Antenna feeding network comprising at least one holding element

Abstract

An antenna feeding network for a multi radiator antenna is provided. The antenna feeding network comprises at least one coaxial line. Each coaxial line comprises a central inner conductor and an elongated outer conductor surrounding the central inner conductor, wherein at least one of the outer conductors of the coaxial lines is provided with an opening, wherein the antenna feeding network further comprises at least one nonconductive holding element configured to be placed in the opening. The holding element is configured to hold at least one of the inner conductors in position. The invention further relates to a multi radiator antenna comprising such an antenna feeding network, and to a method for providing an electrical connection in such an antenna feeding network.

Claims

1. An antenna, feeding network for a multi radiator antenna, the antenna feeding network comprising at least two coaxial lines, wherein each coaxial line comprises a central inner conductor and an elongated outer conductor surrounding the central inner conductor, wherein at least two of the outer conductors of said coaxial lines each are provided with an opening, wherein said at least two outer conductors provided with openings are neighbouring outer conductors, wherein the openings together form a combined opening extending between said at least two outer conductors, wherein said antenna feeding network further comprises at least one non-conductive holding element configured to be placed in said combined opening, further comprising connecting means in the form of a connector device, wherein said non-conductive holding element comprises at least one passage adapted to receive said connector device, wherein said connector device is configured to electrically interconnect the two inner conductors, and wherein said holding element is configured to hold the connector device in position and to engage and hold the inner conductors in said at least two outer conductors in position.

2. The antenna feeding network according to claim 1, wherein said passage of the holding element is adapted to receive said connector device therein.

3. The antenna feeding network according to claim 1, wherein the holding element is adapted to the shape of the opening so that the holding element snugly fits into the opening.

4. The antenna feeding network according to claim 1, wherein the holding element comprises a support portion arranged to support the holding element against a portion of at least one of said outer conductors.

5. The antenna feeding network according to claim 1, wherein said holding element comprises at least one U-shaped portion configured to at least partly surround and engage with at least one of said inner conductors.

6. The antenna feeding network according to claim 5, wherein said inner conductor is provided with a groove or recess, and wherein said at least one U-shaped portion is configured to engage with said groove or recess such that the inner conductor is held in position in the longitudinal direction.

7. The antenna feeding network according to claim 1, wherein said inner conductor is provided with a groove or recess configured to co-operate with said connecting means to position the inner conductor relative to the outer conductor.

8. The antenna feeding network according to claim 1, wherein the holding element is placed and withheld in the opening by a retaining mechanism, wherein the retaining mechanism comprises at least one holding portion on the holding element adapted to engage with at least one complementary holding portion of the outer conductor provided with the opening.

9. The antenna feeding network according to claim 8, wherein the holding portion is wedge-shaped and is configured to engage with the complementary holding portion in the form of the edge of the opening.

10. The antenna feeding network according to claim 8, wherein said retaining mechanism comprises a laterally protruding nose portion of the holding element configured to abut against an outer surface portion of the outer conductor provided with the opening when the holding element is arranged in the opening.

11. The antenna feeding network according to claim 1, wherein said holding element comprises at least one gripping portion extending outside said outer conductor or conductors when the holding element is arranged in the opening.

12. The antenna feeding network according to claim 1, wherein the coaxial lines are substantially air filled.

13. The antenna feeding network according to claim 1, wherein said at least one holding element is made from a dielectric material, and wherein said at least one holding element is configured to provide an impedance matching structure.

