Multi radiator antenna comprising means for indicating antenna main lobe direction

Abstract

A multi radiator antenna comprising an electrically conductive reflector, at least two radiating elements arranged on said reflector, a feeding network connected to the radiating elements, and a protective cover. The feeding network comprises a plurality of conductors for distributing signals to the radiators. The feeding network has means for adjusting relative phases of said signals in order to adjust a direction of the antenna main lobe of said multi-radiator base station antenna. The means for adjusting is provided with, or is connected to, an indicating portion configured to provide a visual indication of said direction. The protective cover is provided with an at least partially transparent wall portion arranged such that said indicating portion is visible there through.

Claims

1. A multi radiator antenna comprising an electrically conductive reflector, at least two radiating elements arranged on said reflector, a feeding network connected to said radiating elements, and a protective cover arranged to protect the feeding network, wherein said feeding network comprises a plurality of conductors for distributing signals to said radiators, said feeding network having means for adjusting relative phases of said signals in order to adjust the direction of the antenna main lobe of said multi-radiator antenna, wherein said means for adjusting is provided with, or is connected to, an indicating portion configured to provide a visual indication of said direction, and wherein said protective cover is provided with an at least partially transparent wall portion having a scale and wherein the protective cover is arranged such that the position of said indicating portion is visible there through and said indicating portion is configured to co-act with said scale to indicate said position.

2. The multi radiator antenna according to claim 1, wherein said means for adjusting relative phases of said signals is configured to adjust the antenna main beam angle in the elevation plane.

3. The multi radiator antenna according to claim 1, wherein said plurality of conductors of said feeding network are configured as substantially air filled coaxial lines, each comprising a central inner conductor and an elongated outer conductor surrounding the central inner conductor.

4. The multi radiator antenna according to claim 3, wherein the substantially air filled coaxial lines are integrally formed with the reflector.

5. The multi radiator antenna according to claim 1, wherein said means for adjusting comprises at least one dielectric element, each configured to co-operate with at least one of said conductors to provide a phase shifting arrangement.

6. The multi radiator antenna according to claim 5, wherein said means for adjusting comprises displacement means configured to displace said at least one dielectric element and said indicating portion.

7. The multi radiator antenna according to claim 6, further comprising a manual actuating arrangement configured to actuate said displacement means, which actuating arrangement comprises a handle or knob.

8. The multi radiator antenna according to claim 6, further comprising an electrical actuating arrangement configured to actuate said displacement means, which electrical actuating arrangement comprises at least one electric motor.

9. The multi radiator antenna according to claim 8, further comprising means for controlling said electrical actuating arrangement from a distance.

10. The multi radiator antenna according to claim 3, further comprising at least one elongated rail element, each being slideably arranged inside an outer conductor of said coaxial lines, said rail element being longitudinally movable in relation to said outer conductor, wherein said means for adjusting further comprises at least one connecting element connected to the rail element of at least one of said coaxial lines, said connecting element being provided with said indicating portion, and wherein each of said at least one dielectric element is configured to co-operate with a corresponding coaxial line by being attached to an elongated rail element arranged therein.

11. The multi radiator antenna according to claim 10, wherein said outer conductor is provided with at least one longitudinally extending slot, and wherein said connecting element is connected to said rail element through said slot.

12. The multi radiator antenna according to claim 1, wherein said protective cover at least partly covers or surrounds the antenna feeding network and/or the reflector and/or the radiators.

13. A multi-radiator antenna with capability for adjustment of the direction of the antenna main lobe of said multi-radiator antenna, comprising: an electrically conductive reflector; at least two radiating elements arranged on said reflector; a feeding network connected to said radiating elements and having: a plurality of conductors connecting a connector to said radiating elements; and a phase adjusting mechanism connected to an indicating portion; a protective cover arranged to protect the feeding network and provided with a scale located adjacent to the indicating portion thereby providing a visual indicate position of the phase shifting mechanism.

14. The multi-radiator antenna with capability for adjustment of the direction of the antenna main lobe of said multi-radiator antenna of claim 13, wherein said phase adjusting mechanism is configured to adjust the antenna main beam angle in the elevation plane.

15. The multi radiator antenna according to claim 13, wherein said plurality of conductors of said feeding network are configured as substantially air filled coaxial lines, each comprising a central inner conductor and an elongated outer conductor surrounding the central inner conductor.

16. The multi radiator antenna according to claim 15, wherein the substantially air filled coaxial lines are integrally formed with the reflector.

17. The multi radiator antenna according to claim 13, wherein said phase adjusting mechanism comprises at least one dielectric element, each configured to co-operate with at least one of said conductors to provide a phase shifting arrangement.

18. The multi radiator antenna according to claim 17, wherein said phase adjusting mechanism is configured to displace said at least one dielectric element and said indicating portion.

