Beam-steerable antenna with configurable polarization

Abstract

Antenna with steerable beam and configurable polarization The invention relates to an antenna (10) with a steerable beam (17) comprising a beamformer (14), a deflector element (12) coupled to a movement mechanism, a second deflector element (11) coupled to a second movement mechanism, the beamformer (14) being fixed, and the movement mechanisms controlling movements of the deflector elements (11, 12). The antenna (10) further comprises a planar polarizing component (13) coupled to a rotation mechanism, said polarizing component (13) being made of dielectric patterns or conductive metallizations, at least one of the dimensions of which is smaller than the minimum operating wavelength of the antenna (10).The polarizing component (13) being designed so as to, depending on its position, transform a first radio wave polarization into a second radio wave polarization or leave a radio wave polarization unchanged, the two deflectors (11, 12) being in coaxial rotation with said polarizing component (13). Figure for abstract: Figure 1.

Description

Title of the invention: Antenna with steerable beam and configurable polarization Technical field

[0001] The present invention relates to a low-profile antenna with a steerable beam. It is particularly applicable in the field of telecommunications, in particular that of antennas and transmission means.

[0002] [BACKGROUND]

[0003] Pointing an antenna is the ability to orient the main beam in a desired direction. In the vast majority of cases, the antenna is reciprocal, this ability therefore applies to both transmission and reception. In communication between two antennas, when an antenna is in motion, for example when it is placed on a vehicle, pointing also allows communication to continue during the movement.

[0004] In the same way, pointing allows communication to be maintained successively with several other antennas, by pointing the beam in the directions associated with the antennas. Pointing is then an important element for satellite, maritime and terrestrial communications. The quality of a communication depends in particular on the pointing speed, the range of accessible directions and the precision of the pointing.

[0005] Thus, solutions exist that allow the beam to be pointed. The antennas can be placed on platforms that pivot along an axis of rotation in order to provide the necessary movement for the beam to be oriented. The antenna beam is thus moved along the axis of rotation, so there is movement in a single direction, i.e. either in elevation or in azimuth.

[0006] According to this solution, to depoint the beam in two directions, it is then necessary to be able to perform a movement along two different axes. When the beam can move in azimuth and elevation, it is then theoretically possible to point it in all directions along a hemisphere. However, it is necessary to ensure that the movements are precise and sufficiently fast to follow a mobile antenna or quickly change antennas with which to communicate.

[0007] Generally, the size of the antenna defines the width of the electromagnetic beam, in particular a thin beam can only be obtained with a large antenna. For the case of satellite communications, such a beam is generally required to be able to discriminate between the different satellites, which imposes a minimum antenna size.

[0008] These solutions are however cumbersome since they generally require a large antenna as well as the associated platform allowing the movement of the antenna and therefore of the beam.

[0009] For antennas on light vehicles or small moving elements such as drones, the size associated with the antenna is also a significant constraint.

[0010] One solution to the problem of bulkiness consists of setting two planar elements in independent rotation around the same axis to perform the pointing. Such a solution is proposed by Thinkom and is called Variable Inclination Continuous Transverse Stub. The first element consists of a feed structure and the lower part of a parallel plate guide. The second element consists of a network of slots partially closing the parallel plate guide and allowing electromagnetic radiation to the outside.

[0011] The two approaches described above also require the creation of a radioelectric junction between the electronic module enabling the generation or reception of signals and the antenna set in motion. Maintaining this junction requires the use of specific components called rotating joints, which are generally expensive and susceptible to mechanical wear and therefore degraded performance.

[0012] Another solution based on the principle of the diasporameter consists of setting in motion at least one element capable of deflecting a beam such as a prism. The elements capable of deflecting the beam act on the wave passing through them by applying a certain spatial phase distribution to it. This phase distribution may be dependent on the angle of incidence of the wave or other characteristics.

[0013] This distribution can be created from surfaces comprising patterns of which at least one of the dimensions is sub-wavelength, that is to say is less than the wavelength of the wave used. These surfaces are generally made up of metallic elements on one or more layers of dielectric materials.

[0014] One solution is to combine a deflector element and a beam former, whose relative positions allow the beam to be aimed. In this case, however, it is still necessary to make a radio-electric connection with the former set in motion.

