EP3506426B1 - Beam pointing device for antenna system, associated antenna system and platform - Google Patents

Description

The present invention relates to a beam pointing device for a telecommunications antenna system, in particular satellite systems, and preferably in the Ka band. The invention also relates to an antenna system comprising such a beam pointing device, a platform, in particular land, air or space, comprising at least one aforementioned antenna system, and a method of telecommunication between two stations using the antenna system. above.

In the field of satellite communications, obtaining a good quality communication implies performance for the electromagnetic waves produced by the antenna system used in the communication in terms of gain and level of the sidelobes (ratio between the intensity of side lobes and the intensity of the main lobe).

In the particular case of the Ka electromagnetic band, two distinct frequency bands are involved. Indeed, in transmission, the electromagnetic waves of the Ka band have a frequency between 27.5 GigaHertzs (GHz) and 31 GHz while in reception, the electromagnetic waves of the Ka band have a frequency between 17.3 GHz and 21.2 GHz. In addition, the polarizations of the waves in transmission and in reception are generally of the circular type, whether or not they are opposed.

These frequencies and these circular polarizations in reception and in transmission impose constraints on the antenna system.

To reduce the visual signature (physical size), solutions of the parabolic antenna type are generally not preferred, particularly in a terrestrial or aerial context.

In addition, in the context of a satellite link, it is advisable to orient the antenna in real time in order to constantly point the satellite making it possible to establish the link.

To obtain such a multi-directional electronic scan, in a context of platform integration, in particular terrestrial, air or satellite, it is known to implement a motorized system for moving the antenna system along a mechanical axis in azimuth or in elevation, by example by means of a turntable, fixed to the platform. However, such a motorized antenna system then has a bulky protuberance limiting the type of integration platform possible.

In this context of platform integration subject to possible movements, in particular in the case of constrained platforms, such as aerial platforms, a stationary antenna system is therefore more desirable.

A first solution for a stationary antenna system consists in using a passive electronically scanned array (PESA). However, the equivalent isotropically radiated power (EIRP) obtained is highly dependent on the amplification used and its implementation requires the use of two antenna panels dedicated respectively to transmission and reception, of which the mass, the energy consumption, and the size are hardly compatible depending on the case of platform integration, in particular the case of constrained platforms, such as aerial platforms

A second solution of a stationary antenna system consists in implementing active antenna systems, or active electronically scanned array antenna (AESA) suitable for electronically pointing to describe a hemisphere commonly called 2D electronic depointing.

This type of immobile active antenna system suitable for implementing multi-directional scanning requires a plurality of active electronic elements, for example patch-type planar antennas supplied by two power supplies to ensure dual polarization, generally distributed over two disjoint antenna panels. , one being dedicated to transmission and the other to reception. However, such an antenna arrangement has a size and high levels of consumption and heat dissipation which are binding for the realization of the platform.

There is therefore a need for a stationary antenna system, suitable for implementing multi-directional scanning, compact and exhibiting reduced energy performance compared to known solutions.

• au moins une source d'alimentation propre à générer des ondes radiofréquences,
• un formateur de faisceaux quasi-optique planaire dont l'entrée est propre à être alimentée par ladite au moins une source et dont la sortie est propre à alimenter un réseau d'éléments rayonnants, le formateur de faisceaux quasi-optique planaire comprenant un guide d'onde à plaques parallèles, l'entrée et la sortie du formateur de faisceau quasi-optique planaire correspondant aux ouvertures linéaires situées entre les deux plaques parallèles du guide d'onde,
• ledit réseau d'éléments rayonnants,

le dispositif comprenant en outre au moins un élément de translation mécanique propre à déplacer, l'un par rapport à l'autre, ladite au moins une source d'alimentation et au moins un élément focalisant dudit formateur de faisceaux quasi-optique planaire selon un mouvement de translation perpendiculaire à la direction d'alimentation du réseau d'éléments rayonnants par la source.To this end, the invention relates to a beam pointing device for a telecommunications antenna system, the device comprising:

