EP1217687A1 - Process for measuring and compensating the deformation of an antenna and antenna for such a process - Google Patents

Process for measuring and compensating the deformation of an antenna and antenna for such a process Download PDF

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Publication number
EP1217687A1
EP1217687A1 EP01403200A EP01403200A EP1217687A1 EP 1217687 A1 EP1217687 A1 EP 1217687A1 EP 01403200 A EP01403200 A EP 01403200A EP 01403200 A EP01403200 A EP 01403200A EP 1217687 A1 EP1217687 A1 EP 1217687A1
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EP
European Patent Office
Prior art keywords
antenna
deformation
radiating surface
electronic scanning
scanning antenna
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP01403200A
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German (de)
French (fr)
Inventor
Michel Thales Intellectual Property Renault
Thomas Thales Intellectual Property Merlet
Veronique Thales Intellectual Property Le Calvez
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Thales SA
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Thales SA
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Publication of EP1217687A1 publication Critical patent/EP1217687A1/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
    • H01Q3/267—Phased-array testing or checking devices
    • 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
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
    • H01Q3/2605—Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays

Definitions

  • the present invention relates to the field of antennas electronic scanning network; and more particularly a method of determination of the radiation pattern error due to the deformation of the radiating face of a network antenna and compensation for this error.
  • Such a antenna consists of a plurality of radiating elements, of the type dipole for example, generally arranged at the nodes of a plane mesh regular (rectangular, triangular, or more generally bi-periodic). AT each of these radiating elements is associated with a phase shifting device electronic control. To orient the radio beam in a pointing direction given, the signals sent or received by the different radiant elements are out of phase with each other so that the contributions to the antenna radiation of the various radiating elements are added in phase in the chosen direction.
  • the setpoint of the control of each phase shifter is developed by a computer called pointer.
  • Electronic antenna pointing control allows implementation of multiple radar functions on the same antenna, by example watch, pursuit and fire control.
  • the array antenna is in the form of a slab comprising a radiating surface and a thickness corresponding to stacking of a radiating element, a phase shifter, a distribution microwave and in some cases a microwave generator.
  • the thickness is for example a few tens of centimeters.
  • the quality of the radiation and pointing accuracy of the radio beam largely depend on the control of the electric wave plane.
  • the method currently used consists in defining a structure mechanical, supporting the radiating elements, the flatness of which provides the quality of the electric wave plane.
  • An antenna network is generally 5 to 10 times heavier than a radar antenna passive. Satisfying the rigidity requirements leads to the design of heavy structures, which penalize mobility and installation of equipment. The moving such equipment may not be possible by air and requires a high capacity road vehicle.
  • the means of installation are important, for example with a crane, and the reception structure is sophisticated. Installation on a ship may in particular be impossible.
  • An object of the invention is in particular to allow the realization an antenna with an electronic scanning array whose mobility, implantation and tactics are improved.
  • the invention has for object a method for determining the error of the radiation diagram of an electronic scanning antenna comprising an array of N elements radiant, the error being due to mechanical deformation of the surface radiating from the antenna, as determined from measurements of the mechanical deformation of n points of said surface in view correcting this error.
  • the invention particularly has the advantage that it allows a realization of an antenna with electronic scanning whose structure is lightened and simplified without compromising the quality of its diagram radiation. It makes it possible to produce an antenna at low cost and whose moving is facilitated.
  • the method uses optical measurements of the deformations of the antenna plane.
  • the method according to the invention is implemented at using light sources and optical sensors attached to the antenna itself. It does not use any error measurement device or system outside the antenna and allows the total autonomy of the antenna to be preserved, especially for a mobile antenna.
  • the invention makes it possible to compensate for mechanical deformations of the mechanical plane of the antenna induced by the conditions of operation and environment.
  • the invention makes it possible to keep a same quality of radiation pattern with an antenna whose deformations are ten to a hundred times higher than the tolerated deformations without implementing the invention.
  • the invention makes it possible to reduce notably the rigidity constraints.
  • the invention makes it possible to compensate for a permanent defect in the radiating surface of the antenna, it has the advantage of increasing the mechanical manufacturing tolerances of the antenna surface.
  • the invention also relates to a scanning antenna.
  • electronics comprising means implementing the method.
  • Figure 1 schematically illustrates an example of realization of an electronic scanning array antenna with a device for measuring the deformation of the radiating surface.
  • the deformation measurement is a type measurement optical.
  • a light source includes for example a laser or a diode electroluminescent placed behind the radiating surface 2 of the antenna.
  • the radiating surface of the antenna is substantially plane, it materializes, apart from defects, a reference plane for radar transmission.
  • a volume hologram 1 is placed at a point of the radiating surface 2 considered as a reference point of the surface radiating 2 from the antenna.
  • the light source associated with a hologram allows the emission, from the reference point of surface 2, of a beam luminous 3 in a plane substantially parallel to the reference plane of the radiant surface.
  • Fiber optic strips 4, 5 are fixed on the radiant surface.
  • the antenna has n fiber optic bars.
  • the receiving plane of a bar 4 is substantially perpendicular to the radiating surface on the one hand and substantially perpendicular to the beam luminous 3 which is received by the bar on the other hand.
  • the hologram is constructed for example by irradiation ultraviolet or short wavelength.
  • the hologram allows you to focus the light from the light source on each of the n bars by forming for example n beams.
  • the light beam 3 is anamorphic.
  • the beam emitted by the source becomes elliptical when passing through the hologram.
  • the volume hologram has the advantages of a small footprint and an easy realization.
  • FIG. 2 illustrates the reception plan of an example bar of optical fibers according to the invention.
  • Each fiber strip is a bundle of optical fibers having a flat and rigid end. The rest of the the beam is preferably flexible.
  • the reception plan includes sections 6 of small diameter optical fibers, for example around 250 micrometers.
  • Each silica fiber core 7 preferably comprises a 8 polymer coating transparent to electronic radar radiation.
  • Optical fiber has the advantage of being immune to radar radiation.
  • the bundle of optical fibers 6 extends behind the plane of the figure 2. In the example illustrated in FIG. 2, the optical fibers are divided into three layers superimposed in the reception plane. A lower layer 9 presents sections of juxtaposed fibers whose centers of the hearts are aligned along a line segment 12.
  • the intermediate layer 10 has juxtaposed sections in which the centers of the hearts are aligned according to a second line segment 13 parallel to the first.
  • a diaper upper 11 is parallel to the two layers already described 9, 10.
  • the centers 14, 15, 16 of the first fiber of each of the three layers are offset in the direction common to the first and second segments of line 12, 13 corresponding to that of an axis 17 of the abscissa of the centers of fibers.
  • the intercentre, or fiber diameter is the gap between the centers of two fibers juxtaposed with the same layer. Spacing between centers 14, 15 of two fibers juxtaposed with two offset layers is less than the Intercentre.
  • the abscissa of the center 15, 16 of the first fiber of a layer 10, 11 is greater than a third of the center to the abscissa of the center of the first fiber 14, 15 of the layer immediately lower 9, 10.
  • Each optical fiber in a strip is connected to a CCD receiver.
  • CCD receivers are installed directly on the fiber strip associated or are carried inside the antenna.
