EP0546913B1 - Antenne mit feststehendem Reflektor für mehrere Strahlen von Kommunikationssystemen - Google Patents

Antenne mit feststehendem Reflektor für mehrere Strahlen von Kommunikationssystemen Download PDF

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Publication number
EP0546913B1
EP0546913B1 EP92403306A EP92403306A EP0546913B1 EP 0546913 B1 EP0546913 B1 EP 0546913B1 EP 92403306 A EP92403306 A EP 92403306A EP 92403306 A EP92403306 A EP 92403306A EP 0546913 B1 EP0546913 B1 EP 0546913B1
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EP
European Patent Office
Prior art keywords
reflector
antenna
axis
grating
antenna according
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EP92403306A
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English (en)
French (fr)
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EP0546913A1 (de
Inventor
Jean-Jacques Delmas
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Telediffusion de France ets Public de Diffusion
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Telediffusion de France ets Public de Diffusion
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/06—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens
    • H01Q19/062—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens for focusing
    • H01Q19/065—Zone plate type antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
    • H01Q19/12—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces wherein the surfaces are concave
    • H01Q19/17—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces wherein the surfaces are concave the primary radiating source comprising two or more radiating elements

Definitions

  • the present invention relates to an antenna for receiving or transmitting telecommunications beams.
  • the antenna is intended for domestic installations in individual houses, for collective installations in buildings, or for community installations used to supply cable network heads to receive several beams emitted by telecommunications satellites. , including conveying television signals.
  • the present invention can be used for professional applications, in particular in data broadcasting networks.
  • the most commercially available satellite reception antenna currently comprises a fixed reflector, the reflecting surface of which is a paraboloid of revolution, or an elliptical paraboloid, with a width of approximately 90 to 120 cm, or a portion of such a paraboloid for a antenna with off-center illumination, called offset antenna.
  • the axis of symmetry of the reflector is pointed towards the satellite whose emissions are to be received.
  • a microwave receiving head generally fixed by guy wires, is positioned at the single focus of the paraboloid reflector.
  • the antenna can receive the beams of these various satellites.
  • the reflector of the receiving antenna must be turned to point towards this other satellite.
  • Two solutions are necessary: either the user climbs on the roof of the pavilion or the building to manually position the reflector, or the antenna must include motorized and remote-controlled means to orient the reflector.
  • the first solution is in practice very rarely implemented by the user, given the difficulties of access to the antenna. It therefore requires the use of a specialized installer, and a new adjustment of the position of the reflector, and consequently is very dissuasive for the user.
  • the second solution is penalized by the cost of the antenna and its installation, a motorized reflector antenna requiring a heavier and bulky infrastructure.
  • antennas are flat and are based on the principle of FRESNEL lenses (DE-A-3 536 348 and DE-A-3 801 301) in order to remedy the high cost and the unsightly appearance of the parabolic antennas.
  • FRESNEL lenses DE-A-3 536 348 and DE-A-3 801 301
  • these antennas also offer a single focus and therefore a single pointing direction.
  • the present invention aims to remedy the drawbacks of the above-mentioned antennas and more particularly to provide an antenna whose reflector is fixed, that is to say is pointed once and for all towards a predetermined direction, while allowing reception or transmission of several beams from or to satellites having different orbital positions included in a wide scanning angle.
  • the antenna can receive several beams of satellites having completely different orbital positions.
  • two microwave heads placed respectively at the two homes can simultaneously receive beams emitted by two telecommunication satellites having orbital positions distant by several tens of degrees in longitude.
  • the axis of symmetry of the reflective surface of the reflector is then pointed once and for all, not towards one of the satellites, but preferably towards the perpendicular bisector of the segment defined by the positions orbitals of the two satellites.
  • the reflector does not have an axial symmetry although it comes from a portion of a surface symmetrical with respect to an axis of symmetry.
  • the antenna comprises only a portion of the annular network similar to that of the reflector, and cut along the contour of the reflector.
  • the diffraction grating is designed using the diffraction principle of FRESNEL optical lenses, as we will see later.
  • the gain of the antenna according to the invention is substantially equal to that of a conventional antenna with the same reflector. Indeed, the rays of the beams are partly diffracted by the diffraction grating, and partly reflected by the annular portions of the reflecting surface of the reflector situated under interstices between the elements of the diffraction grating.
  • the diffraction grating can comprise a central cap-shaped element which is surrounded by the annular elements and which is substantially symmetrical with respect to said axis of symmetry, although in a variant a diffraction grating according to the invention can be composed only annular elements instead of annular interstices between elements of the previous network.
  • Theoretical calculations show that the dimensions of the diffraction grating depend on the wavelength corresponding substantially to the central frequency in a carrier frequency band of satellite beams to be picked up, and that the distance between the reflecting surface of the reflector and the grating. diffraction is substantially equal to a quarter of the wavelength corresponding substantially to the center frequency of the carrier frequency band, particularly for a given gain in diffraction in a direction of a wavelength sufficiently short to allow the use of the antenna in reflection at a lower frequency.
