Dual-Polarized Antenna Array

Abstract

To provide a dual station antenna free from the limitations of known antennas. The present invention relates to an antenna array comprising at least two antennas (1) with dual polarization (P1, P2), each of which: at least one first port (17) for a first signal having a first polarization (P1); at least one second port (18) for a second signal having a second polarization (P2); a polarization unit (5) having a septum (2) that combines the signal at the first port with the signal at the second port; a polarization-maintaining evanescent filter (4), one end of the polarization-maintaining evanescent filter (4) being directly coupled to the polarizing section and the other end of the polarization-maintaining evanescent filter (4) being directly coupled to the ether, the evanescent filter having an internal channel (11) having at least one inner surface provided with a protrusion (3) for matching the impedance of the antenna (1) to the impedance of the ether; The antenna array comprises:

Description

[Technical Field]

[0001] The present invention relates to dual polarized antenna arrays, and in particular to those in which each dual polarized antenna incorporates a polarizer and an evanescent filter. [Background technology]

[0002] An antenna is a component used to transmit electromagnetic signals into free space or to receive such signals. Simple antennas such as dipoles have limited performance in terms of gain and directivity. Parabolic antennas are highly directional but are bulky and heavy, making them unsuitable for applications such as satellites where weight and volume need to be reduced.

[0003] Antenna arrays are also known that combine multiple radiating elements (antenna elements) in a phase-shifted fashion to improve gain and directivity: the signals received or radiated by the various radiating elements are amplified and phase-shifted to control the shape of the receive and transmit lobes of the array.

[0004] Dual-polarized antennas are also known, which can simultaneously transmit and receive signals with two polarizations. In this case, the signals transmitted or received by each antenna element are combined and separated according to their polarization by a polarizer. The polarizer may be integrated within the antenna element. Dual-polarized antennas have two ports for connecting each of the two polarizations separately to electronic circuits or waveguides.

[0005] Furthermore, it is often necessary to reduce the size of the antenna, particularly its width and height in the plane perpendicular to the direction of signal transmission, so that it can be accommodated in the reduced volume available on a satellite or aircraft.

[0006] Such antennas transmitting at high frequencies, especially microwave frequencies, are difficult to design. In particular, it is often desirable to space the individual element antennas of the array as closely as possible to reduce the overall footprint and to attenuate the amplitude of secondary transmit or receive lobes in directions other than the preferred transmit or receive direction. However, this reduction in element antenna size and spacing creates the problem of portions of the transmitted signal being reflected back onto the antenna or onto another port. This results in inefficient transfer of transmitted energy and interference at each port with signals transmitted at other ports. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent Application Publication No. 3147992 [Patent Document 2] U.S. Patent No. 7,746,190 [Patent Document 3] U.S. Patent No. 9,478,838 [Patent Document 4] European Patent Application Publication No. 3618172 [Patent Document 5] U.S. Patent Application Publication No. 2020 / 381794 Summary of the Invention [Problem to be solved by the invention]

[0008] One of the objectives in designing such antennas is also to reduce their weight, especially in space and aeronautical applications.

[0009] It is also an object to provide an antenna suitable for left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) satellite communications.

[0010] Finally, it is also desirable to produce antennas with a modular design that allows the number of element antennas to be changed as needed without redesigning the entire antenna. A design is said to be modular if different types of antennas can be easily designed by adding or removing standardized antenna elements during the antenna design stage, without having to redesign the entire antenna or waveguide array.

[0011] Naturally, the antenna must have very high efficiency, gain and radiation pattern characteristics to meet the application specifications.

[0012] Finally, it must be possible to manufacture the antenna industrially without falling within the scope of existing patent protection.

[0013] Patent document 3 discloses an orthomode coupler that includes a first septum polarization section and a second polarization section with a circular cross section that is coaxially coupled to the first polarization section, and that allows the two polarization sections to be rotated relative to each other in the coaxial direction so as to adjust the phase of the signal generated by the first polarization section.

