EP1194982B1 - Antenna - Google Patents

Abstract

An antenna comprises at least two or more radiators such as, especially dual-polarized radiators, and at least one additional passive conducting decoupling elements. The decoupling element, in its longest direction of extension, or at least one component of the decoupling element, with its longest direction of extension, extends in the propagation direction of the electromagnetic waves and/or perpendicular to the plane of the reflector.

Description

The invention relates to an antenna with at least two fed emitters according to the preamble of the claim 1.

For antennas with at least two, i. fed with several Spotlights, it is known to be important between the different emitters as high as possible To achieve decoupling. Especially with dual-polarized Emitters or arrays is a high decoupling between the emitters of one polarization and the emitters the other orthogonal polarization he wishes. Such arrays can be made, for example several elements in the form of dipoles, slots or Planar radiator elements exist, as for example from EP 0 685 900 A1 or from the prior publication "Antennas", Part 2, bibliographic institute in Mannheim / Vienna / Zurich, 1970, pages 47 to 50 are known.

These are, for example, omnidirectional with horizontal Polarization in the form of a dipole square or a Dipolkreuzes known which a coupling between the have two systems offset by 90 ° spatially.

To increase the directivity such spotlights usually arranged in front of a reflector. As a disadvantage proves that the good decoupling especially between radiators with orthogonal polarizations by the arrangement as an array, in particular by the influences of the reflector is deteriorated.

To compensate for these disadvantages, are already proposed corresponding decoupling elements Service.

From DE 198 29 714 A1 is a doubly polarized Dipole antenna, a so-called bow loop dipole antenna, with an integrated feed over an exposed one Line as known, which between two superimposed dual-polarized individual radiators sitting in the middle of a so-called separating device in the form of a dividing tree. This also below designated as decoupling element separating element has a maximum extent parallel to the reflector. The entire arrangement sits on two so-called distance insulators, with which the separating element on the reflector is attached.

According to the previously published DE 196 27 015 A1 is proposed been, between the radiators decouplers to arrange in the form of stripes or crosses, in particular when using the strips, these longitudinally the connecting line of two offset from each other Antenna devices of an antenna array arranged are. In contrast to previously known solutions these strips are not transverse to the direction of connection two antenna arrays arranged, but in parallel to the connecting line between two adjacent antenna devices.

According to the previously published DE 198 21 223 A1 be as Decoupling elements passive strip arrangements proposed which are offset between two each, arranged in the manner of an antenna array antenna devices centrally between these in the transverse direction to the Attachment direction of the radiator aligned aligned provided are, or parallel to the cultivation direction and are arranged laterally from the radiators. These Arrangement corresponds in this respect already the pre-published US 3,541,559, which also suggests the individual Decoupling elements in the manner of a frame laterally to arrange from the individual antennas.

From GB 2 171 257 A an antenna array is also known, which several vertically stacked Having dipoles, wherein each of two superimposed arranged dipoles arranged a protruding element which is to improve the decoupling between the Should serve dipoles. This prior art antenna array is However, constructed in stripline or triplate technology. In addition, it has no reflector. Only a shield is provided for the triplate structure. But above all, it is in this known Antenna array not around a dual polarized antenna array, but an arrangement in which only one Polarization can be received or sent.

Object of the present invention is in antennas with at least one powered dual polarized radiator (i.e., for example, an antenna having at least two dipole radiators, which are arranged dual polarized), in particular in dual polarized antenna arrays a further improved Possibility to decouple the various spotlights to enable.

The object is according to the invention in the claim 1 specified characteristics solved. Advantageous embodiments The invention are specified in the subclaims.

It must be described as extremely surprising that in complete deviation from the entire pre-published Prior art is now proposed, conductive Decoupling elements to be used, which coincide with their Main extension direction, so with their longest extent parallel to the propagation direction of the electromagnetic Wave in far-field viewing (i.e., parallel to the main beam direction of a single radiator, the adjacent is arranged to the decoupling element on the reflector) and / or with its longest extent perpendicular to one Reflector are aligned (i.e., at least perpendicular to Reflector in the region of the foot of the decoupling element). The alignment does not have to be exactly in the direction of propagation the electromagnetic wave or not exactly correspond to the depression to the plane of a reflector.