  • the embodiment with transfer inside the antenna, behind the radiating elements, by a suitable length of the optical fiber bundle of the strip present the advantage of avoiding a disturbance of the microwave field emitted by the antenna by CCD semiconductors.
  • a CCD group grouping the CCD receptors associated with a strip of fibers identifies the optical fiber or fibers lit by the light beam 3 on the receiving plane of the fiber strip.
  • Each CCD group provides a measurement of the displacement of the light beam on the associated strip of fiber, the displacement is measured along the axis of abscissa. The resolution of the measurement depends on the discreet spacing of the fibers along this axis, the diameter of the fiber core and the width of the illumination beam along this axis. Measuring a bar with a single layer of juxtaposed fibers provides better resolution when the fiber coating is removed. In the example in Figure 2, the different layers of superimposed and offset fibers allow obtain good resolution while retaining the coating of each fibers.
  • the bar according to Figure 2 is robust and inexpensive.
  • Each CCD group measures a displacement in one direction substantially perpendicular to the emission plane of the light beam 3.
  • Each CCD group provides a measurement of the displacement of the fixing point to the radiating surface of the optical fiber strip associated therewith. Each displacement is measured relative to the reference point of the radiant surface.
  • the device described above makes it possible to measure the relative displacement of n points of the radiating surface of the antenna by relative to the reference point and in the direction substantially perpendicular to the reference plane of the radiating surface.
  • All n CCD groups are connected by an interface to a card Calculation. From the number n of points on the radiating surface whose displacement is measured, the calculation card makes an estimate of the actual displacement of each of the N many radiating elements of the radiating surface of the antenna. For example for an antenna presenting a few hundred to a few thousand radiating elements, the number n of displacement measurement points is advantageously between one and a few dozen.
  • the card of calculation elaborates an approximate form of the real deformation of the surface radiant by a linear combination of six elementary forms of deformation corresponding in this example to the first three modes proper deformation of the planar antenna and the three extreme forms of wind deformations.
  • the number of points on the surface whose displacement is measured is between 10 and 20 and preferably between 12 and 18, and these points are placed in characteristic zones of each shape.
  • Some points can be associated with several elementary forms when the method identifies their participation in each of them they. In the method of the invention, the position of each measurement point and their number is calculated beforehand.
  • Every couple of a point measure and of an elementary form is associated a coefficient which characterizes the part of the displacement of the measuring point compared to the displacement maximum seen by the surface in this elementary form.
  • the points of measure used to identify the contribution of each form elementary when the defined coefficients are comparable to the coefficients of an independent system of linear equations.
  • each attachment point of the fiber strips allows to separate the contribution of each elementary form to the form approximate to the real deformation.
  • the elementary forms of deformation depend on the geometry of the radiating surface, for example square, rectangular, round, and the fixing of the antenna plate on its support.
  • the calculation card then elaborates and for each radiating element of the antenna, an estimate of the distance between its theoretical position in the absence of deformation of the surface and its estimated real position. This estimated distance represents a measure of the diagram error radiation from the deformed antenna.
  • the map of calculation develops a phase deviation correction value to be applied to the phase shifting device associated with the radiating element.
  • a digital link transmits the phase deviation correction information to the pointing of the radar which controls the phases of the radiating elements.
  • the number of deformation forms to be used for the estimation of the actual deformation of the antenna depends on the precision of the phase shifters the antenna. It is at least three. For imprecise phase shifters, the number of deformation forms can be limited to 3. For phase shifters high quality with high precision, a number of shapes of larger deformation allows a better estimate.
  • All of the correction calculations and their transmission to the timekeeping calculator is realized in less than ten milliseconds, it allows a fairly quick correction taking into account the mechanical strain rates whose frequencies own are in the range of one tenth to ten Hertz.
  • the optical displacement measurements of the n points of the radiating surface are renewed at a high frequency in the range of one hundred to a thousand Hertz allowing correction of the radar pointing to a faster rate than that of the annoying degradation of the diagram of radiation due to mechanical deformations of the radiating surface.
  • the correction can be made outside of a burst of pulses.
  • the application of the correction calculated according to the invention allows the emission of a radar wave whose radiation pattern is corrected disturbances due to the deformation of the radiating surface of the antenna measured during antenna operation.
  • the invention allows in particular to reduce the increase in the width of the main lobe and the rise in the level of the secondary lobes of the diagram which are observed when a radar antenna deforms.
  • the invention allows improve the performance of a deforming antenna.
  • Radar emission is corrected in real time.
  • the invention allows the emission of a plane electromagnetic wave from a mechanical plane distorted from the antenna surface.
  • the number n of measurement sensors deformation is from one to a few tens.
  • the invention makes it possible to correct deformation amplitudes up to ten millimeters relative to the antenna reference plane.
  • the invention is particularly suitable for a multifunction radar which requires a large precision, it eases the rigidity constraints of its antenna.
  • the invention also makes it possible to improve the performance of an antenna having a permanent geometry defect, for example in manufacturing or accidental.
  • the invention makes it possible in particular to soften the tolerances of flatness in manufacturing.
  • the invention makes it possible to correct amplitudes of deformation increased by a factor of ten to one hundred compared to the amplitudes of tolerated deformations to guarantee control of the electric wave plane in the prior art.
  • the antenna shown in Figure 3 has n sources luminous 19, 20 placed at n points of the radiating surface and illuminating sequentially a sensor 21 fixed at a reference point on the surface radiant, which is represented by its reference plane 22.
  • a light source preferably comprises a laser behind the plane of the radiating surface and a mirror at the point of the surface whose displacement is to be measured.
  • the non-metallic mirror is produced for example by stack of optical dielectric layers, it returns the light wave of the laser towards sensor 21.
  • the light source has the advantage of not disturb the electromagnetic radiation from the antenna.
  • Figure 4 illustrates the sensor 21, it comprises a matrix 24 of micro lenses whose plane, shown in Figure 4 by the line 25, is substantially perpendicular in terms of the radiating surface.
  • the sensor has a CCD 23 strip perpendicular to the surface of the antenna and it is connected to means of calculation.
  • the sensor 21 is preferably placed on the edge of the antenna so avoid disturbance of the electromagnetic field emitted by it.
  • the radius of the light wave 26 emitted by the source placed at a first point 27 of the antenna surface results in a spacing between two successive focusing tasks of micro lenses.
  • the measure of the spacing on the CCD strip 23 allows the distance d between the source at the first point 27 and the matrix 24 with very high precision.
  • the sequential illumination of the sensor by the n sources allows successive evaluation of the relative displacement of each of the n points of the surface of the antenna where the light sources are placed, the displacement being evaluated with respect to the fixation reference point of the sensor 21 and in the direction substantially perpendicular to the plane of reference 22 of the radiating surface.
  • the n light sources illuminate preferably directionally to the sensor 21.
  • This variant has the advantage of using a sensor and a commercially available electronic processing assembly.
  • the variant can be modified by adding a light source additional for example in the center of the radiating surface, and differentiating the displacement of the additional source and the displacements of other sources.
  • This change provides displacement measurements with respect to a reference placed at a point any surface of the antenna, for example the center.