[0014] Patent Document 4 discloses an antenna device and an antenna array device, which are provided with a septum polarization section, one of whose inner surfaces has a protrusion intended to improve the axial ratio of the device.

[0015] Patent document 5 discloses a septum polarizer having four longitudinal ridges and a portion that protrudes inward from the polarizer channel, the protrusion being located on the inner wall of the polarizer immediately adjacent to the widest part of the septum.

[0016] One object of the present invention is to provide an antenna with dual polarization that is free from the limitations of known antennas. [Means for solving the problem]

[0017] In accordance with the invention, these objects are notably achieved by an antenna array comprising a plurality of dual-polarized antennas, each antenna of the antenna array having: at least one first port for a first signal having a first polarization; at least one second port for a second signal having a second polarization; a polarization unit including a septum that combines the signal at the first port with the signal at the second port; a polarization-maintaining evanescent filter, one end of which is directly coupled to the polarizing section and the other end of which is directly coupled to the ether, the evanescent filter having an internal channel with at least one internal surface provided with a protrusion that matches the impedance of the antenna to the impedance of the ether; It is equipped with:

[0018] Polarization-maintaining filters that filter dual-polarized signals are known as such. An example of such a filter is described in EP 3147992 A1. However, this filter is not an evanescent filter and is not intended to couple into the ether. Furthermore, this filter is not subwavelength.

[0019] Evanescent mode waveguide filters ("evanescent mode filters") are also known per se. An example of such a filter is described in US Pat. No. 7,746,190 B2. However, this filter has a single input and is not intended to couple to a downstream polarization, nor is it intended to couple to a downstream ether.

[0020] Evanescent filters generally consist of a hollow waveguide that transmits electromagnetic energy between an input port and an output port. Evanescent mode filters have the advantage of high selectivity and reduced weight and bulk. Evanescent filters are usually used between two components, for example, between two waveguide sections, but not at the output of an antenna's radiating element. Generally, direct coupling to the ether is not intended in evanescent filters.

[0021] An evanescent filter at the output of each antenna of the array (of the present invention) allows the output impedance of the antenna to be matched to the output impedance of the ether, thereby maximizing the transfer of energy from the antenna to the ether by limiting reflections of the transmitted signal at the interface between the antenna and the ether.

[0022] The diameter of this internal channel (ie, its largest cross-sectional dimension) is less than the nominal wavelength of the signal for which each antenna is designed.

[0023] The diameter of this internal channel (ie, its largest cross-sectional dimension) is smaller than the smallest wavelength of the signal that each antenna is designed to transmit (the "nominal minimum wavelength").

[0024] The septum preferably does not extend to the ether end of each antenna.

[0025] Each evanescent filter may comprise a number of successive protrusions symmetrically arranged within the waveguide channel, which form an impedance that, in combination with the capacitance of the channel, forms a resonant filter.

[0026] Each polarizing section may have two ridges, three ridges, or more longitudinal ridges in addition to the septum.

[0027] These ridges preferably do not extend to the ether end of the antenna.

[0028] The last section of each antenna on the ether side is advantageously free of septum and ridges, forming an iris between the polarizer and the ether for impedance matching.

[0029] The last section of each antenna on the ether side is advantageously free of protrusions and forms an iris between the polariser and the ether for impedance matching.

[0030] Each evanescent filter may be provided with several successive projections arranged along its length, for example along three or four longitudinal lines within the filter channel.

[0031] These longitudinal lines may be in the extension of the ridges.

[0032] These protrusions may therefore form three or four discontinuous ridges.

[0033] Each antenna is preferably sub-wavelength.

[0034] The diameter of the second end of each evanescent filter may be less than a nominal half wavelength of the signal.

[0035] This type of antenna is particularly compact, but increases the risk of unwanted reflection of the transmitted signal towards another port. Evanescent filters allow the diameter to be reduced without the risk of unwanted reflections.

