecting surface 12 is formed by spraying a metal on the surface of the dielectric material forming the main reflecting mirror 11 and / or the sub-reflecting mirror.

Further, the antenna device of the present invention has an annular dielectric lens 73 for an antenna having a biconical shape which is formed by an upper cone 71 and a lower cone 72 facing each other and whose center is excited in an axially symmetric mode. And attach it to the opening of the antenna. The cross-sectional shape of the dielectric lens 73 is modified according to the aperture distribution of the biconical antenna so as to realize a linear wave source distribution having a cosecant square characteristic.

The antenna device of the present invention comprises a large number of unit elements 82 such as a microstrip antenna or a dipole antenna, which are arranged outside a truncated cone-shaped or cylindrical support 81. Then, each unit element 82 on the ridge is excited so as to realize a linear wave source distribution in which the excitation phase and the excitation amplitude form a cosecant square characteristic.

[0023]

The antenna device according to the first aspect of the present invention has a main reflecting mirror 11 and a primary radiator 13 as shown in FIG.
It has and. The reflecting surface 12 of the main reflecting mirror 11 is composed of two types of curved surfaces having different directing directions, and passes through the center cross-sectional shape of the double curved reflecting mirror that realizes the directivity of the generally cosecant square characteristic. It is formed by rotating about an axis. Such a rotating double curved reflecting mirror 11 is provided so as to face and coaxial with the primary radiator 13 so that the focal point of the rotating double curved reflecting mirror 11 and the radiation origin of the primary radiator 13 coincide with each other. Since it was made to excite from the primary radiator 13, its directional characteristics are
In addition to having a cosecant square characteristic in the vertical plane and having an axially symmetric characteristic in the horizontal plane, it becomes omnidirectional in the horizontal plane and a desired characteristic can be realized.

An antenna device according to a second aspect of the present invention has a main reflecting mirror 11 and a sub-reflecting mirror 2 as shown in FIG.
1 and a primary radiator 13. This main reflector 1
The reflecting surface 12 of No. 1 is composed of two kinds of curved surfaces having different directing directions, and the central cross-sectional shape of the double curved reflecting mirror that realizes the directivity of the cosecant squared characteristic is centered around the axis passing through the focal point. It is formed by rotating. Such a rotating double-curved surface reflecting mirror 11 is provided coaxially with a sub-reflecting mirror 21 having a reflecting surface 22 consisting of a rotating hyperboloid, and further a primary radiator 13 is provided coaxially therewith.
The focus of the reflecting surface 12 of the rotating double curved reflecting mirror 11 coincides with the radiation origin of the primary radiator 13, and the sub-reflecting mirror 21
Since one of the two focal points of the reflecting surface 22 of is matched with this and is excited from the primary radiator 13, its directional characteristic has a substantially cosecant square characteristic in the vertical plane. Since the characteristic becomes axially symmetric in the horizontal plane, it becomes omnidirectional in the horizontal plane and the desired characteristic can be realized.

An antenna device according to a third aspect of the present invention has a main reflecting mirror 11 and a sub-reflecting mirror 2 as shown in FIG.
3 and a primary radiator 13. This main reflector 1
The reflecting surface 12 of No. 1 is composed of two kinds of curved surfaces having different directing directions, and the central cross-sectional shape of the double curved reflecting mirror that realizes the directivity of the cosecant squared characteristic is centered around the axis passing through the focal point. It is formed by rotating. Such a rotating double curved reflecting mirror 11 is provided coaxially with a sub-reflecting mirror 23 having a reflecting surface 24 composed of a spheroidal surface, and a primary radiator 13 is provided coaxially therewith.
While making the focal point of the reflecting surface 12 of the rotating double curved reflecting mirror 11 coincident with the radiation origin of the primary radiator 13, the sub-reflecting mirror 23
Since one of the two focal points of the reflecting surface 24 of is matched with this and is excited from the primary radiator 13, its directional characteristic has a substantially cosecant square characteristic in the vertical plane. Since the characteristic becomes axially symmetric in the horizontal plane, it becomes omnidirectional in the horizontal plane and the desired characteristic can be realized.

