EP4372910A1 - Device for controlling rf electromagnetic beams according to their angle of incidence and manufacturing method - Google Patents

Abstract

There is provided a radio frequency beam control device (10) comprising a set of cells (100). Each cell comprises a support frame (130) and an excitation element (150), and performs beam transmission and/or reception invariant according to the direction of beam propagation. The frame is inscribed in a generally tubular shape, oriented along the axis Z of a mark (X,Y,Z), having a transverse section of perimeter P, and comprises an inlet (131), an outlet (132) and a number N of slots (133-n) between the output and a position Zo located between the input and the output. Each slot has a variable width along Z. The slot width has a minimum value at position Zo, and a maximum value at the outlet determined according to the perimeter P and the number N.

Description

Technical area

The present invention relates generally to the field of radio frequencies (RF), and in particular to a device for controlling RF electromagnetic beams, in particular for controlling the emission and/or reception of electromagnetic beams according to an angle of incidence of the beam by relating to the device, as well as a method of manufacturing such a device.

It is known to use beam control devices, coming from RF electromagnetic signal sources, consisting of a network of small radiating elements in which an RF electromagnetic wave circulates, as described for example in the application for patent FR3117685A1 . Such devices, generally planar, are configured to emit and/or receive electromagnetic beams characterized by a direction forming an angle of incidence of the beam relative to the planar device. Each radiating element (and thus the induced device) can be characterized by an active impedance.

In such devices, there is significant mutual coupling between adjacent RF electromagnetic waves in the same network. The mutual coupling between radiating elements contributes to modifying, depending on the angle of incidence of a beam relative to the device, the active impedance of the radiating elements and thus significantly limits the transmission performance of RF beams of a device on an angular sector of low elevation and/or on certain specific directions, called “blinding directions”, as described for example in the article " Mutual impedance effects in large beam scanning arrays" by P. Carter et al., IRE Transactions on Antennas and Propagation, vol. 8, no. 3, 1960, pages 276-285 .

Certain known solutions, called adaptation solutions, are used to stabilize the active impedance of a control device according to the direction of beam propagation. These adaptation solutions include for example the implementation of WAIM screens (acronym for the Anglo-Saxon expression of Wide Angle Impedance Matching ) as described for example in the article " Wide angle impedance matching of a planar array antenna by a dielectric sheet" by E. Magill et al., IEEE Transactions on Antennas and Propagation, vol. 14, no. 1, 1966, pages. 49-53 , or in the article " Wide angle impedance matching metamaterials for waveguided phased-array antennas" by S. Sajuyigbe et al., IET Microwaves, Antennas & Propagation, vol. 4, no. 8, 2010, pages. 1063-1072 . Other known adaptation solutions include the use of dipoles strongly coupled together by interdigitated capacitors, as described in the article " The Planar Ultrawideband Modular Antenna (PUMA) Array" by SS Holland et al., IEEE TAP, vol. 60, no. 1, 2012, pages 130-140 . However, the design of these adaptation solutions is complex, and their manufacturing includes numerous constraints, such as the implementation of technologies based on dielectric substrates, likely to induce ohmic losses in the compatible bandwidth frequencies of the telecommunications system.

There is thus a need for an improved device making it possible to control beams of RF electromagnetic waves according to a large angular sector of beam defocusing relative to the device and for reducing blinding directions, via a stability improvement solution. of the active impedance of the device.

Summary of the invention

à la position de fente Z_0n, et une valeur maximale de fente

au niveau de la sortie du cadre, la valeur maximale de fente

étant déterminée en fonction du périmètre P de la section transverse et du nombre N de fentes. Chaque cellule est configurée pour réaliser une émission et/ou une réception de faisceaux radiofréquences invariante selon la direction de propagation.The present invention improves the situation by proposing a device for controlling radiofrequency beams defined in an orthogonal reference frame (X,Y,Z). The device generally extends in the plane (X,Y) of the orthogonal reference frame (X,Y,Z). The device comprises a set of at least one cell corresponding to a radiating element. The cell comprises a support frame and an excitation element of the radiating element, each radio frequency beam being defined in a given direction of propagation having an angle of incidence θ relative to the device. The support frame is in a generally tubular shape oriented along the Z axis of the orthogonal reference frame (X,Y,Z). The tubular shape has a length d _z given along the axis of the frame Z and a transverse section defined in the plane (X,Y). The transverse section has a perimeter P, the support frame includes a frame inlet and a frame outlet. The support frame further comprises a number N of slots extending, along the frame axis Z, between the frame outlet and a slot position Z _0n along the frame axis Z. The slot position Z _0n is located between frame inlet and frame outlet, each slot has a variable slot width w _n along the frame axis Z. The slot width w _n has a minimum slot value

at the slot position Z _0n , and a maximum slot value

at the exit of the frame, the maximum slot value

being determined as a function of the perimeter P of the transverse section and the number N of slots. Each cell is configured to carry out transmission and/or reception of radio frequency beams invariant depending on the direction of propagation.

Each slot may be associated with at least two slot edges, the slot edges representing the boundaries of the support frame connecting the slot position Z _0n to the frame outlet. Each slot edge can be associated with a variability function, the variability function being a concave and/or convex polygonal function.

In embodiments, the excitation element may comprise a number H of longitudinal metal ribs arranged within the tubular shape. A rib can extend along the axis of the frame Z between the frame entry and a rib position Z _h . The rib position Z _h can be set between frame inlet and frame outlet.

In particular, the number H of ribs can be equal to the number N of slots.

The ribs of the cell may be identical to each other and the slots of the cell may be identical to each other. The rib position Z _h can be set between the slot position Z _0n and the frame outlet.

In embodiments, the excitation element may comprise a so-called “Vivaldi” antipodal transition arranged at least partly inside the tubular shape. The transition may comprise at least a first metallic etching and a second metallic etching extending along the axis of the frame Z between the frame entrance and an engraving position Z _0g . The engraving position Z _0g can be set between frame entry and frame exit.

In embodiments, the excitation element may comprise a number T of planar metallic elements arranged inside the tubular shape, a planar element extending along the plane (X,Y) at the level of a planar position Z _t . The planar position Z _t can be set between frame entry and frame exit.

The slots of the cell can be identical to each other, the planar position Z _t being defined between the slot position Z _0n and the frame outlet.

The device may be partly metallic. The transverse section may have the shape of a circle or polygon.

The invention also provides a method of manufacturing the radio frequency beam control device characterized in that the device is at least partially metallic, and the manufacturing method uses at least one 3D printing technique.

The device according to the embodiments of the invention makes it possible to control beams of RF electromagnetic waves according to a wide angular sector of beam depointing relative to the device and a reduction in the blinding directions, thanks to an improvement in stability of the active impedance of the device.

Such a device is particularly suitable for RF bandwidths compatible with telecommunication antenna systems. It also provides an efficient solution, while limiting manufacturing complexity and costs, and allows for reduced weight and significant compactness. In particular, in the space domain, such a device does not impact the payload of the satellite.