• at least one power source suitable for generating radiofrequency waves,
• a planar quasi-optical beam former, the input of which is suitable for being supplied by said at least one source and the output of which is suitable for supplying an array of radiating elements, the planar quasi-optical beam former comprising a guide d 'wave with parallel plates, the input and the output of the planar quasi-optical beamformator corresponding to the linear openings located between the two parallel plates of the waveguide,
• said array of radiating elements,

the device further comprising at least one mechanical translation element suitable for moving, one relative to the other, said at least one power source and at least one focusing element of said planar quasi-optical beam former according to a translational movement perpendicular to the supply direction of the array of radiating elements by the source.

• la source est munie d'au moins un élément de contrôle électronique en phase et en amplitude du faisceau délivré en sortie du réseau d'éléments rayonnants ;
• l'élément de translation mécanique est propre à déplacer ladite au moins une source d'alimentation par rapport audit élément focalisant dudit formateur de faisceaux quasi-optique planaire immobile ;
• l'élément de translation mécanique est propre à déplacer ledit au moins un élément focalisant dudit formateur de faisceaux quasi-optique planaire par rapport à ladite au moins une source d'alimentation immobile ;
• le formateur de faisceaux quasi-optique planaire comprend un guide d'onde à plaques parallèles, le réseau d'éléments rayonnants et le guide d'onde à plaques parallèles présentant une largeur strictement supérieure à la largeur de l'élément focalisant, l'élément de translation mécanique étant propre à déplacer l'élément focalisant selon la largeur du guide d'onde à plaques parallèles ;
• le déplacement maximal de l'élément focalisant, par rapport à sa position initiale centrée selon la largeur du guide d'onde à plaques parallèles, est inférieur à la moitié de la largeur de l'élément focalisant ;
• chaque élément rayonnant du réseau d'éléments rayonnants comprend un cornet comprenant une première partie d'émission-réception et une deuxième partie d'émissionréception alimentées par le formateur de faisceaux quasi-optique,

chacune des première et deuxième parties d'émission-réception étant propre à émettre et recevoir une onde électromagnétique à une première fréquence ou à une deuxième fréquence, le rapport entre la deuxième fréquence et la première fréquence étant supérieur à 1,2, de préférence supérieur à 1,5, la première fréquence et la deuxième fréquence appartenant à la bande Ka du spectre électromagnétique.According to particular embodiments of the invention, the beam pointing device also has one or more of the following characteristics, taken in isolation or in any technically possible combination (s):

• the source is provided with at least one electronic control element in phase and in amplitude of the beam delivered at the output of the array of radiating elements;
• the mechanical translation element is able to move said at least one power source relative to said focusing element of said stationary planar quasi-optical beam former;
• the mechanical translation element is suitable for moving said at least one focusing element of said planar quasi-optical beam former relative to said at least one stationary power source;
• the planar quasi-optical beam former comprises a waveguide with parallel plates, the array of radiating elements and the waveguide with parallel plates having a width strictly greater than the width of the focusing element, the element of mechanical translation being able to move the focusing element along the width of the parallel plate waveguide;
• the maximum displacement of the focusing element, relative to its initial position centered along the width of the parallel plate waveguide, is less than half the width of the focusing element;
• each radiating element of the array of radiating elements comprises a horn comprising a first transmission-reception part and a second transmission-reception part supplied by the quasi-optical beam former,

each of the first and second transmission-reception parts being suitable for transmitting and receiving an electromagnetic wave at a first frequency or at a second frequency, the ratio between the second frequency and the first frequency being greater than 1.2, preferably greater at 1.5, the first frequency and the second frequency belonging to the Ka band of the electromagnetic spectrum.

The subject of the invention is also an antenna system comprising at least one beam pointing device as described above.

In addition, the invention also relates to a platform comprising at least one antenna system as described above.

