ANTENNA AND METHOD

Abstract

We generally describe an antenna, in particular a parabolic antenna, comprising: a primary reflector, in particular a parabolic dish, a feed antenna and/or a secondary reflector for transmitting and/or reflecting an electromagnetic wave towards the primary reflector and/or receiving a said electromagnetic wave reflected from the primary reflector, a feed coupled to the feed antenna and/or secondary reflector, wherein the feed antenna and/or secondary reflector is coupleable, via the feed, to a radio-frequency transmission and/or reception device, and an actuator unit coupled to one or more of the feed antenna, the secondary reflector and the feed, wherein the actuator unit is configured to move the feed antenna and/or the secondary reflector, by exerting a mechanical force on the feed antenna and/or the secondary reflector and/or the feed, relative to the primary reflector.

Claims

1. An antenna, in particular a parabolic antenna, comprising: a primary reflector, in particular a parabolic dish, a feed antenna and/or a secondary reflector for transmitting and/or reflecting an electromagnetic wave towards the primary reflector and/or receiving a said electromagnetic wave reflected from the primary reflector, a feed coupled to the feed antenna and/or secondary reflector, wherein the feed antenna and/or secondary reflector is coupleable, via the feed, to a radio-frequency transmission and/or reception device, and an actuator unit coupled to one or more of the feed antenna, the secondary reflector and the feed, wherein the actuator unit is configured to move the feed antenna and/or the secondary reflector, by exerting a mechanical force on the feed antenna and/or the secondary reflector and/or the feed, relative to the primary reflector.

2. The antenna as claimed in claim 1, wherein the feed extends along an axis normal or substantially normal to a surface of the primary reflector, and wherein the actuator unit is configured to move the feed antenna and/or the secondary reflector in a direction or plane perpendicular or generally perpendicular to the axis.

3. The antenna as claimed in claim 2, wherein the actuator unit is configured to move the feed antenna and/or the secondary reflector in one or two dimensions.

4. The antenna as claimed in claim 1, wherein the feed comprises a flexible feed which is configured to be bent based on the actuator unit exerting a said mechanical force on the feed antenna and/or the secondary reflector and/or the feed for moving the feed antenna and/or the secondary reflector relative to the primary reflector.

5. The antenna as claimed in claim 4, wherein the flexible feed comprises a flexible waveguide.

6. The antenna as claimed in claim 1, wherein the actuator unit comprises an actuator and a linkage, in particular a rod or bar, coupled to the actuator, wherein the linkage is coupled to one or more of the feed antenna, the secondary reflector and the feed, and wherein the actuator is configured to move the feed antenna and/or the secondary reflector, by pulling and/or pushing the feed antenna and/or the secondary reflector and/or the feed via the linkage, relative to the primary reflector.

7. The antenna as claimed in claim 6, wherein the actuator unit comprises a plurality of actuators coupled to a single said linkage or coupled to corresponding, respective linkages, and wherein the actuator is configured to move the feed antenna and/or the secondary reflector, only by pulling the feed antenna and/or the secondary reflector and/or the feed via a said linkage, relative to the primary reflector.

8. The antenna as claimed in claim 1, wherein the primary reflector comprises an opening through which the feed extends generally in a first direction, and wherein the actuator unit is configured to move, by exerting a said mechanical force on the feed antenna and/or the secondary reflector and/or the feed, the feed generally in a second direction which is perpendicular to the first direction, thereby moving the feed antenna and/or the secondary reflector relative to the primary reflector.

9. The antenna as claimed in claim 4, wherein the antenna further comprises a rigid tube, wherein at least a part of the feed is arranged within the rigid tube, wherein the rigid tube is coupled to a moveable portion of the feed, wherein the actuator unit is coupled to the rigid tube, and wherein the actuator unit is configured to exert a rotational force or torque on the rigid tube for bending the flexible feed to move the feed antenna and/or the secondary reflector relative to the primary reflector.