Description of figures

• [Fig.1] La figure 1 est un schéma représentant un dispositif de contrôle de faisceaux radiofréquences, selon des modes de réalisation de l'invention.
• [Fig.2] La figure 2 est un schéma représentant un système antennaire, selon des modes de réalisation de l'invention.
• [Fig.3] La figure 3 est un schéma représentant le cadre de support d'une cellule du dispositif de contrôle de faisceaux radiofréquences, selon des modes de l'invention.
• [Fig.4] La figure 4 est une vue en perspective d'une cellule du dispositif de contrôle de faisceaux radiofréquences montrant le cadre de support et des nervures interne de la cellule, selon des modes de l'invention.
• [Fig.5] La figure 5 est une vue en perspective d'une cellule du dispositif de contrôle de faisceaux radiofréquences montrant le cadre de support et une transition antipodale interne de la cellule, selon des modes de l'invention.
• [Fig.6] La figure 6 est une vue en perspective d'une cellule du dispositif de contrôle de faisceaux radiofréquences montrant le cadre de support et des éléments planaires internes de la cellule, selon des modes de l'invention.
• [Fig.7a] et [Fig 7b] Les figures 7a et 7b sont des ensembles de graphiques illustrant les performances radioélectriques atteintes par un dispositif de contrôle de faisceaux radiofréquences selon des exemples de réalisation de l'invention.
• [Fig.8] La figure 8 est un ensemble de graphiques illustrant les performances radioélectriques atteintes par un dispositif de contrôle de faisceaux radiofréquences, selon des exemples de réalisation de l'invention.

Other characteristics, details and advantages of the invention will emerge on reading the description made with reference to the appended drawings given by way of example.

• [ Fig.1 ] There figure 1 is a diagram representing a radio frequency beam control device, according to embodiments of the invention.
• [ Fig.2 ] There figure 2 is a diagram representing an antenna system, according to embodiments of the invention.
• [ Fig.3 ] There Figure 3 is a diagram representing the support frame of a cell of the radio frequency beam control device, according to modes of the invention.
• [ Fig.4 ] There Figure 4 is a perspective view of a cell of the radio frequency beam control device showing the support frame and internal ribs of the cell, according to embodiments of the invention.
• [ Fig.5 ] There Figure 5 is a perspective view of a cell of the radio frequency beam control device showing the support frame and an internal antipodal transition of the cell, according to embodiments of the invention.
• [ Fig.6 ] There Figure 6 is a perspective view of a cell of the radio frequency beam control device showing the support frame and internal planar elements of the cell, according to embodiments of the invention.
• [ Fig.7a ] And [ Fig 7b ] THE figures 7a And 7b are sets of graphs illustrating the radio performances achieved by a radio frequency beam control device according to exemplary embodiments of the invention.
• [ Fig.8 ] There figure 8 is a set of graphs illustrating the radio performances achieved by a radio frequency beam control device, according to exemplary embodiments of the invention.

Identical references are used in the figures to designate identical or similar elements. For reasons of clarity, the elements shown are not to scale.

detailed description

There figure 1 schematically represents a radio frequency (RF) beam control device 10 according to embodiments of the invention.

The RF beam control device 10 (also called 'device 10' hereinafter) can be used in an antenna system 1. For example and without limitation, an antenna system can be implemented in the form of an active antenna mounted at on board a satellite in low orbit (or LEO for Low Earth Orbit according to the English name) and belonging to a constellation of satellites intended to provide telecommunications services throughout the Earth.

An antenna system 1 can thus be configured to transmit and/or receive beams (or signals) of RF electromagnetic waves. An RF electromagnetic wave beam is associated with an RF frequency band (being inversely proportional to a wavelength λ ). For example, an antenna system 1 can be configured to emit an RF signal in specific frequency bands. Such a specific frequency band may correspond to a low frequency band, such as for example an “L band” or an “S band” typically between 1 and 2 GHz or 2 and 4 GHz. Such a specific frequency band can also correspond to a band of higher frequencies (used for high-speed telecommunications systems for example), such as for example a “Ku band”, a “Ka band” or a “Q/ band”. V » typically between 12 and 18 GHz or 22.5 and 40 GHz. An electromagnetic wave of an RF signal can be further characterized by a given phase, a given amplitude and a given polarization. The RF beams emitted by the antenna system 1 are designated by the notation SRF10 on the figures 1 and 2 , and the RF beams received by the antenna system 1 are designated by the notation SRF20 on the figures 1 and 2 .

The radio frequency beam control device 10 can be configured to emit the SRF10 beams. In addition, the radio frequency beam control device 10 can also be configured to receive external SRF20 beams. Thus, as used herein, the term "radio frequency beam control" (also called 'radio frequency beam manipulation') refers to various phenomena related to electromagnetic waves that can occur when an RF beam interacts with matter. a given object (here device 10). These phenomena may include in particular the emission, reception, transmission, reflection, absorption, diffusion, refraction and/or diffraction of the electromagnetic wave.

As shown on the figure 1 , the RF beam control device 10 is defined in a reference frame (X,Y,Z). In particular, the device 10 comprises a first face 11 (also called 'input face') and a second face 12 (also called 'output face') opposite the first face 11. The beam SRF10 is emitted from the second face 12 of the device 10 while the beam and SRF20 is received by the second face 12. The terms “input” or “output” are used here depending on the direction of circulation of the radio frequency (RF) waves in the device 10 when it it operates in transmission, that is to say in the direction of circulation going from the first face 11 towards the second face 12.

The two faces 11 and 12 are spaced from each other by a distance d _z representing the thickness of the device 10. The thickness value of the device d _z is very small compared to the overall size of the antenna system , the device 10 can have a generally planar structure, defined in the plane (X,Y) orthogonal to the Z axis. Thus, the device 10 generally extends in the plane (X,Y).

In one embodiment, the two faces 11 and 12 of the device 10 can be parallel to each other. In such an embodiment, the two faces 11 and 12 can be surfaces defined in two dimensions in the plane (X,Y) orthogonal to the normal axis Z. Alternatively, the two faces 11 and 12 can be surfaces defined according to three dimensions in the reference frame (X,Y,Z). In these embodiments, the thickness of the device d _z between the two parallel faces 11 and 12 is homogeneous along the device 10.

Alternatively, the thickness of the device d _z between the two faces 11 and 12 is inhomogeneous along the device 10, the thickness of the device d _z varying along the axis X and/or along the axis Y. In this mode of realization with variable thickness of the device, at least one of the two faces 11 and 12 can be defined as a surface defined according to three dimensions in the reference frame (X,Y,Z). For example and in a non-limiting manner, the device 10 may comprise a center O positioned in the plane (X,Y), the thickness of the device d _z varying in an increasing or decreasing manner from this center O along the axis to form a quasi-optical element, which can be a concave or convex element.

The RF beam control device 10 according to the embodiments of the invention comprises a set of cells 100 arranged in the plane (X,Y), as shown in the figure 1 .

An SRF10 beam emitted by the device 10 can be characterized by a given direction of incidence of emission. As shown on the figure 1 , the direction of incidence of emission of a beam SRF10 forms with the normal axis Z of the device 10 an angle of incidence of emission denoted θ _e .

An SRF20 beam received by the device 10 can be characterized by a given reception incidence direction. As shown on the figure 1 , the direction of reception incidence of a beam SRF20 forms with the normal axis Z of the device 10 a reception angle of incidence denoted θ _r .