Abstract

Electronically swept antenna error determination method has a network of radiating elements on a surface. Deformation error is found by optical measurement at a number of points on the surface, in order to correct the error. A hologram (1) is formed at the radiating surface (2) from a luminous beam (3), and fibre optic sections (4,5) detect the beam.

Description

La présente invention concerne le domaine des antennes à réseau à balayage électronique ; et plus particulièrement un procédé de détermination de l'erreur du diagramme de rayonnement due à la déformation de la face rayonnante d'une antenne à réseau et de compensation de cette erreur.The present invention relates to the field of antennas electronic scanning network; and more particularly a method of determination of the radiation pattern error due to the deformation of the radiating face of a network antenna and compensation for this error.

On va d'abord décrire brièvement le fonctionnement d'une telle antenne. Elle est constituée d'une pluralité d'éléments rayonnants, de type dipôle par exemple, généralement disposés aux noeuds d'un maillage plan régulier (rectangulaire, triangulaire, ou plus généralement bi-périodique). A chacun de ces éléments rayonnants est associé un dispositif déphaseur à commande électronique. Pour orienter le faisceau radioélectrique dans une direction de pointage donnée, les signaux émis ou reçus par les différents éléments rayonnants sont déphasés entre eux de telle sorte que les contributions au rayonnement de l'antenne des divers éléments rayonnants s'ajoutent en phase dans la direction choisie. La valeur de consigne de la commande de chaque déphaseur est élaborée par un calculateur appelé pointeur. La commande électronique du pointage de l'antenne permet une mise en oeuvre de multiples fonctions radar sur une même antenne, par exemple une veille, des poursuites et une conduite de tir.We will first briefly describe the functioning of such a antenna. It consists of a plurality of radiating elements, of the type dipole for example, generally arranged at the nodes of a plane mesh regular (rectangular, triangular, or more generally bi-periodic). AT each of these radiating elements is associated with a phase shifting device electronic control. To orient the radio beam in a pointing direction given, the signals sent or received by the different radiant elements are out of phase with each other so that the contributions to the antenna radiation of the various radiating elements are added in phase in the chosen direction. The setpoint of the control of each phase shifter is developed by a computer called pointer. Electronic antenna pointing control allows implementation of multiple radar functions on the same antenna, by example watch, pursuit and fire control.

L'antenne à réseau se présente sous la forme d'une dalle comportant une surface rayonnante et une épaisseur correspondant à l'empilement d'un élément rayonnant, d'un déphaseur, d'une distribution hyperfréquence et dans certains cas d'un générateur hyperfréquence. L'épaisseur est par exemple de quelques dizaines de centimètres.The array antenna is in the form of a slab comprising a radiating surface and a thickness corresponding to stacking of a radiating element, a phase shifter, a distribution microwave and in some cases a microwave generator. The thickness is for example a few tens of centimeters.

Dans une antenne à réseau, la qualité du diagramme de rayonnement et la précision de pointage du faisceau radioélectrique dépendent pour une part importante de la maítrise du plan d'onde électrique. Pour respecter les exigences de précision de pointage et de qualité du diagramme, la méthode utilisée actuellement consiste à définir une structure mécanique, supportant les éléments rayonnants, dont l'état de planéité permet d'obtenir la qualité du plan d'onde électrique. Pour cela, on définit des tolérances de fabrication très serrées pour la structure mécanique et les éléments rayonnants et on conçoit une structure mécanique dont la rigidité est très élevée. Cette rigidité permet d'éviter que les déformations mécaniques induites par les conditions de fonctionnement et d'environnement, notamment le mouvement de rotation de l'antenne et le vent, ne dégradent la planéité de la surface d'émission.In a network antenna, the quality of the radiation and pointing accuracy of the radio beam largely depend on the control of the electric wave plane. To meet the pointing accuracy and quality requirements of the diagram, the method currently used consists in defining a structure mechanical, supporting the radiating elements, the flatness of which provides the quality of the electric wave plane. For this, we define very tight manufacturing tolerances for mechanical structure and radiating elements and we design a mechanical structure whose rigidity is very high. This rigidity prevents deformations mechanical induced by the operating conditions and environment, in particular the antenna's rotational movement and the wind, do not degrade the flatness of the emission surface.

Les inconvénients principaux de la méthode ci-dessus pour assurer la qualité de la surface d'émission de l'antenne à réseau sont de conduire à un matériel dont la masse et le coût sont élevés. Une antenne à réseau est généralement 5 à 10 fois plus lourde qu'une antenne radar passive. La satisfaction des exigences de rigidité entraíne la conception de structures lourdes, qui pénalisent la mobilité et l'implantation du matériel. Le déplacement d'un tel matériel peut être impossible par transport aérien et nécessite un véhicule routier de forte capacité. Les moyens d'installation sont importants, avec par exemple une grue, et la structure d'accueil est sophistiquée. L'installation sur un navire peut notamment être impossible. La mobilité réduite, l'importance des temps et des moyens d'installation d'un système mobile comportant une antenne à réseau actuelle limitent notablement la tactique.The main disadvantages of the above method for ensure the quality of the transmission surface of the network antenna are lead to a material whose mass and cost are high. An antenna network is generally 5 to 10 times heavier than a radar antenna passive. Satisfying the rigidity requirements leads to the design of heavy structures, which penalize mobility and installation of equipment. The moving such equipment may not be possible by air and requires a high capacity road vehicle. The means of installation are important, for example with a crane, and the reception structure is sophisticated. Installation on a ship may in particular be impossible. The reduced mobility, the importance of the times and means of installing a mobile system with current network antenna limit notably the tactics.

Un but de l'invention est notamment de permettre la réalisation d'une antenne à réseau à balayage électronique dont la mobilité, l'implantation et la tactique sont améliorées. A cet effet, l'invention a pour objet un procédé de détermination de l'erreur du diagramme de rayonnement d'une antenne à balayage électronique comportant un réseau de N éléments rayonnants, l'erreur étant due à la déformation mécanique de la surface rayonnante de l'antenne, tel que la détermination est effectuée à partir de mesures de la déformation mécanique de n points de ladite surface en vue de la correction de cette erreur.An object of the invention is in particular to allow the realization an antenna with an electronic scanning array whose mobility, implantation and tactics are improved. To this end, the invention has for object a method for determining the error of the radiation diagram of an electronic scanning antenna comprising an array of N elements radiant, the error being due to mechanical deformation of the surface radiating from the antenna, as determined from measurements of the mechanical deformation of n points of said surface in view correcting this error.

L'invention a notamment pour avantage qu'elle permet une réalisation d'antenne à balayage électronique dont la structure est allégée et simplifiée sans porter atteinte à la qualité de son diagramme de rayonnement. Elle permet de réaliser une antenne à faible coût et dont le déplacement est facilité.The invention particularly has the advantage that it allows a realization of an antenna with electronic scanning whose structure is lightened and simplified without compromising the quality of its diagram radiation. It makes it possible to produce an antenna at low cost and whose moving is facilitated.

