EP1522121A1 - Phase-shifting cell for antenna reflector - Google Patents
Phase-shifting cell for antenna reflectorInfo
- Publication number
- EP1522121A1 EP1522121A1 EP03760729A EP03760729A EP1522121A1 EP 1522121 A1 EP1522121 A1 EP 1522121A1 EP 03760729 A EP03760729 A EP 03760729A EP 03760729 A EP03760729 A EP 03760729A EP 1522121 A1 EP1522121 A1 EP 1522121A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cell according
- membrane
- cell
- strands
- phase
- Prior art date
- 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.)
- Withdrawn
Links
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Classifications
-
- 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
- H01Q3/44—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 electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element
- H01Q3/46—Active lenses or reflecting arrays
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
- H01Q21/061—Two dimensional planar arrays
- H01Q21/062—Two dimensional planar arrays using dipole aerials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/06—Details
- H01Q9/065—Microstrip dipole antennas
Definitions
- the field of the invention is that of passive reflective arrays composed of a mosaic of elementary phase-shifting cells for an antenna with reconfigurable transmission direction operating in the microwave range.
- ground applications millimeter wave communications and weather radar applications.
- FIGS. 1 and 2 The third technical possibility is illustrated in FIGS. 1 and 2, it consists in producing an antenna from a single transmitting source 1 carried by an arm 2 which illuminates a reflective network 3. The whole is controlled by an electronic control module signal 5.
- the network reflector is composed of a mosaic of 4 passive phase shifting cells generally arranged in a honeycomb pattern which will re-emit a beam in the desired direction. To control the direction of retransmission, it suffices to control the phase shift introduced by each cell.
- this solution has the advantage of not requiring moving parts.
- it does not have the disadvantages: the implementation of a single powerful source being simpler and less costly to carry out than that of a multitude of independent sources.
- a first solution consists in making transit then reflect the wave of wavelength ⁇ in a waveguide of given length L.
- the phase shift ⁇ introduced is then proportional to the ratio L / ⁇ .
- the desired phase shift is thus obtained by adapting the length of the waveguide.
- This phase shift also depends, in principle, directly on the wavelength of the transmitted signal and therefore, this type of device can only work for narrow emission spectral bands.
- the phase-shifting cell mainly comprises a planar dielectric substrate 6 of thickness equal to approximately a quarter of the central wavelength of use on which it is deposited on the lower part a ground plane 10 and, on the upper part an even number of strands of conductive dipoles 7 arranged in a regular manner around a central disc 8 also conductive.
- Switching devices 9 allow two strands diametrically opposite the central disc to be connected on command. When two strands are thus connected to the disc, they constitute a radiating dipole having a given geometric orientation, the other unconnected strands not radiating or very weakly.
- the operating principle is as follows: either a circularly polarized wave falling on a phase shifting cell, two of whose strands are connected to form a dipole, we demonstrate that if the field vector electric representing this circular wave forms at the level of the surface of the dipole a phase shift angle + ⁇ with the direction of said dipole, then the re-emitted electric field will make with the direction of the dipole a phase shift angle - ⁇ .
- the phase shift introduced is thus almost independent of the wavelength of the signal.
- phase shifting cell One of the main technological difficulties with this type of phase shifting cell is the production of switching devices.
- Each reflective network can include several tens of phase-shifting cells and therefore several hundred switching devices. They must therefore be reliable, of reduced size, typically the size of each switch must not exceed a few hundred microns, have a low electrical consumption, and not interfere with the operation of the microwave dipole.
- the invention proposes, for its part, an alternative solution making it possible to simplify the production of the device and to reduce the dissipated electrical power.
- the object of the invention is to produce the switches from electro-mechanical micro-devices.
- a micro-switch is thus produced in a surface of the order of a tenth of a square millimeter
- the subject of the invention is a phase-shifting cell of a reconfigurable reflective array for antenna operating in the microwave domain, said array comprising a plurality of phase-shifting cells, each of said phase-shifting cells comprising several electrically conductive strands, characterized in that 'at least two of said strands can be interconnected by means of at least one switching device consisting of an electromechanical micro-system comprising a flexible electrically controllable membrane, the strands thus connected constituting a radiating dipole.
