EP1194982A1

EP1194982A1 - Antenna

Info

Publication number: EP1194982A1
Application number: EP00944010A
Authority: EP
Inventors: Max GÖTTL
Original assignee: Kathrein Werke KG
Current assignee: Kathrein SE
Priority date: 1999-07-08
Filing date: 2000-07-06
Publication date: 2002-04-10
Anticipated expiration: 2020-07-06
Also published as: CA2379846A1; AU5826000A; DE19931907C2; DE19931907A1; ATE279792T1; BRPI0012270B1; EP1194982B1; KR100797981B1; JP2003504925A; NZ516380A; CA2379846C; CN1253967C; CN1391712A; DE50008247D1; AU772733B2; ES2228561T3; HK1050961A1; WO2001004991A1; EP1194982B9; BR0012270A

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

antenna

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

In the case of antennas with at least two, ie with a plurality of supplied radiators, it is known that it is important to achieve the highest possible decoupling between the different radiators. In particular in the case of dual-polarized radiators or arrays, a high level of decoupling between the radiators of one polarization and the radiators of the other polarization orthogonal to it is desirable. Such arrays can consist, for example, of several elements in the form of dipoles, slots or planar emitter elements, such as those from EP 0 685 900 AI or from the prior publication "Antennas", Part 2, Bibliographical Institute in Mannheim / Vienna / Zurich, 1970, pages 47 to 50 are known. This includes, for example, omnidirectional radiators Polarization known in the form of a dipole square or a dipole cross, which have a coupling between the two systems spatially offset by 90 °.

To increase the directivity, such radiators are usually arranged in front of a reflector. It proves to be disadvantageous that the decoupling, which is good per se, in particular between radiators with orthogonal polarizations, is impaired by the arrangement as an array, in particular by the influences of the reflector.

In order to compensate for the disadvantages mentioned above, corresponding decoupling elements have already been proposed.

According to the previously published DE 196 27 015 AI, it has been proposed to arrange decoupling devices in the form of strips or crosses between the radiators, in particular when the strips are used, these are arranged along the connecting line of two antenna devices of an antenna array which are offset from one another. In contrast to previously known solutions, these strips are not arranged transversely to the connecting direction of two antenna arrangements, but parallel to the connecting line between two adjacent antenna devices.

According to the previously published DE 198 21 223 AI as

Decoupling elements propose passive strip arrangements that are staggered between two Antenna devices arranged in the manner of an antenna array are provided centrally between them in the direction transverse to the mounting direction of the radiators, or else parallel to the mounting direction and are arranged laterally from the radiators. In this respect, this arrangement already corresponds to the previously published US Pat. No. 3,541,559, which also proposes to arrange the individual decoupling elements laterally from the individual antennas in the manner of a frame.

GB 2 171 257 A also discloses an antenna array which has a plurality of dipoles arranged vertically one above the other, a projecting element being arranged above two dipoles arranged one above the other, which element is intended to improve the decoupling between the dipoles. However, this antenna array, which is known from this publication, is constructed using stripline technology.

The object of the present invention is to provide a further improved possibility for decoupling the various radiators in antennas with at least two fed radiators, in particular in antenna arrays and in particular in dual-polarized antenna arrays.

The object is achieved according to the features specified in claim 1.

Advantageous embodiments of the invention are specified in the subclaims. It must be said that it is extremely surprising that, in complete deviation from the entire previously published prior art, it is now proposed to use conductive decoupling elements that are oriented with their main direction of extension, i.e. with their longest extension in the direction of propagation of the electromagnetic wave and / or with their longest extension are aligned perpendicular to a reflector. The alignment does not have to correspond exactly to the direction of propagation of the electromagnetic wave or the vertical to the plane of a reflector. According to the invention, it is only provided that the decoupling elements, which are preferably rod-shaped, are aligned with a component in the direction of propagation of the electromagnetic waves, that is to say in particular perpendicular to the plane of the reflector plate, at least these components representing a larger value than a component perpendicular to them. If the decoupling elements are in the form of a rod, this means with others

Words that the angle between the longitudinal extent of the decoupling elements and a perpendicular to the plane of the reflector plate (ie to the direction of propagation of the electromagnetic waves) is less than 45 ".

The system according to the invention - and this is particularly surprising - has decisive advantages, particularly in the case of dual-polarized antennas, which in particular comprise at least one cross dipole or at least one dipole square. In contrast, those from the

GB 2 171 257 A known coupling elements only a dipole arrangement of a polarization, which are also adjacent.