10. The antenna as claimed in claim 9, wherein the actuator unit is arranged outside of an area, in particular a cavity formed by the primary reflector, through which a said electromagnetic wave travels.

11. The antenna as claimed in claim 9, wherein the actuator unit comprises a lever via which the rotational force or torque is exertable on the rigid tube.

12. The antenna as claimed in claim 1, wherein a length of the feed is at least 1.2, preferably at least 1.5, and more preferably at least 2 times a length by which the feed extends through a cavity formed by the primary reflector.

13. The antenna as claimed in claim 1, wherein the feed comprises one or more protrusions, in particular in the form of a rib, a circle or a circular protrusion, arranged on an outer surface of the feed.

14. The antenna as claimed in claim 13, wherein the feed comprises a plurality of protrusions, and wherein a distance between neighboring ones of the protrusions is smaller at an end portion of the feed which is coupleable to the radio-frequency transmission and/or reception device compared to a said distance between neighboring ones of the protrusions at an end portion of the feed which is coupled to the feed antenna and/or secondary reflector.

15. The antenna as claimed in claim 13, wherein the feed comprises a said plurality of protrusions, and wherein a number density of the protrusions is smaller at the end portion of the feed which is coupleable to the radio-frequency transmission and/or reception device compared to a said number density of the protrusions at the end portion of the feed which is coupled to the feed antenna and/or secondary reflector.

16. The antenna as claimed in claim 1, wherein a wall of an inner cavity of the feed is made of non-corrugated walls.

17. The antenna as claimed in claim 1, wherein the feed comprises an elliptical cross-section.

18. The antenna as claimed in claim 17, wherein an aspect ratio between a major axis and a minor axis of the elliptical cross-section is between 1.05 and 1.4, in particular 1.1, 1.15, 1.2, 1.25, 1.3 or 1.35.

19. The antenna as claimed in claim 1, wherein the feed comprises a rectangular cross-section.

20. The antenna as claimed in claim 1, wherein the feed comprises one or more grooves and/or one or more ridges.

21. An antenna, in particular a parabolic antenna, comprising: a primary reflector, in particular a parabolic dish, a feed antenna and/or a secondary reflector for transmitting and/or reflecting an electromagnetic wave towards the primary reflector and/or receiving a said electromagnetic wave reflected from the primary reflector, a flexible feed coupled to the feed antenna and/or secondary reflector, wherein the feed antenna and/or secondary reflector is coupleable, via the flexible feed, to a radio-frequency transmission and/or reception device, and wherein the feed antenna and/or the secondary reflector is movable relative to the primary reflector based on an actuator unit, coupleable to one or more of the feed antenna, the secondary reflector and the flexible feed, exerting a mechanical force on the feed antenna and/or the secondary reflector and/or the flexible feed for moving the feed antenna and/or the secondary reflector.

22. A system comprising: an antenna comprising: a primary reflector, in particular a parabolic dish, a feed antenna and/or a secondary reflector for transmitting and/or reflecting an electromagnetic wave towards the primary reflector and/or receiving a said electromagnetic wave reflected from the primary reflector, a feed coupled to the feed antenna and/or secondary reflector, wherein the feed antenna and/or secondary reflector is coupleable, via the feed, to a radio-frequency transmission and/or reception device, and an actuator unit coupled to one or more of the feed antenna, the secondary reflector and the feed, wherein the actuator unit is configured to move the feed antenna and/or the secondary reflector, by exerting a mechanical force on the feed antenna and/or the secondary reflector and/or the feed, relative to the primary reflector, and an inertial measurement unit coupled to the antenna and configured to measure a physical movement of the antenna, wherein the antenna is configured to compensate, based on said measurement of said physical movement by the inertial measurement unit, for said physical movement during beam steering by moving the feed antenna and/or the secondary reflector relative to the primary reflector by exerting, via the actuator unit, a said mechanical force on the feed antenna and/or the secondary reflector and/or the feed.