- said phase-shifting cell comprises two plane and parallel faces separated by a thickness representing approximately a quarter of the wavelength of the frequency of use, said first face comprising a star network made up of an even number of electrically conductive strands, all identical, regularly arranged around a central disc also conductive, each strand being able to be electrically connected to the central disc by a switching device dependent on a control voltage, each pair of diametrically opposite strands thus constituting, when the two devices connecting them to the central disc are activated, a dipole resonating in the range of frequencies of use of the antenna, the second face comprising a ground plane; said cell being characterized in that the switching device consists of an electromechanical micro-system comprising a flexible membrane supported by at least two pillars placed between said membrane and the first face of the cell, said membrane being thus placed above the end of each strand facing the central disc and the peripheral part of said disc placed opposite this end; said membrane
- the switching device is of the capacitor type and the electrical connection corresponds to a large increase in its capacity.
- An operation of the micro-switch as a simple switch with electrical contact between the flexible membrane and the parts of the dipole has the disadvantage of having very low reliability.
- the use of a micro-capacitor with low capacity typically varying from femtoFarad in open circuit to picoFarad in closed circuit allows to obtain an excellent coupling in closed position and a very good insulation in the open position while considerably increasing the reliability of the device.
- the ratio between the value of the capacitance of the capacitor in the absence of control voltage and the value of the capacity when the control voltage is applied is of the order of hundredth.
- the capacitor plates consist on the one hand of the flexible membrane and on the other hand of the end of the strand and of the peripheral part of the corresponding disc placed under this membrane, the electrical isolation being ensured by a layer of dielectric material covering the strands and the disc.
- This material is preferably silica nitride.
- the geometric and mechanical parameters of the membrane are dimensioned so that the control voltage to be applied to ensure the switching is large compared to the possible parasitic voltages.
- This control voltage is typically thirty volts.
- the reliability of the device, the switching time and the control voltage depend in part on the geometric characteristics of the membrane.
- the membrane is in the form of a thin rectangular parallelepiped, the width of the rectangle typically being worth one hundred microns, its length three hundred microns and its thickness seven hundred nanometers.
- the materials used for the production of the membrane are advantageously Gold, Aluminum or alloys of Tungsten and Titanium arranged in layers. In the absence of control voltage, the capacitor plates are separated by about three microns.
- the end of the strand and the part of the central disc opposite placed under the membrane compose a comb of interdigitated fingers, the total number of fingers is preferably five.
- the interdigitated comb shape of the two surfaces of the end of the strand and of the central disc opposite make it possible to optimize the capacitive effect.
- the control voltages of the switching devices pass through the strands by means of internal resistive lines and the flexible membranes are all connected to the electrical ground by means of other internal resistive lines as well.
- the material used to make the various electrical connections is preferably gold.
- the value of the impedance of the resistive lines at the frequency of use is high enough to isolate all the strands, the central disc and the switching devices from the outside.
- the cell is hexagonal in shape and has twelve strands, each strand preferably having a flared shape, the flare angle being close to 20 degrees.
- the hexagonal shape of the cell allows a complete and uniform tiling of the space of the reflecting network.
- the phase shift introduced by each cell is discrete, the minimum phase shift angle being inversely proportional to the number of strands. It is, of course, advantageous to reduce this angle by increasing the number of strands. However, this is limited by the complexity of the interconnection systems when the number of strands to be controlled increases, the necessary limit of miniaturization of the switches and the possible interference between strands if their spacing is tightened.
- twelve strands per cell are a good compromise between technological complexity and the minimum phase shift angle.
- the coefficient of reflection of the wave by the dipole depends on its size which must be conventionally close to half a wavelength, but also on its shape, the slightly flared shapes being well adapted to obtain a good resonance of the dipole .
- the electronic assembly of said cell formed by the strands, the central disc, the switching devices and the various resistive lines bringing the control voltages and the electrical ground is implanted on a substrate transparent to microwave waves
- the material used can be silicon, quartz or glass, in particular of the Pyrex brand.
- Said substrate is in the form of a straight cylinder with flat and parallel faces, of circular or hexagonal base and is centered on the central disc of the cell.
- the upper parts of the substrates which comprise the central disks and the various switching devices are protected by one or more protective covers.
- Each cell can have its own protective cover or the cover can be unique, common to the entire reflecting network.
- Switching devices which are mechanical parts of very small dimensions, of the order of a few microns to a few hundred microns require a cover making it possible to protect them from external elements such as fluids or dust which would risk seriously degrading their performance. In particular, the performance of metal membranes can be seriously affected by oxidation.