[0036] The protrusions of the evanescent filter may each have a first surface and a second surface in the signal transmission direction, the first surface being inclined relative to the second surface.

[0037] The angled surface of each protrusion may be angled relative to a plane perpendicular to the longitudinal axis of the antenna.

[0038] The inclined surface of each projection may form an angle (α) with said inner surface between 20° and 80°, preferably between 20° and 40°.

[0039] The filter channel of each antenna may have a circular, square, rectangular, hexagonal or octagonal cross section perpendicular to its longitudinal axis (ignoring any ridges or protrusions).

[0040] The protrusions may be located along three sides of the channel.

[0041] The protrusions may be located along the four sides of the channel.

[0042] The evanescent filter of each antenna is preferably non-flared, so that the cross section of its internal channel is substantially constant along its longitudinal axis, except for protrusions that reduce the surface area of ​​the cross section of these internal channels.

[0043] The antenna array is preferably miniaturized in that the periodicity of the antenna array is less than or equal to 80% of the nominal wavelength of the signals transmitted and received by each antenna.

[0044] The channels of each antenna in the array advantageously have a cross section that is invariant to a 120° rotation about the longitudinal axis of the channel and have protrusions and / or longitudinal ridges spaced at 120° intervals.

[0045] Advantageously, the antenna array is monolithically manufactured.

[0046] Each antenna of the antenna array is advantageously manufactured by 3D printing of a metal or polymer core, after which a conductive layer is deposited on at least the inner surface of the antenna.

[0047] The first port may be mounted with a first flange that connects to the first waveguide, and the second port may be mounted with a second flange that connects to the second waveguide.

[0048] Both flanges can be 3D printed.

[0049] Each antenna may be manufactured by a process involving, for example, an SLM-type additive manufacturing process in which a laser or electron beam fuses or sinters multiple thin layers of powdered material.

[0050] Additive manufacturing can be observed in the antennas produced in this way by analyzing the structure of the metal grains sintered into layers.

[0051] Metal additive manufacturing allows for the production of complex shapes with fewer or no assembly steps, thereby reducing manufacturing costs.

[0052] Additive manufacturing also allows the antenna to be manufactured with no or reduced assembly means between subcomponents, thereby reducing the weight of the antenna.

[0053] Waveguide devices are known to be fabricated by additive printing, but the complex geometry of evanescent filters is not amenable to additive manufacturing due to the large number of cantilevered surfaces, especially those that form the roof of the resonator cavity.

[0054] Most additive printing processes, and in particular selective laser melting (SLM) processes, impose a minimum angle of, for example, 20° or 40° to avoid the risk of sagging of the new layer deposited as a cantilever, which makes it impossible to print specific parts of the evanescent filter, or at least to print them with the desired precision.

[0055] Therefore, to avoid these drawbacks, the use of additive printing is proposed for the fabrication of antennas with evanescent filters having unconventional shapes that facilitate high precision additive printing.

[0056] The first signal may be a RHCP signal, and the second signal may be a LHCP signal.

[0057] Embodiments of the invention are illustrated in the accompanying description and drawings. [Brief explanation of the drawings]

[0058] [Figure 1] Figure 1 shows a cross section of a dual polarized antenna without an evanescent filter. [Figure 2] FIG. 2 is a perspective view of an antenna with dual polarization and evanescent filtering. [Figure 3]FIG. 3 is a cross-sectional view of the antenna of FIG. [Figure 4] FIG. 4 is a perspective view showing another variant of an antenna with dual polarization. DETAILED DESCRIPTION OF THE INVENTION

[0059] Figure 1 shows a schematic of a dual-polarized antenna 1 of an antenna array in longitudinal cross section. The antenna comprises a 3D printed core 15, at least its inner surface carrying metallization 16. The core may be made of metal or of an insulating material such as polymer or ceramic. Metallization 16 may also be applied to the outer surface of the antenna.