23. A method for compensating physical movement of an antenna during beam steering, the method comprising: providing an antenna comprising: a primary reflector, in particular a parabolic dish, a feed antenna and/or a secondary reflector for transmitting and/or reflecting an electromagnetic wave towards the primary reflector and/or receiving a said electromagnetic wave reflected from the primary reflector, a feed coupled to the feed antenna and/or secondary reflector, wherein the feed antenna and/or secondary reflector is coupleable, via the feed, to a radio-frequency transmission and/or reception device, and an actuator unit coupled to one or more of the feed antenna, the secondary reflector and the feed, wherein the actuator unit is configured to move the feed antenna and/or the secondary reflector, by exerting a mechanical force on the feed antenna and/or the secondary reflector and/or the feed, relative to the primary reflector; obtaining physical movement data relating to a physical movement of the antenna; and moving the feed antenna and/or the secondary reflector relative to the primary reflector, by exerting, via the actuator unit, a said mechanical force on the feed antenna and/or the secondary reflector and/or the feed, to compensate for said physical movement of the antenna.

24-26. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures, wherein like reference numerals refer to like parts, and in which:

[0047] FIG. 1 shows a side cross-sectional view of a schematic illustration of an antenna according to some example implementations as described herein;

[0048] FIGS. 2a and b show a side cross-sectional view of a schematic illustration of an antenna according to some example implementations as described herein;

[0049] FIG. 3 shows a side cross-sectional view of a schematic illustration of an antenna according to some example implementations as described herein;

[0050] FIG. 4 shows a side cross-sectional view of a schematic illustration of an antenna according to some example implementations as described herein;

[0051] FIGS. 5a and b show a side cross-sectional view of a schematic illustration of an antenna according to some example implementations as described herein;

[0052] FIG. 6 shows a perspective view of a schematic illustration of a waveguide in a partially cut-open view according to some example implementations as described herein;

[0053] FIGS. 7 and 8 show a cross-sectional view of a schematic illustration of a circular waveguide in an undeformed and deformed state, respectively;

[0054] FIG. 9 shows a cross-sectional view of a schematic illustration of a further waveguide according to some example implementations as described herein;

[0055] FIG. 10 shows a cross-sectional view of a schematic illustration of a further waveguide according to some example implementations as described herein;

[0056] FIG. 11 shows a top view of a schematic illustration of an antenna according to some example implementations as described herein;

[0057] FIG. 12 shows a top view of a schematic illustration of an antenna according to some example implementations as described herein;

[0058] FIG. 13 shows a bottom view of a schematic illustration of an antenna according to some example implementations as described herein;

[0059] FIG. 14 shows a bottom view of a schematic illustration of an antenna according to some example implementations as described herein;

[0060] FIG. 15 shows a bottom view of a schematic illustration of an antenna according to some example implementations as described herein

[0061] FIG. 16 shows a block diagram of a system according to some example implementations as described herein;

[0062] FIG. 17 shows a flow diagram of a method according to some example implementations as described herein; and

[0063] FIG. 18 shows a flow diagram of a method according to some example implementations as described herein.

DETAILED DESCRIPTION

[0064] In most current backhaul antennas, a central feed (which is approximately a round tube) protrudes into the main reflector cavity nearly up to its focus. The small sub reflector is often attached to the feed. The present disclosure is, according to some examples, to make the feed flexible so that it could be bent by actuators repeatedly. By bending the feed, its end with the attached sub (secondary) reflector is moved in the area around the main (primary) reflector focus. This may cause the main beam of the antenna to change its direction according to the movement of the sub reflector. This beam steering can be used to mitigate mast sway and mast twist. The present disclosure relates in particular to steerable reflector antennas (of, for example, backhaul point-to-point microwave links) which compensate for link quality decreases introduced, for example, by wind induced mast sway.

[0065] In backhaul microwave links, there is a product evolution over time. Carrier frequencies become higher (now 80 GHz) and diameters of the largest used main reflector antennas become bigger. These factors intensify the negative impact of mast sway/twist on the microwave link quality. (Higher frequencies and larger main dishes make the main beam narrower.) Therefore, mast sway compensation solutions become more desirable. It is to be noted that the antenna according to example implementations described herein may be operated in the E-band, i.e. at frequencies between 60 and 90 GHz, in particular at 80 GHz.