The SRF10 beams emitted and/or SRF20 received by the device 10 can also be characterized by a maximum angular sector θ _max , the emission angles of incidence θ _e and reception θ _r then being between 0 and θ _max . The SRF10 beams transmitted and/or SRF20 received are then described as 'unfocused'. For example and without limitation, the maximum angular sector noted θ _max can be equal to ±55°. The SRF10 beams emitted and/or SRF20 received can also be associated with an angular sector of vision denoted θ ₁ and corresponding to an angular sector where beam transmission must be carried out, that is to say an angular sector without "blinding ".

In the embodiment shown schematically on the figure 2 , the antenna system 1 comprises the RF beam control device 10 and a beam forming unit 20.

The beam forming unit 20 (even more simply called 'unit 20' in the remainder of the description) can be a multi-beam former as described for example in the patent application FR2986377A1 .

The beamforming unit 20 may be configured to generate and transmit to the device 10 one or more electromagnetic wave signals, designated by the notation SRF12 on the figure 2 . Advantageously, the beamforming unit 20 can be configured to transmit to each cell 100 of the device 10 a distinct SRF12 signal.

In certain embodiments of the invention, the unit 20 can be configured to apply to these SRF12 signals a modification of the phase and/or the amplitude, so as to defocus the SRF10 beams emitted according to angles of incidence emission θ _e distinct and/or variable between 0 and θ _max .

In these embodiments, the unit 20 can therefore be configured to receive one or more RF SRF22 signals resulting from the transmission of the external SRF20 beam received by the device 10. Thus, the unit 20 can be configured to receive from each cell 100 a distinct SRF22 signal to process. The unit 20 can be configured to apply to these SRF22 signals a measurement of the phase and/or the amplitude so as to estimate the direction of incidence of reception of the received SRF20 beam. Unit 20 may also be configured to apply a weighted combination of the SRF22 RF signals based on the estimated direction. Advantageously, the antenna system 1 can comprise a processing unit (for example a satellite payload processor not shown in the figures) configured to process the SRF22 signals received and processed by the unit 20.

Each cell 100 of the device 10 corresponds to a radiating element and comprises an external support frame of the cell 130 and an internal excitation element of the cell 150. The device 10 is thus described as a 'radiating panel'.

There Figure 3 only shows the support frame 130, to facilitate understanding of the invention. THE figures 4 , 5 And 6 illustrate perspective views of a cell 100 comprising a support frame 130, according to different embodiments.

The support frame 130 of a cell 100 is in a generally tubular shape having a main axis extending along the Z axis, also called “frame axis”.

As shown on the Figure 3 , the support frame 130 of a cell 100 (also called waveguide) comprises a frame entrance 131, arranged in the plane (X,Y), at the entrance face 11. The position Z ₀ of the frame entry 131 along the Z axis is called “entry position”. The support frame 130 of a cell 100 further comprises a frame outlet 132, aligned in the plane (X,Y) at the outlet face 12. The position Z _c of the frame outlet 132 according to the Z axis is called “output position”.

The support frame 130 consists of a set of “walls” having a wall thickness m. The support frame 130 has a frame length defined along the axis of the frame Z. The length of the support frame can be substantially equal to the thickness of the device d _z , such that d _z = Z _c - Z ₀ . For example and without limitation, the thickness of the device d _z may be less than or equal to a value substantially equal to λ /2. In the embodiments where the thickness of the device d _z is variable in the plane (X,Y), each cell 100 can be associated with a specific length of cell d _{z ( n )} .

The tubular shape of the support frame 130 comprises a transverse section defined in a plane (X,Y) perpendicular to the axis Z. The transverse section is characterized by a given shape and a perimeter value P calculated according to the dimensions of the shape of the transverse section. For example and without limitation, the transverse section can be circular, oval, square, rectangular, or polygonal.

In certain embodiments where the transverse section is a polygon comprising a number N _c of sides, the tubular shape can correspond to a polyhedron with N _c facets each having a parallelogram shape. Each facet (or “prismatic face” corresponding to the walls) extends along the axis of the frame Z. Such a polyhedron can for example be a regular polygon of even order, and in particular a square parallelepiped polygon (where N _c = 4), called a cuboid, or a hexagonal prism (where N _c = 6), as represented on the Figure 3 . In such an embodiment, the N _c facets are connected together by N _c edges oriented along the axis of the frame Z.

The support frame 130 of a cell 100 also includes a number N of slots (or notches) denoted 133-n, “n” being an index associated with the different slots, with n ∈ [1, N ]. Each slot 133-n extends along the axis of the frame Z, from the frame exit position Z _c 132 to a slot position (or initial slot position) denoted Z _{0 n} . As shown on the Figure 3 , the slot position Z _{0 n} is arranged between the frame entrance 131 (ie entry position Z ₀ ) and the frame exit 132 (ie exit position Z _c ). Thus, each slot 133-na has a slot length d _n defined along the axis of the frame Z, such that d _n = Z _c - Z _{0 n} and d _n < d _z (or d _n < d _{z ( n )} ) . Each slot 133-n is further associated with at least two slot edges, denoted respectively n1 and n2, representing the limits of the support frame 130 and connecting the slot position Z _{0 n} to the exit position Z _c as indicated on there Figure 3 . Each edge of slots, n1 or n2, can be characterized by a predefined function called variability, denoted respectively f _{n 1} or f _{n 2} . Consequently, each slot 133-na has a variable slot width w _n , along the axis of the frame Z, constructed from the variability functions f _{n 1} and f _{n 2} .

variable prend une valeur maximale de fente

à la sortie du cadre de support 132 et une valeur minimale de fente

à la position Z _0n . La valeur maximale de fente

peut être déterminée en fonction du périmètre P de la section transverse de la cellule 100 et du nombre N de fentes 133-n. La valeur minimale de fente

est inférieure à la valeur maximale de fente

, soit :
$$w_n^{\max }>w_n^{\min }$$

In particular, the slots can be flared towards the exit position 132. Thus, the slot width

variable takes maximum slot value

at the outlet of the support frame 132 and a minimum slot value

at position Z _{0 n} . Maximum slot value

can be determined as a function of the perimeter P of the transverse section of the cell 100 and the number N of slots 133-n. The minimum slot value

is less than the maximum slot value

, either :
$$w_{\mathrm{not}}^{\max }>w_{\mathrm{not}}^{\min }$$

à une valeur maximale

Avantageusement, une fonction de variabilité de fente f_n peut être définie par une fonction exponentielle de manière à faire varier la largeur w_n de façon exponentielle entre la valeur minimale

à la valeur maximale

For example and without limitation, a slit variability function f _n can be a linear function (cf. Figure 5 ), a step function or any other function (monotonic or not, increasing polygonal called concave and/or convex as illustrated on the figures 3 , 4 And 6 for example) so as to vary the width w _n of the slot 133-n along the axis of the frame Z by a minimum value

at a maximum value

Advantageously, a slot variability function f _n can be defined by an exponential function so as to vary the width w _n exponentially between the minimum value

at the maximum value

In certain embodiments, the edges of slots n1 and n2 of a slot 133-n can be symmetrical to each other with respect to an axis Z defined at the center of this slot 133-n. In particular, in the embodiments where the slot 133-n is positioned on a facet of the support frame 130, the edges of slots n1 and n2 can be symmetrical with respect to an axis Z defined at the center of this facet.

