Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
  • H01P1/00—Auxiliary devices
  • H01P1/165—Auxiliary devices for rotating the plane of polarisation
  • H01P1/17—Auxiliary devices for rotating the plane of polarisation for producing a continuously rotating polarisation, e.g. circular polarisation
  • H01P1/173—Auxiliary devices for rotating the plane of polarisation for producing a continuously rotating polarisation, e.g. circular polarisation using a conductive element
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/27—Adaptation for use in or on movable bodies
  • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
  • H01Q1/288—Satellite antennas
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/02—Waveguide horns
  • H01Q13/0241—Waveguide horns radiating a circularly polarised wave
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/02—Waveguide horns
  • H01Q13/025—Multimode horn antennas; Horns using higher mode of propagation
  • H01Q13/0258—Orthomode horns
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/02—Waveguide horns
  • H01Q13/0275—Ridged horns
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/02—Waveguide horns
  • H01Q13/0283—Apparatus or processes specially provided for manufacturing horns
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/08—Radiating ends of two-conductor microwave transmission lines, e.g. of coaxial lines, of microstrip lines
  • H01Q13/085—Slot-line radiating ends
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
  • H01Q21/061—Two dimensional planar arrays
  • H01Q21/064—Two dimensional planar arrays using horn or slot aerials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
  • H01Q25/001—Crossed polarisation dual antennas