According to the invention, it is merely provided that the decoupling elements, which are preferably designed rod-shaped, with a component in the propagation direction of the electromagnetic Waves, i. in particular perpendicular to Reflector plate plane are aligned, wherein at least these components opposite one perpendicular to it standing component is larger. In rod-shaped design The decoupling elements is called this with others Words, that the angle between the longitudinal extension a decoupling element and a perpendicular to Reflector plate plane (ie at least one vertical perpendicular to the reflector plate plane in the area of the foot of the Decoupling element) or the angle between the longitudinal extension a decoupling element and the Hauptausbreitungsrichtung an electromagnetic wave of a adjacent is less than 45 °.

It is further provided according to the invention that the Decoupling element either electrically galvanic or capacitively connected to the reflector.

The inventive system - and this is particularly surprising - has decisive advantages dual polarized antennas, that is in particular at least one crossed dipole or at least one dipole square include. In contrast, those from GB 2,171,257 A known decoupling only a dipole arrangement a polarization that are also adjacent.

Another difference from the prior art exists in that dual-polarized antennas have two separate ones Inputs are used, between which a decoupling (or isolation) must be measurable while at the improved Decoupling in a simpler arrangement with only one polarization such a decoupling not measurable (since there is only one input).

As mentioned, the decoupling elements according to the invention are preferably rod-shaped and / or cone-shaped.

The decoupling elements according to the invention can thereby for example, between two radiators, for example between two or more vertically polarized or horizontally polarized radiators each in the range of Connecting line of these emitters be arranged.

In cross dipoles, for example, the preferred perpendicular on the reflector sheet sitting inventive Decoupling elements in the immediate area between the individual dipole halves, e.g. in plan view on an angle bisector of a Kreuzdipolanordnung.

Likewise, one or more of the decoupling elements according to the invention for example, at a dipole square be located within the dipole square, and hereby again preferably on an angle bisector of the dipole square.

The rod-shaped decoupling elements according to the invention extend as stated with their greatest longitudinal extent or component in the direction of propagation of magnetic waves and / or perpendicular to the reflector plane. The decoupling elements can be uniform Cross section or different cross-sectional shapes have, for example, with round or regular or irregular n-polygonal, for example square or hexagonal section, etc.

The cross section can also be over the length of vary according to the invention decoupling elements. As well it is possible that the cross-sectional areas are not rotationally symmetric are, but different, for example Longitudinal directions along two perpendicular to each other standing and parallel to the reflector surface extending Have cutting axes.

Finally, it is also possible that the invention Decoupling elements in particular also at their for Reflector plate opposite end with formations or essays that are also transverse to the vertical Extension component of the decoupling elements and thus across the propagation direction of the electromagnetic Waves and / or parallel to the plane of the reflector sheet can extend.

Figur 1 a :

eine schematische Draufsicht auf zwei in vertikaler Anbaurichtung versetzt zueinander angeordneten Dipolen mit dazwischen sitzendem erfindungsgemäßen Entkopplungselement.

Figur 1 b :

eine schematische Seitenansicht des Ausführungsbeispieles nach Figur 1a längs des Pfeiles 2 in Figur 1;

Figur 2 :

ein abgewandeltes Ausführungsbeispiel einer Antenne in Draufsicht;

Figur 3 :

ein erstes erfindungsgemäßes Ausführungsbeispiel mit einem Kreuzdipol, bei welchem ein anhand der Figuren 1a bis 2 erläutertes erfindungsgemäßes Entkopplungselement verwendet wird;

Figur 3a :

eine perspektivische Darstellung des Ausführungsbeispiels gemäß Figur 3;

Figur 3b :

eine Draufsicht auf das Ausführungsbeispiel gemäß Figur 3;

Figur 3c :

eine schematische Seitenansicht des.Ausführungsbeispiels gemäß den Figuren 3 bis 3b längs des Pfeiles 2 in Figur 3;

Figur 4 :

ein abgewandeltes Ausführungsbeispiel der Erfindung für den Fall eines Dipolquadrates;

Figur 5 :

eine erfindungsgemäße Antenne mit zwei versetzt zueinander angeordneten Kreuzdipolen;

Figur 6 :

ein weiteres Ausführungsbeispiel der Erfindung anhand zweier versetzt zueinander angeordneter Dipolquadrate; und

Figuren 7 bis 10:

unterschiedliche Seitendarstellungen verschiedener Ausführungsformen für ein Entkopplungselement.