  • the measurements for antennas according to the invention have shown that the dimensions of the diffraction grating admit a relatively wide tolerance.
  • the widths of the network elements decrease radially from the axis of symmetry, and / or the widths of the interstices between the network elements decrease radially from the axis of symmetry.
  • the contours of at least part of the network elements can then be substantially elliptical, the minor axes of the contours being located in a focal plane containing the first and second focal points and the axis of symmetry.
  • the contours of at least part of the network elements can be circular and concentric, in particular when the first and second focal points are relatively close to the axis of symmetry of the reflector.
  • the symmetrical surface from which the reflector originates is a paraboloid, for example of revolution or elliptical, although the reflective surface of the reflector can be of any other known concave shape with axial symmetry.
  • the diffraction grating is obtained by cutting from a second reflector identical to said antenna reflector, that the reflector is with symmetry of revolution, or with offset illumination (offset) in particular.
  • the antenna can be implemented stamping techniques, or printing or metallic deposition on a machined or molded dielectric material, or techniques for implanting thin layers in a dielectric material.
  • an antenna according to the invention comprises several different arrays of annular diffraction elements which are superimposed parallel to the reflector.
  • the annular elements of the networks are then brought together in groups, at the rate of one element of each network per group, the annular elements of each group having outer edges substantially superimposed perpendicularly to the reflector and having inner edges forming stair treads. of the reflector.
  • the invention envisages various solutions for picking up multiple satellite beams with the same fixed reflector provided with one or more diffraction gratings.
  • the antenna has several microwave heads which are fixed along the focal line passing through the two focal points, after adjusting their orientation.
  • first heads are fixed in the vicinity, that is to say a few centimeters at most, of one of the focal points to respectively receive beams emitted from satellites having orbital positions in substantially equal longitude; and / or several second heads are fixed in proximity, that is to say a few or several tens of centimeters, from one of the focal points for respectively picking up beams emitted from satellites having orbital positions distant in longitude by several degrees or tens of degrees.
  • the heads are positioned so as to receive a maximum of the radiation from the satellites respectively.
  • means are provided, preferably motorized, for adjusting and fixing the positions and orientations of the receiving heads. These means allow various movements of the heads, preferably substantially in the focal plane and along the focal line.
  • the means for adjusting and fixing the heads can comprise means for individually translating the heads substantially in a direction parallel to the right passing through the hearths, and / or means for individually turning the heads around an axis perpendicular to the axis of symmetry and in particular in the focal plane, and / or means for individually translating the heads in a direction substantially converging towards the center of the reflector.
  • the antenna does not includes only one microwave head which is mobile and preferably multipolarized in order to adapt to the various directions and polarizations of the telecommunications beams.
  • motorized means are then fixed to the supporting structure of the reflector to move the head at least substantially along said focal line.
  • the means for moving the head may include an arm passing through a central region of the antenna and having a first end supporting said head, and a second end mounted at least in rotation about an axis substantially perpendicular to the focal plane.
  • the flat lens LP a comprises several concentric rings of opaque material AO a which are concentric with a common center C a .
  • the opaque rings are fixed on a transparent film or plate and are thus alternated with transparent rings AT a .
  • a collimated incident beam FI is perpendicular to the flat lens LP is refracted through the transparent rings AT a.
  • the resulting diffracted beam FD a is focused at a focal point F a situated along the main axis O a - O a of the lens LP a and at a focal distance DF a from the center C a of the lens when the walking delay between two rays of the diffracted beam from the outer and inner edges of an opaque ring is equal to the half wavelength ⁇ / 2 of the electromagnetic wave of the incident beam.
  • the focal point F b of the lens LP b is offset with respect to the main axis O b - O b of the lens, is closer to the center of the lens, and is located on the passing incident ray through the center C b of the lens LP b .
  • the opaque rings AO b and transparent rings AT b of the lens LP b are no longer circular and concentric, but are elliptical rings which are eccentric with respect to each other and with respect to the main axis of the lens.
  • the major axes of the rings are collinear with each other and perpendicular to the main axis of the lens and located in the focal plane F b - O b - O b .
  • Such lenses LP a and LP b can be used for light beams having a predetermined incidence relative to the plane of the lens.
  • the incident beam FI a , FI b is a microwave (or microwave), such as a beam emitted by a satellite at a frequency of several gigahertz
  • the opaque rings AO a , AO b are made of conductive material, c that is to say metallic.
  • German patent application DE-A-3 801 301 recommends a plate antenna having a metallic plane reflector in front of which is disposed a plane assembly of circular and concentric metallic rings, like the opaque rings AO a of the lens of FRESNEL LP a , intended to receive microwaves, particularly millimeter waves.
  • An incident microwave beam directed perpendicular to the antenna is then diffracted and reflected to be focused in a single focal point located vertically from the center of the rings and facing them, that is to say located to the right of the lens.