The present invention also relates to a method of telecommunications, in particular by satellite, between two stations, the method comprising the use of at least one beam pointing device or of an antenna system as described above.

• figure 1, une vue schématique en perspective d'un dispositif de pointage de faisceau selon un premier mode de réalisation ;
• figure 2, une vue schématique en perspective d'un dispositif de pointage de faisceau selon un deuxième mode de réalisation ;
• figure 3, une vue schématique en perspective d'un exemple d'élément rayonnant d'antenne élémentaire selon la présente invention.

Other characteristics and advantages of the invention will become apparent on reading the following detailed description of embodiments of the invention, given by way of example only and with reference to the drawings which are:

• figure 1 , a schematic perspective view of a beam aiming device according to a first embodiment;
• figure 2 , a schematic perspective view of a beam aiming device according to a second embodiment;
• figure 3 , a schematic perspective view of an example of an elementary antenna radiating element according to the present invention.

In the remainder of the description, the expression “substantially” will express a relationship of equality of plus or minus 10%.

The beam aiming device D _P according to the present invention comprises a planar quasi-optical beamformator 10.

Specifically, the beamformer quasi-optics 10 comprises at least one waveguide 12 parallel plate (PPW standing for "Parallel Plate Waveguide") wherein a focusing element 14 is disposed.

Specifically, the waveguide 12 parallel plate (PPW standing for "Parallel Plate Waveguide") is a transmission guide comprising two stacked metal plates, spaced from each other in a thickness E and _G s 'extending, in two longitudinal X and transverse Y directions.

The focusing element 14 rests on the lower plate of the waveguide 12 and has a thickness, not shown, less than or equal to that of the parallel plate waveguide 12.

• à une lentille contrainte, comme décrit par exemple dans les documents US 3170158 et US 5936588 qui illustrent le cas d'une lentille de Rotman, ou
• à un réflecteur comme décrit par exemple dans les documents FR 2944153 et FR 2986377 pour des formateurs de faisceaux Pillbox, ou
• à la structure focalisante décrite dans les documents FR 3 038 457 , US 2002/101386 A1 , US 2003/016097 A1 , US 2 721 263 A Z ou
• une structure focalisante plane à gradient d'indice,
• etc.

Such a focusing element 14 corresponds for example:

• to a constrained lens, as described for example in the documents US 3170158 and US 5936588 which illustrate the case of a Rotman lens, or
• to a reflector as described for example in the documents FR 2944153 and FR 2986377 for Pillbox beamformers, or
• to the focusing structure described in the documents FR 3,038,457 , US 2002/101386 A1 , US 2003/016097 A1 , US 2,721,263 A Z or
• a plane focusing structure with an index gradient,
• etc.

In the pointing device D _P , the input of the quasi-optical beam former 10 is suitable for being supplied by at least one power source 16 suitable for generating radiofrequency waves, and the output of the quasi-optical beam former 10 is suitable for supplying an array of radiating elements 18. The input and the output of the planar quasi-optical beam former 10 correspond to the linear openings located between the two parallel plates of the waveguide 12. The source 16 is on. outside the waveguide with parallel plates 12. The source 16, the planar quasi-optical beam former 10 and the array of radiating elements 18 are aligned and juxtaposed in direction D, supplying the array of radiating elements 18 by the source 16, and rest substantially on the same plane, namely the plane of the lower plate of the waveguide 12.

The deflection of the power supply to the array of radiating elements 18 by the source 16 passing through the planar quasi-optical beam former 10 is therefore limited and strictly less than 90 °. In other words, the deflection of the beam in a plane perpendicular to the parallel plate waveguide 12 (PPW) is substantially zero because the focusing is carried out in transmission in the plane of the PPW.

Moreover, such an alignment on the same plane of the source 16, of the planar quasi-optical beam former 10 and of the array of radiating elements 18 allows a superposition (ie a stack) along the Z axis of a plurality V of beam aiming device D _P each comprising an array of W radiating elements 18.