De préférence, le procédé utilise des mesures optiques des déformations du plan de l'antenne.Preferably, the method uses optical measurements of the deformations of the antenna plane.

De préférence, le procédé selon l'invention est mis en oeuvre à l'aide de sources lumineuses et de capteurs optiques fixés sur l'antenne elle-même. Il ne fait appel à aucun dispositif ou système de mesure d'erreur extérieur à l'antenne et permet de conserver l'autonomie totale de l'antenne, notamment pour une antenne mobile.Preferably, the method according to the invention is implemented at using light sources and optical sensors attached to the antenna itself. It does not use any error measurement device or system outside the antenna and allows the total autonomy of the antenna to be preserved, especially for a mobile antenna.

L'invention permet de compenser des déformations mécaniques du plan mécanique de l'antenne induites par les conditions de fonctionnement et d'environnement. L'invention permet de conserver une même qualité de diagramme de rayonnement avec une antenne dont les déformations sont dix à cent fois plus élevées que les déformations tolérées sans mise en oeuvre de l'invention. L'invention permet de réduire notablement les contraintes de rigidité.The invention makes it possible to compensate for mechanical deformations of the mechanical plane of the antenna induced by the conditions of operation and environment. The invention makes it possible to keep a same quality of radiation pattern with an antenna whose deformations are ten to a hundred times higher than the tolerated deformations without implementing the invention. The invention makes it possible to reduce notably the rigidity constraints.

L'invention permet de compenser un défaut permanent de la surface rayonnante de l'antenne, elle présente l'avantage d'augmenter les tolérances mécaniques de fabrication de la surface de l'antenne.The invention makes it possible to compensate for a permanent defect in the radiating surface of the antenna, it has the advantage of increasing the mechanical manufacturing tolerances of the antenna surface.

L'invention concerne également une antenne à balayage électronique comportant des moyens mettant en oeuvre le procédé.The invention also relates to a scanning antenna. electronics comprising means implementing the method.

D'autres caractéristiques et avantages de l'invention apparaítront à l'aide de la description qui suit faite en regard de dessins annexés qui représentent :

  • la figure 1, un exemple de réalisation d'une antenne permettant la mise en oeuvre du procédé ;
  • la figure 2, un exemple de réalisation d'une barrette de fibres optiques selon l'invention ;
  • la figure 3, une variante de réalisation de mesure de déplacement selon l'invention ;
  • la figure 4, un capteur pour la variante de réalisation de mesure.
Other characteristics and advantages of the invention will become apparent with the aid of the description which follows given with reference to the appended drawings which represent:
  • Figure 1, an embodiment of an antenna for implementing the method;
  • Figure 2, an exemplary embodiment of an optical fiber strip according to the invention;
  • Figure 3, an alternative embodiment of displacement measurement according to the invention;
  • Figure 4, a sensor for the alternative embodiment of measurement.

La figure 1 illustre de façon schématique un exemple de réalisation d'une antenne à balayage électronique à réseau avec un dispositif de mesure de la déformation de la surface rayonnante. Dans l'exemple de réalisation de la figure 1, la mesure de déformation est une mesure de type optique. Une source lumineuse comporte par exemple un laser ou une diode électroluminescente placé en arrière de la surface rayonnante 2 de l'antenne. Dans cet exemple, la surface rayonnante de l'antenne est sensiblement plane, elle matérialise, à des défauts près, un plan de référence pour l'émission radar. Un hologramme volumique 1 est placé en un point de la surface rayonnante 2 considéré comme un point de référence de la surface rayonnante 2 de l'antenne.Figure 1 schematically illustrates an example of realization of an electronic scanning array antenna with a device for measuring the deformation of the radiating surface. In the example of embodiment of FIG. 1, the deformation measurement is a type measurement optical. A light source includes for example a laser or a diode electroluminescent placed behind the radiating surface 2 of the antenna. In this example, the radiating surface of the antenna is substantially plane, it materializes, apart from defects, a reference plane for radar transmission. A volume hologram 1 is placed at a point of the radiating surface 2 considered as a reference point of the surface radiating 2 from the antenna.

La source lumineuse associée à un hologramme permet l'émission, à partir du point de référence de la surface 2, d'un faisceau lumineux 3 dans un plan sensiblement parallèle au plan de référence de la surface rayonnante. Des barrettes de fibres optiques 4, 5 sont fixées sur la surface rayonnante. L'antenne comporte n barrettes de fibres optiques. Le plan de réception d'une barrette 4 est sensiblement perpendiculaire à la surface rayonnante d'une part et sensiblement perpendiculaire au faisceau lumineux 3 qui est reçu par la barrette d'autre part.The light source associated with a hologram allows the emission, from the reference point of surface 2, of a beam luminous 3 in a plane substantially parallel to the reference plane of the radiant surface. Fiber optic strips 4, 5 are fixed on the radiant surface. The antenna has n fiber optic bars. The receiving plane of a bar 4 is substantially perpendicular to the radiating surface on the one hand and substantially perpendicular to the beam luminous 3 which is received by the bar on the other hand.

L'hologramme est construit par exemple par irradiation ultraviolette ou de faible longueur d'onde. L'hologramme permet de focaliser la lumière de la source lumineuse sur chacune des n barrettes en formant par exemple n faisceaux. Le faisceau lumineux 3 est anamorphosé. Le faisceau émis par la source devient elliptique en traversant l'hologramme. L'hologramme volumique présente les avantages d'un faible encombrement et d'une réalisation aisée.The hologram is constructed for example by irradiation ultraviolet or short wavelength. The hologram allows you to focus the light from the light source on each of the n bars by forming for example n beams. The light beam 3 is anamorphic. The beam emitted by the source becomes elliptical when passing through the hologram. The volume hologram has the advantages of a small footprint and an easy realization.