  • LP a in figure 1.
  • the metal rings can rest on a homogeneous material fixed on the reflector, so that the distance between the reflector and the circular rings are equal to approximately a quarter of wavelength.
  • German patent application DE-A-3,536,348 discloses a flat antenna based on the second lens of FRESNEL LP b .
  • This antenna therefore has a flat metal reflector and a flat set of elliptical metal rings.
  • the invention applies in three-dimensional space the principle of diffraction of FRESNEL lenses, and combines this principle with the reflection and symmetry properties of an antenna with axial symmetry, of the type for example with parabolic reflector, to which reference is made below.
  • reception antennas provided with one or more reception heads, although the combinations of reflector and diffraction grating (s) according to the invention can also serve as transmission antennas provided with a or more emission heads.
  • an antenna 1 essentially comprises a reflector 2 and an annular diffraction grating 3 both offering parallel concave reflecting surfaces, for example paraboloid surfaces.
  • an antenna 1 is indicated below by way of nonlimiting example.
  • the dimensions of the diffraction grating 3 are indicated with respect to coordinates in an orthonormal triaxial coordinate system Ox, Oy, Oz.
  • O is the center of the network, very close to that of the reflector, and more precisely the center of a parabolic concave surface from which the network originates, and Oz denotes the axis of symmetry of said surface and here of the network and the reflector.
  • the reflector 2 is conventional and is constituted by a paraboloid cap which is here of revolution and which is manufactured for example from expanded metal such as aluminum.
  • the reflector has a thickness of 1.2 mm, a radius R2 of 437 mm and a height H2 of 163.5 mm.
  • the reflector is supported by a conventional supporting structure (not shown), such as a mast and / or network of reinforcements, and is fixed for example on the roof of a single house.
  • the diffraction grating 3 is composed of a paraboloidal cap 30, and of several rings dishes 31 to 34, here four in number.
  • the diffraction grating is composed only of annular elements in place of the annular interstices between the elements 30 to 34 of the illustrated network 3, in a manner analogous to the distribution of the opaque rings AO a , AO b of the lenses LP a , LP b .
  • the network 3 is obtained from a second reflector which is identical to the reflector 2 and in which the cap and the rings are cut according to the dimensions indicated below.
  • the network 3 is fixed parallel to and on the concave reflective surface of the reflector 2 by means of dielectric shims 31 interposed between the glue 2 and the network 3.
  • the shims 31 are made of an electrically insulating and light material, for example of polystyrene.
  • the thickness of the shims is substantially less than a quarter of the wavelength ⁇ , typically equal to 25 / 4-1.2 ⁇ 5 mm, so that the distance between the concave surfaces of the reflector 1 and of the grating 3 is substantially equal at ⁇ / 4.
  • the wavelength ⁇ of the order of 2.5 cm corresponds to the average wavelength of microwave beams to be picked up by the antenna and emitted by geostationary satellites.
  • the antenna 1 is initially intended to receive two electromagnetic telecommunication beams FS1 and FS2 of a first satellite ST1, such as the satellite TDF 1 (or OLYMPUS, or TV SAT 2) located at 19 ° west longitude, and a second ST2 satellite, such as the ASTRA 1 satellite located at 19 ° east longitude.
  • a first satellite ST1 such as the satellite TDF 1 (or OLYMPUS, or TV SAT 2) located at 19 ° west longitude
  • a second ST2 satellite such as the ASTRA 1 satellite located at 19 ° east longitude.
  • a beam FI b having an angle of incidence i relative to the flat lens LP b was focused in a focal point F b offset from the axis O b -O b of the lens.
  • the paraboloid symmetry of the antenna 1 there are two foci F1 and F2 which are symmetrical with respect to the axis Oz and where two telecommunication beams FS1 and FS2 emitted by two satellites can be focused, insofar as the axis Oz of the antenna 1 is substantially collinear with the bisector of the viewing angle 2 ⁇ of the two satellites.
  • the antenna 1 is not oriented towards one of the satellites whose emissions are to be received, and can simultaneously receive beams emitted by at least two satellites, although the reflector is stationary on the earth, for example on the roof of a house. Under these conditions, two symmetrical foci F1 and F2 are sought on coplanar half-lines OF1 and OF2 directed towards the satellites ST2 and ST1 respectively.
  • an incident ray from the ST1 satellite and belonging to the FS1 beam will pass by the focal point F2 and will be reflected by the center 0 of the cap 30 in a reflected ray passing through the focal point F1, as shown in FIG. 5, and conversely for an incident ray of the beam FS2 passing through the focal point F1 and reflected in a radius from center 0 and passing through the focal point F2.
  • a series of transparent rings can be replaced by a series of reflecting rings, as already indicated.
  • the central parabolic cap 30 may be preferred to a "transparent" central hole in the diffraction grating so as to substantially increase the efficiency of the antenna.
  • microwave heads 41 and 42 placed in these focal points contain all of the reflector.