[0060] Since the antennas of the array of the present invention are essentially identical, the term "antenna" should be understood throughout this specification to mean "each antenna of the antenna array."

[0061] The antenna is provided with a longitudinal channel 11 that opens into an opening 10 at one end of the antenna. The cross section of the channel 11 (disregarding ridges, protrusions and septa) may be, for example, square, rectangular, circular, oval, hexagonal, octagonal, pentagonal, etc.

[0062] The channel 11 is divided into two chambers 12 and 13 by a septum 2 . The first chamber 12 opens to a first port 17 for receiving a first signal P1 having a first polarization. The second chamber 13 opens to a second port 18 for receiving a second signal P2 having a second polarization. The polarization may be circular. The second polarization may be orthogonal to the first polarization. The first signal may be a left-handed circularly polarized (LHCP) signal. The second signal may be a right-handed circularly polarized (RHCP) signal. The two signals P1 and P2 combine at the antenna output to form a single dual-polarized signal that is transmitted into the ether.

[0063] The term "ether" is used in the context of this application to mean the free space outside an antenna, in which the signal radiated by the antenna propagates. In particular, this means that there is no device intended to be coupled to the end of the antenna that is on the ether side. Thus, the ether may correspond to outer space itself, for example, if the antenna is mounted on an orbiting satellite, but more generally, the ether refers to any free space outside an antenna. The ether has its own impedance that depends on the properties of the space surrounding the antenna.

[0064] One problem associated with this arrangement concerns the reflection of part of the transmitted signal. As shown with the arrows in Figure 1, only a part P11 of the first signal P1 is scattered towards the ether, while another part P12 is reflected at the antenna output and back into aperture 12 or even aperture 13. This results in a reduction in the power of the actually transmitted signal P11 and a disruption of the signal in channel 11.

[0065] The problem is amplified if the antenna is subwavelength, i.e., if the diameter of the aperture 10 at the output of the antenna 1 is less than half the wavelength of the nominal signal to be transmitted, and if the impedance of the antenna does not match the impedance of the transmission path through the ether.

[0066] The antennas shown schematically in Figures 2 to 4 make it possible to overcome, or at least attenuate, this reflection of the transmitted signal at the antenna output. The characteristics of these antennas are identical to those of the antenna described above in connection with Figure 1, and the above explanations also apply to the antennas of Figures 2 to 4.

[0067] The main difference between the embodiment shown in Figures 2 to 4 and the antenna shown in Figure 1 is the presence of an evanescent filter 4 attached directly to the output of the polarization section 5, the output aperture 10 of which is directly coupled to the ether. The evanescent filter acts directly as a radiating element, radiating a dual-polarized signal P1+2, which is a combination of the polarization signal P1 and the polarization signal P2. Thus, the antenna consists of a polarization section 5 directly coupled to the evanescent filter 4.

[0068] The evanescent filter 4 preferably does not modify the polarization of the signal passing through the antenna.

[0069] The polarization may be circular.

[0070] Polarisation unit 5 may be the polarisation unit described with reference to Figure 1, but its output is coupled to the input of evanescent filter 4 instead of being coupled to the ether.

[0071] The polarized section of antenna 1 shown in Figures 2 to 4 has two input ports 17 and 18, with only port 17 visible in the cross section of Figure 3. Each port can receive a signal P1 or a signal P2 with a first polarization or a second polarization. Each port can be connected to a waveguide by flanges 170 and 180, respectively, as shown in Figure 4, or can be connected directly to active electronics, for example by coaxial cable.

[0072] Two ports 17, 18 are coupled to chambers 12, 13, respectively, of channel 11 inside the antenna. These two chambers are separated from each other by a septum 2. As can be seen in Figure 3, the height of this septum may taper or decrease in steps from ports 17, 18 towards output opening 10.

[0073] The polariser 5 may be mounted on one or more longitudinal ridges, the use of which makes it possible to favour the transmission of the preferred transmission mode in a compact device.