La figure 2 illustre le plan de réception d'un exemple de barrette de fibres optiques selon l'invention. Chaque barrette de fibres est un faisceau de fibres optiques présentant une extrémité plane et rigide. Le reste du faisceau est de préférence souple. Le plan de réception comporte des sections 6 de fibres optiques de petit diamètre, par exemple d'environ 250 micromètres. Chaque coeur de fibre en silice 7 comporte de préférence un revêtement 8 polymère transparent au rayonnement électronique du radar. La fibre optique présente l'avantage d'être immune au rayonnement radar. Le faisceau des fibres optiques 6 se prolonge en arrière du plan de la figure 2. Dans l'exemple illustré par la figure 2, les fibres optiques sont réparties en trois couches superposées dans le plan de réception. Une couche inférieure 9 présente des sections de fibres juxtaposées dont les centres des coeurs sont alignés le long d'un segment de droite 12. La couche intermédiaire 10 présente des sections juxtaposées dont les centres des coeurs sont alignés selon un second segment de droite 13 parallèle au premier. Une couche supérieure 11 est parallèle aux deux couches déjà décrites 9, 10. Les centres 14, 15, 16 de la première fibre de chacune des trois couches sont décalés dans la direction commune aux premier et second segments de droite 12, 13 correspondant à celle d'un axe 17 des abscisses des centres de fibres. L'intercentre, ou diamètre de fibre, est l'écart entre les centres de deux fibres juxtaposées d'une même couche. L'espacement entre les centres 14, 15 de deux fibres juxtaposées de deux couches décalées est inférieur à l'intercentre. Dans l'exemple de la figure 2, l'abscisse du centre 15, 16 de la première fibre d'une couche 10, 11 est supérieure d'un tiers d'intercentre à l'abscisse du centre de la première fibre 14, 15 de la couche immédiatement inférieure 9, 10.Figure 2 illustrates the reception plan of an example bar of optical fibers according to the invention. Each fiber strip is a bundle of optical fibers having a flat and rigid end. The rest of the the beam is preferably flexible. The reception plan includes sections 6 of small diameter optical fibers, for example around 250 micrometers. Each silica fiber core 7 preferably comprises a 8 polymer coating transparent to electronic radar radiation. Optical fiber has the advantage of being immune to radar radiation. The bundle of optical fibers 6 extends behind the plane of the figure 2. In the example illustrated in FIG. 2, the optical fibers are divided into three layers superimposed in the reception plane. A lower layer 9 presents sections of juxtaposed fibers whose centers of the hearts are aligned along a line segment 12. The intermediate layer 10 has juxtaposed sections in which the centers of the hearts are aligned according to a second line segment 13 parallel to the first. A diaper upper 11 is parallel to the two layers already described 9, 10. The centers 14, 15, 16 of the first fiber of each of the three layers are offset in the direction common to the first and second segments of line 12, 13 corresponding to that of an axis 17 of the abscissa of the centers of fibers. The intercentre, or fiber diameter, is the gap between the centers of two fibers juxtaposed with the same layer. Spacing between centers 14, 15 of two fibers juxtaposed with two offset layers is less than the Intercentre. In the example of Figure 2, the abscissa of the center 15, 16 of the first fiber of a layer 10, 11 is greater than a third of the center to the abscissa of the center of the first fiber 14, 15 of the layer immediately lower 9, 10.

Chaque fibre optique d'une barrette est reliée à un récepteur CCD. Les récepteurs CCD sont installés directement sur la barrette de fibres associée ou sont reportés à l'intérieur de l'antenne. Le mode de réalisation avec report à l'intérieur de l'antenne, en arrière des éléments rayonnants, par une longueur adaptée du faisceau de fibres optiques de la barrette présente l'avantage d'éviter une perturbation du champ hyperfréquence émis par l'antenne par les semi-conducteurs CCD.Each optical fiber in a strip is connected to a CCD receiver. CCD receivers are installed directly on the fiber strip associated or are carried inside the antenna. The embodiment with transfer inside the antenna, behind the radiating elements, by a suitable length of the optical fiber bundle of the strip present the advantage of avoiding a disturbance of the microwave field emitted by the antenna by CCD semiconductors.

Un groupe CCD regroupant les récepteurs CCD associés à une barrette de fibres permet d'identifier la ou les fibres optiques éclairées par le faisceau lumineux 3 sur le plan de réception de la barrette de fibres. Chaque groupe CCD fournit une mesure du déplacement du faisceau lumineux sur la barrette de fibres associée, le déplacement est mesuré selon l'axe des abscisses. La résolution de la mesure dépend de l'espacement discret des fibres le long de cet axe, du diamètre du coeur des fibres et de la largeur du faisceau d'éclairement selon cet axe. La mesure d'une barrette comportant une seule couche de fibres juxtaposées présente une meilleure résolution lorsque le revêtement des fibres est supprimé. Dans l'exemple de la figure 2, les différentes couches de fibres superposées et décalées permettent d'obtenir une bonne résolution tout en conservant le revêtement de chacune des fibres. La barrette selon la figure 2 est robuste et peu coûteuse.A CCD group grouping the CCD receptors associated with a strip of fibers identifies the optical fiber or fibers lit by the light beam 3 on the receiving plane of the fiber strip. Each CCD group provides a measurement of the displacement of the light beam on the associated strip of fiber, the displacement is measured along the axis of abscissa. The resolution of the measurement depends on the discreet spacing of the fibers along this axis, the diameter of the fiber core and the width of the illumination beam along this axis. Measuring a bar with a single layer of juxtaposed fibers provides better resolution when the fiber coating is removed. In the example in Figure 2, the different layers of superimposed and offset fibers allow obtain good resolution while retaining the coating of each fibers. The bar according to Figure 2 is robust and inexpensive.

Chaque groupe CCD mesure un déplacement dans une direction sensiblement perpendiculaire au plan d'émission du faisceau lumineux 3. Chaque groupe CCD fournit une mesure du déplacement du point de fixation à la surface rayonnante de la barrette de fibres optiques qui lui est associée. Chaque déplacement est mesuré par rapport au point de référence de la surface rayonnante. Le dispositif décrit ci-dessus permet de mesurer le déplacement relatif de n points de la surface rayonnante de l'antenne par rapport au point de référence et dans la direction sensiblement perpendiculaire au plan de référence de la surface rayonnante.Each CCD group measures a displacement in one direction substantially perpendicular to the emission plane of the light beam 3. Each CCD group provides a measurement of the displacement of the fixing point to the radiating surface of the optical fiber strip associated therewith. Each displacement is measured relative to the reference point of the radiant surface. The device described above makes it possible to measure the relative displacement of n points of the radiating surface of the antenna by relative to the reference point and in the direction substantially perpendicular to the reference plane of the radiating surface.

L'ensemble des n groupes CCD est relié par une interface à une carte de calcul. A partir du nombre n de points de la surface rayonnante dont le déplacement est mesuré, la carte de calcul élabore une estimation du déplacement réel de chacun des N nombreux éléments rayonnants de la surface rayonnante de l'antenne. Par exemple pour une antenne présentant quelques centaines à quelques milliers d'éléments rayonnants, le nombre n de points de mesure de déplacement est avantageusement compris entre une et quelques dizaines.All n CCD groups are connected by an interface to a card Calculation. From the number n of points on the radiating surface whose displacement is measured, the calculation card makes an estimate of the actual displacement of each of the N many radiating elements of the radiating surface of the antenna. For example for an antenna presenting a few hundred to a few thousand radiating elements, the number n of displacement measurement points is advantageously between one and a few dozen.