The invention will be explained in more detail with reference to embodiments. Show in detail

FIG. 1 a:

a schematic plan view of two mutually offset in the vertical direction of attachment dipoles with interposed decoupling element according to the invention.

FIG. 1 b:

a schematic side view of the embodiment of Figure 1a along the arrow 2 in Figure 1;

FIG. 2:

a modified embodiment of an antenna in plan view;

FIG. 3:

a first embodiment according to the invention with a cross dipole, in which an inventive decoupling element explained with reference to Figures 1a to 2 is used;

FIG. 3a:

a perspective view of the embodiment of Figure 3;

FIG. 3b:

a plan view of the embodiment of Figure 3;

FIG. 3c:

a schematic side view of the exemplary embodiment according to the figures 3 to 3b along the arrow 2 in Figure 3;

FIG. 4:

a modified embodiment of the invention in the case of a Dipolquadrates;

FIG. 5:

an antenna according to the invention with two mutually offset cross dipoles;

FIG. 6:

a further embodiment of the invention with reference to two mutually offset dipole squares; and

FIGS. 7 to 10:

different side views of various embodiments for a decoupling element.

In the following, reference is made to FIGS. 1a and 1b, in FIG which in a schematic plan view of an antenna 1 with at least two radiators 3 is shown, namely two Dipole radiators 3a, each with two dipole halves 13 ', the according to the embodiment of Figure 1 in corresponding suitable distance in front of a reflector 5 or a Reflector plate 5 are arranged. According to the schematic Page representation of Figure 1b are the respectively associated Symmetries 7 can be seen, about which the dipole halves 13 'are held opposite the reflector plate 5.

The dipole radiators 3a are with their dipole halves 13 'in shown embodiment is offset to a cultivation line 11 arranged to each other.

Between the two radiators 3 is a shown in the embodiment parallel to the propagation direction of the electromagnetic wave (ie with far field viewing perpendicular to the viewing or drawing plane), i. at the same time also perpendicular to the plane of the reflector 5 a Decoupling element 17 according to the invention is arranged, which in the illustrated embodiment of a rod-shaped and hexagonal in cross-section, i. like one regular hexagon formed decoupling element 17a exists.

The decoupling element 17 or 17a thus formed is on his foot 21 conductively connected to the reflector 5, for example electrically connected or capacitive.

The length of the rod-shaped element, i. its extension direction parallel to the propagation direction of the electromagnetic Waves of the thus formed antenna 1, i. perpendicular to the reflector 5 is preferably 0.05 to 1 times the wavelength of the frequency range to be transmitted the antenna.

The diameter of the rod-shaped element can also differ widely and is preferably about 0.01 to 0.2 times the wavelengths to be transmitted.

On the basis of Figure 2 is shown that a corresponding Decoupling element 17, 17a between two different to Figure 1 Emitters can be provided. It deals in Figure 2 by two dipole radiators, each in pairs in parallel alignment above and below sit the decoupling element. It turns out while a side view according to arrow 2 in Figure 2, as they with respect to the embodiment of Figure 1b reproduced is.

In the embodiment of Figure 3 and the other FIGS. 3a to 3c show an antenna 1 which has two comprises dipole radiators joined together to form a crossed dipole 3b. On an angle bisector 27 in the plan view Cross-shaped dipole radiators are in the range of the cross dipole 3b lying respectively a corresponding one Decoupling element 17, 17a arranged. It deals So here is a dual polarized antenna arrangement with a cross-dipole, being particularly surprising that the decoupling principle already in such a Cross dipole works. As with cross dipoles (or for example Dipole squares) is basically known, So two separate inputs are used to control, between which a decoupling (or isolation) is measurable, wherein the use of the invention Decoupling device is detectable in this way. It is also surprising that the inventive Principle of decoupling elements works well even then if an asymmetric arrangement is used, ie For example, in the figures 3 to 3c, only one of the two Decoupling elements is used.

In the embodiment of Figure 4 is a plan view a dipole square 3c at a corresponding distance before a reflector 5 shown, wherein on an angle bisector 27 lying in the region of the cross dipoles 3c two Decoupling elements 17, 17 a are shown, each in an area between the vertices 29 of the dipole square and the center 31 of the dipole square.