As shown in FIG. 6, the antenna device according to the fourth aspect is excited by the primary radiator 13, reflected by the sub-reflecting mirror 33, and then further reflected by the main reflecting mirror 3.
The reflection surface 32 of the main reflecting mirror 31 and the reflection surface 34 of the sub-reflecting mirror 33 are reflected by the primary radiator 13 so as to realize a linear wave source distribution having a cosecant square characteristic. It has been mirror-finished according to its characteristics. Therefore, the directional characteristics have a cosecant square characteristic in the vertical plane and are axisymmetric in the horizontal plane, so that the directional characteristic becomes omnidirectional in the horizontal plane and a desired characteristic can be realized.

The antenna device according to a fifth aspect of the present invention is the antenna device according to the first to fourth aspects, wherein the primary radiator 13 is a conical electromagnetic horn and a circular waveguide is provided in front of the primary radiator 13. Tube TM ₀₁ mode or TE ₀₁
Mode generator 1 for generating an axially symmetric mode like a mode
4 is inserted, mode conversion is performed, and then the primary radiator 1
Power 3 Therefore, the radio waves reflected by the reflector and radiated into space have the same polarization direction regardless of the horizontal radiation direction, so even in the case of mobile slave stations, the same receiving antenna is used regardless of the moving position. can do.

An antenna device according to a sixth aspect of the present invention is shown in FIG.
As shown in the embodiment, the main reflecting mirror 11, the sub-reflecting mirror 51, and the primary radiator 53 are provided. The reflecting surface 12 of the main reflecting mirror 11 is composed of two types of curved surfaces having different directing directions, and passes through the center cross-sectional shape of the double curved reflecting mirror that realizes the directivity of the generally cosecant square characteristic. It is formed by rotating about an axis. On the other hand, after being excited from the biconical primary radiator 53 and reflected by the sub-reflecting mirror 51,
Further, since the light is reflected by the rotating double curved reflecting mirror 11, its directional characteristic is approximately cosecant square characteristic in the vertical plane and axially symmetrical in the horizontal plane, so that it becomes omnidirectional in the horizontal plane. The desired characteristics can be realized.

An antenna device according to a seventh aspect of the invention is shown in FIG.
In the antenna device according to any one of claims 1 to 6, a cylinder formed of a dielectric is used as a supporting member for the main reflecting mirror 11 or the sub-reflecting mirror 21 arranged in a portion through which electromagnetic waves pass. Shaped or frusto-conical radome 6
Since 1, 62 are provided, the blocking of the reflected wave from the rotating double curved reflecting mirror 11 by the support does not occur.
Therefore, the influence of rain and snow on the rotating double-curved surface reflecting mirror 11 and the primary radiator 13 is reduced without being affected by the directivity of the radiation from the rotating double-curved surface reflecting mirror 11.

The antenna device according to the eighth aspect of the invention is shown in FIG.
In the antenna device according to any one of claims 1 to 6, the main reflecting mirror 11 or the sub-reflecting mirror supporting member arranged in a portion through which an electromagnetic wave passes, and the main reflecting mirror 11 and / or The sub-reflecting mirror is integrally formed by using a dielectric, and the reflecting surface 12 is formed by spraying a metal on the surface of the main reflecting mirror 11 and / or the dielectric constituting the sub-reflecting mirror. Therefore, since the support does not block the reflected wave from the rotating double curved reflecting mirror 11 or the sub-reflecting mirror, the directivity of the radiation from the rotating double curved reflecting mirror 11 is not affected, and the rotating second curved reflecting mirror 11 is not affected. The influence of rain and snow on the heavy-curved surface reflecting mirror 11, the primary radiator 13, and the like is reduced, high airtightness is obtained, and manufacturing accuracy can be increased.

The antenna device according to a ninth aspect of the invention is shown in FIG.
As shown in the example thereof, an annular dielectric lens 73 is provided in the opening of the biconical antenna. The cross-sectional shape of the dielectric lens 73 is modified according to the aperture distribution of the biconical antenna so as to realize the linear wave source distribution having the cosecant square characteristic. Therefore, the directional characteristics have a cosecant square characteristic in the vertical plane and are axisymmetric in the horizontal plane, so that the directional characteristic becomes omnidirectional in the horizontal plane and a desired characteristic can be realized.

The antenna device according to a tenth aspect of the invention is shown in FIG.
5, a large number of unit elements 82 such as a microstrip antenna or a dipole antenna are arranged outside a truncated cone-shaped or cylindrical support 81, and each unit element 82 on the ridge is The excitation is performed via the feeding layer 83 so that the excitation phase and the excitation amplitude realize a linear wave source distribution having a cosecant square characteristic. Therefore, its directional characteristics have a generally cosecant square characteristic in the vertical plane and are axisymmetric in the horizontal plane.
It becomes omnidirectional in the horizontal plane, and desired characteristics can be realized.