19. The multi radiator antenna according to claim 18, further comprising a manual actuating arrangement configured to actuate displacement of said dielectric element and said indicating portion, which actuating arrangement comprises a handle or knob.

20. The multi radiator antenna according to claim 18, further comprising an electrical actuating arrangement configured to actuate said displacement of said dielectric element and said indicating portion, which electrical actuating arrangement comprises at least one electric motor.

21. The multi radiator antenna according to claim 20, further comprising means for controlling said electrical actuating arrangement from a distance.

22. The multi radiator antenna according to claim 15, further comprising at least one elongated rail element, each being slideably arranged inside an outer conductor of said coaxial lines, said rail element being longitudinally movable in relation to said outer conductor, wherein said means for adjusting further comprises at least one connecting element connected to the rail element of at least one of said coaxial lines, said connecting element being provided with said indicating portion, and wherein each of said at least one dielectric element is configured to co-operate with a corresponding coaxial line by being attached to an elongated rail element arranged therein.

23. The multi radiator antenna according to claim 22, wherein said outer conductor is provided with at least one longitudinally extending slot, and wherein said connecting element is connected to said rail element through said slot.

24. The multi radiator antenna according to claim 13, wherein said protective cover at least partly covers or surrounds the antenna feeding network and/or the reflector and/or the radiators.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the present invention will now be described in more detail with reference to the appended drawings, which show presently preferred embodiments of the invention, wherein:

(2) FIG. 1 shows a schematic view of a multi radiator antenna;

(3) FIG. 2 shows a multi radiator antenna according to an embodiment of the invention;

(4) FIG. 3 shows a detail view of the antenna in FIG. 2;

(5) FIG. 4 shows a cross section view of parts of an antenna feeding network of a multi radiator antenna according to an embodiment of the invention;

(6) FIG. 5 shows parts of the antenna feeding network in FIG. 4 as seen from the side;

(7) FIG. 6 shows parts of an antenna feeding network of a multi radiator antenna according to the invention;

(8) FIG. 7 shows a multi radiator antenna according to an embodiment of the invention;

(9) FIG. 8 shows parts of an antenna feeding network of a multi radiator antenna according to an embodiment the invention;

(10) FIG. 9 shows parts of an antenna feeding network of a multi radiator antenna according to an embodiment of the invention; and

(11) FIG. 10 shows a multi radiator antenna according to an embodiment of the invention.

DETAILED DESCRIPTION

(12) FIG. 1 schematically illustrates a multi radiator antenna 1′ comprising an antenna feeding network 2′, an electrically conductive reflector 17′, which is shown schematically in FIG. 1, and a plurality of radiating elements 14′. The radiating elements 14′ may be dipoles. The antenna feeding network 2′ connects a coaxial connector 10′ to the plurality of radiating elements 14′ via a plurality of lines 6′ which may be coaxial lines, which are schematically illustrated in FIG. 1. The signal to/from the connector 10′ is split/combined using, in this example, three stages of splitters/combiners 18′.

(13) FIG. 2 shows a multi radiator antenna 1 according to an embodiment of the invention, as seen from the rear side of the antenna. The antenna comprises an antenna feeding network 2 and a protective cover 3 which covers the rear side of the antenna feeding network to provide protection therefore. The front side of the antenna feeding network (not visible) is protected by the reflector (also not visible). In other embodiments, the protective cover may cover or encapsulate the entire antenna feeding network or even the entire antenna. In yet other embodiments, two protective covers or cover portions are provided, one which covers the rear side of the antenna/antenna feeding network, and one which covers the front side of the antenna, i.e. covers the reflector and the radiators (not shown in FIG. 2). The protective cover is made of a plastic material. The antenna feeding network 2 comprises a plurality of substantially air filled coaxial lines for distributing signals between the coaxial connectors 10 and the radiators (not shown) of the multi-radiator base station antenna. Each coaxial line comprises a central inner conductor and an elongated outer conductor surrounding the central inner conductor. In the figure, the inner and outer conductors are not shown, being hidden behind the protective cover.

(14) The feeding network has means for adjusting (not shown) relative phases of said signals in order to adjust a direction of the antenna main lobe of said multi-radiator base station antenna. The means for adjusting is provided with an indicating portion 4 formed as a rounded protrusion having an indicating line or groove thereon. The indicating portion is configured to provide a visual indication of the electrical elevation tilt angle. The protective cover is provided with a transparent wall portion 5 through which the indicating portion 4 is visible. The transparent wall portion 5 is formed as a half-cylinder shaped protrusion in which the indicating portion 4 is movable in the longitudinal direction (up- and downwards as seen in the figure). The transparent wall portion 5 comprises a scale, wherein said indicating portion is configured to form an indicator co-acting with said scale to indicate said position. In other embodiments, a wall portion of the protective cover being adjacent the transparent wall portion is provided with a scale, i.e. a graded or scaled reference portion on which, due to its location adjacent the indicating portion, a position of the indicating portion may be read visually.