Definitions

• the present invention relates to a dual polarization antenna of the Vivaldi type, an array of such antennas as well as a satellite supporting such antennas.
• Antennas are elements which are 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 allow higher directivity, but are bulky and heavy, which makes their use unsuitable in applications such as satellites for example, where weight and volume must be reduced.
• Antenna arrays are also known which bring together several radiating elements (antenna elements) out of phase in order to improve the gain and the directivity.
• the signals received on the different radiant elements, or emitted by these elements, are amplified and phase shifted between them so as to control the shape of the reception and transmission lobes of the network.
• dual polarization antennas capable of simultaneously transmitting or receiving signals with two polarizations.
• the signals transmitted or received by each antenna element are combined, respectively separated, according to their polarization by means of a polarizer.
• the polarizer can also be integrated into the antenna element.
• a dual polarization antenna has two ports for connecting each of the two polarizations separately to or from electronic circuitry or waveguides.
• Such antennas intended to transmit high frequencies, particularly for microwave frequencies, are difficult to design. It is in particular often desired to bring the different elementary antennas of the network as close as possible in order to reduce the overall size and to attenuate the amplitude of the secondary transmission or reception lobes, in directions other than the direction of transmission or reception which must be privileged. This reduction in the size of the elementary antennas and their spacing, however, creates problems of reflection of a portion of the transmission signal which returns to the antenna or to another port. This results in a loss of efficiency in the transfer of transmitted energy, and disturbances of each port by the signals transmitted on the other ports.
• a goal when designing such an antenna is also to reduce its weight, particularly in applications for space or aeronautics.
• An aim is also to provide an antenna suitable for satellite communications with LHCP and RHCP polarization.
• An aim is also to provide an antenna whose geometry facilitates its additive printing, for example by making it possible to limit the supports necessary during printing.
• antennas with a modular design which makes it possible to vary the number of elementary antennas according to needs, without having to review the entire design of the antenna.
• the design is said to be modular when different types of antennas can easily be designed by adding or removing standardized antenna elements during the design of the antenna, without having to review the entire design of the antenna or the waveguide network.
• the antenna must also of course have very high efficiency, gain and radiation pattern characteristics that are compatible with the specifications of the application.
• the antenna must be able to be manufactured industrially and without falling within the scope of protection of existing patents.
• a dual polarization antenna obtained by additive manufacturing comprising: a polarizer comprising: a first port intended for a first signal with a first polarization; a second port for a second signal with a second polarization; an output port for a signal with dual polarization; a septum for combining the first signal on the first port with the second signal on the second port; a polarization preserving radiant element, comprising a waveguide having a first end connected to the output port of the polarizer and a second end coupled to free space, the waveguide comprising an internal channel provided with three ridges parallel to a direction of propagation of a signal in the internal channel, characterized in that an external portion of each streak extends out of the waveguide via the second end, a height of the external portion of each streak measured radially with respect to the direction of propagation decreasing away from the second end.
• the streaks inside the internal channel can serve as support for the external portions of the streaks, particularly when the direction of printing of the antenna coincides with the axis of propagation of the waves in the channel.
• a section of the radiant element perpendicular to the direction of propagation can be invariant by rotation of 120° around the direction of propagation.
• This 120° symmetry notably implies a spacing of 120° between each of the streaks.
• this configuration of streaks makes it possible to increase the discrimination of higher order modes compared to the fundamental mode.
• the section of the radiant element can be circular, triangular, hexagonal. Generally speaking, this section can be polygonal with a number of sides that is a multiple of 3. [0019] In one embodiment, one of the three grooves is formed by the extension of the septum along a wall of the internal canal. The septum can then also serve as a support for the streak and the external portion of the streak during additive printing.
• the grooves can be inclined relative to the internal wall of the internal channel.
• the grooves have a height extending radially relative to the axis of propagation, but inclinations relative to the radial direction are possible.
• the diameter of the waveguide may be less than the wavelength at the highest operating frequency of the antenna, preferably less than half the wavelength at the highest frequency d antenna operation.
• the antenna can be in one piece.
• the height of each external portion of at least one streak can decrease linearly, exponentially and/or in stages.
• Each external stripe portion may comprise at least one lateral impedance matching step arranged in the extension of a side wall of the internal channel.
• an antenna array comprising a plurality of antennas as described above.
• the plurality of antennas can be arranged in a matrix in one or two directions.
• Figure 1 schematically illustrates a sectional view of a dual polarization antenna.
• Figure 2 illustrates a dual polarization antenna of circular section.
• Figure 3 illustrates a dual polarization antenna of triangular section whose angles are truncated.
• Figure 4 illustrates a double polarization antenna of hexagonal section.
• Figure 5a illustrates a top view of a dual polarization antenna of hexagonal section.
• Figure 5b illustrates a sectional view of the same antenna shown in Figure 5a.
• Figure 6 illustrates a dual polarization antenna comprising impedance matching elements.
• Figure 7 illustrates an array of dual polarization antennas arranged in a two-dimensional matrix.
• the present invention relates to a dual polarization antenna 1 comprising a septum polarizer 10 and a radiant element 20 provided with three grooves 202 inside the internal channel of the waveguide of the radiant element.
• the three ridges project outward from the channel at the end of the radiant element waveguide intended to be coupled to free space.
• free space is used in the context of the present application to designate the space outside the antenna, and in which the signals emitted by the antenna propagate. This means in particular that no device is intended to be coupled to the end of the antenna on the “free space” side.
• free space can correspond for example to the space itself when the antenna is equipped on a satellite in orbit, but more generally, free space designates any volume of space outside of the antenna.
• the free space has its own impedance depending on the characteristics of the space surrounding the antenna.
• the antenna 1 comprises two main parts, a septum polarizer 10 and a radiant element 20.
• the polarizer 10 comprises an orthomode transducer in the form of a waveguide, one end of which comprises a first port 101 and a second port 102 with simple polarization, and the other end of which comprises an output port intended to a signal with double polarization.
• the two ports are separated by a septum 103 whose height extends along a diameter of the waveguide. In transmission, these two ports are each able to propagate a signal with linear polarization (P1,P2). These two signals are then combined into a dual polarization signal via the septum 103 which is propagated towards the radiant element 20.
• the septum 103 makes it possible to control the phase between the two orthogonal modes so as to create for example a circular polarization, a polarization inclined at 45° or a vertical/horizontal polarization. In reception, the septum 103 separates two polarizations of a dual polarization signal received via the radiant element.