- the substrate common to the whole of the reflective grating comprises two flat and parallel faces, the upper face carrying the various glass substrates corresponding to each cell, and the opposite face comprising a ground plane, the material of this substrate being a material transparent to microwave waves and electrically insulating.
- this material is made from glass fibers and teflon.
- the NELTEC company markets a material of this type under the METCLAD brand.
- connection of each cell is provided by a honeycomb paving of circular connection holes made in the common substrate and arranged in hexagon, each of the hexagons being centered on a central cell disc, each of the internal resistive lines d '' a cell from the strands or membranes being connected to these holes by other resistive external connection links implanted on the common substrate, the internal resistive lines implanted on the glass substrates of each cell being connected to the external resistive lines implanted on the substrate of the reflective network by means of cabled connection wires.
- the lines of connection holes are common to two adjacent cells and each hexagon of connection pads then comprises a number of pads equal to at least twice the total number of strands of each cell increased by two so as to be able to ensure the connection of two adjacent cells.
- connection holes which will act as an electromagnetic barrier if their spacing is sufficiently small compared to the wavelength
- sets of metal separation walls arranged in hexagon above the holes of connection, said walls being connected together and connected to ground by metal centering pins located on the one hand in the walls and on the other hand in certain connection holes reserved for this purpose.
- the set of cell walls then forms a honeycomb grid located above the reflective grating.
- the entire reflecting network is covered with a multilayer dielectric treatment making it possible to increase the efficiency. of the cell when the incidence of incident or reflected radiation is significant.
- the method of making the reflecting array comprises the following steps:
- the process for producing the switches includes the following sub-steps:
- Figure 1 shows the block diagram of an antenna according to the invention.
- Figure 2 shows a top view of the reflective network showing the hexagonal tiling of the phase shifting cells.
- FIG. 3 represents the general principle of the phase-shifting cells with star dipoles in top view.
- the switches are represented by simple switches. In normal use configuration, only two diametrically opposite switches are closed, the others being left open.
- FIG. 5 represents the operating principle of a switch with an electromechanical device when it is in the OFF position, that is to say that there is no difference in potential between the membrane and the conductive surfaces located at the -Dessous.
- FIG. 6 represents the operating principle of a switch with an electromechanical device when it is in the ON position, that is to say that there is a sufficient potential difference between the membrane and the conductive surfaces situated above it. below so that mechanical contact is made.
- Figure 7 shows a top view of two switching assemblies according to the invention. In this figure, only the end of two strands opposite the central disc are represented, the part of the central disc facing them, the resistive connections and the membrane of each switch.
- Figure 8 shows a view of the end of the strand and the part of the central disc opposite, showing the interdigitated combs located under the membrane. Only the contours of the membrane have been shown in dotted lines for the sake of clarity.
- Figure 9 shows a perspective view of the two switches of Figure 7, one of the two switches is in the OFF position (straight membrane), the other in the ON position (curved membrane).
- Figure 10 shows a top view of the cell according to the invention. For the sake of clarity, the switches are represented by dotted lines in the OFF position and by a solid line in the ON position.
- Figure 11 shows a first sectional view of the cell according to the invention passing through the center of the cell.
- the switches are not shown in this figure for the sake of clarity.
- Figure 12 shows a second sectional view of the cell according to the invention passing through the periphery of the cell, showing the connection of a metal wall on the common substrate.
- Figure 13 shows the general arrangement of three neighboring cells in top view.
- FIG. 7 represents a top view of the switching devices according to the invention.
- Two conductive strands 7 adjacent to a phase shifting cell 4 are shown as well as the part of the central disc 8 facing them.
- the switching zone of each strand is formed by the end of the strand located opposite the central disc.
- the switching device essentially comprises a membrane 11 arranged above the switching zone. Control voltages and grounding are carried out using resistive lines 151, 154 and 155.
- Figure 8 shows a detailed view of the switching area.
- the end 71 of each strand placed on the side of the central disc and the corresponding part 81 of the disc placed opposite this end make up a comb of interdigital fingers.
- the area of this comb constitutes the switching area.
- the advantage of this geometrical arrangement is that it makes it possible to distribute the control voltage coming from the strand evenly in the switching zone.