(15) FIG. 3 shows a detail view of the antenna in FIG. 2 in which the indicating portion 4 and the transparent wall portion 5 are seen more clearly. As explained above, the indicating portion 4 is provided with an indicating line or groove 4a, which may be colored to be clearly visible outdoors. In this embodiment, the scale on the transparent wall portion 5 is graded from 0 to 6. When the means for adjusting relative phases is adjusted, the indicating portion 4 is moved, and the position of the indicating line or groove 4a on the scale can be easily read through the transparent wall portion. Thus, a phase shift value between 0 and 6 which is directly correlated to the actual relative phase or electrical tilt angle can be visually determined.

(16) FIG. 4 shows a cross section view of parts of an antenna feeding network of a multi radiator antenna according to an embodiment of the invention. The feeding network comprises a plurality of parallel coaxial lines. The figure shows two coaxial lines 6a, 6b which each comprise a central inner conductor 7a, 7b, an elongated outer conductor 8a, 8b forming a cavity or compartment around the central inner conductor, and an elongated rail element 9a, 9b slideably arranged inside the outer conductor. The outer conductors 8a, 8b have square cross sections and are formed integrally and in parallel to form a self-supporting structure.

(17) The rail elements 9a, 9b are longitudinally movable relative the outer conductors. Each coaxial line 6a, 6b is provided with a dielectric element 11a, 11b which is attached to the corresponding elongated rail element 9a, 9b and is configured to co-operate with the corresponding coaxial line 6a, 6b. The dielectric elements 11a, 11b both have a U-shaped cross section and are arranged around the respective inner conductor 7a, 7b such that it partially surrounds the inner conductor and fills most of the cavity between the conductors. Arranging the dielectric elements 11a, 11b in the cavity between the inner and outer conductor forms a phase shifting device arranged to adjust the phase of signals in coaxial line 6a, 6b. Since the dielectric elements 11a, 11b are each attached to a corresponding rail element 9a, 9b, the phase may be adjusted by moving or sliding the rail elements longitudinally until the desired position and phase shift is achieved. By varying the phase shift in the feeding network, it is possible to control the direction of the antenna main beam in the elevation angle; this is often referred to as controlling the antenna downtilt, or antenna tilt. The indicating portion 4 is formed as a portion of the connecting element 13. In other embodiments, the indicating portion 4 is a separate part or element which is connected to (but separate from) the connecting element 13.

(18) The rail elements are moved or displaced using displacement means which comprises a threaded rod 12 which extends longitudinally (in the depth direction as seen in the figure) and a connecting element 13 which comprises a first arm portion 13a and a second arm portion 13b, each connected to a respective rail element 9a, 9b via respective attachment portions 13d, 13e. The connecting element is provided with an internally threaded portion 13c having pitch and dimensions adapted to co-operate with the threaded rod. The rail element is connected to dielectric elements 11a, 11b. Thus, when the rod 12 is rotated, the connecting element 13 and the thereto connected rail element 9a, 9b and consequently also the dielectric elements 11a, 11b move in the longitudinal direction, thus adjusting the phase shift of the coaxial lines. The rod may be rotated manually or using an electric motor controlled by a controlling device such as micro-controller. When using electric motors, the dielectric elements, and hence the downtilt of the antenna, can be controlled remotely. Remote control can be achieved e.g. by connecting the motor and micro-controller to a network control center, or a lap top computer, or some other means for control. Although only two of the outer conductors or channels are provided with inner conductors in FIG. 4, it is realized that one or a plurality of the shown empty outer conductors may also be provided inner conductors, and optionally rail elements and dielectric elements. The connecting element 13 is connected to the rail elements 9a, 9b via attachment portions 13d, 13e arranged through elongated slots 15a, 15b in the respective outer conductor.

(19) FIG. 5 shows parts of the antenna feeding network in FIG. 4 as seen from the side, where the threaded rod 12 and the connecting element 13 are shown. The indicating portion 4 is formed as a rounded protrusion having an indicating line or groove 4a thereon.