  • these microwave heads are in the form of a box containing a given gain source supplying an amplifier followed by a frequency converter which converts the frequency modulated signal in the 12 GHz band (centimeter waves) into a first intermediate frequency of the order of 1 to 2 GHz.
  • These heads are connected by transmission lines, such as conventional flexible waveguides (coaxial cables), and power cables 411 and 422 to a terminal for processing the received signals.
  • a microwave signal switch again transposes into baseband frequency and selects the signals received before applying them, for example to a television signal receiver.
  • the heads 41 and 42 are fixed on a support, such as gantry 5, which is integral with the carrying structure (not shown) of the reflector, and which will be described later according to several variants.
  • the widths b1, b3 - b2 to b9 - b8 of the metallic elements of the network decrease from the center 0 towards the periphery of the reflector.
  • the widths of the metallic elements of the network along the axis Oy decrease from the center 0 towards the periphery of the reflector.
  • the widths of the elements and the interstices along the major axes 2a1 to 2a9 are substantially greater than the widths of the elements and interstices along the minor axes 2b1 to 2b9.
  • the eccentricities of the elliptical edges of the elements 3 O to 34 of the diffraction grating increase appreciably away from the periphery.
  • the antenna is of the type as defined above with reference to FIGS. 5 and 6.
  • the focal points F1 and F2 are merged into a focal point FO on the focal line LF and the axis Oz, towards which an electromagnetic beam diffracted by the networks converges.
  • the networks R1 to R m-1 R3, according to the increasing rank 1 to m-1 thereof from the reflector 2, comprise a group of superimposed rings whose inner edges move away from the central axis "stairway" Oz and which correspond to walking delays of ((n-1) m + 1) ⁇ / m, ((n-1) m +2) ⁇ / m, ...
  • the ring of the second network R2 has a width 2w substantially equal to two thirds of the width 3w of the ring of the first network R1 just above the reflector 2 and substantially covers the two -third of this ring of the network R1 from the edge B n , on the one hand, and has a width substantially equal to one third of the width w of the ring of the third network R3 and is substantially covered by the third of this ring network R3 from edge B n , on the other hand; the inner edges of the aforementioned rings of the networks R1 to R3 are separated from the main edge B n-1 by annular interstices having widths w, 2w and 3w.
  • a homogeneous continuous dielectric layer can cover the reflector 2 according to the variants shown in FIGS. 5 and 7 in order to support the network 3, respectively the network R1; similarly, in the antenna of the type of FIG. 7, the sets of dielectric rings can be replaced by continuous dielectric layers superimposed with the networks.
  • the gratings can be produced in the form of layers annular metal printed or deposited by any known process on superimposed and glued dielectric layers, or else printed or deposited on a single dielectric layer machined or molded in stair treads; or else each ring is made in the form of concentric metallic wires and separated from each other by a small distance from the wavelength and integral or integrated in a preferably transparent dielectric material; or even the networks are produced according to the technique of thin layers also called multilayer.
  • the dielectric material may be partially or completely opaque such as polystyrene, or transparent such as glass.
  • the risers, substantially of thickness ⁇ / (2m) can be coated with a metallic layer, or else with an absorbing layer anti-reflection of electromagnetic waves in order to avoid any undesirable parasitic reflection.
  • the continuous profile of the diffraction gratings and of the staircase reflector according to the section shown in FIG. 7 is obtained by stamping a homogeneous or perforated metal plate, or made of expanded metal, which constitutes at itself both the reflector and the diffraction gratings.
  • the antenna can result from the assembly of two, three, four or more substantially identical curvilinear sectors, following a regular radial division in top view of the antenna shown in FIG. 6 or 8, or substantially curvilinear "petals" having substantially rectangular contours and assembled along sides parallel to the axes Ox and Oy.
  • antennas having an elliptical paraboloid reflector that is to say having circular cross sections perpendicular to the axis Oz
  • the invention also applies to antennas having an elliptical paraboloid reflector, and more generally to any antenna which comprises a reflector with a concave reflecting surface offering an axis of symmetry in a focal plane,
  • the reflector may consist of a portion of such a reflecting surface so as to constitute an antenna of the type with off-center source, also called offset source.
  • the diffraction grating or all of the diffraction grating is cut into a second portion identical to the portion of reflecting surface of the reflector, along the contour of the offset reflector, and certain elements of the or each grating, in particular peripheral , can only be annular sectors.
  • the microwave heads 41 and 42 are supported for example by a thin gantry 5 of light material, placed in front of the reflector 2.
  • the gantry essentially comprises, as shown in FIG. 5, a beam 51 arranged perpendicular to the axis Oz and located in the focal plane F1 - O - F2, as well as two uprights 52 substantially parallel to the axis Oz and connecting the ends of the beam to peripheral ends of the support structure (not shown) of the reflector.
  • the beam and the uprights can be light alloy tubes in which the cables 411 and 412 run in the direction of the reception terminal.
