Classifications

• • 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
  • H01Q13/10—Resonant slot antennas
  • H01Q13/106—Microstrip slot antennas
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/002—Protection against seismic waves, thermal radiation or other disturbances, e.g. nuclear explosion; Arrangements for improving the power handling capability of an antenna
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/40—Radiating elements coated with or embedded in protective material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
  • H01Q9/0428—Substantially flat resonant element parallel to ground plane, e.g. patch antenna radiating a circular polarised wave

Definitions

• the present invention relates to a planar antenna for equipping a space vehicle, such as a space launcher or a satellite.
• Space vehicles are equipped with antennas that provide communication during flight phases between these vehicles and the ground stations.
• GNSS Global Navigation Satellite System
• the invention aims, according to a first aspect, a planar antenna intended to equip a space vehicle, the antenna comprising:
• the radiating antenna element present on the dielectric substrate, the radiating antenna element having a center of symmetry and a zone devoid of material, the center of symmetry being present in the zone devoid of material, and
• radiating antenna element will be referred to as "antenna element”.
• the area devoid of material has a polygonal shape.
• the antenna element has at least two symmetrical corners with respect to the center of symmetry, a first axis connecting these two corners, and the material-free zone extending from the center of symmetry. along a second axis forming an angle less than or equal to 5 ° with the first axis.
• Such a characteristic makes it possible to obtain a circular polarization for the radiation produced, and thus a reduced attenuation during its propagation.
• the second axis may form an angle less than or equal to 2 ° with the first axis.
• the area devoid of material is a slot.
• Such a characteristic makes it possible to obtain a hemispherical radiation pattern over an enlarged frequency band.
• the antenna element is positioned on the center of gravity of the dielectric substrate.
• the thickness of the protective layer is less than or equal to 5 mm.
• the protective layer is directly in contact with the antenna element and the dielectric substrate.
• Such a characteristic advantageously makes it possible to eliminate the risk of a Corona effect which could lead to a temporary loss of transmission.
• the protective layer is a thermal protection layer or a protective layer against space radiation.
• the present invention also relates to a vehicle equipped on its outer surface with at least one antenna as described above.
• the vehicle comprises on its outer surface a plurality of antennas as described above distributed uniformly on this surface.
• the vehicle is a space launcher or a satellite.
• FIG. 1 is a schematic and partial sectional view of a first example of a planar antenna according to the invention
• FIG. 2 is a view from above of the first example of planar antenna in transparency through the protective layer
• FIG. 3 is a perspective view of the first antenna example on the protective layer side
• FIG. 4 is a perspective view of the first antenna example on the ground plane side
• FIG. 5 represents, schematically and partially, a space vehicle equipped with two antennas according to the first example
• FIG. 6 to 8 show, schematically and partially, variants of planar antennas according to the invention.
• FIGS. 1 to 4 show a first example of a planar antenna 1 according to the invention.
• the planar antenna 1 comprises a dielectric substrate 3 on which is present an antenna element 5.
• the dielectric substrate 3 has a planar shape.
• the dielectric substrate 3 may be made of a composite material, for example glass-reinforced polytetrafluoroethene (PTFE).
• PTFE polytetrafluoroethene
• the dielectric substrate 3 may for example be a substrate sold under the reference TLC30 by the company Taconic. There is shown in this example a monolayer substrate 3 but it is not beyond the scope of the invention when the latter is formed by a plurality of stacked layers.
• the thickness of the dielectric substrate 3 can for example be less than or equal to 5 mm, and for example be between 2 mm and 5 mm.
• the dielectric substrate 3 may have a plurality of through apertures 8 each permitting the passage of a fixing element, such as a screw.
• the fixing elements make it possible to fix the antenna 1 to the spacecraft.
• the openings 8 may be present at the corners of the dielectric substrate 3, as illustrated in FIG.
• the antenna element 5 is formed by a metallization, for example copper.
• the antenna element 5 has a planar shape.
• the thickness e 5 of the antenna element 5 may for example be less than or equal to 40 ⁇ m, and for example be between 15 ⁇ m and 40 ⁇ m.
• the antenna element 5 is present on a first face F1 of the dielectric substrate 3. The antenna element 5 can be in contact with the dielectric substrate 3.
• FIG. 2 is a view in transparency through the protective layer 9, which may be transparent or opaque.
• Figure 1 is, in turn, a partial sectional view showing the antenna 1 only at the area where the antenna element 5 is present.
• the dielectric substrate 3 may carry a single antenna element 5.
• the antenna element 5 may cover the barycentre of the dielectric substrate 3.
• the barycentre of the dielectric substrate 3 may be a center of symmetry of this substrate 3.
• a ground plane 12 is present on a second face F2 of the dielectric substrate 3, opposite to the first face F1.
• the ground plane 12 is formed by a metallization, for example copper.
• a connector 14 is present on the second face F2 (shown in Figure 4, not shown in Figure 1).
• a coaxial power cable is intended to be connected to the connector 14.
• the dielectric substrate 3 may have a bore through which the central conductor of the connector extends which connects the input of the connector 14 to the antenna element 5 and which thus allows the supply of this antenna element 5 (drilling and central electrical conductor not shown).
• the antenna element 5 is intended to emit a signal in the radiofrequency spectrum.
• the antenna element 5 has a center of symmetry C1.