The dimensions of the slots (that is to say the widths w _n and variabilities f _n , and/or the lengths of slots d _n for example) of the same cell 100 and/or the slots of all the cells 100 of the RF beam control device 10 may be identical or different from each other depending on the applications of the invention. For example, and in a non-limiting manner, an RF beam control device 10 may include modulations of slot profile 133-n (of a few micrometers for example) relative to the center O of the device 10 in order to spatially modulate the phase of the incident beam, so as to deal with certain edge effects. Thus, the RF beam control device 10, generally extending in a plane (X,Y), can comprise a set of several cells 100 having geometric shapes and dimensions of support frame and slots variable in the plane (X,Y) chosen so as to modify in a very fine manner (at the cell scale) the phase and the associated wavefront of the electromagnetic wave in the plane (X,Y).

• Une première partie de longueur d _0n (ou d ₀) correspondant à un cadre de support 130 sans fente, et
• Une deuxième partie de longueur d_n (ou d) correspondant à un cadre de support 130 avec fentes.

In the embodiments where the slot lengths d _n of the slots of the same cell 100 are identical, the support frame 130 of this cell 100 can be broken down into two parts, represented on the Figure 3 , including:

• A first part of length d _{0 n} (or d ₀ ) corresponding to a support frame 130 without slot, and
• A second part of length d _n (or d ) corresponding to a support frame 130 with slots.

According to certain embodiments, the length of the first part d _{0 n} of a slot 133-n (such that d _{0 n} = Z _{0 n} - Z _c ) can be equal to the wall thickness m . For example, the first part without slots may be negligible compared to the second part with slots in the case where all the slots of the same cell 100 are characterized by the same length d _{0 n} of the first part then equal to the thickness of wall m, such that Z _{0 n} ≅ Z ₀ , as shown in the Figure 6 .

de la largeur d'une fente 133-n peut être égale à 0, soit

et

comme représenté sur les figures 5 et 6. Alternativement, la valeur minimale de fente

peut être supérieure ou égale à l'épaisseur de mur m, comme représenté sur les figures 3 et 4. Une telle valeur minimale de fente

différente de zéro permet d'obtenir une conception de cellule 100 compacte selon l'axe Z.The minimum value

of the width of a slot 133-n can be equal to 0, i.e.

And

as shown on the figures 5 And 6 . Alternatively, the minimum slot value

can be greater than or equal to the wall thickness m, as shown in the figures 3 And 4 . Such a minimum slot value

different from zero makes it possible to obtain a compact 100 cell design along the Z axis.

de la largeur d'une fente 133-n est supérieure à l'épaisseur de mur m. En particulier, la valeur maximale de fente

peut être définie en fonction du rapport entre le périmètre P de la section transverse, du nombre N de fentes 133-n, et d'un coefficient de proportion noté ε_n , tel que défini par l'expression (02) suivante :
$$w_n^{\max }={\epsilon }_n\times \frac{P}{N}$$

The maximum value

of the width of a slot 133-n is greater than the wall thickness m. In particular, the maximum slot value

can be defined as a function of the ratio between the perimeter P of the transverse section, the number N of slots 133-n, and a coefficient of proportion noted ε _n , as defined by the following expression (02):
$$w_{\mathrm{not}}^{\max }={\epsilon }_{\mathrm{not}}\times \frac{P}{\mathrm{NOT}}$$

In particular, the sum of the proportion coefficients ε _n over all the slots 133-n is less than or equal to N, according to the following expression (03):
$${\displaystyle {\sum }_{\mathrm{not}}{\epsilon }_{\mathrm{not}}}\le \mathrm{NOT}$$

de largeur des fentes d'une même cellule 100 peuvent être identiques.In embodiments, the maximum values

width of the slots of the same cell 100 can be identical.

de largeur de fente 133-n sont définies selon l'équation (04) suivante :
$$w_n^{\max }=w^{\max }=\frac{P}{N}$$

In particular, the proportion coefficients ε _n can be equal for the N 130-n slots of a cell. For example and without limitation, the width parameters ε _n = ε can be equal to 1, with Σ _n ε _n = Σ ε = N , as shown in the figures 3 , 4 And 6 , while the maximum values

of slot width 133-n are defined according to the following equation (04):
$$w_{\mathrm{not}}^{\max }=w^{\max }=\frac{P}{\mathrm{NOT}}$$

Alternatively, the width parameters can be less than 1, with Σ ε < N , as shown in Figure figure 5 where Σ ε = N /2, while the maximum values of slit width 133-n are equal to w ^max = P /4 .

. La valeur maximale

de largeur d'une fente peut être par exemple définie selon l'équation (05) suivante :
$$w_n^{\max }\le l_c$$

In the embodiments where the transverse section is a regular polygon, a slot 133-n can be positioned on one of the facets of the polyhedron of width $L_{\mathrm{vs}}=\frac{P}{\mathrm{NOT}}$

. The maximum value

width of a slot can for example be defined according to the following equation (05):
$$w_{\mathrm{not}}^{\max }\le L_{\mathrm{vs}}$$

In certain embodiments where the transverse section is a regular polygon, a slot 133-n can be positioned so that it coincides with an edge of the polyhedron.

The number N of slots 133-n can be equal to the number N _c of sides, as shown on the figures 3 , 4 And 6 .

Alternatively, the number N of slots 133-n may be less than the number N _c of sides, as shown on the figure 5 . In particular, in the embodiments where the transverse section is a square and where the electromagnetic wave of the RF signal circulating in the waveguide 130 comprises a given linear polarization defined along an axis X' defined in the plane (X, Y), the number N of slots 133-n can be equal to 2 and each slot 133-n can be positioned on a facet of the polyhedron parallel to the polarization axis X' (ie the slots then being arranged parallel to the electric field of the electromagnetic wave of the RF signal circulating in the waveguide 130).

Alternatively, the number N of slots 133-n may be greater than the number N _c of sides (not shown in the figures). For example and without limitation, a facet of the polyhedron may comprise at least two slots 133-n. In particular, in these embodiments, the slots 133-n positioned on the same facet of support frame 130 can be symmetrical with respect to a Z axis defined at the center of this facet.

Advantageously, in the embodiments where the thickness of the device d _{z ( n )} is variable in the plane (X,Y), the dimensions associated with the longitudinal slots 133-n (in particular, different lengths of slots d _n d' the same support frame 130) are adapted to compensate for this variability in thickness d _{z ( n )} , allowing the adjustment of the slots 133-n to the variability of the lengths of walls between adjacent cells.

Furthermore, the support frame 130 can be entirely or partially metallic so as to form an electrically conductive structure. The notched opening of the support frames 132 at the level of the N slots 133-n makes it possible to simulate a partially dielectric material and to significantly widen the transmission band of the RF beam control device 10.

The support frame 130 of a cell 100 is further characterized by an impedance. In particular, the dimensions associated with the longitudinal slots 133-n make it possible to adjust the characteristic impedance of the cell 100. The variability of the width w _n of the longitudinal slots 133-n, and in particular a variability function defined by a function increasing or exponential, makes it possible to progressively modify the impedance of the second part of frame with slots, from an input impedance of the waveguide (following the impedance of a first part of frame without slot, typically about a hundred ohms) until the free space impedance is adapted (i.e. to 377 Ω). This progressive modification of the impedance of the support frame 130 (and therefore of the device 10) makes it possible in particular to stabilize the active impedance of the radiating elements of the device 10 in an antenna system whatever the angle of depointing of the incident beam.