- five fingers are interdigitated, two belonging to the central disc and three belonging to each strand.
- the entire switching area is covered with a layer of insulating material such as, for example, silica nitride, not shown in the figure.
- FIG. 9 represents a perspective view of the two switches represented in FIG. 7.
- Each membrane is supported by at least two pillars 14 arranged on either side of the switching zone.
- the membrane is thus isolated at a certain distance above the switching area. This distance is typically worth a few microns.
- Said metal membrane has a roughly parallelepiped shape. This form represents a good compromise between the mechanical resistance of the membrane which conditions its service life and its reliability and the voltages necessary to be implemented to obtain the switching which should not be too great.
- the control voltages are of the order of thirty volts.
- the membrane is also pierced with a multitude of holes 110 during its production.
- the membrane is metallic.
- the possible metals and alloys are preferably gold, aluminum, tungsten or titanium.
- the assembly constituted by the membrane and the end of the strand and the part of the central disc located below form the reinforcements of a capacitor whose capacity at rest is worth a few femtofarads.
- the membrane When the membrane is stressed, it deforms, bringing the two plates of the capacitor closer together. Its capacity increases and is then worth a few picofarads.
- Figures 10, 11 and 12 show the top view and two sectional views of a network cell according to the invention.
- FIGS. 7, 8 and 9 show the top view of the cell.
- the central part of the cell 4 comprises a substrate 61 on which is installed the star network of the electrically conductive strands 7 constituting the different dipoles, said network being centered on a central electrically conductive disc 8.
- the substrate is electrically insulating and transparent to microwave waves. It must be compatible with the implantation technologies of the various electronic components of the cell.
- This substrate is, for example, silicon or quartz or glass, in particular of the pyrex brand.
- the strands are necessarily in even number and arranged symmetrically so that each strand is a diametrically opposite vis-à-vis. Each pair of diametrically opposite strands thus constitutes a dipole when it is connected to the central disc by the switching devices shown in FIGS. 7, 8 and 9.
- control voltages and grounding are carried out by means of resistive lines 151, 154 and 155 connected on the one hand to the different strands and to the switching membranes and on the other hand to connection pads 161 arranged on the periphery of the central substrate.
- a first series of control lines 151 is connected to the end of each strand as shown in FIG. 10.
- Two diametrically opposite grounding lines 154 connect two membranes to ground, the other membranes and the central disc are connected to these two membranes by other resistive lines 155 as shown in FIG. 10.
- the resistive lines 151, 154 and 155 have sufficient resistance to obtain complete electrical isolation from the microwave of all the strands and switching devices.
- resistive deposits typically have an ohmic resistance of a few hundred square ohms.
- the strands are preferably flared so as to increase the yield of the dipole.
- the flare angle is about twenty degrees.
- the length of each strand is approximately one quarter of the microwave wavelength of use.
- the central substrates corresponding to a given cell are regularly implanted on a common substrate 62 for all of the cells 4 of the reflective network.
- This substrate is also electrically insulating and transparent to microwave waves. It must be compatible with the implantation technologies of the various electronic components of the cell.
- This substrate is produced in particular from a composite based on glass fibers and Teflon. This type of material is marketed by the company NELTEC under the brand METCLAD.
- the total thickness of the common substrate and of each central substrate is approximately one quarter of the microwave wavelength of use, that is to say of the order of one to two millimeters taking into account the frequencies of use.
- This substrate comprises on the face opposite to that of the central substrates a ground plane 10.
- the common substrate comprises a paving of electrical connection pads 171 and 172 regularly arranged in a hexagonal pattern.
- Each hexagon is centered on a central cell substrate as it is indicated in Figures 7 and 13 and is composed of six lines of at least six connection pads. The pads of each line are regularly spaced between them. They completely cross the common substrate ( Figure 12).
- Each cell is surmounted by a set of six metal walls 18 (FIG. 12) also arranged in hexagon and placed above the lines of connection pads, the assembly forming a honeycomb grid (FIGS. 10 and 13) .
- the first type is used to connect the resistive control lines outside the reflective network to the electronic control module and are isolated from the ground plane.
- the second type is used on the one hand to mechanically fix the metal walls on the common substrate by means of fixing pins 172 and on the other hand to connect these walls to the ground plane as indicated in FIG. 12.