[0015] Another solution is to combine a fixed beamformer with two deflector elements. This solution is sometimes called a Risley prism antenna. This allows beam pointing to be carried out without any rotation of the beamformer.

[0016] In both cases described above, it is possible to reduce the size by using thin deflector elements.

[0017] A solution to provide an antenna, equipped with a fixed former and two deflector elements, with a steerable beam and with a small footprint is proposed by Hoang et al, “Low-Profile Highly Directive 2D-Beam-steering Antenna in Ka-band with 3D-printed All-dielectric Sub-wavelength Deflectors”. In: 52nd European Microwave Conference (EuMc), Milan, Italy, 2022, pp. 852-855.

[0018] The proposed solution is a compact antenna with a steerable beam. The described antenna comprises a beamformer in the form of a planar disk, the former is fixed and fed by a feed port. The antenna comprises two dielectric deflectors also in the form of a disk which are arranged above the beamformer.

[0019] The deflectors are rotated around an axis common to all the elements of the antenna, thus making it possible to orient the antenna beam in elevation and azimuth during the rotation of the deflectors. The deflectors presented consist of sub-wavelength structures in the form of pillars surmounted by a pyramid. The deflectors are manufactured by additive manufacturing in a dielectric material.

[0020] The beamformer is a radial slot antenna which transmits to the deflectors a beam along the axis of the device with a right circular polarization. Although the assembly constitutes a compact antenna of approximately 4 cm thickness for a diameter of 28 cm, it operates on a narrow band of approximately 7% around 29 GHz, this being limited by the narrow band behavior of the beamformer.

[0021] Furthermore, in this solution the antenna can only transmit or receive right circularly polarized electromagnetic waves. This characteristic is restrictive because several usage scenarios rely on the use of a diversity of polarization of electromagnetic waves.

[0022] An antenna is generally designed to operate according to a given polarization, that is to say that it mainly emits waves in this state of polarization, and is only sensitive in reception mainly to waves having this same state of polarization.

[0023] When an antenna is in communication successively with several entities adopting different polarizations, it may therefore be necessary to change the polarization of the antenna to maintain the quality of the link.

[0024] Polarization change can be achieved through the integration of a polarization-agile beamformer, which however can represent significant complexity, especially for large apertures.

[0025] The change of polarization can also be done using polarizers which allow switching from one polarization to another. These polarizers can be composed of birefringent materials which will induce a phase shift between two orthogonal components of the electromagnetic wave.

[0026] In the same way, it is possible to modify the polarization using artificial materials, consisting of structures of which at least one of the dimensions is less than the minimum wavelength used, as is the case for microwave waves using for example metal coils. These structures are also called sub-wavelength structures.

[0027] Thus, pointing an antenna and changing polarization are two means of greatly improving the quality of transmissions between several antennas of which at least one of the communication antennas is moving.

[0028] [FEATURES OF THE INVENTION AND ASSOCIATED ADVANTAGES]

[0029] In order to overcome all or part of the aforementioned drawbacks, the invention consists of a beam-steerable antenna comprising, for operating with a generator and / or a receiver of radio-electric signals, a beam former, a first deflector element coupled to a first movement mechanism, a second deflector element coupled to a second movement mechanism. The beam former is fixed relative to a frame of the antenna, and the first and second movement mechanisms control rotations of the deflector elements relative to the frame.

[0030] The antenna further comprises a plane polarizing component coupled to a rotation mechanism, the polarizing component being adapted to, depending on its position, transform a first wave polarization into a second wave polarization or leave a wave polarization unchanged, one of the first and second deflector elements having a metal-free face and the polarizing component also having a face and the face of the polarizing component being placed opposite the metal-free face of the deflector element.

[0031] The two deflector elements are coaxially rotated with the polarizing component, signals can also be received by the receiver and generated by the generator over a wide frequency band, the deflector elements and the polarizing component maintaining a bandwidth of these signals for the purposes of transmission.

[0032] The beamformer, because it is fixed, is free from the constraints linked to a movement and in particular the mechanical stress which results from a movement. In addition, the beamformer is in certain cases a heavy element, immobilizing this element makes it possible to eliminate a heavy movement mechanism capable of moving the former. The resulting antenna is then lighter. Furthermore, the use of a fixed beamformer makes it possible to eliminate the need for a rotating joint which can be a complex and expensive element.