[0033]

(Embodiment 1) FIG. 1 shows an embodiment of the present invention, in which 11 is a conical or frustoconical rotating double curved reflecting mirror, 12 is its reflecting surface, and 13 is its reflecting surface. Is a primary radiator composed of a conical electromagnetic horn, and 14 is a primary radiator 13
On the other hand, 15 is a waveguide for generating an electromagnetic wave of a desired mode, 16 is a transceiver for transmitting and receiving electromagnetic waves.

The electromagnetic wave sent from the transceiver 16 through the waveguide 15 generates a desired mode through the mode generator 14 to excite the primary radiator 13 so that the electric wave is conical rotating double curved surface. Reflecting surface 12 of reflecting mirror 11
It is reflected by and radiated in the horizontal plane. When receiving, it can operate reversibly as when transmitting.

FIG. 2 shows a double-curved surface reflecting mirror, where 17 is a central cross-sectional shape of the double-curved surface reflecting mirror, and 18 is a rotation axis.

The mirror surface shape of an antenna having a generally cosecant square characteristic in a vertical plane and a pencil beam characteristic in a horizontal plane is known as a double curved reflector (for example, Ito et al .: a reflector antenna for a search radar). Design theory and examples; IEICE Technical Committee Material AP77-7
5). In FIG. 2, reference numeral 17 denotes a central cross-sectional shape of such a double curved reflecting mirror, and two curves a having different directing directions are shown.
It is formed of _1, a ₂ . The double-curved surface reflecting mirror 11 shown in FIG. 1 is formed by rotating the central cross-sectional shape 17 of such a double-curved surface reflecting mirror about a rotation axis 18 that passes through the focal point thereof. , Has a substantially conical shape or a truncated cone shape.

In the antenna device shown in FIG. 1, such a rotating double curved reflecting mirror 11 faces the primary radiator 13 and is coaxial with the primary radiator 13 so that the focus of the rotating double curved reflecting mirror 11 and the primary radiator are the same. Since the radiation origin of 13 is provided so as to coincide with the radiation origin, and the primary radiator 13 is excited, its directional characteristic is
In addition to having substantially cosecant square characteristics in the vertical plane and having axially symmetric characteristics in the horizontal plane, it becomes omnidirectional in the horizontal plane, and desired characteristics can be realized.

(Embodiment 2) FIG. 3 shows another embodiment of the present invention, in which the same components as those in FIG. 1 are designated by the same reference numerals, and 21 is a sub-reflecting mirror composed of a rotating hyperboloid. 22
Is the reflective surface.

In the embodiment shown in FIG. 3, the rotating double curved reflecting mirror 11 is oriented in the opposite direction to that of FIG. 1, the primary radiator 13 is provided coaxially with the primary radiator 13 and the primary radiator 13 is provided.
The sub-reflecting mirror 21 is coaxially provided so as to be opposed to. The sub-reflecting mirror 21 has a hyperbolic cross-sectional shape,
It has a substantially conical shape or a truncated cone shape formed by rotating it about its axis, and its reflecting surface 22 is a hyperboloid of rotation. In this case, normally, the focal point of the reflecting surface 12 of the rotating double curved reflecting mirror 11 is made to coincide with the radiation origin of the primary radiator 13, and one of the two focal points of the reflecting surface 22 of the sub-reflecting mirror 21 is set to this. Try to match.

The antenna device shown in FIG. 3 is excited by the primary radiator 13 and reflected by the sub-reflecting mirror 21.
Further, since the light is reflected by the rotating double curved reflecting mirror 11, its directional characteristic is approximately cosecant square characteristic in the vertical plane and axially symmetrical in the horizontal plane, so that it becomes omnidirectional in the horizontal plane. The desired characteristics can be realized.

(Embodiment 3) FIG. 4 shows still another embodiment of the present invention, in which the same components as those in FIG. 1 are designated by the same reference numerals, and 23 is a sub-reflecting mirror having a spheroidal surface.
Reference numeral 24 is its reflecting surface.