- the pads of the first type are connected to the resistive lines 151 and 154 of the common substrates by other resistive lines 153 interconnected by means of cabled connection wires 152 as indicated in FIG. 10.
- Said resistive lines 153 have sufficient resistance to obtain complete electrical isolation from microwave waves of all the strands and switching devices.
- resistive deposits typically have an ohmic resistance of about one square kiloOhm.
- the pads are isolated from the metal walls by insulating pads 173.
- the arrangement of the resistive lines connected to the interconnection pads is indicated in FIGS. 10 and 13. This arrangement makes it possible both to have the same geometrical arrangement for all the cells. of the network and on the other hand to minimize the lengths of the resistive lines.
- This protection is provided either at the level of each cell by a protective cover 19 as indicated in FIG. 11 which represents a sectional view of the cell.
- This cover 19 must also be transparent to microwave waves.
- This cover can also be common to the entire reflective network.
- the central substrates can also be covered with a multilayer dielectric treatment so as to increase the yield of the cells at high angular incidence.
- the operating principle of the reflective network is as follows:
- the electronic module calculates for each cell the geometric arrangement of the dipoles to be activated.
- the electronic module For each cell, the electronic module generates the control voltages which are sent to the two diametrically opposite strands to be activated.
- the switching devices are implemented simultaneously for two opposite strands by two separate voltage commands, the geometry of the device not making it possible to connect the two strands simultaneously to the central disk by a common command.
- the method of making the reflecting array comprises the following steps:
- the method for producing the switches comprises the following substeps:
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Abstract
Description
CELLULE DEPHASEUSE POUR RESEAU REFLECTEUR D'ANTENNE PHASE CELL FOR ANTENNA REFLECTIVE ARRAY
Le domaine de l'invention est celui des réseaux réflecteurs passifs composés d'une mosaïque de cellules déphaseuses élémentaires pour antenne à direction d'émission reconfigurable fonctionnant dans la gamme des hyperfréquences.The field of the invention is that of passive reflective arrays composed of a mosaic of elementary phase-shifting cells for an antenna with reconfigurable transmission direction operating in the microwave range.
Dans un grand nombre d'applications, il est nécessaire de pouvoir orienter le faisceau électromagnétique d'émission d'une antenne dans la direction souhaitée. Les applications possibles sont notamment :In a large number of applications, it is necessary to be able to orient the electromagnetic beam of emission of an antenna in the desired direction. Possible applications include:
• les télécommunications spatiales : suivi de zone au sol dans le cas d'un satellite défilant, minimisation du rayonnement interférant en cas d'utilisation simultanée de plusieurs signaux, reprogrammation de l'antenne liée à une évolution de trafic et redondance en vol pour pallier des antennes défaillantes ;• space telecommunications: ground area monitoring in the case of a traveling satellite, minimization of interfering radiation in the event of the simultaneous use of several signals, reprogramming of the antenna linked to an evolution in traffic and redundancy in flight to compensate faulty antennas;
• les applications embarquées sur aéronefs : communications avion-satellite et applications aux radars ;• applications on board aircraft: aircraft-satellite communications and radar applications;
• les applications sol : communications en ondes millimétriques et applications aux radars météo.• ground applications: millimeter wave communications and weather radar applications.
Pour réaliser cette orientation, il existe trois techniques possibles. Il est possible d'orienter mécaniquement toute l'antenne dans la direction souhaitée. Cette solution nécessite des dispositifs de positionnement mécaniques complexes à mettre en œuvre dans le cas, par exemple, d'applications spatiales. Dans une seconde solution, on réalise une antenne dite active composée d'une pluralité de cellules élémentaires émettrices. En contrôlant la phase des différents signaux émis par chaque cellule, on obtient l'émission dans la direction souhaitée. Cependant, cette solution, bien que plus souple que la précédente, présente les inconvénients d'être chère et de masse élevée.To achieve this orientation, there are three possible techniques. It is possible to mechanically orient the entire antenna in the desired direction. This solution requires complex mechanical positioning devices to be implemented in the case, for example, of space applications. In a second solution, a so-called active antenna is made up composed of a plurality of elementary emitting cells. By controlling the phase of the various signals emitted by each cell, the emission is obtained in the desired direction. However, this solution, although more flexible than the previous one, has the disadvantages of being expensive and of high mass.