(20) FIG. 6 shows parts of an antenna feeding network of a multi radiator antenna according to an embodiment of invention. The embodiment is similar to that shown in FIGS. 4-5, but differs mainly in that the displacement means is configured to move at least two rail elements simultaneously at different speeds. This is achieved by having two threaded portions 12a, 12b with different pitch on the longitudinally extending rod 12, and first and second connecting elements 13, 16, each connecting element being provided with an internally threaded portion 13c, 16, the internally threaded portions being configured to co-operate with corresponding (externally) threaded segments or portions 12a, 12b of the rod 12. The threaded segment or portion 12a of the rod has a greater pitch than the other threaded segment or portion 12b, such that the first connecting element 13 moves at a greater speed than the second connecting element 16 when the rod is rotated. The connecting elements 13, 16 are connected to respective rail elements (not shown) through elongated slots in the outer conductors in the same way as shown in FIG. 4. The displacement means illustrated in FIG. 6 may be combined with two or more splitter/combiners of the differential phase shifting type. Thus, the means for moving may be configured to move a rail element and dielectric element of a first splitter/combiner simultaneously and at a different speed than a rail element and dielectric of a second splitter/combiner. Such a combination including a plurality of differential phase shifters may be used in an antenna to provide a variable electrical tilt angle. It is noted that it is only necessary to provide one of the connecting elements with an indicating portion 4 since the relative movement between the two connecting elements is predetermined due to the ratio of their pitches.

(21) FIG. 7 shows parts of a multi radiator antenna according to an embodiment of the invention as seen from the reflector front side. The antenna comprises an antenna feeding network 1, a reflector 17 and three radiating elements or dipoles 14a-c arranged on the reflector. For illustrative purposes, the antenna is shown without its protective cover(s) which normally cover(s) the reflector, the radiating elements and the antenna feeding network (at least partly). The antenna feeding network is provided with coaxial lines 6a, 6b having central inner conductors 7a, 7b and outer conductors 8a, 8b. The outer conductors 8a, 8b have square cross sections and are formed integrally and in parallel to form a self-supporting structure. The wall which separates the coaxial lines 6a, 6b constitute vertical parts of the outer conductors 8a, 8b of both lines. In this figure, it is illustrated how the coaxial lines are integrally formed with the reflector in the sense that the reflector 17 is formed by the upper walls of the outer conductors. The antenna feeding network is thus similar to that shown in FIG. 4 except for that different outer conductors are provided with inner conductors to form coaxial lines. The antenna feeding network is further provided, on its rear side (opposite of the reflector front side 17), with means for adjusting relative phase of the same type as illustrated in FIG. 4 and described above, but this is not visible in the figure. It is realized that the number of inner conductors (two) and number of radiators (three) shown are only for illustrative purposes, and that further inner conductors may be used to provide a splitting/combing antenna feeding network of the type shown in FIG. 1.

(22) FIG. 8 shows parts of an antenna feeding network of a multi radiator antenna according to an embodiment of the invention. The embodiment corresponds to that shown in FIG. 6 and further comprises an electrical actuating arrangement including an electric motor unit 19′ comprising an electric motor 19 connected to the longitudinally extending threaded rod 12 to allow rotation thereof.

(23) FIG. 9 shows a similar embodiment to that shown in FIG. 8, but differs in that a manual actuating arrangement comprising a handle or knob 20 is provided (instead of the electrical actuating arrangement), which handle or knob allows manual rotation of the longitudinally extending threaded rod 12.

(24) FIG. 10 shows a multi radiator antenna 1 according to an embodiment of the invention. The multi radiator antenna comprises an electrical actuating arrangement (not visible since the antenna is provided with a protective cover). The electrical actuating arrangement may be of the type shown in FIG. 8 and described above. The antenna further comprises means for controlling said electrical actuating arrangement from a distance in the form of a control unit 21 which is connected to the electrical actuating arrangement via a wired connection or cable. The control unit is in turn connected to a computer 22 provided with software for communicating with the control unit 21 in order to send/receive signals thereto. The computer 22 can be located in a network control center, or it can be a portable computer brought to a cellular base station, or any other location. In this embodiment, the control unit is physically connected to the computer by means of a wired connection or cable. In other embodiments, the control unit may be connected to the computer or another device such as a smart phone or a tablet via a wireless connection. In this embodiment, relative phases of the signals in the antenna may be adjusted from the computer, i.e. from a distance, in order to adjust the antenna main beam angle in the elevation plane. The control unit can be a specific unit designed just for communicating with the electrical motor unit, or it can be a cellular base station which is equipped for communicating with the motor unit, or some other type of device.

(25) The description above and the appended drawings are to be considered as non-limiting examples of the invention. The person skilled in the art realizes that several changes and modifications may be made within the scope of the invention. For example, the tilt angle range may be varied, the number of coaxial lines may be varied, the number of radiators or dipoles may be varied, the number of coaxial lines provided with rail elements may be varied, the number of coaxial lines provided with dielectric elements and/or support elements may be varied, and the shape of the support element(s) and dielectric element(s) may be varied. Furthermore, the reflector does not necessarily need to be formed integrally with the coaxial lines, but may on the contrary be a separate element. The scope of protection is determined by the appended patent claims.