• the septum 103 also extends longitudinally relative to the waveguide of the polarizer (that is to say relative to the direction of propagation of the waves in the polarizer) and its height decreases until it disappears completely. or until forming a longitudinal streak on an internal wall of the antenna.
• the decrease in height is typically done in stairs (that is to say in successive steps) in the longitudinal direction but it can also be linear, exponential, or according to another decreasing profile depending on particular needs.
• the radiant element 20 is intended to be coupled on the one hand to the output port of the polarizer 10 and on the other hand to the free space. It therefore forms the extension of the polarizer in the direction of emission of the antenna.
• the term “coupling” does not exclude the two coupled elements from being formed and/or manufactured in one piece. It may be a theoretical coupling of two elements having a different function, but forming an object not resulting from the mechanical assembly of these two elements.
• the radiant element 20 comprises a waveguide of which a first end is coupled to the output port of the polarizer 10 and of which a second end 201 is coupled to the free space.
• This waveguide comprises an internal channel whose walls are provided with three grooves 202 extending parallel to the direction of propagation of the waves in the internal channel.
• Each of the three grooves includes an external portion 203 extending out of the waveguide through its second end 201 so as to form protruding fins in the longitudinal direction.
• the streaks 202 make it possible in particular to lower the cutoff frequency of the waveguide and thus allow the miniaturization of the antenna.
• the streaks also make it possible to adapt the impedance of the antenna to the impedance of the free space in order to reduce the phenomenon of signal reflection at the radiating element - free space interface.
• the height of the streaks can be constant or variable along the longitudinal direction.
• Figure 5b illustrates an embodiment in which the height of the streaks is variable longitudinally in the waveguide.
• the external portion 203 of each groove 202 has a height, measured in the radial direction relative to the direction of propagation, which decreases moving away from the second end 201 of the guide waves of the radiant element.
• This decreasing profile of the external portions 203 makes it possible in particular to significantly increase the bandwidth of the antenna in the manner of a traditional Vivaldi antenna. They are also particularly suitable for questions of adaptation of the impedance of the antenna to the impedance of free space.
• the combination of the grooves 202 inside the waveguide and the external portions 203 makes it possible to facilitate the additive printing of the antenna 1, in particular the printing of the external portions.
• the streaks 202 can serve as support for the external portions 203 during their printing. This helps reduce the amount of necessary collateral media that must be manually removed after printing. This results in a saving in weight and cost since manufacturing time is reduced.
• the waveguide of the polarizer and the radiant element 10 have an invariance by rotation of 120° around the direction of propagation. In other words, a section of these waveguides perpendicular to the direction of propagation in the antenna is invariant by rotation of 120° relative to the direction of propagation. This implies in particular that the streaks 202 are distributed in the internal channel of the waveguides so as to be spaced 120° apart from each other.
• the section of the waveguide of the polarizer 10 and of the radiant element 20 is circular, triangular or hexagonal so as to respect the invariance by rotation of 120° around the direction of propagation. More generally, polygonal sections with 3n sides, where n is a positive integer, make it possible to respect symmetry at 120°.
• the waveguides can thus form cylinders if the section is circular, or prisms with a triangular, hexagonal base, etc. The angles of the prisms can be truncated.
• the grooves 202 can be arranged on the internal walls of the internal channel of the waveguides corresponding to the faces or angles of the prisms.
• Figure 2 illustrates an antenna 1 whose section of the radiating element and the polarizer is circular.
• the grooves 202, and therefore the external portions 203, are spaced 120° apart on the internal wall of the waveguides.
• Figure 3 illustrates an antenna 1 whose section of the radiating element and the polarizer is triangular.
• the angles of the triangular base prism formed by the polarizer and element waveguides radiant may be truncated.
• the striations 202 can be arranged on the internal walls of the waveguides corresponding to the truncated parts of the prism or corresponding to the faces of the prism.
• the triangles forming the waveguide section can be equilateral, which implies invariance by rotation of 120° around the direction of propagation, or isosceles.
• one or more grooves are inclined relative to the radial direction. This means that the direction of the height of the streaks is not aligned with the radial direction relative to the propagation direction.
• the angle between the direction of the height of the streak and the wall of the waveguide supporting the streak may be different from 90°.
• the diameter of the waveguide of the radiant element is less than the wavelength at the highest operating frequency of the antenna, preferably less than half the wavelength at the highest operating frequency of the antenna.
• the antenna 1 comprises a core which is preferably manufactured by an additive manufacturing process.
• the polarizer 10 and the radiant element 20 are preferably made monolithic, their core being manufactured in a single additive printing step.
• additive manufacturing designates any process for manufacturing the core by adding material, according to the computer data stored on the computer medium and defining the geometric shape of the core.
• the core can for example be manufactured by an additive manufacturing process of the SLM (Selective Laser Melting) type.
• the core can also be manufactured by other additive manufacturing methods, for example by hardening or coagulation of liquid or powder in particular, including without limitation methods based on stereolithography, ink jets (binder jetting), DED (Direct Energy Deposition), EBFF (Electron Beam Freedom Fabrication), FDM (Fused Deposition Modeling) PFF (Plastic Free Forming), aerosol, BPM (Ballistic Particle Manufacturing), SLS (Selective Laser Sintering), ALM (Additive Layer Manufacturing) ), polyjet, EBM (Electron Beam Melting, photopolymerization, etc.
• SLM Selective Laser Melting
• other additive manufacturing methods for example by hardening or coagulation of liquid or powder in particular, including without limitation methods based on stereolithography, ink jets (binder jetting), DED (Direct Energy Deposition), EBFF (Electron Beam Freedom Fabrication), FDM
• the core can also be formed from a conductive material, for example a metallic material, by an additive manufacturing process of the SLM type in which a laser or an electron beam melts or sinters several thin layers of a powdery material.
• the application of the metal layer can be preceded by a step of surface treatment of the internal faces of the core in order to promote adhesion of the metal layer.
• Surface treatment can include an increase in surface roughness, and/or the deposition of an intermediate bonding layer.
• 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/received by each antenna.
• the present invention also relates to a satellite comprising at least one antenna as described above or an antenna array as described above.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Astronomy & Astrophysics (AREA)
• General Physics & Mathematics (AREA)
• Remote Sensing (AREA)
• Aviation & Aerospace Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Waveguide Aerials (AREA)
• Details Of Aerials (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=85283846

Family Applications (1)

Country Status (7)

Family Cites Families (3)

• 2022
  • 2022-11-11 CH CH001348/2022A patent/CH720221A1/fr unknown
• 2023
  • 2023-11-10 CN CN202380078014.2A patent/CN120188336A/zh active Pending
  • 2023-11-10 IL IL320453A patent/IL320453A/en unknown
  • 2023-11-10 EP EP23806062.8A patent/EP4616480A1/de active Pending
  • 2023-11-10 JP JP2025525334A patent/JP2025538972A/ja active Pending
  • 2023-11-10 WO PCT/IB2023/061377 patent/WO2024100614A1/fr not_active Ceased
  • 2023-11-10 KR KR1020257014828A patent/KR20250084175A/ko active Pending

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