[0066] Actual mast sway compensation solutions are much too expensive.

[0067] Because of wear out problems occurring due to high repetitions of movement over a lifetime of approximately 10 years, special consideration may have to be given to the design of joints. The present disclosure uses, in some examples, flexures as joints, because flexures, if designed accordingly, may withstand very high repetitions of movement.

[0068] In some examples, the waveguide is bent by connected linkages which are connected to actuators.

[0069] There are multiple different topologies which may allow for beam steering in particular in order to compensate for movement of the antenna due to external influences.

[0070] FIG. 1 shows a side cross-sectional view of a schematic illustration of an antenna 100 according to some example implementations as described herein.

[0071] In this example, the antenna 100 comprises a primary (main) reflector 102 in the form of a parabolic dish. A top hat retro reflector 104 (generally secondary reflector) with a dielectric is coupled, in this example, to a flexible waveguide 106. Instead of (or additionally to) a reflector 104, a feed antenna may be provided.

[0072] The top hat retro reflector 104 is coupled to a radio-frequency transmission and/or reception device 108.

[0073] Throughout the present disclosure, the top hat retro reflector may be (any kind of) a subreflector. Therefore, wherever the term top hat retro reflector is used, this may be replaced anywhere or everywhere throughout the present disclosure with subreflector (or generally secondary reflector).

[0074] Reference numeral 110 denotes the radome of the antenna.

[0075] The top hat retro reflector 104 is movable, in this example, in a direction generally perpendicular to a central axis of the primary reflector 102, as indicated by arrow 112.

[0076] FIGS. 2a and b show a side cross-sectional view of a schematic illustration of an antenna 200 (which may be made in part of the antenna 100 of FIG. 1 as indicated using the same reference numerals) according to some example implementations as described herein.

[0077] In this example, the top hat retro reflector 104 is coupled to actuators 114 and 116, respectively, via corresponding, respective pull rods 118 and 120. The base of the actuators 114 and 116 is connected, in this example, to the base of the waveguide 106. This can be done, for example, by connecting them to the main reflector 102 (dish) or to a separate frame. In some examples, by letting the actuators 114 and 116 only pull and not push, the pull rods 118 and 120 can be made very light. The pull rods 118 and 120 may be made out of a material which has a high transparency (i.e. transparency above a predefined threshold) to the used radio frequency.

[0078] In FIG. 2a, the top hat retro reflector 104 is in a central position in relation to the cavity formed by the main reflector 102. As shown in FIG. 2b, the top hat retro reflector 104 is moved as indicated via arrow 122. This may be achieved by pulling on the top hat retro reflector 104 by the actuator 116 via the pull rod 120.

[0079] As FIGS. 2a and b show, in this example, there is only movement of the top hat retro reflector 104 in one dimension (say in the x-dimension). In some examples, actuators and pull rods may additionally be arranged orthogonally to the plane of the figure so that movement of the top hat retro reflector 104 in the y-dimension can be performed. There may, in some examples, be four actuator and pull rod groups equally angled at 90 degrees around the waveguide 106. One can also achieve full x- and y-direction movement of the waveguide 106 by placing three actuator and pull rod groups equally angled at 120 degrees around the waveguide 106. Other examples will be readily known to those with skill in the art.

[0080] FIG. 3 shows a side cross-sectional view of a schematic illustration of an antenna 300 (which may be made in part of the antenna 100 and/or 200 of FIGS. 1 and 2 as indicated using the same reference numerals) according to some example implementations as described herein.

[0081] The antenna 300 shows a structure which slightly differs from antenna 200. The difference is that, in antenna 300, the pull rods 118 and 120 are coupled at the waveguide 106. The advantage is that the top hat retro reflector 104 (dielectric) (which may be made of plastic) does not have to bear the actuation forces. A drawback may be that the pull rods 118 and 120 are intersecting the radio waves two times instead of once. However, this may (at least partially) be compensated for by choosing a material for the pull rods 118 and 120 which are, as much as possible, transparent to the radio frequency used.

