EP2118963B1 - Array for influencing the radiation characteristics of a reflector antenna, particularly a centrally focused reflector antenna - Google Patents

Abstract

The invention relates to an array for influencing the radiation characteristics of a reflector antenna, particularly a centrally focused reflector antenna (1) consisting of a hollow conductor (3) with a horn (4) and a sub-reflector component (2), whereby the assembly consists of at least two immoveable triggerable radiator elements (5; 6; 7; 8), which influence the beam path between the reflector (9) and sub-reflector (10) in the operating state. The array has the advantage of providing a small-size technical solution which requires minimal mechanical and electrical efforts for reflector antennas and allows the antenna to track a satellite with high accuracy. Within certain limits, signal reception and the antenna diagram can be controlled such that reception and transmission can be simultaneous. The beam of diagram can be controlled in real time. Another advantage is that the hemisphere can be reproduced in full, i.e. at an angle of elevation ranging from 0° to 180° and an azimuthal angle ranging from 0° to 360°. The array can be used in previously known reflector antennas, is tolerant towards the ambient temperature, humidity, and vibrations and is inexpensive to produce since it requires a small number of control elements.

Description

The invention relates to an improved arrangement for influencing the radiation characteristic of a reflector antenna, in particular a centrally focused reflector antenna.
The purpose of the arrangement is primarily to change the radiation characteristic of such an antenna with the aid of control signals in a clearly repeatable manner, so that the invention is also suitable for the purpose of tracking an antenna.

It is known that either a corrugated horn or a flat widened hollow conductor piece is used to excite a centrally focused reflector antenna system or for beam control as an exciter system at the end of the waveguide.
The excitation system is arranged in the focal point, the phase center, the reflector antenna and should illuminate this optimally. Of particular importance is the largely uniform illumination of the reflector with uniform phase assignment.

However, the problem with the known technical solutions is that the functionalities of the groove exciter system or of the flat widened waveguide do not achieve an optimal field distribution in the reflector system or optimal illumination.

In addition, the known exciter systems can not be combined with follow-on modules, such as downconverters, without any reaction. Therefore, there are generally additional expenses for the optimal adaptation of such a known excitation system to the follower assembly with the associated costs required.

The problems associated with this are due to EP 1 384 287 B1 disclosed technical solution can be solved.
The EP 1 384 287 B1 describes an arrangement for exciting a centrally-focused reflector antenna having a waveguide and a dielectric support, wherein a dielectric field transformer and the dielectric support is arranged in front of the waveguide in the vicinity of the dielectric field transformer without mechanically or electrically connected to the waveguide. The dielectric carrier has in its center a circular bore whose diameter corresponds to the diameter of the dielectric field transformer. In this arrangement, the dielectric field transformer projects partially into the circular bore. At the end of the waveguide an assembly platform for follower modules is formed.
This arrangement fully fulfills its function, provided that this reflector antenna is used for the reception of satellite signals. It ensures a field-optimal and broadband excitation of the centrally focused reflector antenna at its focus without mechanically moving components and is also inexpensive to produce. However, the arrangement requires a field transformer. For the transmission of signals an antenna with this arrangement is not suitable. In addition, this type of excitation is unsuitable for dual-focused reflector antennas, as they are required for satellite transmission, among other things, due to the substantial wider bandwidth.

The US3276022 discloses a reflector antenna with elements in the subrejector.

In the publication W0002002013310 a reflector antenna with radiating elements is arranged between the central receiving unit and the subreflector.

pamphlet WO001982004503A1 discloses rod-shaped receiving elements in a reflector antenna. There are no arrangements for influencing the radiation characteristic provided.

In US4928109A is disclosed to place electrically conductive elements in the horn. As a result, undesired polarized vibration modes are suppressed.

In " Hochfrequenztechnik "Volume 2 by Meinke Grundlach, Springer Verlag 1986 the Cassegrain antenna principle is explained.

Finally, in citation GB760388 discloses placing disk-shaped dielectric beam shaping elements in the waveguides of a reflector antenna to compensate for phase differences in the incoming microwaves.

The object of the invention is therefore to provide an improved arrangement for influencing the radiation characteristic of a reflector antenna, in particular a centrally focused reflector antenna, the radiation characteristic of the antenna by means of control signals repeatedly changed with smaller design and without field transformer so that the arrangement for tracking of antennas is suitable and antennas with this arrangement can be used to receive transmission signals from satellites and / or to transmit such signals to satellites.

According to the invention the object is achieved by an arrangement according to claim 1.