In the embodiment shown in FIG. 4, the rotating double-curved surface reflecting mirror 11 is oriented in the opposite direction to that of FIG. 1, the primary radiator 13 is provided coaxially with the central radiator 13 and the primary radiator 13 is provided.
The sub-reflecting mirror 23 is coaxially provided so as to face the above. The sub-reflecting mirror 23 has an elliptical cross-sectional shape, and has a substantially conical shape or a truncated cone shape formed by rotating it about its axis. Is becoming In this case, usually
While making the focal point of the reflecting surface 12 of the rotating double curved reflecting mirror 11 coincident with the radiation origin of the primary radiator 13, the sub-reflecting mirror 23
One of the two focal points of the reflecting surface 24 of the above is made to coincide with this.

The antenna device shown in FIG. 4 is excited by the primary radiator 13 and reflected by the sub-reflecting mirror 23.
Further, since the light is reflected by the rotating double curved reflecting mirror 11, its directional characteristic is approximately cosecant square characteristic in the vertical plane and axially symmetrical in the horizontal plane, so that it becomes omnidirectional in the horizontal plane. The desired characteristics can be realized.

(Embodiment 4) The reflecting mirror surface which realizes the cosecant square characteristic can be determined as follows. That is, a method for obtaining the linear wave source distribution that realizes the cosecant square directivity is well known, and for example, Woodyard (Woodyard)
Yard) method or the like (for example, Antenna Engineering Handbook, p207; edited by the Institute of Electronics and Communication Engineers).

On the other hand, it is known that the aperture distribution of an antenna system having two main and sub reflecting mirrors can be controlled in both amplitude and phase by applying a mirror surface correction (eg, Antenna Engineering Handbook). , P171-
172; The Institute of Electronics and Communication Engineers).

FIG. 5 shows an example of an antenna system having two main and sub reflecting mirrors. In the figure, the broken lines indicate the main and sub-reflecting mirrors having a quadric surface of revolution. If the curved surfaces of the rotationally symmetric main and sub-reflecting mirrors to be obtained in such a system are represented by y = y (x) and r = r (θ) as shown by solid lines, in general, ) The Snell's law on both the primary and secondary reflecting surfaces is established. Further, (2) the energy is constant in the bundle of rays that exits the phase center of the primary radiator and is reflected by the sub-reflecting mirror and the main reflecting mirror and reaches the aperture plane. (3) The passage length is constant. 3 conditions are satisfied.

Now, assuming that the characteristic of the primary radiator is F (x) and the coordinates of the phase center are (0, -a) in the coordinate system of FIG. 5, desired aperture plane electric field distributions I (x), P (x) are obtained. ) Is a mirror surface system (x _, y), (r, θ), the following simultaneous ordinary differential equations obtained from the above three conditions: dr / dθ = r (dθ / dr) · tan (θ + α) / 2 ( 1) dθ / dx = x · I (x) / sin θ · F (θ) (2) dy / dx = -tan (α / 2) (3) and optical path length condition r + y + (y + r · cos θ-a ) / Cos α = l ₀ + P (x) (4) where F (θ) is the characteristic of the primary radiator I (x) is the electric field distribution (amplitude) on the aperture plane P (x) is the electric field distribution on the aperture plane (phase) ) L ₀ is obtained by solving a constant.

FIG. 6 shows still another embodiment of the present invention, which shows a case where a reflecting mirror obtained by solving the above equations (1) to (4) is used. The same parts as those in FIG. 1 are indicated by the same numbers, 31 is a main reflecting mirror, 32
Is a reflecting surface thereof, 33 is a sub-reflecting mirror, and 34 is a reflecting surface thereof.

In the embodiment shown in FIG. 6, the main reflecting mirror 3 having a substantially truncated cone shape or an annular shape obtained by rotating the mirror surface shape obtained as described above about a certain axis.
1 is reversed, a primary radiator 13 is provided in the center thereof coaxially therewith, and the mirror surface shape obtained as described above is rotated about a certain axis so as to face the primary radiator 13. The obtained sub-reflecting mirror 3 having a substantially truncated cone shape or an annular shape
It has a configuration in which 3 is provided coaxially. That is, the main and sub-reflecting mirrors 31 and 33 have reflecting surfaces 32 and 34 whose cross-sectional shapes are modified according to the primary radiator characteristics so as to realize a linear wave source distribution having a cosecant square characteristic. There is.

The antenna device shown in FIG. 6 is excited by the primary radiator 13 and reflected by the sub-reflecting mirror 33.
Further, since the light is reflected by the main reflecting mirror 31, its directional characteristics have substantially cosecant square characteristics in a vertical plane and are axisymmetric in a horizontal plane.
It becomes omnidirectional in the horizontal plane, and desired characteristics can be realized.