[0074] In one embodiment, the polarizing section 5 has two longitudinal ridges 19 in addition to the septum 2. The two ridges can be at 120° to each other and to the septum. The two ridges can be 180° apart and 90° on either side of the septum.

[0075] The use of two ridges 19 in addition to the septum 2 significantly increases the single mode bandwidth of the antenna.

[0076] In the embodiment with two ridges in addition to septum 2, the 120° spacing of the two ridges on either side of the septum results in a channel shape that is invariant to a 120° rotation about the longitudinal axis of the channel. This ridge configuration significantly improves discrimination of higher order modes from the fundamental mode.

[0077] In one embodiment, the polarizing section has three longitudinal ridges 19 in addition to the septum 2. The three ridges may be at 90° to each other and to the septum.

[0078] More than three ridges may be used.

[0079] The ridges may be straight or twisted.

[0080] The average radial height of the ridges 19 is less than that of the septum 2. The height of the ridges may decrease from the ports 17, 18 towards the output opening 10.

[0081] In the example shown in Figures 2 to 3, the polarizer 5 has an outer surface shaped, for example, like a right prism. Other outer shapes and cross sections of other channels 11 are conceivable. The shape of the cross section of the polarizer, as well as its surface, may be such that it gradually changes from the input of the polarizer in the direction of the evanescent filter 4, as shown in Figures 2 to 4.

[0082] In the context of the present invention, the evanescent filter may be seen as an impedance adapter between the polarized section and the ether.

[0083] As the array is miniaturized, the diameter of the internal channel of each evanescent filter no longer allows such signal propagation, i.e., the filter waveguide is below the cutoff frequency, and therefore the protrusion of the filter internal channel is necessary for signal propagation within the antenna.

[0084] The evanescent filter 4 coupled to the output of the polarizer 5 has protrusions 3 (or teeth) and for this purpose the channel 11 of the antenna 1 is provided with a number of protrusions 3 separated from each other by portions of the channel 11.

[0085] Adjacent projections 3 are longitudinally spaced in pairs at a regular or variable pitch p.

[0086] The protrusions 3 may be arranged symmetrically around the longitudinal axis of the evanescent filter.

[0087] The protrusions 3 may be arranged in several rows, for example aligned with the ridges 19 of the polarizing section.

[0088] The protrusion 3 does not extend to the end of the antenna on the ether side. The ridge 19 does not extend to the end of the antenna on the ether side. Therefore, the antenna's internal channel terminates on the ether side without a ridge, protrusion, or septum. The antenna's internal channel terminates with a void on the ether side, forming an iris between the polarization section and the ether for impedance matching.

[0089] 2 to 4, the evanescent filter 4 has an outer surface shaped, for example, like a cylinder, and the channel 11 within the filter has a number of protrusions that form the filter portion. Other outer shapes and other portions of the channel 11 are also possible.

[0090] Antennas 1 with square, rectangular, hexagonal or octagonal outer cross-sections may be used. Similarly, the number of lines of projection may be different from three, although three is the preferred embodiment in view of the advantages mentioned above.

[0091] The cross-sectional shape of the evanescent filter may differ from the cross-sectional shape of the associated polarizing section 5. For example, in Figures 2 and 3, the polarizing section 5 has a rectangular or square input cross-section which gradually becomes circular for direct coupling to the evanescent filter 4 of circular cross-section.

[0092] The geometry of the protrusions 3 and their arrangement may be determined by computing software, for example, as a function of the desired bandwidth. The calculated geometry may be stored on a computer data medium.

[0093] It is important to note that the evanescent filter has identical phase performance for both modes, which means that the evanescent filter does not act as a polarizer, i.e. the phase of the two polarizations does not change within the filter.

[0094] The core 15 of the antenna 1 is preferably manufactured using an additive manufacturing process. The polarizer 5 and the evanescent filter 4 are preferably realized monolithically, and the core 15 is manufactured in a single additive printing step. In this application, the expression "additive manufacturing" refers to any process of manufacturing a core by adding material according to computer data stored on a computer medium and defining the geometry of the core.