According to the invention, therefore, two orthogonal polarizations are preferably affected in each case, in which no vertically adjacent radiators, which could be decoupled, are provided. Another difference from the prior art is that dual-polarized antennas use two separate inputs, between which a decoupling (or isolation) must be measurable, while with the improved decoupling, such a decoupling cannot be measured in a deeper arrangement with only one polarization is (since there is only one input).

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

The decoupling elements according to the invention can be arranged, for example, between two radiators, for example between two or more vertically polarized or horizontally polarized radiators, in each case in the region of the connecting line of these radiators.

In the case of cross dipoles, for example, the decoupling elements according to the invention, which are preferably perpendicular to the reflector plate, can be arranged in the immediate region between the individual dipole halves, for example in a plan view of an bisector of a cross dipole arrangement. Likewise, one or more of the inventive Coupling elements can be arranged, for example, in the case of a dipole square within the dipole square, and in turn here preferably on an bisector of the dipole square.

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

The cross section can also vary over the length of the decoupling elements according to the invention. It is also possible that the cross-sectional areas are not rotationally symmetrical, but, for example, have different longitudinal extensions along two intersecting axes that are perpendicular to one another and run parallel to the reflector surface.

Finally, it is also possible for the decoupling elements according to the invention to be provided, in particular also at their end opposite the reflector plate, with formations or attachments which also extend transversely to the vertical extension component of the decoupling elements and thus transversely to the direction of propagation of the electromagnetic waves and / or parallel to the level of the reflector sheet can extend.

The invention is explained in more detail below on the basis of exemplary embodiments. Show in detail

Figure 1 a: a schematic plan view of two dipoles arranged offset in the vertical mounting direction with the decoupling element according to the invention located therebetween.

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

Figure 2: a modified embodiment of an antenna in plan view;

FIG. 3: a further modified exemplary embodiment of the invention using a cross dipole;

Figure 3a: a perspective view of the embodiment of Figure 3;

FIG. 3b: a top view of the exemplary embodiment according to FIG. 3;

Figure 3c: a schematic side view of the embodiment shown in Figures 3 to 3b along the arrow 2 in Figure 3;

Figure 4: a modified embodiment of the

Invention for the case of a dipole square;

FIG. 5: an antenna according to the invention with two cross dipoles arranged offset from one another;

FIG. 6: a further exemplary embodiment of the invention on the basis of two dipole squares arranged offset from one another;

Figures 7 to 10: different side representations of different embodiments for a decoupling element.

Reference is made below to FIGS. 1 a and 1 b, in which an antenna 1 with at least two radiators 3 is shown in a schematic plan view, namely from two dipole radiators 3 a, each with two dipole halves 13 ′, which according to the exemplary embodiment according to FIG. 1 are at a suitable distance a reflector 5 or a reflector plate 5 are arranged. According to the schematic side view according to FIG. 1b, the associated symmetries 7 can be seen, by means of which the dipole halves 13 'are held relative to the reflector plate 5.

The dipole emitters 3a are with their dipole halves 13 'in Embodiment shown on a mounting line 11 arranged offset from each other.

Between the two emitters 3 there is a parallel to the direction of propagation of the electromagnetic wave in the exemplary embodiment shown (i.e. in the case of far-field observation perpendicular to the viewing or drawing plane), i.e. At the same time, a decoupling element 17 according to the invention is also arranged perpendicular to the plane of the reflector 5, which in the exemplary embodiment shown consists of a rod-shaped and hexagonal in cross-section, i.e. Decoupling element 17a formed in the manner of a regular hexagon.

The decoupling element 17 or 17a formed in this way is conductively connected at its base 21 to the reflector 5, for example galvanically conductively connected or capacitively.

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

The diameter of the rod-shaped element can also vary widely and is preferably approximately 0.01 to 0.2 times the wavelengths to be transmitted. 2 shows that a corresponding decoupling element 17, 17a can be provided between two radiators different from FIG. 1. In FIG. 2 there are two dipole emitters, each sitting in pairs in parallel alignment above and below the decoupling element. This results in a side view according to arrow 2 in FIG. 2, as shown in relation to the exemplary embodiment in FIG. 1b.