14. A multi radiator antenna comprising an electrically conductive reflector, at least one radiating element arranged on a front side of said reflector and an antenna feeding network, said radiating elements being connected to said antenna feeding network, the antenna feeding network comprising at least two coaxial lines, wherein each coaxial line comprises a central inner conductor and an elongated outer conductor surrounding the central inner conductor, wherein at least two of the outer conductors of said coaxial lines each are provided with an opening, wherein said at least two outer conductors provided with openings are neighbouring outer conductors, wherein the openings together form a combined opening extending between said at least two outer conductors, wherein said antenna feeding network further comprises at least one non-conductive holding element configured to be placed in said combined opening, further comprising connecting means in the form of a connector device, wherein said non-conductive holding element comprises at least one passage adapted to receive said connector device, wherein said connector is configured to electrically interconnect the two inner conductors, and wherein said holding element is configured to hold the connector device in position and to engage and hold the inner conductors in said at least two outer conductors in position.

15. The multi radiator antenna according to claim 14, wherein said opening is provided through said front side of said reflector.

16. The multi radiator antenna of claim 14, wherein said passage of the holding element is adapted to receive said connector device therein.

17. The multi radiator antenna of claim 14, wherein the holding element is adapted to the shape of the opening so that the holding element snugly fits into the opening.

18. The multi radiator antenna of claim 14, wherein the holding element comprises a support portion arranged to support the holding element against a portion of at least one of said outer conductors.

19. The multi radiator antenna of claim 14, wherein said holding element comprises at least one U-shaped portion configured to at least partly surround and engage with at least one of said inner conductors.

20. The multi radiator antenna of claim 19, wherein said inner conductor is provided with a groove or recess, and wherein said at least one U-shaped portion is configured to engage with said groove or recess such that the inner conductor is held in position in the longitudinal direction.

21. The multi radiator antenna of claim 14, wherein said inner conductor is provided with a groove or recess configured to co-operate with said connecting means to position the inner conductor relative to the outer conductor.

22. The multi radiator antenna of claim 14, wherein the holding element is placed and withheld in the opening by a retaining mechanism, wherein the retaining mechanism comprises at least one holding portion on the holding element adapted to engage with at least one complementary holding portion of the outer conductor provided with the opening.

23. The multi radiator antenna of claim 22, wherein the holding portion is wedge-shaped and is configured to engage with the complementary holding portion in the form of the edge of the opening.

24. The multi radiator antenna of claim 22, wherein said retaining mechanism comprises a laterally protruding nose portion of the holding element configured to abut against an outer surface portion of the outer conductor provided with the opening when the holding element is arranged in the opening.

25. The multi radiator antenna of claim 14, wherein the coaxial lines are substantially air filled.

26. The multi radiator antenna of claim 14, wherein said at least one holding element is made from a dielectric material, and wherein said at least one holding element is configured to provide an impedance matching structure.

27. A method for providing an electrical connection in an antenna feeding network for a multi radiator antenna, said antenna feeding network comprising at least two coaxial lines, wherein each coaxial line comprises a central inner conductor and an elongated outer conductor surrounding the central inner conductor, said method comprising: providing at least two neighbouring outer conductors of said at least two coaxial lines with openings to form a combined opening extending between said at least two outer conductors; providing at least one non-conductive holding element in the openings, wherein said non-conductive holding element is provided with a through passage adapted to provide access to at least one of said inner conductors, and wherein said holding element is configured to hold at least one of the inner conductors in position; and inserting connecting means in the form of a connector device in said passage and connecting said connector device electrically to the at least two inner conductors.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, in which:

(2) FIG. 1 schematically illustrates an antenna feeding network;

(3) FIG. 2 schematically illustrates an embodiment of a multi-radiator antenna according to the second aspect of the invention;

(4) FIG. 3 schematically illustrates a holding element of an embodiment of an antenna feeding according to the first aspect of the invention;

(5) FIG. 4 schematically illustrates a perspective view of a cross section cut transversally to coaxial lines through the holding element of an embodiment of an antenna feeding according to the first aspect of the invention;

(6) FIG. 5 schematically illustrates another view of a holding element of an embodiment of an antenna feeding according to the first aspect of the invention;

(7) FIG. 6 schematically illustrates a perspective view of a holding element of an embodiment of an antenna feeding according to the first aspect of the invention, where the holding element is installed in an opening of the outer conductors; and

(8) FIG. 7 schematically illustrates a perspective view of parts of an embodiment of an antenna feeding network according to the first aspect of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(9) FIG. 1 schematically illustrates an antenna arrangement 1 comprising an antenna feeding network 2, an electrically conductive reflector 4, which is shown schematically in FIG. 1, and a plurality of radiating elements 6. The radiating elements 6 may be dipoles.