[0033] The assembly composed of the deflector elements and the polarizing component makes it possible to orient the antenna beam and to choose a polarization for the transmitted or received wave. The deflectors, when they are rotating, will thus make it possible to orient the beam in azimuth or in elevation. Thus, the orientation of the beam makes it possible to follow a communication with a transmitting or receiving antenna in motion, such as for example with an antenna placed on a satellite or on a terrestrial vehicle.

[0034] The polarizing component allows the polarization to be chosen using a rotation according to predefined positions. When the beamformer provides a linearly polarized wave, the polarizing component can transform this polarization into right or left circular polarization or make no change depending on its position.

[0035] The polarizing component is placed opposite one of the deflectors, the two elements are then close and this thus makes it possible to obtain a compact antenna.

[0036] Furthermore, because the polarizing component is planar and shares its axis of rotation with the deflectors, the size of the antenna is then reduced. Thus, the antenna is then light and compact.

[0037] Furthermore, the signal generator provides a signal that can occupy a wide frequency band, or else occupy a restricted frequency band but located successively at different frequencies of a wide frequency band. In the same way, the receiver makes it possible to receive a signal over a wide frequency band. The antenna can therefore operate in transmission, in reception and in both modes. The correct operation of the antenna may therefore require wideband behavior. This bandwidth is preserved by the antenna and all the elements that compose it, thus making it possible to obtain a compact wideband antenna, with an orientable beam and whose polarization can be chosen. The antenna can therefore be used in communications requiring a high throughput during transmissions, as is the case for satellite communications and other types of communications.

[0038] In a particular embodiment, the polarizing component is made up of at least one dielectric material, at least one layer comprising patterns in the dielectric material, at least one of the dimensions of which is less than a minimum wavelength of use of the antenna, metal patterns arranged on at least one of the dielectric layers or both such patterns in at least one dielectric material and such metal patterns.

[0039] The patterns, whether metallic or in a dielectric material or a combination of both, make it possible to induce a phase shift necessary for the transformation of the polarization. In addition, it is possible to use patterns ensuring the necessary phase shift over a maximum of the bandwidth of use of the antenna. The polarizing component can be made of one or more dielectric materials. Thus, when the antenna is used with a wide bandwidth, the polarizing component has a limited impact on reducing this bandwidth.

[0040] In a particular embodiment, at least one of the first and second deflector elements is made from at least one dielectric material of at least one layer comprising patterns in the dielectric material of which at least one of the dimensions is less than a minimum wavelength of use of the antenna.

[0041] The patterns in a dielectric material make it possible to create a phase distribution on the deflectors. This phase distribution allows, when the wave passes through the deflector, to be deflected. The combination of these two mobile deflectors rotating around the axis of the device makes it possible to orient the beam in the desired direction. In addition, the use of sub-wavelength dielectric patterns makes it possible to advantageously reduce the resonance effects when the emitted wave passes through the deflector elements. Thus, for a wideband signal, the deflectors have a limited impact on the reduction of the bandwidth. The antenna can therefore be used for wideband emissions without loss of performance. In addition, the deflector elements can be made of one or more dielectric materials.

[0042] In a particular embodiment, the polarizing component is positioned between the beamformer which is also planar and the first deflector element, which is also planar.

[0043] When the polarizing component is located closest to the beamformer, the beam has not been deflected by the deflectors and the performance during the transformation of the polarization is better. Thus this position makes it possible to reduce the design constraints on the polarizing component.

[0044] In a particular embodiment, the polarizing component is positioned between the two deflector elements.

[0045] The polarizing component can therefore be placed differently depending on the architecture of the antenna that it integrates and offers great freedom of use compared to existing systems.

[0046] In a particular embodiment, the polarizing component is positioned such that the two deflector elements rotating coaxially with the polarizing component are between the beamformer and the polarizing component.

[0047] The polarizing component is positioned after the deflectors, i.e. furthest from the beamformer. The polarizing component can thus be placed on existing systems comprising deflectors without changing the internal architecture of the system.

[0048] In a particular embodiment, the beamformer is a radial slot antenna, a continuous slot antenna, a leaky wave surface or an array of radiating elements.