In the exemplary embodiment according to FIG. 3 and the further FIGS. 3a to 3c, an antenna 1 is shown which comprises two dipole radiators joined to form a cross dipole 3b. A corresponding decoupling element 17, 17a is arranged in the region of the cross dipole 3b on an angle bisector 27 in the dipole radiator arranged in a cross shape. This is therefore a dual-polarized antenna arrangement with a cross dipole, it being particularly surprising that the decoupling principle already works with such a cross dipole. As is generally known in the case of cross dipoles (or, for example, dipole squares), two separate inputs are used for the control, between which a decoupling (or isolation) can be measured, the use of the decoupling device according to the invention being verifiable in this way. It is also surprising that the principle of the decoupling elements according to the invention also works when an asymmetrical arrangement is used, that is to say, for example, in FIGS. 3 to 3c only one of the two the decoupling elements is used.

4, a dipole square 3c is shown in a corresponding distance in front of a reflector 5, two decoupling elements 17, 17a lying on an bisector 27 in the area of the cross dipole 3c being shown, each in an area between the corner points 29 of the dipole square and the center point 31 of the dipole square.

In the exemplary embodiment according to FIG. 5, two radiator devices arranged vertically one above the other in the form of two cross-radiators 36 are shown in front of a vertically running reflector 5, a decoupling element 17, 17a according to the invention being shown in the center on the vertical attachment or connecting line 11, which is also parallel again to the direction of propagation of the electromagnetic waves of the radiators, in other words perpendicular to the plane of the reflector 5.

In the exemplary embodiment according to FIG. 6, two dipole squares 3, 3c shown with reference to FIG. 4 are arranged at a vertical distance along a vertical connection axis 11 in front of a reflector 5, each with two decoupling elements 17, 17a explained within the dipole square according to FIG. In addition, along the vertical connecting line 11 in the exemplary embodiment shown, a fifth rod-shaped rod perpendicular to the reflector 5 is centered between the two mutually facing corner points 35 of the dipole squares 3c thus formed. shaped decoupling element.

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

In a departure from the exemplary embodiments shown, the decoupling elements 17, 17a can also be shaped differently in wide areas, in particular also be provided with a different cross section. The cross section of the decoupling elements 17, 17a can, for example, be n-polygonal, round, elliptical, with partially convex and concave successive circumferential sections or else in some other way, the entire longitudinal extent of the decoupling element 17, 17a formed in this way or its extension component being vertical to the reflector 5 and / or parallel to the direction of propagation of the electromagnetic waves of the antenna 1 has a dimension which is greater than the cross-sectional dimension in any transverse direction parallel to the plane of the reflector 5. Thus the cross-sectional shape can be transverse to the direction of extension or parallel to the reflector 5 Vary the length of the decoupling element 17, 17a not only in terms of its extent, but also in terms of its shape. In particular, at the upper end of the decoupling element tes 17, 17a, that is, opposite to its foot 21 sitting on the reflector 5, further structural elements may be provided, for example conical or spherical attachments, or asymmetrical attachments, bar-shaped attachments etc., these attachments being a measure parallel to the reflector 5 or have electromagnetic waves transverse to the direction of propagation, which is shorter than the extension component in the direction of propagation of the electromagnetic waves, that is to say perpendicular to the reflector 5.

The main direction of extent 25 (FIG. 1 a) of the decoupling element 17 according to the invention is therefore provided in an angular range of more than 45 ° with respect to the plane of the reflector 5 up to preferably 90 °, that is to say perpendicular to the plane of the reflector 5.

With the help of FIG. 7, further possible variations regarding of the decoupling elements 17 shown. FIG. 7 shows a cross-sectional illustration of the reflector plane 5 and a decoupling element 17 seated thereon, which, as explained, can also be arranged obliquely, that is to say not perpendicular to the plane of the reflector plate 5. The angle, ie the angle formed by the vertical 41 on the plane of the reflector 5 to the direction of extent 43 of the decoupling element 17, is less than 45 ^' , preferably less than 30' or 15 ", preferably just 0". The normal 41, based on the plane of the reflector 5, corresponds in the far field view to the direction of propagation of the electromagnetic waves. On the basis of FIG. 8 it is shown that the decoupling element can also have different cross-sectional shapes and dimensions in terms of its length.

It is shown on the basis of FIG. 9 that attachments or shoulders 45 can be formed on the coupling element, in particular at the upper end of the decoupling element 17, which also protrude beyond the outside dimension of the part of the decoupling element 17 underneath. With reference to Figure 9, for. B. shown a spherical attachment.