[0095] The core 15 can be manufactured, for example, by an additive manufacturing process of the SLM (Selective Laser Melting) type. The core 15 can also be manufactured by other additive manufacturing methods such as liquid or powder hardening or solidification (additive manufacturing methods including, but not limited to, methods based on stereolithography, binder jetting, DED (Direct Energy Deposition), EBFF (Electron Beam Freeform Fabrication), FDM (Fused Deposition Modeling), PFF (Plastic Free Forming), aerosol, BPM (Particle Manufacturing), SLS (Selective Laser Sintering), ALM (Additive Layer Manufacturing), Polyjet, EBM (Electron Beam Melting), photopolymerization, etc.).

[0096] The core may be, for example, a photopolymer made by multiple surface layers of liquid polymer cured by UV radiation in an additive manufacturing process.

[0097] The core may also be formed from a conductive material, such as a metallic material, by an SLM type additive manufacturing process in which a laser or electron beam melts or sinters multiple thin layers of powdered material.

[0098] In one embodiment, metal layer 16 is deposited as a film by electroplating or galvanoplasty (a method of coating a metal object with a thin film of another metal) on the interior wall surface of core 15. The metallization covers the interior surface of the core with a conductive layer.

[0099] The application of the metal layer may be preceded by a surface treatment step on the inner wall surface of the core to promote adhesion of the metal layer, which may include increasing the surface roughness and / or depositing an intermediate bonding layer.

[0100] However, conventional additive manufacturing processes are not particularly suitable for conventional evanescent filters, especially those featuring a large number of protrusions 3 or cavities, because the placement of these protrusions creates cantilevered sections within the channels that are difficult to maintain when printing the various layers. Therefore, reinforcements for these cantilevered sections must be placed during the additive manufacturing process to prevent these parts from collapsing under the effects of gravity.

[0101] In one embodiment, and to remedy this drawback, the antenna 1 may be printed with the longitudinal axis z of the channel 11 in a vertical, or at least substantially vertical, position.

[0102] In another embodiment, the protrusions 3 of the channel 11 may be designed to facilitate additive printing in a vertical position. Thus, each protrusion 3 may have a surface that is cantilevered when the filter is manufactured in a vertical position. In the example shown in Figures 2 and 3, the surface 30 of the protrusion 3 is cantilevered during additive manufacturing. The top surface 31 of the protrusion 3 may extend in a plane that is substantially perpendicular to the longitudinal axis of the channel 11, i.e., in the horizontal plane during manufacturing. Alternatively, the top surface 31 may be inclined relative to this plane.

[0103] To allow for additive printing, the cantilevered lower surface 30 may be tilted relative to the horizontal in the vertical production position during printing. In a preferred embodiment, the lower surface 30 forms an angle α with the horizontal that is between 20° and 80°, and preferably between 20° and 40°.

[0104] The geometrical configuration of the antenna 1 according to this embodiment has the advantage that it allows the core to be manufactured by an additive manufacturing process in a vertical orientation against gravity, without having to resort to stiffeners to prevent sagging of parts of the core due to the influence of gravity during the manufacturing process. Indeed, the angle α of the cantilever surface 30 with respect to the horizontal is preferably sufficient to allow the superposed layers to adhere to each other before hardening during printing.

[0105] The projections 3 shown in the examples have a polygonal longitudinal cross section, for example in the shape of a triangle or trapezoid, however, other projection or tooth shapes are also conceivable, including for example projections with rounded portions (undulations) in cross section.

[0106] The protrusions 3 shown in the examples have fixed dimensions, in particular fixed depth and height. However, crenellations and / or teeth may be made with variable depth and / or height. In addition, the pitch p between successive crenellations or teeth does not have to be a fixed value.