With the arrangement according to the invention combines the advantage that in a small dimension, a technical solution with minimal mechanical and electrical expenses for reflector antennas, especially those on moving platforms, is provided, which allows the tracking of the antenna to a satellite in high accuracy. Both the reception of signals, such as the TV reception, and the antenna diagram can be controlled within certain limits so that the parallel operation of reception and transmission is simultaneously feasible. The beam or diagram control is possible in real time. While it is limited to a specific spectral range when it is being received, it does not or hardly affects the transmission range.
Another essential advantage of the technical solution according to the invention over the known prior art is that with it the hemisphere can be completely imaged from 0 ° to 180 ° in elevation and from 0 ° to 360 ° in azimuth.

The arrangement according to the invention can be used in known reflector antennas. It is also environmentally tolerant to temperature, humidity and vibration and is also inexpensive to produce with a small number of controls.

According to preferred embodiments, the arrangement comprises four radiator elements which are arranged concentrically on the horn, wherein the radiator elements are those elements which are suitable for generating an interaction with an alternating electromagnetic field and are preferably dipoles, monopolies or active components, such as tunnel diodes ,

Further advantageous embodiments of the invention provide that the radiator elements have a resonance frequency which lies within the reception frequency range of the reflector antenna and that the radiator elements can be controlled sequentially, individually or in groups.

According to a preferred embodiment of the invention, the control of the radiator elements takes place in a frequency range that is different from the useful frequency range of the reflector antenna.

Finally, a further embodiment of the arrangement provides that the radiator elements have control lines which are magnetically and electrically shielded and protected against mechanical influences.

According to a further embodiment of the invention, the radiating elements are arranged in their axis on a locating cross, with respect to the center of the horn, at 45 degrees to the axis of the polarization cross.

The radiator elements are connected according to a further embodiment of the invention in itself by a controllable active or passive control element, preferably by means of a switching diode.

Figur 1

Prinzipdarstellung einer doppelt und zentral fokussierten Reflektorantenne

Figur 2

Prinzipdarstellung der Anordnung der Elemente am Horn

Figur 3

Prinzipdarstellung eines Strahlerelementes mit Steuerleitungen auf einem dielektrischen Träger

Figur 4

Prinzipdarstellung der Vorderansicht des erregenden Homes mit Strahlerelementen (Betrachter befindet sich an der Stelle des Subreflektors) mit zugehöriger Ansicht des Polarisationskreuzes

Figur 5

Gleiche Darstellung und Ansicht wie Figur 4 jedoch unter Einbeziehung des Polarisationskreuzes im Hommittelpunkt

Figur 6

Gleiche Darstellung wie Figur 4 und Figur 5 jedoch unter Darstellung des Anordnungskreuzes für Strahlerelemente und Stützenelemente

Figur 7

Konstruktiver Schnitt durch einen Teil der Reflektorantennen - Anordnung

In the following, the invention and its operation will be explained in more detail with reference to drawings. Show it

FIG. 1

Schematic representation of a double and centrally focused reflector antenna

FIG. 2

Schematic representation of the arrangement of the elements on the horn

FIG. 3

Schematic representation of a radiator element with control lines on a dielectric support

FIG. 4

Schematic representation of the front view of the exciting home with radiator elements (observer is located at the location of the subreflector) with associated view of the polarization cross

FIG. 5

Same presentation and view as FIG. 4 but with the inclusion of the polarization cross in the Hommittelpunkt

FIG. 6

Same presentation as FIG. 4 and FIG. 5 however, showing the assembly cross for radiator elements and support elements

FIG. 7

Structural section through a part of the reflector antenna arrangement

The Fig. 1 intended to illustrate the basic structure of a reflector antenna. It is a total of a two-focus, centrally excited reflector antenna (1) shown. The components were shown schematically. The antenna consists of a reflector (8) which is excited by means of a horn (4) and a subreflector (2). The horn (4) is fed via a waveguide (3). At the end of the waveguide (3) is a mounting option (22) for subsequent assemblies.

Fig. 2 shows a schematic side view of the Fig. 1 originating waveguide (3) with the horn (4). It should be clarified that the radiator elements (5) on dielectric supports (12; 13; 14; 15) are arranged laterally on the horn (4) and protrude slightly beyond the edge of the horn (4). The radiator elements (5) shown here are located at the end of the dielectric support (11) and project beyond the horn opening.