Dans un exemple d'une antenne plane montée en extérieur, la carte de calcul élabore une forme approchée de la déformation réelle de la surface rayonnante par une combinaison linéaire de six formes élémentaires de déformation correspondant dans cet exemple aux trois premiers modes propres de déformation de l'antenne plane et aux trois formes extrêmes de déformations dues au vent. Pour une combinaison de six formes élémentaires, le nombre des points de la surface dont le déplacement est mesuré est entre 10 et 20 et de préférence entre 12 et 18, et ces points sont placés dans des zones caractéristiques de chaque forme. Certains points peuvent être associés à plusieurs formes élémentaires lorsque la méthode d'identification permet de discriminer leur participation à chacune d'entre elles. Dans le procédé de l'invention, la position de chaque point de mesure et leur nombre est préalablement calculé. A chaque couple d'un point de mesure et d'une forme élémentaire est associé un coefficient qui caractérise la part du déplacement du point de mesure par rapport au déplacement maximal vu par la surface dans cette forme élémentaire. Les points de mesure retenus permettent l'identification de la contribution de chaque forme élémentaire lorsque les coefficients définis sont assimilables aux coefficients d'un système d'équations linéaires indépendant.In an example of a flat antenna mounted outdoors, the card of calculation elaborates an approximate form of the real deformation of the surface radiant by a linear combination of six elementary forms of deformation corresponding in this example to the first three modes proper deformation of the planar antenna and the three extreme forms of wind deformations. For a combination of six shapes elementary, the number of points on the surface whose displacement is measured is between 10 and 20 and preferably between 12 and 18, and these points are placed in characteristic zones of each shape. Some points can be associated with several elementary forms when the method identifies their participation in each of them they. In the method of the invention, the position of each measurement point and their number is calculated beforehand. Every couple of a point measure and of an elementary form is associated a coefficient which characterizes the part of the displacement of the measuring point compared to the displacement maximum seen by the surface in this elementary form. The points of measure used to identify the contribution of each form elementary when the defined coefficients are comparable to the coefficients of an independent system of linear equations.

La position de chaque point de fixation des barrettes de fibres permet de séparer la contribution de chaque forme élémentaire à la forme approchée de la déformation réelle.The position of each attachment point of the fiber strips allows to separate the contribution of each elementary form to the form approximate to the real deformation.

Les formes élémentaires de déformation dépendent de la géométrie de la surface rayonnante, par exemple carrée, rectangulaire, ronde, et de la fixation de la dalle de l'antenne sur son support. The elementary forms of deformation depend on the geometry of the radiating surface, for example square, rectangular, round, and the fixing of the antenna plate on its support.

La carte de calcul élabore ensuite et pour chaque élément rayonnant de l'antenne, une estimation de la distance entre sa position théorique en l'absence de déformation de la surface et sa position réelle estimée. Cette distance estimée représente une mesure de l'erreur du diagramme de rayonnement de l'antenne déformée.The calculation card then elaborates and for each radiating element of the antenna, an estimate of the distance between its theoretical position in the absence of deformation of the surface and its estimated real position. This estimated distance represents a measure of the diagram error radiation from the deformed antenna.

A partir de la distance estimée d'un élément rayonnant, la carte de calcul élabore une valeur de correction d'écart de phase à appliquer sur le dispositif déphaseur associé à l'élément rayonnant. Une liaison numérique transmet les informations de correction d'écart de phase au calculateur de pointage du radar qui pilote les phases des éléments rayonnants. Dans l'invention, le nombre de formes de déformation à utiliser pour l'estimation de la déformation réelle de l'antenne dépend de la précision des déphaseurs de l'antenne. Il est au moins égal à trois. Pour des déphaseurs peu précis, le nombre de formes de déformation peut être limité à 3. Pour des déphaseurs de haute qualité présentant une précision élevée, un nombre de formes de déformation plus important permet une meilleure estimation. L'ensemble des calculs de correction et leur transmission au calculateur de pointage est réalisé en moins de dix millisecondes, il permet une correction assez rapide compte tenu des vitesses de déformation mécanique dont les fréquences propres sont dans une plage d'un dixième à une dizaine de Hertz. Les mesures optiques de déplacement des n points de la surface rayonnante sont renouvelées à une fréquence élevée dans une plage d'une centaine à un millier de Hertz permettant une correction du pointage du radar à une cadence plus rapide que celle de la dégradation gênante du diagramme de rayonnement due aux déformations mécaniques de la surface rayonnante. La correction peut être effectuée en dehors d'une rafale d'impulsions.From the estimated distance of a radiating element, the map of calculation develops a phase deviation correction value to be applied to the phase shifting device associated with the radiating element. A digital link transmits the phase deviation correction information to the pointing of the radar which controls the phases of the radiating elements. In the invention, the number of deformation forms to be used for the estimation of the actual deformation of the antenna depends on the precision of the phase shifters the antenna. It is at least three. For imprecise phase shifters, the number of deformation forms can be limited to 3. For phase shifters high quality with high precision, a number of shapes of larger deformation allows a better estimate. All of the correction calculations and their transmission to the timekeeping calculator is realized in less than ten milliseconds, it allows a fairly quick correction taking into account the mechanical strain rates whose frequencies own are in the range of one tenth to ten Hertz. The optical displacement measurements of the n points of the radiating surface are renewed at a high frequency in the range of one hundred to a thousand Hertz allowing correction of the radar pointing to a faster rate than that of the annoying degradation of the diagram of radiation due to mechanical deformations of the radiating surface. The correction can be made outside of a burst of pulses.

L'application de la correction calculée selon l'invention permet l'émission d'une onde radar dont le diagramme de rayonnement est corrigé des perturbations dues à la déformation de la surface rayonnante de l'antenne mesurée pendant le fonctionnement de l'antenne. L'invention permet notamment de réduire l'augmentation de la largeur du lobe principal et la remontée du niveau des lobes secondaires du diagramme qui sont constatées lorsqu'une antenne radar se déforme. L'invention permet d'améliorer les performances d'une antenne se déformant. The application of the correction calculated according to the invention allows the emission of a radar wave whose radiation pattern is corrected disturbances due to the deformation of the radiating surface of the antenna measured during antenna operation. The invention allows in particular to reduce the increase in the width of the main lobe and the rise in the level of the secondary lobes of the diagram which are observed when a radar antenna deforms. The invention allows improve the performance of a deforming antenna.

L'émission radar est corrigée en temps réel. L'invention permet l'émission d'une onde électromagnétique plane à partir d'un plan mécanique déformé de la surface de l'antenne.Radar emission is corrected in real time. The invention allows the emission of a plane electromagnetic wave from a mechanical plane distorted from the antenna surface.

Pour une antenne d'une surface entre quelques mètres carrés et quelques dizaines de mètres carrés, le nombre n de capteurs de mesure de déformation est de une à quelques dizaines. Par exemple avec une précision de mesure de déformation d'un dixième de millimètre, l'invention permet de corriger des amplitudes de déformation jusqu'à une dizaine de millimètres par rapport au plan de référence de l'antenne. L'invention est particulièrement adaptée à un radar multifonction qui nécessite une grande précision, elle permet d'assouplir les contraintes de rigidité de son antenne.For an antenna with a surface area between a few square meters and a few tens of square meters, the number n of measurement sensors deformation is from one to a few tens. For example with precision measuring a tenth of a millimeter deformation, the invention makes it possible to correct deformation amplitudes up to ten millimeters relative to the antenna reference plane. The invention is particularly suitable for a multifunction radar which requires a large precision, it eases the rigidity constraints of its antenna.

L'invention permet aussi d'améliorer les performances d'une antenne présentant un défaut de géométrie permanent par exemple de fabrication ou accidentel. L'invention permet notamment d'assouplir les tolérances de planéité en fabrication. L'invention permet de corriger des amplitudes de déformation augmentées d'un facteur dix à cent par rapport aux amplitudes de déformations tolérées pour garantir la maítrise du plan d'onde électrique dans l'art antérieur.The invention also makes it possible to improve the performance of an antenna having a permanent geometry defect, for example in manufacturing or accidental. The invention makes it possible in particular to soften the tolerances of flatness in manufacturing. The invention makes it possible to correct amplitudes of deformation increased by a factor of ten to one hundred compared to the amplitudes of tolerated deformations to guarantee control of the electric wave plane in the prior art.