Consequently, a support frame 130, metallic and notched by the N longitudinal slots 133-n (or slotted), acts as a waveguide allowing the propagation of electromagnetic waves in TEM mode to be transmitted by the control device of RF beams 10. Such support frames 130 can thus function as radiating elements in all frequency bands of RF signals, and can in particular be used for L, S, C, Ku, Ka and Q/V bands. In fact, the longitudinal slots allow electric fields not to completely cancel out on the sides of the waveguide, allowing electromagnetic waves in TEM mode to settle.

The set of cells 100 forms a periodic arrangement of waveguides (or a network of cells 100) whose dimensioning is small compared to the wavelength λ associated with the frequency band of the RF beam transmitted or received ( SRF10 and SRF20). The electric field excited in a waveguide then couples to neighboring waveguides, inducing significant coupling between cells, which makes it possible to propagate the electromagnetic waves in mode over a wide frequency band, and to ensure a strong mutual coupling with between adjacent guides. Such a set of cells 100 forms a wideband transmission window making it possible not to introduce frequency dispersion into the sections of the waveguide.

The different cells 100 of the device 10 are adjacent and connected to each other, along the frame axis Z, by common cell parts. For example and without limitation, for a transverse section of a polygonal cell, the different cells 100 can be connected by the prismatic faces.

The periodic arrangement of cells can be characterized by a mesh size of the network denoted φ defined from the shape and dimensions associated with the transverse sections of the cells 100.

In an embodiment in which the transverse section of the cells 100 is of circular shape, the mesh size φ corresponds to the diameter of the circular section. In an embodiment in which the transverse section of the cells 100 is of polygonal shape, the mesh of the network φ corresponds for example to the diameter of the circle circumscribed by the polygonal section or to the side width l _c of the polygon.

Advantageously, the mesh of the network φ of the device 10 can be uniform or variable in the plane (X,Y) depending on the modes of application of the invention. In particular, the network mesh φ can be determined in relation to a maximum mesh value denoted φ _max . The maximum mesh value φ _max can be defined as a function of the wavelength λ of the RF beam transmitted or received (SRF10 and SRF20), the maximum angular sector of defocusing ± θ _max and the angular sector vision ± θ ₁ . The maximum mesh value φ _max can be defined for example according to the following expression (06):
$${\phi }_{\max }=\frac{\lambda }{\sin \left(\left|{\theta }_{\max }\right|\right)+\mathrm{<figure-callout\; id="1"\; label="sin\; \theta "\; filenames="imgf0001.png"\; state="\{\{state\}\}">sin</figure-callout>}\left(\left|{\theta }_{}\right|\right)\left(\left|{}_{\mathrm{1}}\right|\right)}$$

For example, the network mesh φ can be less than the maximum mesh value φ _max such that φ < φ _max . In this embodiment, the mesh of the network φ makes it possible to avoid causing the appearance of network lobes generated by a periodicity effect associated with the mesh. In addition, the mesh of the network φ can be determined so as to minimize the number of radiating elements in the RF beam control device 10. Advantageously, the mesh of the network φ can be between 0.4 λ and 0.6 λ . In particular, in the embodiments where the SRF10 and/or SRF20 beams are so-called dual-band signals, that is to say comprising two distinct RF frequency bands, the network mesh φ can be equal to 0.4.

Furthermore, the thickness of common walls between two cells 100 can be defined as being equal to a value 2 × m . The thickness m of the support frame 132 can be small and can also be adjusted, for example minimized, so as to attenuate the transmission losses of the SRF10 and/or SRF20 beams at the interfaces between the air and the waveguide ( for example at the entrance to frame 131 and/or at the exit from frame 132). It should be noted that the transmission losses on a given frequency band and angular sector are proportional to the ratio m / φ . The reduction in the bandwidth and the reduction in the angular sector associated with the RF wave can be correlated to the quantity of metallic material forming the support frame 130. The minimization of the wall thickness m can also result in a minimization of the total mass of the device 10, while guaranteeing its rigidity. Advantageously, the wall thickness m is less than the wavelength λ , which makes it possible to confer stability of transmission of the RF wave with respect to the variation of the opening angle of incidence (in particular of reception θ _r ) on the device 10. In particular, the wall thickness m according to the modes of the invention can be between 250µ m and 500µ m . The wall thickness m can be further defined as a function of the advantages and constraints associated with the manufacturing process of the device 10. For example and in a non-limiting manner, when the device is manufactured using an additive manufacturing process (or technique 3D printing), the thickness of walls between two cells 100 of an RF beam control device 300 can be equal to a value 2 × m = 500µ m . When the device is manufactured using a so-called traditional manufacturing process, the thickness of the walls between two cells 100 can be equal to a value 2 × m = 1 mm.

In certain embodiments, the frame entrance 131 can be “closed” (or “sealed”) in the plane (X,Y) by a closing wall 11 -0 (not shown in the figure). Figure 3 but illustrated on the Figure 6 ). Advantageously, the thickness of this closing wall 11 -0 can be equal to the wall thickness m. In particular, each support frame 130 may comprise a frame entrance 131 closed along the entrance face 11 of the device 10. A device 10 comprising closing walls 11-0 of the frame entrance 131 of the cells has advantages manufacturing and structural solidity. This closing wall 11 -0 may be metallic.

In the embodiments where the transverse section of the cells 100 of the device 10 is polygonal, the different cells 100 being adjacent and connected to each other by the prismatic faces, all of the closing walls 11-0 of the frame entrance 131 cells can form a single entrance plaque. This input plate corresponds to a ground plane of the device 10.

For a device 10 comprising cells 100 of polygonal transverse section comprising a number of sides N _c ≤ 4, the device 10 can present manufacturing advantages since the overall structure has less material. Alternatively, for a device 10 comprising cells 100 of circular or polygonal transverse section defined according to N _c > 4, the device 10 can present better impedance properties (partly active input) of the radiating elements with respect to the variation of the opening angle (ie the angular orientation) of the SRF10 and/or SRF20 beams at the interfaces between the air and the waveguide.

Each cell 100 of the RF beam control device 10 comprises an internal excitation element 150 of the cell 100 as shown in the figures 4 , 5 And 6 . The implementation of an excitation element 150 internal to the support frame 130 makes it possible to preserve the intrinsic broadband properties of the waveguide. In in particular, the implementation of an internal excitation element 150 in the support frame 130 allows the progressive conversion of the fundamental mode of the RF signal circulating in the waveguide towards the TEM mode of the RF signal which propagates in the sections slotted.

According to certain embodiments, an excitation element 150 may comprise a number H of longitudinal metal structures 152-h extending along the axis of the frame Z and arranged inside the cell 100. "h" is a index associated with the different slots, with h ∈ [1, H ]. Each metal structure 152-h, also called "rib", is connected to the support frame 130 by a rib edge h0 defined, along the axis of the frame Z, extending from the frame entrance 131 (ie position d 'entry Z ₀ ) up to a rib position denoted Z _h . As shown in the perspective view of a cell of the figure 4 , the rib position Z _h is arranged between the frame entry 131 (ie entry position Z ₀ ) and the frame exit 132 (ie exit position Z _c ). Thus, each rib 152-ha has a rib length d _h along the axis of the frame Z, such that d _h = Z _h - Z ₀ and that d _h < d _z (or d _h < d _{z ( n )} ) .