According to an aspect not shown, the source 16 is provided with a duplexer suitable for selecting at least the generation of an electromagnetic wave at a first frequency f ₁ , dedicated, for example, to the emission of the electromagnetic waves of the Ka band, f ₁ then being between 27.5 GHz and 31 GHz, or the generation of an electromagnetic wave at a second frequency f ₂ , dedicated, for example, to the reception of the electromagnetic waves of the Ka band, f ₂ then being included between 17.3 GHz and 21.2 GHz.

According to the present invention, the pointing device D _{P further} comprises at least one mechanical translation element E _TM suitable for moving, one relative to the other, said at least one power source 16 and at least one focusing element 14 of said quasi-optical beam former 10 according to a translational movement T perpendicular to the direction D, supplying the array of radiating elements 18 by the source 16, as shown according to two embodiments illustrated by the figures 1 and 2 .

According to a particular aspect, the dimensioning of the pointing device D _P is directly dependent on the maximum angular excursion of the desired pointing.

In other words, the mechanical translation element E _TM makes it possible to control the illumination of the beam produced by the focusing element 14 on the line of radiating elements 18 forming an array, which delivers a mechanical depointing of the beam in the plane of the beam. line of radiating elements 18.

Unlike the known solutions for optimizing stationary electronic scanning antenna systems, such a mechanical element exhibits, by its passive nature, low energy consumption and reduced bulk proportional to the size of the array of radiating elements 18 used.

Thus the line of radiating elements 18 has a mechanical pointing capacity (hereinafter referred to as 1DM). Such a mechanical pointing capability has the advantage of being stable in frequency.

Two embodiments of such a mechanical translation between the focusing element 14 and the source 16 can be envisaged depending on whether the mechanical translation is applied to the source 16, as illustrated by figure 1 , or to the focusing element 14, as illustrated by figure 2 .

For example, on the figure 1 , the focusing element 14 is stationary, and the source 16 is movable in the direction T while being movable on a rail, the movement being actuated by the mechanical translation element E _TM corresponding to a gear, a spring, an arm of return, etc., automatically actuated by means of a motor, not shown, as a function of the desired deflection.

When the source 16 is in a centered position C _S with respect to the width L _EF of the focusing element 14 in the direction Y, the focusing element 14 is suitable for illuminating the entire array of radiating elements 18. In other words , L _EF is substantially equal to the width L _R along the Y axis of the array of radiating elements 18 which substantially corresponds to the width of the waveguide 12.

On the other hand, when the source 16 is moved in the direction T at a non-zero distance from this centered position C _S , only a part of the radiating elements 18 is illuminated, which causes a deflection of the beam obtained for this off-center position of the source 16 relative to the centered position previously described.

Depending on the embodiment of the figure 1 , the maximum displacement T _Smax of the source is limited by its own width L _S and by the width L _R of the planar quasi-optical beamformator 10 so that L _R = 2 * T _Smax + L _S.

In relation to the figure 2 , the mechanical translation element E _TM is this time suitable for moving the focusing element 14 in the direction of translation T (collinear with the Y axis on the example of figure 2 ) while the source 16 is stationary.

For example, the mechanical translation element E _TM corresponds to a worm.

According to this configuration, it is therefore necessary that the waveguide 12, where the focusing element 14 rests flat on its lower metal plate, has a width (substantially corresponding to the width L _R of the array of radiating elements 18) greater than the width L _EF of the focusing element 14 so as to allow the displacement of the focusing element 14 in the direction T corresponding to the width of the waveguide 12 and, on the example of figure 2 , also in the Y direction of the line of the array of radiating elements 18 contiguous to one another.

In other words, depending on the embodiment of the figure 2 where the focusing element 14 of the quasi-optical beam former 10 is moved according to a displacement T _EF with respect to the stationary source 16 of the pointing device D _P , the width L _R along the Y axis of the array of radiating elements 18, substantially equal to that of the waveguide 12, is such that L _R ≥ (L _EF + 2 * T _EF ).