[0049] Thus, the assembly comprising the deflectors and the polarizing component forms an architecture that can be combined with different beamformers. As a result, the assembly can be used with beamformers with wide bandwidths, also called broad bands, as is the case with continuous slot antennas for example.

[0050] In a particular embodiment, the polarizing component and the deflectors are disks whose thicknesses are of the order of the wavelength.

[0051] The disc shape for the deflectors and the polarizing component makes it easier to rotate the system. In addition, thin discs make it possible to limit the size associated with the antenna while maintaining a large aperture thanks to the shared rotation axis between the rotating elements.

[0052] In a particular embodiment, an emission of electromagnetic waves is carried out using a steerable beam antenna. The signal generator provides a signal to the beamformer, then the beamformer forms a collimated beam with a polarization, the beam then passes through a set of elements of the antenna comprising the polarizing component and the two deflector elements, the two rotating deflector elements steer the beam in azimuth and elevation and the rotating polarizing component modifies the polarization of the collimated beam or leaves it unchanged depending on its position and the antenna during reception, receives a signal using the beam steered by the deflector elements, the rotating polarizing component modifies the polarization of the received signal depending on its position.

[0053] Advantageously, carrying out a transmission from an antenna comprising the beam former, the polarizing component and the two deflectors makes it possible to orient the beam and to change the polarization while maintaining a wide band for the transmission in question. In the same way, the antenna can be used for reception and therefore receive a wide band signal and modify the polarization of the signal received through the beam oriented by the deflectors.

[0054] The use of deflectors composed of a dielectric material structured at a sub-wavelength scale makes it possible to maintain this wide band during transmission. As a result, the antenna can be used in wide band, which makes it possible to obtain a higher throughput. Thus, the antenna can be used for communications requiring a high throughput, such as satellite communications for example.

[0055] Furthermore, since the antenna can be used for transmission and reception, these characteristics also apply when receiving a signal.

[0056] In a particular embodiment, the signal generator provides a signal and / or the receiver receives a signal over a wide frequency band, the width of the band being at least 10%, or at least 15% of the center frequency of the generated signal and the polarizing component as well as the deflector elements retain their operation over a width of this frequency band.

[0057] Thus, the generator provides the beamformer with a signal over a wide available frequency band. This signal can occupy either one or the entire wide frequency band or be a signal over a narrow band but located on different frequencies of the total available band. In the same way, the receiver can receive a signal over a wide frequency band. The width being defined as at least 10% of the value of the central frequency. This wide band is little impacted by all the components of the antenna and more particularly, by the polarizing component and the two deflectors. The antenna can therefore operate with a wide frequency band in transmission and reception and allows a higher transmission rate.

[0058] In a particular embodiment, the Ka-band emitting beamformer and the polarizing component is a disk having approximately 60 centimeters in diameter, based on structured dielectric or metallic patterns on a multi-layer substrate or foam.

[0059] For example, the antenna receives in Ka band over a frequency range between 17.3 GHz and 21.2 GHz. This frequency range is used in particular for satellite communications. Thus, the antenna according to the invention makes it possible to pursue satellite communication efficiently through its steerable beam and its change of polarization by the polarizing component while offering a small footprint and reduced weight.

[0060] Furthermore, the structure of the antenna according to the invention is compatible with a large aperture. This characteristic being required for satellite communications.

[0061] In a particular embodiment, the dimensions of the dielectric structures or the metallic patterns of the polarizing component are less than the minimum wavelength of the operating band.

[0062] Thus, the polarizing component is effective over the entire bandwidth of use of the antenna. Brief description of the drawings

[0063] The invention will be better understood and other advantages, details and characteristics will appear on reading the explanatory description which follows, given by way of example and thanks to the figures among which: • [Fig.l] represents a low-profile, steerable beam antenna according to one embodiment of the invention; • [Fig.2] represents a sectional view of a low-profile antenna according to one embodiment of the invention. Description of the embodiments

[0064] [Fig.l] [Fig.l] shows a low profile antenna 10 with a steerable beam 17 according to one embodiment of the invention. The steerable antenna 10 comprises a feed port 15 which supplies the signal to be transmitted in the form of a wave to the beamformer 14. The antenna 10 comprises an axis of rotation 16 and around which the various elements which can be rotated carry out their movement. This axis is shared by the various rotating elements, the elements are therefore in coaxial rotation.