Dans une variante de réalisation de l'invention illustrée par les figures 3 et 4, les mesures de déplacement des n points de l'antenne sont estimées de la façon suivante.In an alternative embodiment of the invention illustrated by Figures 3 and 4, the displacement measurements of the n points of the antenna are estimated as follows.

L'antenne représentée sur la figure 3 comporte n sources lumineuses 19, 20 placées en n points de la surface rayonnante et éclairant séquentiellement un capteur 21 fixé en un point de référence de la surface rayonnante, laquelle est représentée par son plan de référence 22. Une source lumineuse comporte de préférence un laser en arrière du plan de la surface rayonnante et un miroir au point de la surface dont le déplacement est à mesurer. Le miroir non métallique est réalisé par exemple par empilement de couches diélectriques optiques, il renvoie l'onde lumineuse du laser vers le capteur 21. La source lumineuse présente l'avantage de ne pas perturber le rayonnement électromagnétique de l'antenne. La figure 4 illustre le capteur 21, il comporte une matrice 24 de micro lentilles dont le plan, représenté sur la figure 4 par la droite 25, est sensiblement perpendiculaire au plan de la surface rayonnante. Le capteur comporte une barrette CCD 23 perpendiculaire à la surface de l'antenne et il est relié à des moyens de calcul. Le capteur 21 est placé de préférence sur le bord de l'antenne afin d'éviter les perturbations du champ électromagnétique émis par celle-ci. Le rayon de l'onde lumineuse 26 émise par la source placée en un premier point 27 de la surface de l'antenne se traduit par un espacement entre deux taches successives de focalisation des micro lentilles. La mesure de l'espacement sur la barrette CCD 23 permet d'estimer la distance d entre la source au premier point 27 et la matrice 24 avec une très grande précision. Lorsque l'antenne se déforme, la source se déplace notamment dans la direction perpendiculaire au plan initial de l'antenne, c'est-à-dire parallèlement à la barrette CCD et elle est représentée sur la figure 4 par le second point 28, les taches de focalisation des micro lentilles se déplacent et la mesure du déplacement général D permet aux moyens de calcul d'évaluer la distance x du déplacement de la source entre les premier et second points 27 et 28.The antenna shown in Figure 3 has n sources luminous 19, 20 placed at n points of the radiating surface and illuminating sequentially a sensor 21 fixed at a reference point on the surface radiant, which is represented by its reference plane 22. A light source preferably comprises a laser behind the plane of the radiating surface and a mirror at the point of the surface whose displacement is to be measured. The non-metallic mirror is produced for example by stack of optical dielectric layers, it returns the light wave of the laser towards sensor 21. The light source has the advantage of not disturb the electromagnetic radiation from the antenna. Figure 4 illustrates the sensor 21, it comprises a matrix 24 of micro lenses whose plane, shown in Figure 4 by the line 25, is substantially perpendicular in terms of the radiating surface. The sensor has a CCD 23 strip perpendicular to the surface of the antenna and it is connected to means of calculation. The sensor 21 is preferably placed on the edge of the antenna so avoid disturbance of the electromagnetic field emitted by it. The radius of the light wave 26 emitted by the source placed at a first point 27 of the antenna surface results in a spacing between two successive focusing tasks of micro lenses. The measure of the spacing on the CCD strip 23 allows the distance d between the source at the first point 27 and the matrix 24 with very high precision. When the antenna deforms, the source moves in particular in the direction perpendicular to the initial plane of the antenna, i.e. parallel to the CCD strip and it is represented in FIG. 4 by the second point 28, the focusing spots of the micro lenses move and the measurement of the general displacement D allows the calculation means to evaluate the distance x of the displacement of the source between the first and second points 27 and 28.

L'éclairage séquentiel du capteur par les n sources permet l'évaluation successive du déplacement relatif de chacun des n points de la surface de l'antenne où sont placées les sources lumineuses, le déplacement étant évalué par rapport au point de référence de fixation du capteur 21 et dans la direction sensiblement perpendiculaire au plan de référence 22 de la surface rayonnante. Les n sources lumineuses éclairent de préférence de façon directionnelle vers le capteur 21.The sequential illumination of the sensor by the n sources allows successive evaluation of the relative displacement of each of the n points of the surface of the antenna where the light sources are placed, the displacement being evaluated with respect to the fixation reference point of the sensor 21 and in the direction substantially perpendicular to the plane of reference 22 of the radiating surface. The n light sources illuminate preferably directionally to the sensor 21.

Cette variante présente l'avantage de mettre en oeuvre un capteur et un ensemble électronique de traitement disponibles dans le commerce.This variant has the advantage of using a sensor and a commercially available electronic processing assembly.

La variante peut être modifiée en ajoutant une source lumineuse supplémentaire par exemple au centre de la surface rayonnante, et en effectuant la différence du déplacement de la source supplémentaire et des déplacements des autres sources. Cette modification permet de fournir des mesures de déplacement par rapport à une référence placée en un point quelconque de la surface de l'antenne, par exemple le centre.The variant can be modified by adding a light source additional for example in the center of the radiating surface, and differentiating the displacement of the additional source and the displacements of other sources. This change provides displacement measurements with respect to a reference placed at a point any surface of the antenna, for example the center.

Claims (22)