The distribution of all the ribs inside the support frame 130 can be determined as a function of the perimeter P of the transverse section of the cell 100 and the number H of ribs 152-h.

), tandis que chaque fente 133-n peut être positionnée sur un côté de la cellule 100. Dans une variante, chaque nervure 152-h peut être positionnée au niveau d'une surface latérale intérieure de la cellule 100.In the embodiment where the transverse section of the cell 100 is a polygonal transverse section, a rib 152-h can be arranged inside the frame at the level of an edge of the polyhedron forming the cell and oriented along the axis of the frame Z. The number H of ribs in a cell can also be defined as a function of the number N of slots 133-n and/or the number N _c of sides of the polygonal transverse section of a cell 100. For example and without limitation, the number H of ribs 152-h can be equal to the number N of slots 133-n. All of the ribs can be regularly distributed around the waveguide according to a regular spacing between the ribs, for example equal to the ratio of the perimeter P to the number H. As shown in the example of the Figure 4 , each rib 152-h can be positioned at the level of each edge of the polyhedron forming the cell (such as $\frac{P}{H}=L_{\mathrm{vs}}$

), while each slot 133-n can be positioned on a side of the cell 100. In a variant, each rib 152-h can be positioned at an interior side surface of the cell 100.

In particular, in the embodiments where the electromagnetic wave of the RF signal circulating in the waveguide 130 comprises a given linear polarization defined along an axis X' defined in the plane (X,Y), each rib 152-h can be positioned in a plane orthogonal to the slots 133-n of the cell 100, the slots then being arranged parallel to the electric field of the electromagnetic wave of the RF signal circulating in the waveguide 130.

In embodiments, the rib position Z _h along the axis of the frame Z can be arranged between the frame entry 131 (ie entry position Z ₀ ) and a slot position Z _{0 n} , so that the rib 152-h is located in a first part of length d _{0 n} corresponding to the support frame 130 without slot with d _h ≤ d _{0 n} . Alternatively, the rib position Z _h can be arranged between the frame outlet 132 (ie outlet position Z _c ) and a position Z _{0 n} of a slot 133-n, such d _h > d _{0 n} . In this case, part of the rib 152-h and part of the slot 133-n can overlap (or be “superimposed”) at least partially over an overlap distance between Z _h and Z _{0 n} . A cell 100 comprising a superposition between ribs and slots ensures a progressive conversion of the fundamental mode of the RF signal circulating in the waveguide (ribbed guide in this case) towards the TEM mode of the RF signal which propagates in slotted sections (slotted guide). Such superposition between ribs and slots also makes it possible to obtain a compact cell 100 design.

In addition, each rib 152-ha has a thickness m _h and a width l _h . The rib thickness m _h and/or the rib width l _h are variable dimensions along the axis Z such that each rib 152-h comprises a plurality of “steps” distributed along the axis of the frame Z.

et $l_h^{\max }$

) à l'entrée de cadre 131 (i.e. position d'entrée Z ₀), et une valeur minimale (respectivement $m_h^{\min }$

et $l_h^{\min }$

) à la position de nervure Z_h . Le nombre de marches et leur dimensions peuvent être déterminées en fonction de la longueur de nervure d_h et de valeurs maximales et minimales de nervures ( $m_h^{\max },l_h^{\max },m_h^{\min }$

et $l_h^{\min }$

), selon un profil de variabilité de nervure noté f_h. Avantageusement, la valeur minimale de l'épaisseur de nervure $m_h^{\min }$

et/ou de la largeur de nervure $l_h^{\min }$

peut être égale à l'épaisseur de mur m.In certain embodiments, the rib thickness m _h and/or the rib width l _h takes a maximum value (respectively $m_h^{\max }$

And $L_h^{\max }$

) at frame input 131 (ie input position Z ₀ ), and a minimum value (respectively $m_h^{\min }$

And $L_h^{\min }$

) at the rib position Z _h . The number of steps and their dimensions can be determined based on the rib length d _h and maximum and minimum rib values ( $m_h^{\max },L_h^{\max },m_h^{\min }$

And $L_h^{\min }$

), according to a variability profile of rib noted f _h . Advantageously, the minimum value of the rib thickness $m_h^{\min }$

and/or rib width $L_h^{\min }$

can be equal to the wall thickness m.

The different dimensions of the rib 152-h are configured to contribute to the conversion of modes in the waveguide of the cell 100. In general, the thicknesses and heights of the steps of the ribs 152-h can vary in particular in a manner decreasing along the Z axis, from the entry position Z ₀ to the rib position Z _h .

Advantageously, the dimensions of the ribs of the same cell 100 and/or of the slots of all the cells 100 of the RF beam control device 10 can be identical or different from each other depending on the modes of application of the invention .

In the absence of these 152-h rib elements, and with a low φ network mesh (between 0.4 λ and 0.6 λ ), it is no longer possible to propagate a mode over a wide RF band to excite the element radiant.

In embodiments, a support frame 130 associated with ribs 152-h may comprise a polarizer (or so-called 'septum' polarizer and not shown in the figures) making it possible to generate radiation with double circular polarization. As used herein, a "polarizer" refers to an element intended to convert, on the one hand, the received SRF20 signals having a circular polarization into SRF22 signals having a linear polarization and, on the other hand, the SRF12 signals to be transmitted having a linear polarization into SRF10 signals having a circular polarization. The polarizer can be formed by an internal blade extending along the axis of the frame Z and generated from two ribs 152-h connected at least in part to each other inside the cell 100. For example, the two Ribs 152-h connected to form the polarizer may originate from opposing edges of the straight polygonal cylinder or on two opposing interior side surfaces of the straight polygonal cylinder.

THE figures 7(a) , 7(b) And 8 are graphs illustrating examples of radio performance achieved by a device 10 comprising an excitation element 150.

In particular, the graphics of the figure 7(a) show the evolution of the simulated active reflection coefficient as a function of frequency for a device 10 each cell 100 of which comprises ribs 152-h, according to embodiments of the invention. The determination by simulation of the active reflection coefficient makes it possible in particular to characterize the variation of the active impedance of the device 10, by taking into account a radiating element surrounded by an infinity of similar radiating elements (ie infinite network) associated with a gradient phase of an electromagnetic wave. The phase gradient makes it possible to orient the beam resulting in emission from the device 10 at a given angle of incidence θ. The graphics of the figure 7(a) highlight a stabilization of the active impedance over a large angular sector. Indeed, the active reflection coefficient represented on the figure 7(a) is less than -10 dB for a wide frequency band Ka and ).

The graphics of the figure 7(b) show the evolution of the simulated gain of an electromagnetic wave in a continuity of given emission directions θ (or phi) of the beam resulting in emission, co-polarization and cross-polarization of the RF source, for a device 10 including each cell 100 comprises ribs 152-h, according to embodiments of the invention. The determination by simulation of such a radiation pattern on a given angular sector can be correlated to the variation of the active impedance on this angular sector of a radiating element powered by an electromagnetic wave and positioned at the center of a small network (for example at the center of 24 other similar radiating elements and connected to a load), thus taking into account the mutual coupling between the radiating elements as well as the edge effects associated with this small network. The graphics of the figure 7(b) demonstrate a stabilization of the radiation pattern in all the emission planes of the device 10, as well as a slight reduction in cross-polarization gain ranging from 3 to 5 dB. Indeed, the variation of the main polarization gain of this so-called “surrounded” radiation diagram (i.e. graphs of the figure 7(b) ) is linked to the variation of the active impedance as a function of the direction of the beam. Thus, the more stable the gain is over a set of directions of incidence of the beam, the lower the degradation of the active impedance when a beam is pointed in these directions.