[0107] In one embodiment, the channel 11 of each antenna 1 of the antenna array has a cross section perpendicular to the longitudinal axis of the channel that is invariant to a rotation of 120° about the longitudinal axis, in particular when the protrusions are 120° apart and / or when the polarizing sections have three longitudinal ridges 120° apart.

[0108] The 120° rotational invariance of the channel cross section also imposes restrictions on the channel shape: thus, the external contour of the channel cross section can be, for example, circular, triangular, hexagonal, etc.

[0109] The antenna array of the present invention comprises at least two antennas 1, but is generally intended to comprise several tens of antennas 1 arranged in parallel and succession. In such an antenna arrangement, the periodicity of the array means the distance separating the centers of two consecutive antennas in the array, this distance being usually measured in the plane comprising the aperture of the antenna on the ether side.

[0110] In certain embodiments, the periodicity of the antenna array is less than or equal to 80% of the nominal wavelength of the signal intended to be radiated or transmitted by each antenna, which generally constitutes the threshold above which reflection of the signal towards a neighboring antenna becomes problematic. The present application provides the following aspects, for example: [Point 1] An antenna array comprising at least two antennas (1) with dual polarization (P1, P2), each antenna having: at least one first port (17) for a first signal having a first polarization (P1); at least one second port (18) for a second signal having a second polarization (P2); a polarization unit (5) having a septum (2) that combines the signal at the first port with the signal at the second port; a polarization-maintaining evanescent filter (4), one end of which is directly coupled to the polarizing section and the other end of which is directly coupled to the ether, the evanescent filter having an internal channel (11) with at least one inner surface provided with a protrusion (3) for matching the impedance of the antenna (1) to the impedance of the ether; An antenna array comprising: [Point 2] 2. The antenna array of claim 1, wherein the diameter of the internal channel (11) of each antenna is smaller than the nominal wavelength of the signal for which the antenna is designed. [Point 3] 3. The antenna array of claim 1 or 2, wherein the septum does not extend to the end of the antenna on the ether side. [Point 4] 4. The antenna array according to any one of the preceding aspects, wherein the polarizing portion (5) is provided with a longitudinal ridge (19) in addition to the septum (2). [Point 5] 5. An antenna array according to claim 4, wherein the longitudinal ridges (19) do not extend to the ends of each antenna on the ether side. [Point 6] 6. The antenna array according to any one of aspects 1 to 5, wherein the evanescent filter (4) is provided with a plurality of protrusions (3) that are continuous along a longitudinal line. [Point 7] 7. The antenna array according to claim 6, wherein the protrusions (3) do not extend to the ends of each antenna on the ether side. [Point 8] 8. The array of antennas according to aspect 7, wherein the protrusions are arranged along three or four longitudinal lines. [Point 9] 9. An antenna array according to any one of aspects 4, 7 and 8, wherein the longitudinal line is an extension of the longitudinal ridge (19). [Point 10] 10. The antenna array of any one of aspects 1 to 9, wherein the diameter (d) of the second end of the evanescent filter of each antenna (4) is smaller than a nominal half wavelength of the signal. [Point 11] 11. The antenna array of any one of aspects 1 to 10, manufactured as a single unit. [Point 12] 12. An antenna array according to any one of aspects 1 to 11, manufactured by 3D printing at least two metal or polymer cores (15) and depositing a conductive layer (16) on at least the inner surface of each antenna. [Point 13] The antenna array of aspect 12, wherein each of the plurality of protrusions (3) has a first surface and a second surface in the signal transmission direction, and the first surface (30) is inclined relative to the second surface (31) as an inclined surface. [Point 14] 14. The antenna array according to aspect 13, characterized in that the inclined surface (30) of each projection (3) is oblique to a plane perpendicular to the longitudinal axis of the antenna (1). [Point 15] 15. An antenna array according to aspect 13 or 14, characterized in that the inclined surface (30) of each protrusion (3) has an angle (α) with respect to the inner surface between 20° and 80°, preferably between 20° and 40°. [Point 16] 16. The antenna array of any one of aspects 1 to 15, wherein the channel (11) of each antenna (1) has a circular, square, rectangular, hexagonal or octagonal cross section at the longitudinal axis of the channel, and wherein a plurality of the protrusions are arranged along three faces of the channel (11). [Point 17] the channel (11) of each antenna (1) has a circular cross section perpendicular to the longitudinal axis of the channel; 17. The antenna array of any one of aspects 1 to 16, wherein the protrusions are arranged along three lines spaced at 120° intervals. [Point 18] the channel (11) of each antenna (1) has a cross section perpendicular to its longitudinal axis that is invariant to a rotation of 120° about the longitudinal axis; The protrusions are spaced at intervals of 120°. 18. The antenna array of any one of aspects 1 to 17. [Point 19] 19. The antenna array of any one of aspects 1 to 18, wherein the periodicity of at least two antennas (1) is less than or equal to 80% of the nominal wavelength of the signal. [Point of View 20] 5. The antenna array of claim 4, wherein the longitudinal ridges are spaced at 120° intervals. [Explanation of symbols]