[0082] FIG. 4 shows a side cross-sectional view of a schematic illustration of an antenna 400 (which may be made in part of the antenna 100 and/or 200 and/or 300 of FIGS. 1, 2 and 3 as indicated using the same reference numerals) according to some example implementations as described herein.

[0083] The antenna 400 comprises a waveguide 106 which is longer than the waveguide used in antennae 100, 200 and 300. If a longer waveguide (with otherwise same parameters) is used, bending forces may be lowered and crosspolar isolation may be increased.

[0084] In this example, the antenna 400 further comprises an opening 402 provided at a lower part of the primary reflector 102, through which the waveguide 106 extends. In this example, by pulling via the actuators 114 and 116 on the top hat retro reflector 104 via the pull rods 118 and 120, respectively, the waveguide 106 also moves within the opening 402.

[0085] As will be appreciated, such an opening 402 may be provided in any one of the example implementations of the antenna as described throughout the present disclosure.

[0086] FIGS. 5a and b show a side cross-sectional view of a schematic illustration of an antenna 500 (which may be made in part of the antenna 100 and/or 200 and/or 300 and/or 400 of FIGS. 1, 2, 3 and 4 as indicated using the same reference numerals) according to some example implementations as described herein.

[0087] In this example, the antenna 500 comprises a rigid tube 502 within which a part of the waveguide 106 is arranged. The rigid tube 502 is coupled (attached) to the movable end of the waveguide 106. The rigid tube 502 is used in order to actuate the waveguide 106. Connecting rods 504 and 506 are coupled to the actuators 114 and 116, respectively. Furthermore, in this example, the connecting rods 504 and 506 are coupled to the rigid tube 502 via rigid actuation levers 508 and 510, respectively. On the base of the rigid tube 502, a rotational force/torque is introduced.

[0088] As can be seen, in the antenna 500, pull rods (i.e. rigid actuation levers 508 and 510) do not intersect the aperture of the antenna. In FIGS. 5a and b, rigid actuation levers 508 and 510 connected to actuators 114 and 116 are used to show one possible implementation; other implementations in which the actuator unit does not intersect the aperture of the antenna through which electromagnetic waves travel are possible.

[0089] FIG. 6 shows a perspective view of a schematic illustration of a waveguide 106 in a partially cut-open view according to some example implementations as described herein.

[0090] The example of FIG. 6 shows a way to structure the outer wall of the waveguide 106 to prevent the inner cross section from changing from a circle to something less circular (maybe elliptical) when the waveguide 106 is bent. Having a non-circular cross section may potentially affect the cross polar isolation. The protrusions 602 (e.g. ribs) keep the inner cross section circular and the non-ribbed sections allow the waveguide 106 to be bendable.

[0091] The flexible waveguide 106 may, in some examples, have solid walls and the inner cavity 604 may have flat (non-corrugated) walls.

[0092] The end 606 of the flexible waveguide 106 is to be coupled to the top hat retro reflector. The end 608 is to be coupled to the base (e.g. the radio-frequency transmission and/or reception device and/or a frame of the antenna).

[0093] Bending of the waveguide may alter the shape of the inner cross section of the waveguide. If the orientations of the exploited waveguide modes are changed by such cross section deformation, energy leakage between the two modes can occur with poor cross polar isolation as a result.

[0094] FIG. 7 shows a cross-sectional view of a schematic illustration of a circular waveguide 106a. It may be implemented in, for example, any one of the antennae of FIGS. 1 to 5.

[0095] Let the two exploited modes be oriented, e.g., along the 0 degrees (702) and 90 degrees (704) planes. The worst case bending direction at 45 degrees is then indicated via arrow 706, and the worst case bending direction at 135 degrees is indicated via arrow 708. When the waveguide 106a is bent, the circular cross section is deformed into a shape which may resemble an ellipse.