In the embodiment according to FIG. 5, two are vertical superimposed radiator devices in the form of two cross radiators 36 in front of a vertically extending Reflector 5 shown, wherein on the vertical cultivation or Connecting line 11 in the middle of an inventive decoupling element 17, 17a, which is also shown again parallel to the propagation direction of the electromagnetic Waves of the spotlights, in other words vertical extends to the plane of the reflector 5.

In the embodiment of Figure 6 are two based shown in Figure 4 dipole squares 3, 3c in the vertical distance along a vertical connection axis 11 in front of a Reflector 5 is arranged, each with two inside of the dipole square according to FIG. 4 explained decoupling elements 17, 17a. In addition is along the vertical connecting line 11 in the shown Embodiment centered between the two on each other assigning vertices 35 of the dipole squares thus formed 3c a fifth perpendicular to the reflector 5 seated rod-shaped Decoupling element drawn.

The basic structure of the antenna device and the Use of corresponding decoupling elements 17, 17a has been described for different types of antennas. There are any further modifications of antennas, i.e. in particular other antenna types and the structure and the arrangement of different radiators conceivable, at all of which the explained decoupling elements 17, 17a can be used.

Notwithstanding the embodiments shown can the decoupling elements 17, 17a in wide areas be shaped differently, especially with another Cross section be provided. The cross-section of the decoupling elements 17, 17a may be, for example, n-polygonal, round, elliptical, with partly convex and concave successive peripheral sections or in other Be formed manner, wherein the entire longitudinal extent of the decoupling element 17, 17a thus formed or its extension component perpendicular to the reflector 5 and / or parallel to the propagation direction of the electromagnetic Waves of the antenna 1 has a degree, which is greater than the cross-sectional dimension in any one Transverse direction parallel to the plane of the reflector 5. So can the cross-sectional shape transverse to the direction of extension or parallel to the reflector 5 over the length of the decoupling element 17, 17a not only on its extent but also vary in shape. Especially can at the upper end of the decoupling element 17, 17a, so opposite to his on the reflector 5 sitting foot 21 even more structural elements be provided, for example, cone or spherical Essays, or asymmetrical approaches, beam-shaped approaches etc., these approaches being a measure in the parallel direction to the reflector 5 or transversely to the propagation direction have electromagnetic waves which is shorter, as the extension component in the propagation direction of electromagnetic waves, ie perpendicular to the reflector 5th

Therefore, the main extension direction 25 (FIG. 1a) is of the decoupling element 17 according to the invention in one Angular range of more than 45 ° relative to the plane of the Reflector 5 up to preferably 90 °, ie perpendicular to Level of the reflector 5 extending provided.

With reference to Figure 7 are further variations with respect to the decoupling elements 17 shown. Figure 7 shows while a cross-sectional representation of the reflector plane. 5 and a decoupling element 17 seated thereon, which as explained also obliquely, so not perpendicular to the plane of the reflector sheet 5 can be arranged. The angle α, i.e. that of the vertical 41 to the plane of the reflector 5 to the extension direction 43 of the decoupling element 17 formed angle α is less than 45 °, preferably less than 30 ° or 15 °, preferably just 0 °. The normal 41, with respect to the plane of the reflector 5, corresponds to the propagation direction in the far field view the electromagnetic waves.

With reference to Figure 8 is shown that the decoupling element also different over its longitudinal extent in height Have cross-sectional shapes and dimensions can.

With reference to FIG. 9, it is shown that on the decoupling element Up or approaches 45 especially at the top of the decoupling element 17 may be formed, the also the external dimensions of the part underneath beyond the decoupling element 17. With reference to FIG. 9 is z. B. a spherical attachment shown.

By contrast, FIG. 10 shows a short rod-shaped one Attachment 45 indicated, whose maximum transverse extent but less than the total height of the decoupling element 17th

Claims (21)

1. Antenna having at least one dual-polarized (3) or two or more dual-polarized antenna elements (3), which is arranged in front of a reflector plane (5) or are arranged in front of a reflector plane (5) such that the main propagation direction of the electromagnetic wave from each dual-polarized antenna element (3) in the far field is at right angles to the reflector plane (5) in the foot area of the antenna element (3), with each dual-polarized antenna element (3) comprising differently polarized individual antenna elements, and having at least one passive conductive decoupling element (17) for decoupling the differently polarized individual antenna elements, with the decoupling element (17) having a foot (21) which is conductively or capacitively connected to the reflector (5), and with the decoupling element (17) having a longest extent in one direction, by which means its main extent direction is defined,
   characterized by the following features:

   the main extent direction of the decoupling element (17)

   a) is arranged at right angles to the reflector plane (5), or

   b) includes an angle (α) which is less than 45° with a vertical, which is at right angles to the reflector plane (5) in the area of the foot (21) of the decoupling element (17).
2. Antenna according to Claim 1, characterized in that the length of the decoupling element (17) or the projection of the length of the decoupling element (17) on the vertical which is at right angles to the plane of the reflector (5) in the area of the foot (21) of the decoupling element (17) is greater than 0.05 times the wavelength of the electromagnetic waves which are transmitted or received via the antenna elements (3).
3. Antenna according to one of Claims 1 or 2, characterized in that the length of the decoupling element (17) or its component with respect to a vertical at right angles to the plane of the reflector (5) adjacent to the foot (21) of the decoupling element (17) is less than the wavelength of the electromagnetic waves which are transmitted or received via the antenna elements (3).
4. Antenna according to one of Claims 1 to 3, characterized in that the thickness of the decoupling element (17) is greater than 0.01 times the operating wavelength.
5. Antenna according to one of Claims 1 to 4, characterized in that the thickness of the decoupling element (17) is less than 0.2 times the operating wavelength.
6. Antenna according to one of Claims 1 to 5, characterized in that the cross section transversely with respect to the extent direction of the decoupling element (17) is n-sided polygonal, round, elliptical or irregular.
7. Antenna according to one of Claims 1 to 6, characterized in that the angle (α) between the extent direction (43) in the longitudinal direction of the decoupling element (17) and the normal (41) to the plane of the reflector (5) is less than 30°, preferably less than 15°, and, in particular, is around 0°.
8. Antenna according to one of Claims 1 to 7, characterized in that the decoupling element (17) has a foot (21) and, in particular at its end opposite the foot (21), is provided with a fitting or attachment (45) which projects beyond the cross-sectional size of that section of the decoupling element (17) which is located underneath it.
9. Antenna according to Claim 8, characterized in that the fitting or attachment (45) is spherical, or in the form of a polygon, or a rod etc.
10. Antenna according to one of Claims 1 to 9, characterized in that the decoupling element (17) is in the form of a rod, in the form of a strip, or in the form of a waveguide.
11. Antenna according to one of Claims 1 to 10, characterized in that at least two antenna elements (3) are provided, and in that the at least one decoupling element (17) is arranged between two adjacent antenna elements (3).
12. Antenna according to Claim 11, characterized in that the at least one decoupling element (17) is arranged on the connecting line (11) between two adjacent antenna elements (3), preferably centrally between them.
13. Antenna according to one of Claims 1 to 12, characterized in that, in the case of a cruciform dipole (3, 3b), at least one and preferably at least two decoupling elements (17) is or are arranged in the area of the cruciform dipole (3b).
14. Antenna according to one of Claims 1 to 13, characterized in that, in the case of a dipole square (3, 3c), at least one and preferably at least two decoupling elements (17) is or are arranged in the area of the dipole square (3, 3c).
15. Antenna according to Claim 12 or 13, characterized in that the at least one or preferably at least two decoupling elements (17) is or are arranged on an angle bisector with respect to the cruciform dipole (3, 3b) or with respect to the dipole square (3, 3c).
16. Antenna according to Claims 13 to 15, characterized in that the at least one and preferably the at least two decoupling elements (17) is or are arranged on the angle bisector (27) between the centre point of the antenna element and in front of its outer boundary.
17. Antenna according to one of Claims 1 to 16, characterized in that the antenna elements (3) comprise antenna elements for transmission of vertical polarizations, horizontal polarizations or orthogonal polarizations, and in particular comprise dipole antenna elements or patch antenna elements.
18. Antenna according to one of Claims 1 to 17, characterized in that the entire antenna arrangement including the at least one decoupling element (17) is asymmetric.
19. Antenna according to one of Claims 1 to 18, characterized in that the at least two separate inputs which are associated with the dual-polarized antennas are measurably decoupled from one another.
20. Antenna according to one of Claims 1 to 19, characterized in that all of the decoupling elements (17) are the same.
21. Antenna according to one of Claims 1 to 19, characterized in that two or more decoupling elements (17) are provided, and in that at least one and preferably two or more decoupling elements (17) is or are designed differently to the remaining decoupling elements (17).

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