Depending on the configuration of the figure 2 , the array of radiating elements 18 contiguous to one another therefore has more radiating elements 18 than illuminated radiating elements suitable for receiving the plane wave focused by the focusing element 14.

According to a particular aspect, the waveguide 12 will be dimensioned so that the maximum displacement T _EFmax with respect to its initial position (ie by default centered at the point M center of the planes of the parallel plate waveguide 12) is less at half the width L _EF , _i.e. T EFmax ≤ LEF / 2.

Furthermore, according to a complementary aspect, the source 16 is provided with at least one E _CPA element for electronic control of the phase and amplitude of the wave supplied by the source 16, which consequently makes it possible to orient the delivered beam. by the pointing device D _P in the plane of the networking of the line of radiating elements 18.

Thus, according to this complementary aspect of the pointing device D _P according to the present invention, to the mechanical pointing capacity in a 1DM dimension of the line of radiating elements 18 is added an electronic pointing capacity in another dimension perpendicular to the line. previous (hereinafter called 1DE).

The 1DM mechanical pointing capability is more frequency stable than the 1DE electronic pointing capability, the electronic control element in phase and amplitude being inherently more sensitive to the operating frequency of the D _P pointing device than is the case. is a mechanical element whose operation is not impacted by an operating frequency.

Thus, while increasing the beam aiming precision by electronic adjustment in amplitude and phase, aiming stability is guaranteed. independently of the operating frequency by the pointing device D _P according to the present invention.

The invention also relates to an antenna system, not shown, comprising at least one beam pointing device D _P as described above.

For example, such an antenna system corresponds to the superposition (ie the stack) along the Z axis of a plurality V of beam pointing device D _P each comprising an array of W radiating elements 18.

The corresponding antenna system therefore comprises a matrix of WxV radiating elements 18, V sources 16 distinct respectively supplying each of the V lines of W radiating elements 18 (for example on the figures 1 and 2 W = 13), V mechanical translation elements E _TM and in addition V electronic phase and amplitude control elements E _CPA being implemented to automatically control locally on the platform, or even remotely, in particular in the case of a platform spatial, mechanical and / or electronic deflection (ie beam aiming in a given direction with respect to a default aiming direction) of V beams in the plane of each of the V lines of radiating elements 18.

The V mechanical translation elements E _TM are controlled by the same motor or by two motors each dedicated to the displacement on either side of the median line passing through the center M of the planar quasi-optical beam former 10 and the centered position Cs from source 16.

Multidirectional electronic scanning is thus obtained while avoiding the use of a mechanical axis in azimuth or in elevation, for example by means of a rotating plate, fixed to the platform.

According to a particular aspect, the radiating elements 18 supplied by the planar quasi-optical beam former 10 according to the invention, have a parallelepipedal shape as illustrated in the figures. figures 1 and 2 described above and include two parts, namely a first polarizing part 20 and a second part or output 22 dedicated to transmission / reception as such.

Alternatively, the shape of these radiating elements 18 is cylindrical and conforms to the subject of the application. FR 3 013 909 A1 as illustrated by figure 3 .

More precisely, as illustrated by figure 3 , the radiating element 18 comprises a horn 24, a polarizing part 20 comprising dielectric elements 26 and two ports 28, 30 for the waves emitted or received by the radiating element 18.

The horn 24 comprises a first transmission-reception part 22 ₁ suitable for transmitting and receiving a wave according to a state of polarization and a second part according to another state of polarization 22 ₂ , distinct from the first transmission-reception part 22 ₁ .

As indicated above, each part 22 ₁ and 22 ₂ is respectively supplied via the ports 28 and 30 by the previously described planar quasi-optical beam former 10.

The parts 22 ₁ and 22 ₂ according to an alternative embodiment are suitable for being associated in a single block.