  • the same antenna 1 according to the invention that is to say the same combination of the reflector 2 and the diffraction grating 3 or the set of gratings diffraction R1 to R m-1 , naturally accepts positions of the reception heads in the vicinity of the focal points F1 and F2 in order to pick up beams from satellites having neighboring orbital positions and thus corresponding to substantially equal viewing angles.
  • the same antenna 1 can be used to receive beams from satellites associated with viewing angles which differ by several degrees from the angle ⁇ , that is to say directions of radiation which are very different from the OF1 and OF2 directions. Indeed, for example a beam coming from the line in FIG. 5, like the beam FS1, but associated with a viewing angle relative to the axis Oy which is even smaller, will be picked up with an acceptable yield when a receiving head is placed between the focal point F1 and the axis Oz.
  • the reception heads must be substantially centered on a focal curved line LF symmetrical with respect to the axis Oz, passing through the foci F1 and F2, and having the radius of curvature greater than the distance between the center of the reflector and a focus F1, F2; however, in practice, the focal line LF can be approximately defined by an arc of circle having for center the center of the reflector or the center O of the diffraction grating or networks and a radius of the order of OF1 to (2.OF1) . Under these conditions, the beam 51 is preferably substantially curved along the focal line LF.
  • the beam 51 thus supports several first reception heads, such as heads 41, 43 and 44, which are fixed in the vicinity of one F1 of the homes to respectively receive beams of satellites coming from the right of the Oz axis.
  • heads 41, 43 and 44 are fixed in the vicinity of one F1 of the homes to respectively receive beams of satellites coming from the right of the Oz axis.
  • heads 41, 43 and 44 are fixed in the vicinity of one F1 of the homes to respectively receive beams of satellites coming from the right of the Oz axis.
  • heads 41, 43 and 44 are fixed in the vicinity of one F1 of the homes to respectively receive beams of satellites coming from the right of the Oz axis.
  • the beam 51 also supports several second reception heads, such as the heads 45, 46 and 47, which are fixed near the foci F1 and F2 relative to the axis Oz of the antenna to pick up respectively beams coming from satellites having orbital directions, seen from the antenna, which differ markedly from OF2 and OF1.
  • a second head 45 assigned to receiving the beam from the EUTELSAT 1 F1 satellite located at 16 ° east longitude is positioned
  • another second 46 head assigned to the reception of the beam from the KOPERNIKUS 1 satellite located at 23.5 ° east longitude is positioned near the focus F1 to receive the beam emitted by the TELECOM 1A satellite having an orbital position of 8 ° west longitude.
  • each of the heads is adapted to the carrier frequency of the signals transmitted by the respective satellite.
  • the carrier frequency band has a width of a few gigahertz
  • the dimensions of the diffraction grating 3 or of the diffraction grids R1 to R n-1 as well as the distances ⁇ / (2.m) between grids and reflector are not critical. So these dimensions are calculated for a substantially average frequency in the band of frequencies carrying the telecommunication beams, typically equal to 12 GHz for frequencies substantially between 11 and 13 GHz.
  • the beam 51 of the antenna 1 comprises mechanical means for manually adjusting the positions of the heads 41 to 47 in order to properly orient the opening angles ⁇ of each of the heads as a function of the dimensions of the reflector 2 and thus capture the maximum of radiation.
  • the adjustment means consist, for example, of a beam 51 comprising one or more longitudinal slides 53 parallel to the plane yOz, or to the focal line LF, in which slides 54 can slide, integral with the head mounts.
  • each head is mounted on the one hand, in rotation about an axis substantially perpendicular to the axis of symmetry Oz, preferably parallel to the axis Ox, on the other hand in translation along its longitudinal axis and thus in a direction substantially converging towards the center of the reflector, as indicated by double arrows RO and TR for the head 42 in FIG. 5.
  • these various displacement means are associated known locking means so as to stabilize the position of the head along the beam 51 and the orientation of the latter in a plane substantially parallel to the focal plane yOz. Under these conditions, each head can be positioned effectively near one of the focal points F1 and F2 or more generally at an optimal position of transmission / reception substantially along the focal line LF.
  • the means for adjusting the positions of the heads may be partially or fully motorized, and preferably remotely controlled by cables attached to the gantry 5.
  • This motorization of the adjustment means is particularly appreciable when the antenna is fixed to the roof of a pavilion, by nature not very accessible.
  • the antenna user adjusts the positions of the heads from the ground, and can reduce the number of heads carried by the beam, by means of adaptations and frequency selections.
  • the antenna comprises only a single microwave head 4, as shown in FIG. 9.
  • the head 4 is fixed to the upper end of a support arm 6 which passes through a double hole 32-22 formed in the centers of the cap 30 of the diffraction grating 3 and of the reflector 2 for the embodiment illustrated in FIG. 9 in agreement with FIG. 5, or a simple hole 22 central to the reflector for an embodiment in accordance with FIG. 7.