In Fig. 3 the principle of the arrangement of the radiator elements (5) on the dielectric support (11) is outlined. The radiator elements (5) are exemplified as a dipole and connected controllably by means of a switching device. In this case, the control line (25) should be shown schematically, which in turn is connected to the active or passive control element (26). In the exemplary embodiment, these control lines (25) from the dielectric support (12) are connected to subsequent assemblies by guiding in a thin metal tube (20) having electrical and magnetic shielding properties. At the same time, the metal tube (20) is fixedly connected to the dielectric carrier (11) and to the side facing away from the radiator element (5). As a result, several functions are realized simultaneously, the shielding of the control lines (25) in the direction of subsequent assemblies, the mechanical fixation of the control lines (25), the mechanical fixation of the dielectric support (12) and also the possibility of fixing the horn (4) is given ,

Fig. 4 shows the exemplary arrangement of the polarization cross (23) for linear polarization with respect to the arrangement of the radiator elements (5). It does not matter how the axes of horizontal and vertical polarization are assigned. It is assumed that the axes are orthogonal to each other.

In Fig. 5 the polarization cross is projected into the central axis of the horn (4).
For better representability because of the cross arrangement of the radiator and support elements (24) is not in Fig. 5 but separately in Fig. 6 shown. Out Fig. 5 and Fig. 6 It is clear that both crosses are arranged at an angle of 45 degrees with respect to the central axis of the horn (4). On the in Fig. 6 Plane shown are all required support elements (18), as will be apparent from Fig. 8 .

In Fig. 7 a section of an exemplary construction of the antenna (1) is shown. On the reflector (9) are both the support elements (18), in the example 4 pieces, as well as the entire waveguide structure for excitation of the subreflector (10) attached, consisting of a waveguide (3), a metal cylinder (21) which on the waveguide ( 3) is fixed and in which the exciting horn (4) is introduced. The fastening rings (19) are in turn mounted on the waveguide (3) and the cylinder (21) and in turn receive the thin metal tube (20) in which run the control lines. The waveguide (3) and the elements connected to it are protected by a metal tube (16), which is also fixed to the mounting rings (19). The sectional view also shows how the sub-reflector (10) with its mounting option (11), together with the support elements (18) with the Mulitfunktionshalterung (17) is positively connected.

REFERENCE SIGNS LIST

1

reflector antenna

2

Subreflector with mounting option

3

waveguide

4

horn

5

radiating element

9

reflector

10

subreflector

11

Holder of the subreflector

12

dielectric carrier

13

dielectric carrier

14

dielectric carrier

15

dielectric carrier

16

metal pipe

17

Multifunctional mount

18

support element

19

fixing ring

20

Thin metal tube

21

metal cylinder

22

Connection possibility for follow-on modules (HL flange)

23

Polarization cross for linear polarization

24

Arrangement cross for radiator elements and support elements

25

control lines

26

Passive or active control

Claims (9)

1. Arrangement for influencing the radiation pattern of a centrally focused reflector antenna (1), whereby the arrangement comprises a reflector antenna (1) with a reflector (9), a wave guide (3) with a horn (4) and ecitable transducer elements (5),
   characterized in that
   the arrangement comprises a sub-reflector (2, 10) and at least two excitable transducer elements (5), which are arranged in a stationary manner at the horn (4) and which in active status influence the course of beam between reflector (9) and sub-reflector (2, 10), whereby the at least two transducer elements (5) each are arranged on a dielectrical carrier (12, 13, 14, 15), and these are arranged on the dielectrical carriers laterally outwards at the horn and protrude over the rim of the horn.
2. Arrangement according to claim 1, characterized in that the arrangement comprises four transducer elements (5), which are arranged concentrically at the horn (4).
3. Arrangement according to any one of claims 1 or 2, characterized in that the transducer elements (5) are such elements, which are able to create an interaction with an electromagnetic field and which preferably are dipoles, monopoles or active circuit elements like tunnel diodes.
4. Arrangement according to any one of claims 1 to 3, characterized in that the transducer elements (5) comprise a resonance frequency, which lies within the receiving frequency range of the reflector antenna (1).
5. Arrangement according to any one of claims 1 to 4, characterized in that the transducer elements (5) are excitable sequentially, singular or in groups.
6. Arrangement according to any one of claims 1 to 5, characterized in that the excitation of the transducer elements (5) takes place within a frequency range, which is different from the operational frequency range of the reflector antenna (1).
7. Arrangement according to any one of claims 1 to 6, characterized in that the transducer elements (5) comprise control lines (25), which are magnetically and electrically shielded and are protected against mechanic influences.
8. Arrangement according to any one of claims 1 to 7, characterized in that the transducer elements (5) are arranged with their axis on an arrangement cross (24), with respect to the center of the horn (4), at 45 degrees with respect to the axis of the polarization cross (23).
9. Arrangement according to any one of claims 1 to 8, characterized in that the transducer elements (5) within themselves are connected via an excitable active or passive switch element (26), preferably via a switching diode.

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