(Embodiment 5) In the above Embodiments 1 to 4, the electromagnetic wave supplied from the transceiver 16 through the waveguide 15 is usually TE ₁₁ which is the fundamental mode of the circular waveguide. Mode. When the primary radiator 13 is excited by such an asymmetrical mode input, the radio waves reflected by the reflecting mirror and radiated into space have different polarization directions depending on the horizontal radiation direction. Is
Must receive different polarization depending on the moving position,
Designing the receiving antenna becomes difficult.

In order to solve such a problem, a conical electromagnetic horn which produces an axially symmetrical electric field distribution is used as the primary radiator 13, and a TM ₀₁ mode or TE ₀₁ is provided in front of the primary radiator 13. If a mode generator that generates an axially symmetric mode of a circular waveguide like a mode is inserted to perform mode conversion and then feed the primary radiator 13, the reflected light is reflected by a reflecting mirror and radiated into space. Since the polarization direction of the generated radio waves is constant regardless of the horizontal radiation direction, even in the case of a mobile slave station, the same receiving antenna can be used regardless of the moving position.

FIG. 7 shows an example of the mode generator in the embodiment of the present invention, which converts the square TE ₁₀ mode into the circular TM ₀₁ mode.

The mode generator shown in FIG. 7 has a circular waveguide 42 on the H surface of the short-circuited end of the rectangular waveguide 41 for transmitting the TE ₁₀ mode.
The primary radiator 13 can be excited by generating the TM ₀₁ mode in which only the electric field in the radial direction exists in the circular waveguide 42. In this case, the antenna device generates vertically polarized waves regardless of the horizontal radiation direction.

FIG. 8 shows another example of the mode generator in the embodiment of the present invention, in which the circular TE ₁₁ mode is converted into the circular TM ₀₁ mode.

In the mode generator of FIG. 8, a metal plate 44 is inserted into a circular waveguide 43 that transmits the TE ₁₁ mode, and the input side of the metal plate 44 is directed from one pipe wall to the other pipe wall. In which the output side is tapered from both tube walls toward the center to generate the TM ₀₁ mode in which only the radial electric field exists in the circular waveguide 43. The primary radiator 13 can be excited. In this case, the antenna device generates vertically polarized waves regardless of the horizontal radiation direction.

FIG. 9 shows still another example of the mode generator in the embodiment of the present invention, which is a rectangular TE ₁₀
The mode is converted to the circular TE ₀₁ mode.

The mode generator of FIG. 9 connects a rectangular waveguide 45 transmitting the TE ₁₀ mode and a circular waveguide 46 transmitting the TE ₀₁ mode to form a rectangular waveguide as shown in the lower part of FIG. The cross section of the wave tube 45 is gradually changed from a square shape to a fan shape, and the cross section of the circular waveguide 46 is gradually changed from a fan shape to a circular shape. Only the electric field in the circumferential direction exists in the circular waveguide tube 46. Generates TE ₀₁ mode to generate primary radiator 13
Can be excited. In this case, the antenna device
Horizontal polarization is generated regardless of the horizontal radiation direction.

(Embodiment 6) FIG. 10 shows still another embodiment of the present invention, in which the same components as those in FIG. 1 are designated by the same reference numerals, and 51 indicates a hyperboloid of revolution or an ellipsoid of revolution. Is a sub-reflecting mirror, 52 is its reflecting surface, 53 is a biconical primary radiator, and 54 is a feeder line.

In the embodiment shown in FIG. 10, a biconical primary radiator 53 is provided at the center of the rotating double-curved curved reflecting mirror 11 and is coaxial with the primary radiator 53.
The sub-reflecting mirror 51 is coaxially provided to face. The sub-reflecting mirror 51 has a cross-sectional shape that is a hyperbola or an ellipse and is formed by rotating the sub-reflecting mirror 51 about a certain axis. The sub-reflecting mirror 51 has a substantially conical shape or an annular shape, and its reflecting surface is 52 is a rotating hyperboloid or a spheroid.

FIG. 11 shows a biconical primary radiator. The biconical primary radiator has two conical (biconical) shapes that are opposed to each other obtained by rotating the electromagnetic horn shown in FIG. 1 about the phase origin by 360 °, and has a coaxial feed line. 5
4 inner conductor 57 is connected to one cone and outer conductor 58
Is connected to the transceiver 16 by connecting to the other cone. The biconical primary radiator has a uniform donut-shaped directional characteristic in the horizontal plane.