The mode of transmission of microwave waves in the amplifiers and in the radiating panel 10 are different. In fact, the waves at the output of the radiating panel are transmitted via a wave guide (ridged) while the waves in the amplifier generally propagate using a line called a “microstrip line”. » or “microstrip line” which can be any type of suitable microwave transmission line. The passage of the HF wave propagation mode in waveguide from the radiating panel to the microstrip line of the amplifiers is carried out via a suitable transition.

According to certain embodiments, an excitation element 150 may comprise a so-called “Vivaldi” antipodal transition 154 arranged inside the cell 100, making it possible to produce a transition between a waveguide and a microstrip line.

As shown in the perspective view of a cell of the figure 5 , an antipodal transition 154 comprises a first metallic structure 154-1 extending in a first plane (X', Z), and a second metallic structure 154-2 extending in a second plane (X', Z) parallel to the foreground (X',Z).

According to certain embodiments, the antipodal transition 154 may be a “tri-plane structure” (or “tri-plate line”) such that the antipodal transition 154 comprises a third metallic structure 154-3 extending in a third plane ( X',Z) parallel to the first and second planes (X',Z). In particular, the first metal structure 154-1 can be placed between the second metal structure 154-2 and the third metal structure 154-3. In this case, the third metallic structure 154-3 has a shape equivalent to the second metallic structure 154-2.

In embodiments, an antipodal transition 154 may further comprise a dielectric substrate 154-0 comprising at least a first dielectric face and a second dielectric face, the second dielectric face being opposite and parallel to the first dielectric face, the first and second dielectric faces extending the axis of the frame Z. In these embodiments, the first metallic structure 154-1 corresponds to a first metallic engraving 154-1 arranged on the first dielectric face, and the second metallic structure 154-2 corresponds to a second metallic engraving 154-2 arranged on the second dielectric face. In embodiments where the antipodal transition 154 is a "tri-plane structure", the dielectric substrate 154-0 may include a third dielectric face extending the frame axis Z and parallel to the first and second dielectric faces. In particular, the first dielectric face can be placed between the second and the third face of the dielectric substrate 154-0. In this case, the third metallic structure 154-3 corresponds to a third metallic etching 154-3 arranged on the third dielectric face and having a shape equivalent to the second metallic etching 154-2.

In some embodiments, the dielectric substrate 154-0 may be positioned inside the support frame 130 and connected by one or two opposing edges or by two opposing interior side surfaces of the support frame 130, by an edge of substrate, and/or a first and a second substrate edges denoted g0-1 or g0-2, of substrate length d _g and defined along the axis of the frame Z, from the frame entrance 131 (ie position input Z ₀ ) to a substrate position denoted Z _g , such that d _g = Z _g - Z ₀ and that d _g < d _z (or d _g < d _{z ( n )} ) .

In embodiments, the substrate position Z _g along the frame axis Z may be arranged between the frame entrance 131 and a slot position Z _{0 n} , such that the dielectric substrate 154-0 is located in a first part of length d _{0 n} corresponding to the support frame 130 without slot with d _g ≤ d _{0 n} . Alternatively, the substrate position Z _g can be arranged between the frame output 132 (ie output position Z _c ) and a position Z _{0 n} of a slot 133-n, such d _g > d _{0 n} . In this case, part of the dielectric substrate 154-0 and part of the slot 133-n can overlap (or be “superimposed”) over an overlap distance between Z _g and Z _{0 n} .

In addition, the first metallic structure (or etching) 154-1 can form a conductive microstrip arranged at the frame entrance 131 (ie entry position Z ₀ ). The first metallic structure (or etching) 154-1 is progressively widened in the first plane (X', Z), inside the waveguide up to a first etching position Z _{0 g} so as to be connected to a first substrate edge g0-1. The second metallic structure (or engraving) 154-2 (and possibly the third metallic structure or engraving 154-3) can form a ground plane from a position Z _m less than the input position Z ₀ of the frame entry 131 up to a second engraving position Z _mg . The second metallic structure (or engraving) 154-2 (and possibly the third metallic structure or engraving 154-3) can also form a conductive microstrip progressively widened in the second plane (X', Z), inside the guide d 'wave from the second etching position Z _mg to the first etching position Z _g so as to be connected to the second substrate edge g0-2. It should be noted that the electric field is then established between the first metallic structure (or engraving) 154-1 and the second metallic structure (or engraving) 154-2 (and possibly between the first metallic structure or engraving 154-1 and the third metallic structure or engraving 154-3) along the polarization axis Figure 5 .

Advantageously, the first engraving position Z _{0 g} , along the axis of the frame Z, is arranged between the frame entrance 131 and the substrate position Z _g , and the second engraving position Z _mg , along the axis of the frame Z, is arranged between the frame entrance 131 and the first engraving position Z _{0 g} .

In the embodiments where the substrate position Z _g is arranged between the frame outlet 132 and a position Z _{0 n} of a slot 133-n, the first engraving position Z _{0 g} along the axis of the frame Z can be arranged between the substrate position Z _g and the position Z _{0 n} of the slot 133-n. In this case, part of the first and second metal engravings and part of the slot 133-n can overlap (or be “superimposed”) at least partially over an overlap distance between Z _g and Z _{0 n} .

In embodiments, the metal structures (or engravings) 154-1, 154-2 (and optionally 154-3) can be characterized by a thickness m _s defined in a plane perpendicular to the planes (X',Z). In particular, the thickness m _s of each metal structure (or engraving) can be equal to the wall thickness m.

Advantageously, the shape of each metal etching of the antipodal transition 154 is configured to “rotate” the electric field.

According to certain embodiments, an excitation element 150 may comprise a number T of planar metal elements 156-t extending in the plane (X,Y) and arranged one above the other along the axis of the frame Z. “t” is an index associated with the different slots, with t ∈ [1, T ]. Advantageously, in such embodiments, the excitation element 150 further comprises a closing wall 11-0 arranged at the level of the frame entrance 131 of the cell (and by extension of the entrance face 11 of the device 10) .

In particular, each planar element 156-t (also called planar radiating element or 'patch') can be of any shape. For example and without limitation, a planar element 156-t may be of circular shape or of polygonal shape comprising a number N _c of sides. A planar element 156-t can also be centered inside the support frame 130. Each planar element 156-t can be arranged at a planar position Z _t defined between the frame entrance 131 (ie entry position Z ₀ ) and the frame output 132 (ie output position Z _c ), as shown in the Figure 6 .

In embodiments, a planar position Z _t defined along the axis of the frame Z can be located between the frame entry 131 (ie entry position Z ₀ ) and a slot position Z _{0 n} , so that a planar element 156-t is located in a first part of length d _{0 n} corresponding to the support frame 130 without slot with d _h ≤ d _{0 n} . Alternatively, a planar position Z _t can be located between the frame output 132 (ie output position Z _c ) and a position Z _{0 n} of a slot 133-n, such d _h > d _{0 n} . In this case, the planar element 156-t can be located above the position Z _{0 n} of slot 133-n at the position Z _t . A cell 100 comprising at least one planar element 156-t located above the base of all the slots (ie position Z _{0 n} ) makes it possible to obtain a compact cell design.