[0065] The antenna 10 thus presented then makes it possible to obtain a configurable polarization with an orientable beam 17 while retaining a small footprint and a large aperture.

[0066] The feed port 15 feeds the beamformer 14 with a signal. This signal is generated by a generator which makes it possible to obtain the electromagnetic wave which will be emitted when the antenna is used in transmission. This generator can, for example, generate a signal over a wide frequency band, typically at least 10 to 15% of the value of the central frequency of the signal. The wideband signal is then transmitted by the feed port 15 to the rest of the antenna.

[0067] The feed port 15 is generally in the form of a waveguide or a coaxial cable. It provides the signal to the beamformer 14 so that the latter forms a collimated beam for transmission.

[0068] The beamformer 14 is fixed, it is an element making it possible to obtain a transmission or reception beam 17. This beam 17 is defined in width by the characteristics of the former 14. In the same way, the width of the bandwidth is defined mainly by the beamformer 14, thus making it possible to obtain a low-profile antenna 10 with a wide band.

[0069] The trainer 14 is not driven by a rotational movement around the axis 16. Thus, the beam trainer as well as the feed port 15 are not subjected to mechanical stress linked to the movement.

[0070] The beamformer 14 may be, for example, a radial slot antenna or a continuous slot antenna, also called a continuous transverse stub (CTS). The beamformer 14 generates a wave propagating towards the polarizing component 13 making it possible to change the polarization of the wave incident thereon.

[0071] The polarizing component 13 is associated with a mechanism which makes it possible to rotate the component 13 around the axis 16. The rotation around this axis 16 of the component 13 makes it possible to transform the linear polarization into right or left circular polarization, according to a rotation angle. The rotation angle being defined relative to a reference direction. It is thus possible to choose the direction of the circular polarization that is desired by a simple rotation of the polarizing component 13. Thus, the change of polarization is inexpensive in terms of energy since it only requires a rotation upstream of the transmission of the polarizing component 13.

[0072] The antenna 10 comprises a first deflector 12 and a second deflector 11. The two deflectors 11-12 are each associated with separate mechanisms allowing rotation around the axis 16 of each of the two elements independently of one another.

[0073] The deflectors 11 and 12 are placed above the beam former 14 and the polarizing component 13. The collimated beam is therefore transmitted directly to the polarizing component 13 before being deflected by the two deflectors 11 and 12. The resulting beam 17 is then steerable with a polarization that can be modified.

[0074] In a particular embodiment, the two deflectors 11 and 12 are placed between the polarizing component 13 and the beamformer 14. In this case, the polarizing component 13 at the output can be placed after the two deflectors 11 and 12, and makes it possible to obtain an extremely compact set of two deflectors 11 and 12. Furthermore, this architecture makes it possible to place the polarizing component 13 above an already existing system comprising deflectors.

[0075] In a particular embodiment, the polarizing component 13 can be placed between the two deflectors 11 and 12. As a result, the polarizing component 13 acts on the polarization of the beam between the two successive deviations.

[0076] The displacement of the beam 17 according to the azimuth is carried out when the deflectors 11 and 12 are fixed relative to each other and therefore their relative movement is zero, while rotating around the axis of the device. To vary the elevation of the beam, the relative angular position between the two deflectors 11 and 12 is varied.

[0077] [Fig.2] [Fig.2] shows a sectional view of a low-profile antenna 10 according to one embodiment of the invention. The antenna 10 then comprises two deflector elements 12 and 11, a polarizing component 13, a beamformer 14 and a feed port 15.

[0078] The beamformer 14 is shown here in the form of an antenna comprising slots. The thickness of the beamformer 14 is variable, depending on the usage requirements of the antenna and more particularly, the frequencies and bandwidths used. The beamformer 14 is a compact element, and generally a thickness of a few tenths of a wavelength to a few wavelengths.

[0079] In particular embodiments, the beamformer 14 may be a continuous transverse slot (CTS) antenna, a discrete array of radiating elements, a radial slot antenna, or a leaky wave antenna.

[0080] The polarizing component 13 is placed between the beamformer 14 and the deflector 12.

[0081] The polarizing component 13 consists of a dielectric base of at least one layer represented here by a thick line. This dielectric base comprises a plurality of patterns represented by spaced rectangles. In one embodiment, these patterns are metallic and arranged on at least one layer of the dielectric material.