The antenna device shown in FIG. 10 is similar to that shown in FIG.
Excited from the primary radiator 53 shown in FIG.
Since it is reflected by the rotating double-curved curved surface reflection mirror 11, the directional characteristics thereof have a substantially cosecant square characteristic in the vertical plane and are axisymmetric in the horizontal plane. It becomes omnidirectional in the horizontal plane, and desired characteristics can be realized.

(Embodiment 7) The antenna devices of Embodiments 1 to 6 have a structure in which the main reflecting mirror and the other parts are separated from each other. Therefore, a pillar or the like is required to support the main reflecting mirror. However, in this case, the supporting column and the like are provided in a portion through which the electromagnetic wave reflected by the main reflecting mirror and radiated into the space passes, so that blocking occurs and the efficiency of the antenna decreases.
On the other hand, if a radome is formed by using a member made of a dielectric cylinder to support the main reflecting mirror, blocking can be prevented without being affected by directivity and the effect of rain and snow can be prevented. Can be reduced.

FIG. 12 shows an example of the construction of the radome of the embodiment of the present invention, (a) shows the case applied to the embodiment of FIG. 1, and (b) shows the embodiment of FIG. It has been applied to.

In FIG. 12A, the same components as those in FIG. 1 are designated by the same reference numerals, and 61 is a resin-made cylindrical radome, in which the primary radiator 13 and the like are housed and the radome 61 is Rotating double curved reflector 11 on top
It has a configuration in which is mounted. According to this configuration, since the support does not block the reflected wave from the rotating double-curved surface reflecting mirror 11, the directivity of the radiation from the rotating double-curved surface reflecting mirror 11 is not affected, and the rotating mirror is not affected. The influence of rain and snow on the heavy-curved surface reflecting mirror 11, the primary radiator 13, and the like is reduced.

In FIG. 12B, the same components as those in FIG. 3 are designated by the same reference numerals, and 62 is a resin-made cylindrical radome, in which the sub-reflecting mirror 21, the primary radiator 13 and the like are housed. At the same time, the rotating double curved reflecting mirror 11 is provided below the radome 61. According to this configuration, since the support does not block the reflected wave from the sub-reflecting mirror 21, the directivity of the radiation from the rotating double-curved curved reflecting mirror 11 is not affected, and the sub-reflecting mirror 21 and the like. The effect of rain and snow on

(Embodiment 8) In Embodiment 7, a radome is formed by using a member made of a dielectric cylinder to support the main reflecting mirror and other portions in the antenna devices of Embodiments 1 to 6. ing. At this time, it is possible to adopt a structure in which the main reflecting mirror and the sub-reflecting mirror are integrally molded using a dielectric, and a metal is sprayed on the surface of the dielectric.

FIG. 13 shows a constitutional example of the integrally molded antenna of the embodiment of the present invention, and shows the case of being applied to the embodiment of FIG.

In FIG. 13, the same parts as those in FIG. 1 are indicated by the same numbers, and 63 is a resin-made cylindrical radome in which the primary radiator 13 and the like are housed and which is rotated above the radome 63. The double curved reflecting mirror 11 is integrally molded. The rotating double curved reflecting mirror 11 is
The inner surface of the radome 63 is formed into a rotating double curved surface, and is formed by a method such as metallizing the surface, so that the surface forms the reflecting surface 12.
According to this configuration, the rotating double curved reflecting mirror 1 with the support body
Since it does not block the reflected wave from 1,
It is possible to obtain high airtightness without being affected by the directivity of radiation from the rotating double-curved surface reflecting mirror 11 and reducing the influence of rain and snow on the rotating double-curved surface reflecting mirror 11 and the primary radiator 13 and the like. .. In addition, the rotating double curved reflector 1
1 is integrally molded with the radome 63, so that the manufacturing accuracy can be increased and the number of parts can be reduced.
Assembly adjustment becomes easy. In the case of an antenna device having a sub-reflecting mirror, the main and sub-reflecting mirrors are integrally molded with the radome, and a metal is sprayed on the surface,
You may make it form the reflective surface of a main and a subreflector.

(Embodiment 9) FIG. 14 shows still another embodiment of the present invention, showing the case where the cosecant square characteristic in the vertical plane is realized by the radio wave lens, which is the same as that in FIG. Are indicated by the same number. In the figure, 71 is an upper cone, 72 is a lower cone, and 73 is a dielectric lens.