• the center of symmetry Cl of the antenna element 5 can be superimposed on the center of symmetry of the dielectric substrate 3, which is the case in the illustrated example.
• the antenna element 5 has a zone 7 devoid of material.
• the antenna element 5 may have a single zone 7 devoid of material.
• the center of symmetry Cl is present in zone 7 devoid of material. Area 7 devoid of material does not have a metal deposit. Area 7 devoid of material is symmetrical with respect to the center of symmetry Cl as illustrated.
• the surface of the dielectric substrate 3 may be entirely covered with a metallization. Then, a selective elimination of this metallization deposited in the zone 7 and around the radiating element 5 is carried out. The selective elimination carried out can be carried out through openings of a mask superimposed on the metallization carried out.
• the zone 7 devoid of material may have a polygonal shape, and for example a rectangular shape as illustrated. In a variant not shown, the material-free zone is square. Area 7 devoid of material may be a slot, as illustrated. As indicated above, this characteristic makes it possible to obtain a hemispherical radiation pattern over an enlarged frequency band, for example approximately 90 MHz in width.
• the ratio between the length L1 and the width L2 (L1 / L2) of the zone 7 devoid of material may be greater than or equal to 5, for example 10.
• the antenna element 5 may have a polygonal shape, and here has a square shape.
• the antenna element 5 may have corners COI and CO2 symmetrical to each other with respect to the center of symmetry Cl.
• the corners COI and CO2 may each form an apex of the antenna element 5.
• COI and C02 corners can each form an angle less than or equal to 90 °. In the example shown, the corners COI and CO2 each form a right angle, equal to 90 °.
• the corners COI and CO2 can be connected by a first axis XI.
• the first axis XI may define a diagonal of the antenna element 5.
• the zone 7 devoid of material may extend along a second axis X2.
• the second axis X2 may correspond to the longitudinal axis of the zone 7 devoid of material.
• the second axis X2 may form an angle less than or equal to 5 °, for example less than or equal to 2 °, with the first axis XI.
• the second axis X2 is, in the example illustrated in FIG. Figure 1, collinear with the first axis XI but it is not beyond the scope of the invention when this is not the case as will be described below.
• the protective layer 9 covers the antenna element 5 to protect it from the outside environment.
• the protective layer 9 has a planar shape.
• the protective layer 9 may be of dielectric material.
• the protective layer 9 covers the first face F1 of the dielectric substrate 3.
• the protective layer 9 may cover the entire dielectric substrate 3 (see FIG. 3).
• the protective layer 9 may be in contact with the antenna element 5 and the dielectric substrate 3. Thus, the antenna 1 may not have a cavity therein.
• the thickness e 9 of the protective layer 9 may be less than or equal to 5 mm.
• the protective layer 9 may be a thermal protection layer or a protective layer against space radiation.
• the thermal protection layer may have a thermal conductivity, measured at 50 ° C., of less than or equal to 0.3 W.rrf 1 .K 1 , for example at 0.2 Wm ⁇ .K 1 .
• a thermal conductivity measured at 50 ° C.
• the material forming the protective layer against space radiation may not be degraded after absorption of a dose of gamma radiation greater than or equal to 10,000 Gray, for example 15,000 Gray.
• the antenna When it equips a space launcher, it is advantageous to provide the antenna with a thermal protection layer in order to protect the underlying elements from the high temperatures encountered during operation.
• FIG. 5 schematically shows a space vehicle V equipped with two antennas 1 according to the first example.
• the substrate 3 is sufficiently flexible to conform to the shape of the surface S of the vehicle V. It is thus possible in this case to give the substrate 3 a non-zero curvature when it is mounted on the outer surface S of the vehicle. V.
• the antenna 1 is in this case directly attached to the surface S without requiring the use of an additional sheet of adaptation to the curvature of the surface of the spacecraft V.
• the spacecraft V can be a launcher space or a satellite. The space launcher can allow the positioning of one or more satellites.
• the antennas 1 can be uniformly distributed over the surface of the spacecraft V.
• the antennas can each occupy the same angular coverage.
• FIG. 6 shows an alternative antenna element
• the antenna element 15 differs from the antenna element 5 only in that it comprises corners C03 and C04 symmetrical with respect to the center of symmetry C1 which correspond to truncated vertices. .
• the antenna element 15 here has a square shape with two truncated peaks C03 and C04.
• FIG. 7 shows another variant of antenna element 25.
• the antenna element 25 differs from the antenna element 5 only in that the second axis X2 forms an antenna element 25. non-zero angle with the first axis XI, here equal to 5 °.
• the other characteristics described above in the context of the example of Figures 1 to 4 remain applicable to this embodiment.
• antenna element 35 differs from antenna element 5 only in that it has a circular shape. and no longer square.
• the antenna element could have another shape such as an oval shape, or rectangular non square.
• the other characteristics described above in the context of the example of Figures 1 to 4 remain applicable to this embodiment.
• the expression "understood between ... and " must be understood as including boundaries.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Astronomy & Astrophysics (AREA)
• Aviation & Aerospace Engineering (AREA)
• General Physics & Mathematics (AREA)
• Remote Sensing (AREA)
• Waveguide Aerials (AREA)
• Details Of Aerials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62222827

Family Applications (1)

Country Status (4)

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Citations (1)

Family Cites Families (11)

• 2018
  • 2018-01-19 FR FR1850443A patent/FR3077165B1/fr active Active
• 2019
  • 2019-01-17 EP EP19706730.9A patent/EP3741003A1/de active Pending
  • 2019-01-17 US US16/962,766 patent/US11489248B2/en active Active
  • 2019-01-17 WO PCT/FR2019/050095 patent/WO2019141947A1/fr unknown

Patent Citations (1)

Non-Patent Citations (2)

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