Each of the first and second transmission-reception parts 22 ₁ , 22 ₂ is suitable for transmitting and receiving an electromagnetic wave at a first frequency f ₁ or at a second frequency f ₂ , the ratio between the second frequency f ₂ and the first frequency f ₁ is greater than 1.2, and preferably greater than 1.5.

According to one particular characteristic, the horn 24 has a cylindrical shape giving the emission of each radiating element 18 a broadband character. The band covered by a horn typically extends 40% on either side of the operating frequency f ₁ and f ₂ .

Thus, in this variant, the first transmission-reception part 22 ₁ and the second transmission-reception part 22 ₂ each have the shape of a half-disc, the association of the two transmission-reception parts forming the cornet 24.

Conventionally, a horn dimensioned to operate over a wide frequency band has external dimensions which are constrained by the operating wavelength corresponding to the lowest of the frequencies to be transmitted or received. In addition, the interior of it is empty.

In the example presented, identically to the dielectric elements 26, the interior of the horn 24 is filled with a dielectric material in order to reduce the physical dimensions of the horn 24. Indeed, the wavelength in a dielectric material is smaller. than in the corresponding wavelength in air. Thus, for a given horn structure, a widening towards the operating frequency band is achieved. This dielectric material is a substrate having a permittivity of between two and five depending on the production constraints.

In addition, for example for a Ka-band application of the electromagnetic spectrum, the polarizing part 20 of the radiating element 18 comprises a polarizer 32 arranged so as to polarize the waves that the first emission-reception part 22 ₁ and the second part d 'transmission-reception 22 ₂ are suitable for transmitting.

The polarizer 32 comprises two parts arranged, not shown, so as to circularly polarize in a first direction the waves that the first part transmission-reception 22 ₁ is suitable for transmitting and circularly polarizing the waves that the second transmission-reception part 22 ₂ is suitable for transmitting in a direction opposite to the first direction.

For the remainder of the description, the first meaning is right-hand polarization.

Thus, such a radiating element 18 in accordance with the subject of the application FR 3 013 909 A1 is for example suitable for emitting and / or receiving waves having a right circular polarization at the first frequency f ₁ . Such a radiating element 18 is also suitable for emitting and / or receiving waves having a left circular polarization at the second frequency f ₂ .

According to one variant, the polarizer 32 is also part of the horn 24 (i.e. also extends into the horn 24).

In the radiating element 18, the dielectric elements 26 are inserted in order to reduce the electrical dimension with respect to the wavelength and thus to obtain an elementary antenna A with dimensions allowing the radiating elements 18 to be brought together sufficiently during the networking in order to facilitate angular scanning over a sufficiently large range while keeping radiation performance compatible with the satellite link type application envisaged. The dielectric elements 26 are preferably only located at the level of the accesses 28, 30 as well as in the polarizer 32. As a variant, the dielectric elements 26 are extended in the parts 22 ₁ and 22 ₂ .

Each access 28, 30 is opposite a transmission-reception part of the horn 24. For example, an access 28 for a left circular polarized wave is therefore provided opposite the first transmission-reception part 22 ₁ of the. horn 24 while an access 30 for a right circular polarized wave is provided opposite the second transmission-reception part 22 ₂ .

In operation, the first transmission-reception part 22 ₁ receives electromagnetic waves according to a state of polarization as soon as the horn 24 is electrically excited. This wave is left circular polarized by the polarizer 32. This wave then passes through the port 28 provided for a left circular polarized wave.

A right circular polarized wave passes through the port 30 provided for a right circular polarized wave. This wave then passes through the polarizer 32 before being emitted by the second transmission-reception part 22 ₂ . This transmission-reception operation can be reversed between accesses 28 and 30.

It thus appears that a single radiating element 18 makes it possible to ensure both the transmission and reception functions, for two frequencies f ₁ and f ₂ whose ratio is greater than to 1.2. It is a compact dual-band horn 24 with circular polarization which makes each radiating element 18 dual-band.