[0082] In a particular embodiment, the patterns are made of a dielectric material and at least one of the dimensions of the patterns is less than a wavelength of the antenna.

[0083] In a particular embodiment, the polarizing component 13 comprises both metallic patterns arranged on at least one of the layers of the dielectric material and dielectric patterns of which at least one of the dimensions is less than a wavelength of the antenna.

[0084] These patterns can therefore be made from a dielectric, metallic or metallo-dielectric material. Thus, these patterns can be made directly by additive manufacturing.

[0085] The patterns, dielectric or metallic, then induce a phase shift making it possible to modify the polarization of the incident wave on the polarizing component 13. The component 13 which receives the collimated beam from the beam former 14 in transmission can therefore transform the polarization coming from the former 14. In the same way, when the antenna is in reception, the incident beam is directed towards the polarizing component 13 which transforms the Fonde polarization according to a chosen polarization.

[0086] Furthermore, the polarizing component 13 is of a thickness less than the maximum wavelength of the antenna, which makes it a compact element.

[0087] The dielectric deflectors 11 and 12 are located above the polarizing component 13. The two deflectors 11 and 12 are shown identically in [Fig. 2]. In a particular embodiment, the first deflector 12 is different from the second deflector 11.

[0088] The deflectors 11 and 12 are made of a dielectric base comprising patterns. These patterns may be metallic and arranged on at least one of the layers of the dielectric material constituting the base.

[0089] The patterns of the deflectors 11 and 12 may also be made of a dielectric material, and the patterns then have at least one dimension smaller than a wavelength of the antenna. For example, these patterns may be in the form of pillars of variable widths distributed over their upper surface. These pillars may be arranged, for example, according to a period 22. This period 22 is established as a function of the desired deflection angle relative to a wavelength used by the antenna.

[0090] Thus by varying the period 22, it is possible to vary the deflection angle. A small angle makes it possible to obtain a precise scan. For a period 22 of 3.55 cm, the elevation deflection angle is for example 25 degrees at 20 GHz.

[0091] In a particular embodiment, the patterns of the deflectors 11 and 12 can be arranged in a non-periodic arrangement making it possible to achieve beam deflection.

[0092] The top of the pillars 23 is flat and the width of the pillars gradually decreases periodically according to the period 22. In a particular embodiment, the pillars are capped with a pyramid or another volume making it possible to minimize the reflection on the deflectors 11 or 12.

[0093] Alternatively, in a particular embodiment, the deflectors 11 and 12 may comprise both dielectric patterns of which at least one of the dimensions is less than the wavelength of the antenna and metallic patterns on at least one of the layers of the dielectric material.

[0094] The use of a dielectric material provided with patterns at a sub-wavelength scale makes it possible to reduce the resonance effects of the system and to obtain a more homogeneous transmission level over the entire bandwidth. As a result, the device is then suitable for operation over wide bandwidths.

[0095] The deflectors 11 and 12 can also be manufactured from the selective metallization of a dielectric substrate, the metallized patterns are then geometric shapes on one or more layers of the substrate, which makes it possible to obtain a low profile deflector.

[0096] In order to obtain a low-profile antenna, the deflectors 11 and 12 have a thickness of the order of the wavelength. Thus, for an antenna 10 used in the Ka band (26.5-40 GHz), this thickness for each of the deflectors 11 and 12 is of the order of 2 centimeters for the bottom of the band and of the order of a centimeter for the top of the band.

[0097] The diameter 20 of the antenna 10 is several tens of wavelengths, for example between 10 and 60 centimeters in Ka band. Each of the elements constituting the antenna is of the same diameter. The thickness of the different elements does not vary or varies little with the width, thus it is possible to increase or decrease the width of the deflectors 11 and 12 and of the polarizing component 13 without increasing the thickness 21 of the final antenna. In addition, for elements of the antenna 10 such as the polarizing component 13 and the deflectors 11-12, the diameter is greater than the thickness of these same components. The thickness of these elements being linked to the wavelength of the antenna, this can be a few centimeters for a diameter of several tens of centimeters. These elements are then wider than thick, which makes it possible to obtain a compact antenna 10.