Procédé de détermination de l'erreur du diagramme de rayonnement d'une antenne à balayage électronique comportant un réseau de N éléments rayonnants, caractérisé en ce que l'erreur étant due à la déformation mécanique de la surface rayonnante de l'antenne, la détermination est effectuée à partir de mesures de la déformation mécanique de n points de ladite surface en vue de la correction de cette erreur.Method for determining the error of the radiation pattern of an electronic scanning antenna comprising an array of N radiating elements, characterized in that the error being due to the mechanical deformation of the radiating surface of the antenna, the determination is carried out from measurements of the mechanical deformation of n points of said surface with a view to correcting this error. Procédé selon la revendication 1, caractérisé en ce que les mesures de la déformation mécanique sont des mesures optiques.Method according to claim 1, characterized in that the measurements of mechanical deformation are optical measurements. Procédé selon la revendication 2, caractérisé en ce que les mesures de la déformation mécanique sont effectuées au moyen d'une source lumineuse et de n capteurs optiques.Method according to claim 2, characterized in that the measurements of the mechanical deformation are carried out by means of a light source and n optical sensors. Procédé selon la revendication 2, caractérisé en ce que les mesures de la déformation mécanique sont effectuées au moyen de n sources lumineuses et d'un unique capteur optique.Method according to claim 2, characterized in that the measurements of the mechanical deformation are carried out by means of n light sources and a single optical sensor. Procédé selon la revendication 4, caractérisé en ce que les n sources lumineuses éclairent de façon séquentielle ledit capteur.Method according to claim 4, characterized in that the n light sources sequentially illuminate said sensor. Procédé selon l'une des revendications précédentes, caractérisé en ce que la surface rayonnante de l'antenne présentant des formes élémentaires de déformation, la position des n points de mesure est déterminée par calcul en fonction d'un nombre entier de ces formes élémentaires de déformation.Method according to one of the preceding claims, characterized in that the radiating surface of the antenna having elementary forms of deformation, the position of the n measurement points is determined by calculation as a function of an integer of these elementary forms of deformation. Procédé selon l'une des revendications précédentes, caractérisé en ce que la surface rayonnante de l'antenne présentant des formes élémentaires de déformation, le nombre entier de formes élémentaires est au moins égal à 3. Method according to one of the preceding claims, characterized in that the radiating surface of the antenna having elementary forms of deformation, the whole number of elementary forms is at least equal to 3. Procédé selon l'une des revendications précédentes, caractérisé en ce que la surface rayonnante de l'antenne présentant des formes élémentaires de déformation, le nombre entier de formes élémentaires est égal à 6 et en ce que le nombre n de points de mesures est compris entre 12 et 18.Method according to one of the preceding claims, characterized in that the radiating surface of the antenna having elementary forms of deformation, the whole number of elementary forms is equal to 6 and in that the number n of measurement points is included between 12 and 18. Procédé selon l'une des revendications précédentes, caractérisé en ce que la surface rayonnante de l'antenne est sensiblement plane.Method according to one of the preceding claims, characterized in that the radiating surface of the antenna is substantially planar. Procédé selon l'une des revendications précédentes, caractérisé en ce qu'il compense ladite erreur en calculant et en appliquant une correction d'écart de phase sur les déphaseurs associés aux N éléments rayonnants.Method according to one of the preceding claims, characterized in that it compensates for said error by calculating and applying a phase difference correction on the phase shifters associated with the N radiating elements. Antenne à balayage électronique comportant un réseau de N éléments rayonnants, caractérisée en ce qu'elle comporte des moyens de mesure de déformation de sa surface rayonnante, lesdits moyens estimant la déformation à partir de n points de ladite surface.Electronic scanning antenna comprising an array of N radiating elements, characterized in that it comprises means for measuring the deformation of its radiating surface, said means estimating the deformation from n points on said surface. Antenne à balayage électronique selon la revendication 11, caractérisée en ce que la surface rayonnante de l'antenne présentant des formes élémentaires de déformation, la position des n points de mesure est déterminée par calcul en fonction d'un nombre entier de ces formes élémentaires de déformation.Electronic scanning antenna according to claim 11, characterized in that the radiating surface of the antenna having elementary forms of deformation, the position of the n measurement points is determined by calculation as a function of an integer of these elementary forms of deformation. Antenne à balayage électronique selon la revendication 12, caractérisée en ce que la surface rayonnante de l'antenne présentant des formes élémentaires de déformation, le nombre entier de formes élémentaires est au moins égal à 3.Electronic scanning antenna according to claim 12, characterized in that the radiating surface of the antenna having elementary forms of deformation, the whole number of elementary forms is at least equal to 3. Antenne à balayage électronique selon la revendication 12, caractérisée en ce que la surface rayonnante de l'antenne présentant des formes élémentaires de déformation, le nombre entier de formes élémentaires est égal à 6 et en ce que le nombre n de points de mesures est compris entre 12 et 18.Electronic scanning antenna according to claim 12, characterized in that the radiating surface of the antenna having elementary forms of deformation, the whole number of elementary forms is equal to 6 and in that the number n of measurement points is included between 12 and 18. Antenne à balayage électronique selon l'une des revendications 11 à 14, caractérisée en ce que la surface rayonnante de l'antenne est sensiblement plane.Electronic scanning antenna according to one of claims 11 to 14, characterized in that the radiating surface of the antenna is substantially planar. Antenne à balayage électronique selon l'une des revendications 11 à 15, caractérisée en ce qu'elle comporte des moyens de calcul d'écarts de phase, lesdits écarts de phase étant appliqués sur les déphaseurs des éléments rayonnants compensent l'erreur du diagramme de rayonnement due à la déformation mécanique de la surface rayonnanteElectronic scanning antenna according to one of claims 11 to 15, characterized in that it includes means for calculating phase differences, said phase differences being applied to the phase shifters of the radiating elements compensate for the error of the radiation due to mechanical deformation of the radiating surface Antenne à balayage électronique selon l'une des revendications 11 à 16, caractérisée en ce que lesdits moyens comportent des barrettes optiques éclairées par une source laser.Electronic scanning antenna according to one of claims 11 to 16, characterized in that said means comprise light bars illuminated by a laser source. Antenne à balayage électronique selon la revendication 17, caractérisée en ce que lesdits moyens comportent un hologramme volumique situé entre la source laser et les barrettes optiques.Electronic scanning antenna according to claim 17, characterized in that said means comprise a volume hologram located between the laser source and the optical strips. Antenne à balayage électronique selon l'une des revendications 17 et 18, caractérisée en ce que lesdites barrettes optiques comportent au moins deux couches de fibres optiques superposées et décalées.Electronic scanning antenna according to one of claims 17 and 18, characterized in that said optical strips comprise at least two layers of optical fibers superimposed and offset. Antenne à balayage électronique selon l'une des revendications 17 et 18, caractérisée en ce que lesdites barrettes optiques comportent trois couches de fibres optiques superposées et décalées.Electronic scanning antenna according to one of claims 17 and 18, characterized in that said optical strips comprise three layers of optical fibers superimposed and offset. Antenne à balayage électronique selon l'une des revendications 11 à 16, caractérisée en ce que lesdits moyens comportent des sources lumineuses éclairant séquentiellement un capteur optique situé sur la surface rayonnante. Electronic scanning antenna according to one of claims 11 to 16, characterized in that said means comprise light sources sequentially illuminating an optical sensor located on the radiating surface. Antenne à balayage électronique selon la revendication 21, caractérisée en ce que lesdites sources lumineuses comportent des moyens de renvoi de la lumière vers ledit capteur, lesdits moyens comportant un miroir non métallique situé sur la surface rayonnante.Electronic scanning antenna according to claim 21, characterized in that said light sources comprise means for returning light to said sensor, said means comprising a non-metallic mirror located on the radiating surface.
EP01403200A 2000-12-21 2001-12-11 Process for measuring and compensating the deformation of an antenna and antenna for such a process Withdrawn EP1217687A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0016774A FR2818812B1 (en) 2000-12-21 2000-12-21 METHOD FOR MEASURING AND COMPENSATING FOR THE DEFORMATION OF THE RADIANT SURFACE OF AN ANTENNA AND ANTENNA COMPRISING MEANS EMPLOYING SUCH A METHOD
FR0016774 2000-12-21

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EP1217687A1 true EP1217687A1 (en) 2002-06-26

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FR2934676B1 (en) * 2008-08-01 2010-08-20 Thales Sa POLARIMETRIC SENSOR FOR MEASURING DEFORMATION SUBJECTED BY A SURFACE.

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FR2818812B1 (en) 2004-06-04

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