In addition, each radiating element 18 is suitable for emitting and / or receiving waves in two different states of polarization, for example, left and right circular polarizations. In the case where a linearly polarized wave is desired, either the two ports 28, 30 are used simultaneously by applying to them, via the quasi-optical beam former 10, the sources 16 and the electronic control element in phase and in phase. amplitude E _CPA , a certain phase shift depending on the orientation of the desired polarization, or a single port 28 or 30 is selectively excited by the source 16.

Thus, the _{specific pointing device D P} according to the present invention, based on a mechanical depointing in the plane of a line of an array of radiating elements 18, combined or not with an electronic depointing, allows in association with one or more several radiating elements 18 such as those of the request FR 3 013 909 A1 , or radiating elements 18 of parallelepiped shape having a similar operation, to obtain a very efficient stationary antenna system because it is mainly focusing and able to provide an easily reconfigurable multi-directional scan while having reduced energy consumption and heat dissipation compared to known solutions.

Claims (10)

1. A beam steering device (D_P) for a telecommunications antenna system, the device comprising:

   - at least one power source (16) adapted to generate radiofrequency waves,

   - a planar quasi-optical beamformer (10), the inlet of which is adapted to be powered by said at least one source and the outlet of which is adapted to supply an array of radiating elements (18), the planar quasi-optical beamformer (10) comprising a parallel plate waveguide (12), the inlet and outlet of the planar quasi-optical beamformer (10) corresponding to the linear openings between the two parallel plates of the waveguide (12),

   - said array of radiating elements (18),

   wherein the device (D_P) further comprises at least one mechanical translation element adapted to move, relative to one another, said at least one power supply source (16) and at least one focusing element (14) of said quasi-optical planar beamformer (10) in a translational movement (T) perpendicular to the supply direction (D) of the array of radiating elements (18) by the source (16).
2. The beam steering device (D_P) according to claim 1, wherein the source (16) is supplied with at least one electronic phase and amplitude control element (E_CPA) of the beam delivered at the output of the array of radiating elements (18).
3. The beam steering device (D_P) according to claim 1 or 2, wherein the mechanical translation element (E_TM) is adapted to move said at least one power supply source (16) relative to said focusing element (14) of said immobile quasi-optical planar beamformer (10).
4. The beam steering device (D_P) according to claim 1 or 2, wherein the mechanical translation element (E_TM) is adapted to move said at least one focusing element (14) of said quasi-optical planar beamformer (10) relative to said at least one immobile power supply source (16).
5. The beam steering device (D_P) according to claim 4, wherein the array of radiating elements (18) and the parallel plate waveguide (12) having a width (L_R) strictly greater than the width (L_EF) of the focusing element (14), the mechanical translation element (E_TM) being adapted to move the focusing element (14) along the width (L_R) of the parallel plate waveguide.
6. The beam steering device (D_P) according to claim 5, wherein the maximum movement (T_max) of the focusing element (14), relative to its initial position centered along the width (L_R) of the parallel plate waveguide (12), is less than half the width (L_EF) of the focusing element (14).
7. The beam steering device (D_P) according to claim 5, wherein each radiating element of the array of radiating elements (18) comprises a feed horn (24) comprising a first transceiver part (22₁) and a second transceiver part (22₂) that are supplied by the quasi-optical beamformer (10),
   each of the first and second transceiver parts (22₁, 22₂) being adapted to send and receive an electromagnetic wave at a first frequency (f₁) or a second frequency (f₂), the ratio between the second frequency and the first frequency being greater than 1.2, preferably greater than 1.5, the first frequency (f₁) and the second frequency (f₂) belonging to the Ka band of the electromagnetic spectrum.
8. An antenna system comprising at least one beam steering device according to any one of claims 1 to 7.
9. A platform including an antenna system according to claim 8.
10. A telecommunications method between two telecommunications stations, the method comprising the use of at least one beam steering device according to any one of claims 1 to 7 or an antenna system according to claim 8.

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