[0098] The antenna 10 then makes it possible to orient a beam using the deflectors 11 and 12 and to choose the polarization using the polarizing component 13 while preserving the width of the frequency band. This ability to preserve the bandwidth makes it possible to use the antenna 10, for example, in satellite communications in broadband transmission. These satellite communications are mainly carried out in the Ku (12-18 GHz) and Ka (26.5-40 GHz) bands, but the device is applicable to other frequency bands.

[0099] In a particular embodiment, the elements constituting the antenna may have different diameters.

Claims

Claims

1. An antenna (10) with a steerable beam (17) comprising, for operation with a radio signal generator and / or receiver, a beamformer (14), a first deflector element (12) coupled to a first movement mechanism, a second deflector element (11) coupled to a second movement mechanism, the beamformer (14) being fixed relative to a frame of the antenna (10), and the first and second movement mechanisms controlling rotations of the deflector elements (11, 12) relative to said frame, said antenna (10) being characterized in that the antenna (10) further comprises a plane polarizing component (13) coupled to a rotation mechanism, said polarizing component (13) being adapted to, depending on its position, transform a first wave polarization into a second wave polarization or leave a wave polarization unchanged, one of the first and second deflector elements (11,12) having a metal-free face and the polarizing component (13) also having a face and said face of the polarizing component (13) being placed opposite the metal-free face of the deflector element (11, 12), the two deflector elements (11, 12) being in coaxial rotation with said polarizing component (13), signals being able to be further received by the receiver as well as generated by the generator over a wide frequency band, the deflector elements (11, 12) and the polarizing component (13) maintaining for the purposes of transmission a bandwidth of said signal.,

2. Antenna (10) with steerable beam (17) according to claim 1, characterized in that the polarizing component (13) is made from at least one dielectric material of at least one layer comprising patterns in the dielectric material of which at least one of the dimensions is less than a minimum wavelength of use of the antenna, metallic patterns arranged on at least one of the dielectric layers or both such patterns in at least one dielectric material and such metallic patterns.

3. An antenna (10) with a steerable beam (17) according to claim 1 or claim 2, characterized in that at least one of the first and second deflector elements (11, 12) is constituted by base of at least one dielectric material of at least one layer comprising patterns in the dielectric material of which at least one of the dimensions is less than a minimum wavelength of use of the antenna.

4. Antenna (10) with steerable beam (17) according to one of claims 1 to 3, characterized in that the polarizing component (13) is positioned between the beam former (14) which is also planar and the first deflector element (11), which is also planar.

5. Antenna (10) with steerable beam (17) according to one of claims 1 to 3, characterized in that the polarizing component (13) is positioned between the two deflector elements (11, 12).

6. Antenna (10) with steerable radio beam (17) one of claims 1 to 3, characterized in that the polarizing component (13) is positioned such that the two deflector elements (11, 12) in coaxial rotation with the polarizing component (13) are between the beamformer (14) and said polarizing component (13).

7. Antenna (10) with steerable beam (17) according to one of claims 1 to 6, characterized in that the beamformer (14) comprises a radial slot antenna, a continuous slot antenna, a leaky wave surface or an array of radiating elements.

8. Antenna (10) with steerable beam (17) according to one of claims 1 to 7, characterized in that the polarizing component (13) and the deflector elements (11, 12) are discs whose thicknesses are of the order of the wavelength.

9. A method of transmitting electromagnetic waves carried out using an antenna (10) with a steerable beam according to one of claims 1 to 8, characterized in that the signal generator provides a signal to the beam former, then said beam former forms a collimated beam with a polarization, said beam then passes through a set of elements of the antenna comprising the polarizing component (13) and the two deflector elements (11, 12), the two rotating deflector elements (11, 12) steer the beam in azimuth and elevation and the rotating polarizing component (13) modifies the polarization of said collimated beam or leaves it unchanged depending on its position, and said antenna (10) upon reception, receives a signal using the

10. beam oriented by the deflector elements (11, 12), the rotating polarizing component (13) modifies the polarization of said received signal depending on its position. A method of transmitting radiofrequency waves according to claim 9, characterized in that the signal generator provides a signal and / or the receiver receives a signal, the signals being over a wide frequency band, the width of said frequency band being at least 10%, or at least 15% of the value of a central frequency of the signal and the polarizing component (13) as well as the deflector elements (11, 12) retain their operation over a width of said frequency band.

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