In addition, each planar element 156-t can be separated by a spacing δz between the closing wall 11-0 and/or one of the other planar elements 156-t. Each planar element 156-t can be characterized by a thickness m _t and a width D _t . In particular, the thickness m _t of each planar element 156-t can be equal to the wall thickness m .

Advantageously, the planar elements 156-t can be connected to each other and/or to the closing wall 11-0 by one or more substrates 156-0, extending along the axis of the frame Z inside the frame. support 130. For example and without limitation, a substrate 156-0 of a planar element 156-t may be metallic so as to form an entirely metallic cell 100. Alternatively, a substrate 156-0 of a planar element 156-t may be dielectric.

The electromagnetic coupling between several patches of different dimensions produces additional resonances which make it possible to increase the bandwidth, as illustrated in the graphs of the figure 8 presenting the evolution of the simulated active reflection coefficient as a function of frequency, for a device 10 whose cells 100 comprise planar elements 156-t according to embodiments of the invention, as a function of different beam directions emission (ie θ = 25° and θ = 50°).

In embodiments, a planar element 156-t may comprise a number _T t of the cell 100 also makes it possible to reduce the mass of the planar element 156-t.

The different dimensions of the planar elements of the same cell 100 and/or of the planar elements of all the cells 100 of the RF beam control device 10 may be identical or different from each other depending on the applications of the invention. For example and without limitation, the width D _t of the planar elements can be progressively reduced between the width of a planar element at the exit of cell 100 relative to the width of a planar element at the entrance to cell 100 This reduction in width D _t of planar elements contributes to the progressive adaptation of the impedance of the cell with the impedance of the free space.

The embodiments where the excitation element 150 comprises planar metallic elements are particularly suitable for use for radiating elements in low frequency bands L or S. In addition, these embodiments allow the design of a compact device, with reduced vertical dimensions, particularly along the Z axis, and low mass, beneficial for satellite antenna applications.

The RF beam control device 10 can be manufactured using different techniques. A manufacturing technique can be a 3D printing technique, also called additive manufacturing. Certain 3D printing techniques make it possible to obtain a uniform device 10, containing no dielectric and entirely metallic, using an electrically conductor such as aluminum or titanium for example. The electrically conductive material such as titanium can then be covered with another electrically conductive material such as silver for example in order to reduce ohmic losses. These 3D printing techniques are particularly suitable for use of the device 10 in Ku, Ka and Q/V bands. A technique for manufacturing patches relating to use of the device 10 in low frequency bands L or S, can be implemented by conventional manufacturing and assembly of all-metal parts, or by additive manufacturing of the support frame associated with an assembly of patches obtained by printed technology.

It should be noted that, unless otherwise indicated or technically impossible, the different modes, variants and alternatives for carrying out the invention can be combined. The RF beam control device in particular may thus include one or more of the previously stated characteristics taken in isolation or in any possible technical combination.

Furthermore, the present invention is not limited to the embodiments described above by way of non-limiting example. It encompasses all the alternative embodiments which could be envisaged by those skilled in the art. In particular, those skilled in the art will understand that the invention is not limited to the geometries of cells, of frame corresponding to the radiating element, and of the excitation element described by way of non-limiting example.

Claims (10)

Radio frequency beam control device (10) defined in an orthogonal reference frame (X,Y,Z), the device (10) generally extending in the plane (X,Y) of said orthogonal reference frame (X,Y,Z), the device comprising an array of cells (100), each cell corresponding to a radiating element, said cell comprising a support frame (130) and an excitation element (150) of said radiating element, each radio frequency beam being defined in a direction of given propagation having an angle of incidence θ with respect to said device, characterized in that said support frame (130) is inscribed in a generally tubular shape oriented along the Z axis of said orthogonal reference mark (X,Y,Z), said tubular shape having a length d _z given along the axis of the frame Z and a transverse section defined in the plane (X,Y), said transverse section having a perimeter P , said support frame (130) comprising a frame entry ( 131) and a frame outlet (132), said support frame further comprising a number N of slots (133-n) extending, along the axis of the frame Z, between said frame outlet (132) and a slot position Z _{0 n} along the frame axis Z, said slot position Z _{0 n} being located between said frame inlet (131) and said frame outlet (132), each slot having a slot width w _n variable along the axis of the frame Z, said slot width w _n having a minimum slot value

at said slot position Z _{0 n} , and a maximum slot value

at the exit of the frame (132), the maximum slot value

being determined as a function of the perimeter P of the transverse section and the number N of slots (133-n),
each cell (100) being configured to carry out transmission and/or reception of radio frequency beams invariant according to said direction of propagation. Radio frequency beam monitoring device (10) according to claim 1, wherein each slot (133-n) is associated with at least two slot edges (n1 and n2), the slot edges representing the limits of the support frame (130) connecting said slot position Z _{0 n} to said frame output (132), each slot edge (n1, n2) being associated with a variability function (f _n1 f _n2 ), said variability function being a function concave and/or convex polygonal. Device for controlling radio frequency beams (10), according to one of claims 1 or 2, in which the excitation element (150) comprises a number H of longitudinal metal ribs (152-h) arranged inside said tubular shape, a rib (152-h) extending along the axis of the frame Z between said frame inlet (131) and a rib position Z _h , said rib position Z _h being defined between said frame inlet (131) and said frame outlet (132). Radio frequency beam control device (10) according to claim 3, wherein the number H of ribs (152-h) is equal to the number N of slots (133-n). Device for controlling radio frequency beams (10), according to one of claims 3 or 4, in which the ribs (152-h) of the cell (100) are identical to each other and the slots (133-n) of the cell (100) are identical to each other, said rib position Z _h being defined between said slot position Z _{0 n} and said frame outlet (132). Radio frequency beam control device (10), according to one of the preceding claims, in which the excitation element (150) comprises an antipodal transition called “Vivaldi” (154) arranged at least partly inside the said tubular shape, the transition (154) comprising at least a first metallic engraving 154-1 and a second metallic engraving 154-2 extending along the axis of the frame Z between said frame entrance (131) and an engraving position Z _0g , said engraving position Z _0g being defined between said frame entrance (131) and said frame exit (132). Radio frequency beam control device (10), according to one of the preceding claims, wherein the excitation element (150) comprises a number T of planar metallic elements (156-t) arranged inside said tubular shape, a planar element (152-h) extending along the plane (X,Y) at a planar position Z _t , said planar position Z _t being defined between said frame inlet (131) and said outlet frame (132). Radio frequency beam control device (10) according to claim 7, wherein the slots (133-n) of the cell (100) are identical to each other, said planar position Z _t being defined between said slot position Z _{0 n} and said frame outlet (132). Device for controlling radio frequency beams (10), according to one of the preceding claims, in which the device (10) is partly metallic, and in which the transverse section has the shape of a circle or polygon. Method of manufacturing the radio frequency beam control device (10) according to one of claims 1 to 9, characterized in that the manufacturing method uses at least one 3D printing technique to manufacture said device (10).

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