[0096] FIG. 8 shows a cross-sectional view of a schematic illustration of the waveguide 106a in the deformed (elliptical) shape. The ellipticity is, in this example, exaggerated for illustrative purposes.

[0097] For an elliptic cross section, the two modes are oriented along the major (806) and minor (808) axes of the ellipse. Consider the smallest angle between any of the two signal planes 702, 704 and the two axes 806, 808 of the ellipse. This angle will be between 0 and 45 degrees. For an angle of 0 degrees, cross polar isolation is not affected. In contrast, cross polar isolation degrades more and more for larger angles with the poorest cross polar isolation performance occurring for an angle of 45 degrees. This yields that the worst-case bending direction is 45 degrees, which is depicted in FIG. 8. Since only a slight deformation of the cross section suffices to shift the waveguide mode orientations substantially, the circular cross section may not be robust to deformations.

[0098] It is thus proposed to use waveguides with cross sections that are robust to deformations. FIG. 9 shows a cross-sectional view of a schematic illustration of such a waveguide 106c according to some example implementations as described herein. It may be implemented in, for example, any one of the antennae of FIGS. 1 to 5.

[0099] In the example of FIG. 9, an elliptical cross section is used with its axes oriented along the signal planes. In this example, the ellipse major axis 902 is aligned with the 0 degrees signal plane, and the ellipse minor axis 904 is aligned with the 90 degrees signal plane.

[0100] If the elliptical cross section is made sufficiently elliptic, i.e. the aspect ratio between the longer (major) axis and the shorter (minor) axis is, in some examples, between 1.05 and 1.4 (in particular 1.05, 1.1, 1.15, . . . , 1.4), bending-induced deformations of the cross section may lead to only minor rotations of the waveguide mode directions. Thus, cross polar isolation performance may drastically be improved compared to the circular waveguide.

[0101] Other examples of waveguides with cross sections that are robust to deformations include, for example, rectangular waveguides, waveguides with grooves and/or ridges etc. (may be implemented in, for example, any one of the antennae of FIGS. 1 to 5). FIG. 10 shows a cross-sectional view of a schematic illustration of a waveguide 106d (for which the 0 degrees signal plane 1002 and the 90 degrees signal plane 1004 are shown) with a ridge 1006, which may be implemented in, for example, any one of the antennae of FIGS. 1 to 5.

[0102] Different options in actuator placements may be exploited, as will be outlined in the following. FIGS. 11 to 15 show schematic illustrations of antennae according to some example implementations as described herein. This may be the antenna of any of the examples previously described.

[0103] In FIG. 11, a front view of the antenna 1100 with a front actuated 4 actuator design with four pull rods 1104a-d for the respective actuators 1102a-d is shown.

[0104] In FIG. 12, a front view of the antenna 1200 with a front actuated three actuator design with three pull rods 1204a-c for the respective actuators 1202a-c is shown.

[0105] In FIG. 13, a back view of the antenna 1300 with a rigid tube back actuated four actuator design is shown. Levers 1304a-d are provided for the corresponding actuators 1302a-d.

[0106] In FIG. 14, a back view of the antenna 1400 with a rigid tube back actuated two actuator and two counter bearings (e.g. implemented as springs/spring bearings) design is shown. In this example, levers 1406a and b are provided for actuator 1402a and b, respectively. Levers 1406c and d are provided for counter bearings 1404a and b, respectively.

[0107] In FIG. 15, a back view of the antenna 1500 with a rigid tube back actuated three actuator design is shown. Levers 1504a-c are provided for corresponding actuators 1502a-c.

[0108] The actuators may be implemented, in some examples, as voice coils. Some voice coils have built-in flexures to keep their armature from leaving the motion axis. For voice coils without flexures or without sufficiently dimensioned flexures, extra flexures may be added.

[0109] By having every moving component been held by a flexure, these components may reach a very high lifetime. Compared to traditional components like ball bearings, whose lifetime is especially low, if their range of motion in the product is so low that the ball bearing balls do not perform a full revolution. Thereby they wear off in a non-uniform way. Furthermore, lubrication of the ball bearing balls cannot be guaranteed in this situation.