(10) The antenna feeding network 2 connects a coaxial connector 10 to the plurality of radiating elements 6 via a plurality of lines 14, 15, 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 12.

(11) Turning now to FIG. 2, which illustrates a multi-radiator antenna 1 in a perspective view, the antenna 1 comprises the electrically conductive reflector 4 and radiating elements 6a-c.

(12) The electrically conductive reflector 4 comprises a front side 17, where the radiating elements 6a-c are mounted and a back side 19.

(13) FIG. 2 shows a first coaxial line 20a which comprises a first central inner conductor 14a, an elongated outer conductor 15a forming a cavity or compartment around the central inner conductor, and a corresponding second coaxial line 20b having a second inner conductor 14b and an elongated outer conductor 15b. The outer conductors 15a, 15b have square cross sections and are formed integrally and in parallel to form a self-supporting structure. The wall which separates the coaxial lines 20a, 20b constitute vertical parts of the outer conductors 15a, 15b of both lines. The first and second outer conductors 15a, 15b are formed integrally with the reflector 4 in the sense that the upper and lower walls of the outer conductors are formed by the front side 17 and the back side 19 of the reflector, respectively.

(14) Although the first and second inner conductors 14a, 14b are illustrated as neighbouring inner conductors they may actually be further apart thus having one or more coaxial lines or empty outer conductors in between.

(15) In FIG. 2 not all longitudinal channels or outer conductors are illustrated with inner conductors, it is however clear that they may comprise such inner conductors.

(16) The front side 17 of the reflector may comprise at least one opening 40 for the installation of the connector device 11. The opening 40 extends over the two neighbouring coaxial lines 20a, 20b so that the connector device 11 can engage the first and the second inner conductor 14a, 14b. The connector device 11 is configured to electrically interconnect the two inner conductors 14a-b. The opening 40 is larger than the connector device 11 to avoid arcing or short-circuit between the outer conductors and the connector device.

(17) Although the invention is illustrated with two neighbouring inner conductors 14a, 14b it falls within the scope to have an opening (not shown) that extends across more than two coaxial lines 20a, 20b and to provide a connector device 11 than can bridge two or even more inner conductors. Such a connector device (not shown) may thus be designed so that it extends over a plurality of coaxial lines between two inner conductors or over empty cavities or compartments. Such a connector device (not shown) may also be used to connect three or more inner conductors.

(18) Referring now to FIGS. 3 and 4, a holding element 8 is illustrated. FIG. 3 illustrates a perspective view of the holding element 8 of an embodiment of an antenna feeding network according to the first aspect of the invention. The holding element is made of plastic, but may in other embodiments be made from other electrically insulating materials. The holding element 8 comprises a body portion 64 having an opening or passage 68. The body portion 64 is adapted to have a shape that corresponds at least more or less to the shape of the opening 40 (c.f. FIG. 4). The holding element 8 further comprises two downwardly extending support portions 52 as shown in FIG. 3, the support extension portions 52 being configured to support the holding element against a protrusion or ridge 58 extending horizontally from the vertical separating wall portion 22, which is cut down from its original height in the area of the opening, as shown in FIG. 4. The support portions 52 may further comprise a step 57 as illustrated in FIG. 3. The step 57 is used for providing support to the connector device 11, as illustrated in FIG. 4.

(19) The connector device 11 can be installed on the two inner conductors 14 after the holding element 8 is put in place. The connector device 11 is inserted and guided through the opening or passage 68 when the two or more inner conductors are engaged. In embodiments, the connector device 11 may engage with a groove in the inner conductor 14 in order to position the inner conductor relative the outer conductor in a longitudinal direction.