  • the lower end of the arm 6 under the reflector is mounted to rotate about an axis 61 which is substantially parallel to the axis Ox and connected by mechanical transmission means, of the gear type for example, to a small electric motor 62 remotely controllable from the ground.
  • the motor 62 and the axis 61 are fixed to the support structure of the reflector.
  • the width of the hole 32-22, or 22, is such that the arm can sweep a plane parallel to and close to the focal plane yOz and consequently the head 4 can travel substantially along the focal line LF on either side from the axis of symmetry Oz to an angle ⁇ greater than ⁇ , that is to say on the order of 40 °.
  • the head 4 is preferably mounted in longitudinal sliding at the upper end of the arm so as to travel more precisely along the predetermined focal line LF.
  • the motor 62 when the motor 62 is activated, for example stepping or automatically for predetermined head positions, the user controls the rotation of the arm from the ground in order to position the head at one of the desired positions to receive the beam from one of the satellites. Simultaneously, the microwave switch in the reception terminal is set to the associated carrier frequency (after frequency conversion in the head).
  • the lower end of the arm 6 can be movable inside a cone with a circular or elliptical cross section, in particular depending on the type of reflector used.
  • the movement means 61-62 of the arm are equivalent to a motorized universal joint.
  • the head 4 is of the multipolarization type of the propeller source type. It is connected to the reception terminal by a conventional low-loss waveguide, or by an optical fiber housed in the arm 6.
  • the double hole 32-22 or the single hole 22 is coated with a dielectric layer, or is closed by a flexible dielectric membrane 33 crossed by the arm 6 in order to avoid any radiation reflected at the center of the antenna susceptible to adversely disturb the beam received to diffract.

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Claims (17)

  1. Antenne (1) für mehrere Strahlen von Kommunikationssytemen (FS₁, FS₂) beinhaltend einen feststehenden Reflektor (2), ein Netz von ringförmigen (3₁ - 3₄) Diffraktionselementen (3; R₁-R m-1), oder einen Teil des genannten Netzes (3; R₁-R m-1), parallel zum Reflektor angeordnet, und einen dem Reflektor gegenübergestellten Höchstfrequenzkopf (4), dadurch gekennzeichnet, daß der Reflektor (2) und das Netz (3 ; R₁-R m-1) beide reflektierende Oberflächen haben, die konkav sind und von in bezug auf die Symmetrieachse (Oz) in etwa symmetrischen Teilflächen herkommen, wobei obiges Diffraktionsnetz einen ersten und einen zweiten Herd (F₁, F₂) definiert, die in bezug auf genannte Symmetrieachse (Oz) symmetrisch sind, und in welche ein erster und ein zweiter Strahl von Kommunikationssystemen (FS₁, FS₂) eventuell zusammenlaufen können, die in etwa parallel zu Geraden (OF₂, OF₁) geleitet werden und durch die Mitte (O) der Symmetriefläche und jeweils durch den zweiten und den ersten Herd durchgehen, und dadurch, daß der Höchstfrequenzkopf (4) etwa entlang einer leicht krummen Fokallinie (LF) positioniert ist, welche auf der Symmetrieachse (Oz) zentriert ist, einen Krümmungsradius hat, der mindestens in etwa gleich dem Abstand zwischen genannter Mitte (O) und jedem Herd (F₁, F₂) ist, und durch den ersten und den zweiten Herd (F₁, F₂) durchgeht.
  2. Antenne nach Anspruch 1, dadurch gekennzeichnet, daß die Breiten (b₁, b₃ - b₂, b₅ - b₄, b₇ - b₆, b₉ - b₈) der Netzelemente 3₀ bis 3₄ von der Syammetrieachse (Oz) aus radial abnehmen, und/oder die Breiten (b₂ - b₁, b₄ - b₃, b₆ - b₅, b₈ - b₇) der Zwischenräume zwischen den Netzelementen (3₀ bis 3₄) ab der Symmetrieachse radial abnehmen.
  3. Antenne nach Anspruch 1 cder 2, dadurch gekennzeichnet, daß die Konturen von mindestens einem Teil der Netzelemente (3₀ bis 3₄) in etwa elliptisch sind, wobei sich die kleinen Achsen (2b₁ bis 2b₉) der Konturen in einer Fokalebene (yOz) befinden, die die Herde (F₁, F₂) und die Symetrieachse (Oz) beinhaltet.
  4. Antenne nach irgendeinem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die Konturen von mindestens einem Teil der Netzelemente (3₀ bis 3₄) kreisförmig und konzentrisch sind.
  5. Antenne nach irgendeinem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß das Diffraktionsnetz (3; R₁ - Rm-1) mit der konkaven reflektierenden Fläche des Reflektors (2) mittels des dielektrischen Materials (31) verbunden ist.
  6. Antenne nach irgendeinem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Gesamtheit Diffraktionsnetz (3; R₁ - Rm-1) und Reflektor (2) auf ein dielektrisches Material eingedrückt oder abgesetzt wird, das wie ringförmige Treppenstufen bearbeitet oder geformt ist, oder dünne Schichten in einem dielektrischen Material bildet.