[0111] 1. Dual-polarized antenna 2 Septum 3 ridges 4 Evanescent Filter 5 Septum polarization section 10 Opening 11 Internal Channels 12 rooms 13 rooms 15 cores 16 Metallization 17 Port 1 18 Second Port 30 Underside of protrusion 31 Top of the protrusion 170 First flange 180 Second flange P1 First signal P2 2nd signal P1+2 dual polarization signal

Claims

1. 1. An antenna array comprising at least two antennas fabricated as a single unit, each antenna having dual polarization, at least one first port for a first signal having a first polarization; at least one second port for a second signal having a second polarization; a polarization section comprising a septum for combining signals at at least one of the first ports with signals at at least one of the second ports; a polarization-maintaining evanescent filter, one end of which is directly coupled to the polarizing section and the other end of which is directly coupled to an ether which is free space outside the antenna and serves as a radiating element of the antenna, the evanescent filter having an internal channel with at least one inner surface provided with a protrusion for matching the impedance of the antenna to the impedance of the ether; An antenna array comprising:

2. 10. The antenna array of claim 1, wherein the diameter of the internal channel of each antenna is less than the nominal wavelength of a signal for which the antenna is designed.

3. 2. The antenna array of claim 1, wherein the septum does not extend to the end of the antenna on the ether side.

4. 2. The antenna array of claim 1, wherein the polarizing portion is provided with a longitudinal ridge in addition to the septum.

5. 5. The antenna array of claim 4, wherein the longitudinal ridges do not extend to the ends of each antenna on the ether side.

6. 10. The antenna array of claim 1, wherein the evanescent filter is provided with a plurality of successive protrusions along a longitudinal line.

7. 7. The antenna array of claim 6, wherein the protrusions do not extend to the ends of each antenna on the ether side.

8. 8. The antenna array of claim 7, wherein the projections are arranged along three or four longitudinal lines.

9. 2. The antenna array of claim 1, wherein the diameter of the second end of the evanescent filter of each antenna is less than a nominal half wavelength of the signal.

10. 2. The antenna array of claim 1, wherein each of the plurality of protrusions comprises a first surface and a second surface in a signal transmission direction, the first surface being inclined relative to the second surface as an inclined surface.

11. 11. The antenna array of claim 10, wherein the angled surface of each protrusion is oblique to a plane perpendicular to the longitudinal axis of the antenna.

12. 11. The antenna array of claim 10, wherein the angled surface of each protrusion is at an angle to the inner surface between 20° and 80°, or between 20° and 40°.

13. the channels of each antenna have a cross section perpendicular to the longitudinal axis of the channel that is invariant to a 120° rotation about the longitudinal axis; 2. The antenna array of claim 1, wherein the protrusions are spaced at 120° intervals.

14. 10. The antenna array of claim 1, wherein the periodicity of at least two antennas is less than or equal to 80% of the nominal wavelength of the signal.

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