The upper cone 71 and the lower cone 7 in FIG.
2 constitutes a biconical radiator similar to that of FIG. 11, and is excited in an axially symmetric mode. Figure 1
In the case of 4, directivity is given to a certain depression angle, so that an asymmetrical biconical shape is formed, and the inclination of the upper cone 71 is small and the inclination of the lower cone 72 is large, so that directivity is obtained downward. It has become. In addition,
To give directivity to a certain elevation angle, this relationship may be reversed. Further, by mounting an annular dielectric lens 73 on the radiator aperture surface, it is possible to give an arbitrary aperture surface electric field distribution, similar to the mirror surface modification in the case of the main and sub-reflecting mirrors. Therefore, by selecting the cross-sectional shape of the dielectric lens 73, it is adjusted according to the aperture distribution characteristic of the biconical antenna so that the linear wave source distribution exhibiting the cosecant square characteristic is realized. The connection between the radiator and the transceiver 16 can be made in the same manner as described in FIG.

The antenna device shown in FIG. 14 is excited by the transmitter / receiver 16 via the power supply line 54, so that its directional characteristic has a substantially cosecant square characteristic in the vertical plane and is axisymmetric in the horizontal plane. Since it has the characteristics, it becomes omnidirectional in the horizontal plane, and the desired characteristics can be realized.

(Embodiment 10) FIG. 15 shows still another embodiment of the present invention in which a cosecant square characteristic in a vertical plane is realized by an array type antenna, and 81 is a truncated cone, Reference numeral 82 is a unit element such as a microstrip antenna or dipole antenna, and 83 is a power feeding device.

In FIG. 15, the circumference of the truncated cone 81 is
A large number of unit elements 82 are arranged. By exciting these unit elements 82 from the transceiver 16 via the power feeding device 83, each unit element 8 on the ridgeline of the truncated cone 81
The excitation phase and the excitation amplitude of 2 have a linear distribution that realizes the cosecant square characteristic. Instead of the truncated cone 81, it is possible to use a cylinder or the like having another axially symmetric shape.

By doing so, the directional characteristic of the antenna device shown in the embodiment of FIG. 15 has a substantially cosecant square characteristic in the vertical plane and an axisymmetric characteristic in the horizontal plane. It becomes omnidirectional, and desired characteristics can be realized.

[0076]

As described above, according to the present invention, it is possible to realize an antenna device which has cosecant square characteristics in a vertical plane and is omnidirectional in a horizontal plane. A large number of stationary stations scattered around,
Or, in a communication system that communicates with a large number of mobile slave stations moving around, it is possible to make the incoming electric field strength from the central station constant for all the slave stations regardless of the distance. If the slave station transmits at the same EIRP, the central station can obtain the same incoming electric field strength, which is convenient for improving communication quality.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a double curved reflecting mirror.

FIG. 3 is a diagram showing another embodiment of the present invention.

FIG. 4 is a diagram showing still another embodiment of the present invention.

FIG. 5 is a diagram showing an antenna system having two main and sub reflecting mirrors.

FIG. 6 is a diagram showing still another embodiment of the present invention.

FIG. 7 is a diagram showing an example of a mode generator according to an embodiment of the present invention.

FIG. 8 is a diagram showing another example of the mode generator according to the embodiment of the present invention.

FIG. 9 is a diagram showing still another example of the mode generator according to the embodiment of the present invention.

FIG. 10 is a diagram showing still another embodiment of the present invention.

FIG. 11 shows a biconical primary radiator.

12A and 12B show an example of the structure of a radome according to an embodiment of the present invention, in which FIG. 12A shows the case applied to the embodiment shown in FIG. 1, and FIG. 12B shows the case applied to the embodiment shown in FIG. Indicate the case.

FIG. 13 is a diagram showing a configuration example of an integrally formed antenna according to an embodiment of the present invention.

FIG. 14 is a diagram showing still another embodiment of the present invention.

FIG. 15 is a diagram showing still another embodiment of the present invention.