  7. Antenne nach irgendeinem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß das Diffraktionsnetz (3; R₁ - Rm-1) durch Aufteilung in einem zweiten Reflektor erreicht wird, welcher dem genannten Reflektor (2) der Antenne identisch ist.
  8. Antenne nach irgendeinem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß das Diffraktionsnetz (3; R₁ - Rm-1) und der Reflektor aus einer Stulpblech-Platte bestehen.
  9. Antenne nach irgendeinem der Ansprüche 1 bis 8, dadurch gekennzeichnet, daß das Diffraktionsnetz (3) ein haubenförmiges Mittelelement (3O) enthält, das in etwa symmetrisch in bezug auf die Symmetrieachse (Oz) ist.
  10. Antenne nach irgendeinem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß der Reflektor (2) und das Netz (3) in etwa ein Viertel Wellenlänge (λ) voneinander entfernt sind, die in etwa einer Frequenz in einem Frequenzband mit Strahlen von Kommunikationssystemen (FS₁, FS₂) entspricht.
  11. Antenne nach irgendeinem der Ansprüche 1 bis 8 mit mehreren verschiedenen Netzen von ringförmigen Diffraktionselementen (R₁ - Rm-1), die vor dem Reflektor parallel übereinandergelegt sind.
  12. Antenne nach Anspruch 11, in welcher die ringförmigen Elemente der Netze in Gruppen gesammelt sind, in einem Verhältnis von einem Element von jedem Netz pro Gruppe, wobei die ringförmigen Elemente jeder Gruppe Außenränder (Bn) in etwa senkrecht zum Reflektor übereinanderliegen und die Innenränder ausgehend vom Reflektor Treppenstufen bilden.
  13. Antenne nach Anspruch 12, dadurch gekennzeichnet, daß die Breiten der ringförmigen Elemente in jeder der genannten Gruppen arithmetisch abnehmen, ausgehend vom Reflektor mit einem Verhältnis von in etwa gleich der Breite des Elements (Rm-1) der vom Reflektor (2) entferntesten Gruppe.
  14. Antenne nach irgendeinem der Ansprüche 11 bis 13, dadurch gekennzeichnet, daß die Entfernung zwischen dem Reflektor (2) und dem unmittelbar benachbarten Netz und die Entfernungen zwischen beiden benachbarten Netzen (R₁ - Rm-1) in etwa gleich λ/(2.m) sind, wobei λ eine Wellenlänge ist, die in etwa der Frequenz in einem Frequenzband mit Strahlen von Kommunikationsystemen (FS₁, FS₂) entspricht, und m-1 die Zahl der Diffraktionsstrahlen bezeichnet.
  15. Empfangsantenne nach irgendeinem der Ansprüche 1 bis 14, dadurch gekennzeichnet, daß sie mehrere Höchstfrequenzköpfe enthält (4₁ bis 4₇), die in etwa in der Nähe der genannten Fokallinie (LF) liegen.
  16. Antenne nach Anspruch 15, dadurch gekennzeichnet, daß sie Mittel (5) und zwar vorzugsweise motorisierte Mittel zur Regelung und Fixierung der Positionen und der Orientierung der Köpfe (4₁ bis 4₇) enthält.
  17. Antenne nach irgendeinem der Ansprüche 1 bis 15, dadurch gekennzeichnet, daß sie Mittel und zwar vorzugsweise motorisierte Mittel beinhaltet, um den Kopf (4) in etwa längs der genannten Fokallinie (LF) zu bewegen, wobei genannte Mittel zum Bewegen des Kopfes vorzugsweise einen durch einen zentralen Bereich (32, 22) der Antenne durchgehenden Arm (6) beinhalten, und ein den genannten Kopf (4) tragendes erstes Ende sowie ein zweites Ende aufweisen, das um eine Achse (61) mindestens rotierbar montiert ist, und in etwa senkrecht zu einer Fokalebene (yOz), welche genannte Herde (F₁, F₂) und genannte Symmetrieachse (Oz) enthält.
EP92403306A 1991-12-11 1992-12-07 Antenne mit feststehendem Reflektor für mehrere Strahlen von Kommunikationssystemen Expired - Lifetime EP0546913B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9115376A FR2685131B1 (fr) 1991-12-11 1991-12-11 Antenne de reception a reflecteur fixe pour plusieurs faisceaux de satellite.
FR9115376 1991-12-11

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EP0546913A1 EP0546913A1 (de) 1993-06-16
EP0546913B1 true EP0546913B1 (de) 1996-04-17

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US (1) US5283591A (de)
EP (1) EP0546913B1 (de)
JP (1) JPH05308221A (de)
DE (1) DE69209992T2 (de)
ES (1) ES2086100T3 (de)
FR (1) FR2685131B1 (de)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2701169B1 (fr) * 1993-02-02 1995-04-14 Telediffusion Fse Réflecteur d'antenne à diffraction pour plusieurs faisceaux de télécommunications.