In contrast, FIG. 10 indicates a short rod-shaped attachment 45, the maximum transverse extent of which, however, is less than the total height of the decoupling element 17.

Any other modifications within the scope of the inventive concept are possible to this extent.

Claims

Claims;

1. Antenna with at least one or more dual-polarized radiators (13, 13 '), in particular in the form of at least one cross dipole or at least one dipole square, and with at least one additional passive conductive coupling element (17), characterized in that the decoupling element (17) with its narrowest direction of extension or at least one component of the decoupling element (17) with its longest direction of extension oriented in the direction of propagation of the electromagnetic waves and / or perpendicular to the plane of the reflector (5).

2. Antenna according to claim 1, characterized in that the decoupling element (17) on its foot (21) with the

Reflector (5) is electrically connected.

3. Antenna according to claim 1, characterized in that the decoupling element (17) is capacitively connected at its base (21) to the reflector (5).

4. Antenna according to one of claims 1 to 3, characterized in that the extension length of the decoupling element (17) or its component in the direction of propagation of the electromagnetic waves or perpendicular to the plane of the reflector (5) is greater than 0.05. times the wavelength of the electromagnetic waves transmitted or received via the radiators (3).

5. Antenna according to one of claims 1 to 4, characterized in that the extension length of the decoupling element (17) or its component in the direction of propagation of the electromagnetic waves or perpendicular to the plane of the reflector (5) is smaller than the 1- times the wavelength of the electromagnetic waves sent or received via the emitters (3).

6. Antenna according to one of claims 1 to 5, characterized in that the diameter of the decoupling element (17) is greater than 0.01 times the operating wavelength.

7. Antenna according to one of claims 1 to 6, characterized in that the diameter of the decoupling element (17) is smaller than 0.2 times the operating wavelength.

8. Antenna according to one of claims 1 to 7, characterized in that the diameter transverse to the direction of extension of the decoupling element (17) is n-polygonal, round, elliptical or irregular.

9. Antenna according to one of claims 1 to 8, characterized in that the angle () between the longitudinal extent (43) of the decoupling element (17) and the direction of propagation (41) of the electromagnetic waves or the normal (41) on the The plane of the reflector (5) is less than 45 ^' , preferably less than 30', 15 ', in particular by 0'.

10. Antenna according to one of claims 1 to 9, characterized in that the decoupling element (17), in particular at its end opposite the foot (21), is provided with an attachment or attachment (45) which corresponds to the cross-sectional dimension of the portion of the portion underneath Decoupling element (17) protrudes.

11. Antenna according to one of claims 1 to 10, characterized in that the attachment or attachment (45) is spherical, in the manner of a polygon, rod-shaped, etc.

12. Antenna according to one of claims 1 to 11, characterized in that the decoupling element (17) is rod-shaped or strip-shaped or waveguide-shaped.

13. Antenna according to one of claims 1 to 12, characterized in that the at least one decoupling element (17) is arranged between two adjacent radiators (3).

14. Antenna according to claim 13, characterized in that the at least one decoupling element (17) on the connecting line (11) between two adjacent radiators

(3) is preferably arranged centrally.

15. Antenna according to one of claims 1 to 14, characterized in that in the case of a cross dipole (3b) or a dipole square (3c) at least one, preferably at least two decoupling elements (17) are arranged in the region of the cross dipole or dipole square.

16. Antenna according to claim 15, characterized in that the at least one or preferably at least two decoupling elements (17) is arranged on an angle bisector to the cross dipole (3b) or to the dipole square (3c).

17. Antenna according to claim 15 or 16, characterized in that the at least one, preferably the at least two decoupling elements (17) are arranged on the bisector (27) between the center of the radiator and in front of its outer boundary.

18. Antenna according to one of claims 1 to 17, characterized in that the radiators (3) consist of radiators for

Transmission of vertical polarizations, horizontal polarizations, orthogonal polarizations, in particular consist of dipole radiators or patch radiators.

19. Antenna according to one of claims 1 to 18, characterized in that the entire antenna arrangement including the at least one coupling element (17) is asymmetrical.

20. Antenna according to one of claims 1 to 19, characterized in that the at least two separate inputs assigned to the dual-polarized antennas are measurably decoupled from one another.

21. Antenna according to one of claims 1 to 20, characterized in that all coupling elements (17) are of identical design.

22. Antenna according to one of claims 1 to 20, characterized in that at least one, preferably a plurality of coupling elements (17) is or are designed differently with respect to the remaining coupling elements (17).