[Explanation of symbols]

 11 main reflecting mirror 12 reflecting surface 13 primary radiator 14 mode generator 21 sub-reflecting mirror 22 reflecting surface 23 sub-reflecting mirror 24 reflecting surface 31 main reflecting mirror 32 reflecting surface 33 sub-reflecting mirror 34 reflecting surface 51 sub-reflecting mirror 52 reflecting surface 53 primary radiator 61 radome 62 radome 71 upper cone 72 lower cone 73 dielectric lens 81 support 82 unit element

Claims (10)

[Claims] 1. A center section of a double-curved surface reflecting mirror, which is composed of two kinds of curved surfaces having different directing directions and which realizes a directivity of approximately a cosecant square characteristic, is formed by rotating about a center of an axis passing through its focal point. A main conical mirror (1) having a reflecting surface (12) of
1) and a primary radiator (1) for exciting the main reflecting mirror (11)
3) An antenna device comprising: 2. A double-curved surface reflector having two kinds of curved surfaces with different directing directions and which realizes a directivity with a generally cosecant square characteristic is formed by rotating a central cross-sectional shape about an axis passing through its focal point. A main conical mirror (1) having a reflecting surface (12) of
1) and a sub-reflecting mirror (21) having a reflecting surface (22) composed of a rotating hyperboloid and provided coaxially with the main reflecting mirror (11) and having a substantially conical or truncated cone shape, and the sub-reflecting mirror. (21)
And a primary radiator (13) for exciting the antenna. 3. A double-curved surface reflecting mirror which is composed of two kinds of curved surfaces having different directing directions and which realizes a directivity of approximately a cosecant square characteristic is formed by rotating a central cross-sectional shape about an axis passing through its focal point. A main conical mirror (1) having a reflecting surface (12) of
1) and a sub-reflecting mirror (23) which has a reflecting surface (24) formed of a spheroidal surface and is provided coaxially with the main reflecting mirror (11) and which has a substantially conical or truncated cone shape, and the sub-reflecting mirror. (23)
And a primary radiator (13) for exciting the antenna. 4. A main reflecting mirror (31) having a substantially conical shape or a truncated cone shape, and a sub-reflecting mirror (33) having a substantially truncated cone shape or an annular shape provided coaxially with the main reflecting mirror (31). ,
A primary radiator (13) for exciting the sub-reflector (33), wherein the main reflector (31) and the sub-reflector (33) are
An antenna device having a reflecting surface (32, 34) that is mirror-finished in accordance with the characteristics of the primary radiator (13) so as to realize a linear wave source distribution having a cosecant square characteristic. 5. The antenna device according to any one of claims 1 to 4, wherein the primary radiator (13) is composed of a conical electromagnetic horn, and an axially symmetric mode of a circular waveguide is provided in the preceding stage. An antenna device comprising a mode generator (14) for generating. 6. A double-curved surface reflector having two kinds of curved surfaces with different directing directions and which realizes a directivity of approximately a cosecant square characteristic is formed by rotating a central cross-sectional shape about an axis passing through its focal point. A main conical mirror (1) having a reflecting surface (12) of
1) and a sub-reflecting mirror (51) having a reflecting surface (52) formed of a rotating hyperboloid or a spheroid and being provided coaxially with the main reflecting mirror (11) and having a substantially conical or annular shape. An antenna device comprising a biconical primary radiator (53) for exciting the sub-reflecting mirror (51). 7. The antenna device according to claim 1, wherein a dielectric is used as a supporting member for the main reflecting mirror (11) or the sub-reflecting mirror (21) arranged in a portion through which electromagnetic waves pass. An antenna device having a radome (61, 62) having a cylindrical shape or a truncated cone shape formed by. 8. The antenna device according to claim 1, further comprising a support member for the main reflecting mirror (11) or the sub-reflecting mirror, which is arranged in a portion through which an electromagnetic wave passes.
Forming the main reflecting mirror (11) and / or the sub-reflecting mirror integrally with a dielectric, and spraying a metal on the surface of the dielectric constituting the main reflecting mirror (11) and / or the sub-reflecting mirror. An antenna device characterized in that a reflecting surface (12) is formed by. 9. An annular ring attached to the opening of an antenna having a biconical shape formed by an upper cone (71) and a lower cone (72) which face each other and whose center is excited in an axially symmetric mode. The dielectric lens (73) is provided, and the cross-sectional shape of the dielectric lens (73) is modified according to the aperture distribution of the biconical antenna so as to realize the linear wave source distribution having the cosecant square characteristic. An antenna device characterized by. 10. A plurality of unit elements (82) such as a microstrip antenna or a dipole antenna are arranged outside a truncated cone-shaped or cylindrical support body (81), and each unit element (82) on a ridge line is arranged in the unit element. An antenna device characterized in that an excitation phase and an excitation amplitude are excited so as to realize a linear wave source distribution having a cosecant square characteristic.