TW274170B (en) * 1994-06-17 1996-04-11 Terrastar Inc Satellite communication system, receiving antenna & components for use therein
US5745084A (en) * 1994-06-17 1998-04-28 Lusignan; Bruce B. Very small aperture terminal & antenna for use therein
WO1996002953A1 (en) * 1994-07-20 1996-02-01 Commonwealth Scientific And Industrial Research Organisation Feed movement mechanism and control system for a multibeam antenna
FR2724059B1 (fr) 1994-08-31 1997-01-03 Telediffusion Fse Reflecteur d'antenne pour plusieurs faisceaux de telecommunications
US6011517A (en) * 1997-09-15 2000-01-04 Matsushita Communication Industrial Corporation Of U.S.A. Supporting and holding device for strip metal RF antenna
JP3547989B2 (ja) * 1998-04-10 2004-07-28 Ｄｘアンテナ株式会社 マルチビームアンテナ用反射鏡
FR2793073B1 (fr) 1999-04-30 2003-04-11 France Telecom Antenne a reflecteur continu pour reception multiple de faisceaux de satellite
US6285332B1 (en) * 1999-09-10 2001-09-04 Trw Inc. Frequency selective reflector
US6208312B1 (en) * 2000-03-15 2001-03-27 Harry J. Gould Multi-feed multi-band antenna
US7084836B2 (en) * 2003-05-15 2006-08-01 Espenscheid Mark W Flat panel antenna array
WO2007095310A2 (en) * 2006-02-10 2007-08-23 Ems Technologies, Inc. Bicone pattern shaping device
DE102007029528A1 (de) 2006-06-27 2008-01-03 Ipcopter Gmbh & Co. Kg Verfahren zum Betreiben einer Satellitenkommunikationsanlage
US20080309545A1 (en) * 2007-06-15 2008-12-18 Emag Technologies, Inc. Speed Measuring Device Including Fresnel Zone Plate Lens Antenna
JP5207713B2 (ja) * 2007-11-29 2013-06-12 上田日本無線株式会社 ミリ波レーダ用リフレクタ
WO2011022819A1 (en) * 2009-08-28 2011-03-03 Belair Networks Inc. Vault antenna for wlan or cellular application
US8384614B2 (en) * 2010-09-30 2013-02-26 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Deployable wireless Fresnel lens
US10249951B2 (en) 2014-10-02 2019-04-02 Viasat, Inc. Multi-beam bi-focal shaped reflector antenna for concurrent communication with multiple non-collocated geostationary satellites and associated method
KR102020581B1 (ko) * 2015-02-24 2019-09-11 프라운호퍼 게젤샤프트 쭈르 푀르데룽 데어 안겐반텐 포르슝 에. 베. 집속 안테나를 가지는 통합된 트랜시버
US11955714B2 (en) * 2019-06-17 2024-04-09 Nec Corporation Antenna apparatus, radio transmitter, and antenna diameter adjustment method

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR726531A (fr) * 1931-01-21 1932-05-30 Materiel Telephonique Perfectionnements aux systèmes électriques à haute fréquence, tels que les systèmes de signalisation à ondes très courtes
CH302592A (de) * 1952-08-06 1954-10-31 Patelhold Patentverwertung Antennensystem mit einem Strahlungsdiagramm, dessen Maximum um die Systemachse rotiert.
FR1178316A (fr) * 1957-07-09 1959-05-06 Csf Perfectionnements aux systèmes de détection électromagnétique
US3189907A (en) * 1961-08-11 1965-06-15 Lylnan F Van Buskirk Zone plate radio transmission system
US3384895A (en) * 1966-01-19 1968-05-21 James E. Webb Nose cone mounted heat-resistant antenna
DE3536348A1 (de) * 1985-10-11 1987-04-16 Max Planck Gesellschaft Fresnel'sche zonenplatte zur fokussierung von mikrowellen-strahlung fuer eine mikrowellen-antenne
FR2594600B1 (fr) * 1986-02-18 1988-04-15 Alcatel Thomson Faisceaux Dispositif de reglage de la polarisation d'une antenne et procede de mise en oeuvre d'un tel dispositif
DE3801301C2 (de) * 1988-01-19 1995-11-30 Daimler Benz Aerospace Ag Fresnel'sche Zonenplatte als Reflektor für eine Mikrowellen-Sende/Empfangsantenne
GB2227609A (en) * 1989-01-30 1990-08-01 David James George Martin Double aerial [daerial]

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Publication number Publication date
US5283591A (en) 1994-02-01
FR2685131B1 (fr) 1994-05-27
EP0546913A1 (de) 1993-06-16
DE69209992D1 (de) 1996-05-23
ES2086100T3 (es) 1996-06-16
JPH05308221A (ja) 1993-11-19
FR2685131A1 (fr) 1993-06-18
DE69209992T2 (de) 1996-11-28

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