[0110] FIG. 16 shows a block diagram of a system 1600 according to some example implementations as described herein.

[0111] The system 1600 comprises, in this example, an antenna (e.g. antenna 100, 200, 300, 400, 500, or any other antenna as described throughout the present disclosure), and an inertial measurement unit 1602 coupled to the antenna and configured to measure a physical movement of the antenna. The antenna is, in this example, configured to compensate, based on a measurement of the physical movement by the inertial measurement unit, for the physical movement during beam steering by moving the feed antenna and/or the secondary reflector relative to the primary reflector by exerting, via the actuator unit, a mechanical force on the feed antenna and/or the secondary reflector and/or the feed.

[0112] FIG. 17 shows a flow diagram of a method 1700 for compensating physical movement of an antenna during beam steering according to some example implementations as described herein.

[0113] In this example, the method 1700 comprises, at step S1702, providing an antenna or system according to any one or more of the example implementations as described herein.

[0114] At step S1704, physical movement data relating to a physical movement of the antenna is obtained. This may be done by the inertial measurement unit 1602, or by other means (for example optically). Obtaining of the physical movement data may, in some examples, comprise retrieving stored physical movement data generated/obtained previously.

[0115] At step S1706, the feed antenna and/or the secondary reflector are moved relative to the primary reflector, by exerting, via the actuator unit, a mechanical force on the feed antenna and/or the secondary reflector and/or the feed, to compensate for the physical movement of the antenna.

[0116] In some examples, the method 1700 comprises, at step S1708, outputting compensation data relating to the compensation for the physical movement of the antenna, and, at step S1710, storing said compensation data for later use.

[0117] FIG. 18 shows a flow diagram of a method 1800 for steering a reflector antenna beam according to some example implementations as described herein.

[0118] The method 1800 comprises, at step S1802, providing an antenna, in particular a parabolic antenna, comprising a flexible feed, in particular a flexible waveguide, in particular according to any one or more of the example implementations of the antenna and the system as described herein, and, at step S1804, steering the reflector antenna beam by bending the flexible feed.

[0119] In any of the example implementations as described herein, a Cloud Environment may be used to save data about the amount of movement measured by, e.g., the inertial measurement unit and the amount of compensation movement generated. Data could be used for mast/tower sway profiling of sites/regions and dimensioning/manufacturing of future products, in particular in relation to their mechanical stability and/or maximum steering angle and/or maximum actuation speed.

[0120] Advantages of (in particular a flexible feed for) beam steering according to the present disclosure are in particular: [0121] Only a very low mass (the mass of the feed (waveguide), small sub (i.e. secondary) reflector and actuator linkage) has to be moved by the actuators. When moving a low mass instead of a large mass, the actuators could be smaller, cheaper and consume less power. Furthermore, a smaller mass allows for faster movements to compensate faster mast sway motions. [0122] The whole actuation mechanics can be easily shielded from outside elements (e.g. rain) because of their small size and the fact that the (flexible) feed (e.g. waveguide) is inside the antenna which is already shielded by the radome against elements. [0123] By carefully designing the shape and material of the flexible waveguide, one can make sure that the very high lifetime requirements of the joint (flexure) are met. [0124] By designing the waveguide cross section (e.g. elliptic, ridge, groove, etc.) such that the orientations of the exploited waveguide modes are stable under deformations of the cross section caused by bending of the waveguide, the cross polar isolation performance of the waveguide can be improved especially in the worst case bending directions of 45 degrees and 135 degrees relative to the orientation of the waveguide modes.

[0125] As has been shown, some examples outlined herein relate in particular to a flexible waveguide that allows the feed of a reflector antenna to be moved away from the focal point to thereby steer the antenna beam. The flexible waveguide is bent within its flexible limits which allows virtually infinite lifetime.

[0126] No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art and lying within the scope of the claims appended hereto.