(20) Referring to FIG. 3, the holding element 8 may further comprise gripping portions 56. The gripping portions 56 are embodied as protrusions that extend over the top surface 17 of the electrically conductive reflector 4.

(21) FIG. 6 illustrates further that the holding element 8 comprises a pair of gripping portions 56 arranged opposite one another on the long side of the body portion 64.

(22) The holding element 8 may further comprise a pair of U-shaped conductor engaging portions 62 that are configured to at least partly surround and engage at least one of the inner conductors 14. In this embodiment, the pair of conductor engaging portions 62 are arranged on a long side of the body portion 64. In embodiments, the engaging portions 62 may engage with a groove made in the inner conductor (not shown) which allows the inner conductor to be positioned in a longitudinal direction. The holding element 8 further comprises a laterally protruding nose portion 66 that is configured to rest on the top side 17 of the reflector.

(23) The holding element 8 may further comprise a retaining mechanism 9 of a snap-on type, which is described further on referring to FIGS. 5 and 6. The retaining mechanism 9 comprises snap on holding portions 35 that are arranged on the body portion 64 of the holding element 8 on the outer side of the body portion 64 which are thus directed away from the opening or passage 68. The illustrated embodiment of the holding element 8 comprises three snap on portions 35, one on each longitudinal side of the body portion 64 and one on the front side of the body portion 64 on the opposite side of the nose portion 66. The body portion 64 may however in other embodiments comprise another number of snap on portions 35.

(24) The snap on portions are formed as downwardly tapering wedges. An end surface or step 70 of the snap on portions, as shown in FIG. 5 is configured to engage with a complementary snap on portion 37 embodied in the form of the lower edge of the opening 40, as illustrated in FIG. 6. The tapering part of the snap on portion 35 is used to allow the holding element 8 to be smoothly pushed into the opening 40. Since the holding element 8 is made of a slightly flexible material such as plastic, it is allowed to bend a bit so that the end surfaces 70 can engage the lower edge of the opening 40.

(25) FIG. 6 further illustrates how the conductor engaging portions 62 engages at least one of the inner conductors 14.

(26) FIG. 7 shows a view of parts of an embodiment of the antenna feeding network shown without outer conductors and holding element. The connector device 11 engages the first and second inner conductors 14a, 14b. The connector device 11 and the inner conductors 14a, 14b together form a splitter/combiner. When operating as a splitter, the inner conductor 14a is part of the incoming line, and the two ends of the inner conductor 14b are the two outputs of the splitter. The U-shaped dielectric element 13 can be moved along the inner conductor 14b, which, together with an outer conductor (not shown), forms first and second coaxial output lines on opposite sides of the connector device 11. The dielectric element thus has various positions along those coaxial output lines.

(27) We first consider the case when the dielectric element 13 is placed in a central position, equally filling the first and second output coaxial lines. When a signal is entered at the input coaxial line 14a, it will be divided between the first output coaxial line and the second output coaxial line, and the signals coming from the two output coaxial lines will be equal in phase. If the dielectric element 13 is moved in such a way that the first output coaxial line will be more filled with dielectric material than the second output coaxial line, the phase shift from the input to the first output will increase. At the same time the second output coaxial line will be less filled with dielectric, and the phase shift from the input to the second output will decrease. Hence, the phase at the first output will lag the phase at the second output. If the dielectric element is moved in the opposite direction, the phase of the first output will lead the phase of the second output. The splitter/combiner may thus be described as a differential phase shifter.

(28) 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 number of coaxial lines may be varied, the number of radiators or dipoles may be varied, and the holding element may be fixed in the opening by another type of retaining mechanism. Further, the holding element may comprise two pairs of conductor engaging portions each pair being assigned to one of the plurality of inner conductors. 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.