La troisième possibilité technique est illustrée en figures 1 et 2, elle consiste à réaliser une antenne à partir d'une source émettrice 1 unique portée par un bras 2 qui illumine un réseau réflecteur 3. L'ensemble est commandé par un module électronique de commande du signal 5. Le réseau réflecteur est composé d'une mosaïque de cellules 4 déphaseuses passives généralement disposées en nid d'abeille qui vont réémettre un faisceau dans la direction souhaitée. Pour contrôler la direction de réémission, il suffit alors de contrôler le déphasage introduit par chaque cellule. Cette solution présente, comme l'antenne active, l'avantage de ne pas nécessiter de pièces mobiles. Elle n'en a cependant pas les inconvénients : la mise en œuvre d'une seule source puissante étant plus simple et moins coûteuse à réaliser que celle d'une multitude de sources indépendantes.The third technical possibility is illustrated in FIGS. 1 and 2, it consists in producing an antenna from a single transmitting source 1 carried by an arm 2 which illuminates a reflective network 3. The whole is controlled by an electronic control module signal 5. The network reflector is composed of a mosaic of 4 passive phase shifting cells generally arranged in a honeycomb pattern which will re-emit a beam in the desired direction. To control the direction of retransmission, it suffices to control the phase shift introduced by each cell. Like the active antenna, this solution has the advantage of not requiring moving parts. However, it does not have the disadvantages: the implementation of a single powerful source being simpler and less costly to carry out than that of a multitude of independent sources.
Il existe plusieurs solutions pour réaliser les cellules déphaseuses élémentaires. Une première solution consiste à faire transiter puis réfléchir l'onde de longueur d'onde λ dans un guide d'onde de longueur L donnée. Le déphasage φ introduit est alors proportionnel au rapport L/λ. On obtient ainsi le déphasage souhaité en adaptant la longueur du guide d'onde. Ce déphasage dépend également, par principe même, directement de la longueur d'onde du signal émis et par conséquent, ce type de dispositif ne peut fonctionner que pour des bandes spectrales d'émission étroites.There are several solutions for making elementary phase shifting cells. A first solution consists in making transit then reflect the wave of wavelength λ in a waveguide of given length L. The phase shift φ introduced is then proportional to the ratio L / λ. The desired phase shift is thus obtained by adapting the length of the waveguide. This phase shift also depends, in principle, directly on the wavelength of the transmitted signal and therefore, this type of device can only work for narrow emission spectral bands.
Pour pallier cet inconvénient, un type de dispositif permet d'obtenir un déphasage dont la valeur est quasi-indépendante de la longueur d'onde (James P. Mongomery : A Microstrip ReflectArray Antenna Elément - Antenna Applications Symposium - Sep. 20-22, 1978, pp 1-16, University of Illinois). Celui-ci est adapté à des ondes émises en polarisation circulaire.To overcome this drawback, a type of device makes it possible to obtain a phase shift whose value is almost independent of the wavelength (James P. Mongomery: A Microstrip ReflectArray Antenna Element - Antenna Applications Symposium - Sep. 20-22, 1978, pp 1-16, University of Illinois). This is suitable for waves emitted in circular polarization.
Le schéma de principe de ce type de dispositif est décrit en figures 3 et 4. La cellule déphaseuse comprend principalement un substrat diélectrique plan 6 d'épaisseur égale à environ le quart de la longueur d'onde centrale d'utilisation sur lequel on dépose sur la partie inférieure un plan de masse 10 et, sur la partie supérieure un nombre pair de brins de dipôles conducteurs 7 disposés de façon régulière autour d'un disque central 8 également conducteur. Des dispositifs de commutation 9 permettent de relier sur commande deux brins diamétralement opposés au disque central. Lorsque deux brins sont ainsi reliés au disque, ils constituent un dipole rayonnant ayant une orientation géométrique donnée, les autres brins non reliés ne rayonnant pas ou très faiblement.The basic diagram of this type of device is described in FIGS. 3 and 4. The phase-shifting cell mainly comprises a planar dielectric substrate 6 of thickness equal to approximately a quarter of the central wavelength of use on which it is deposited on the lower part a ground plane 10 and, on the upper part an even number of strands of conductive dipoles 7 arranged in a regular manner around a central disc 8 also conductive. Switching devices 9 allow two strands diametrically opposite the central disc to be connected on command. When two strands are thus connected to the disc, they constitute a radiating dipole having a given geometric orientation, the other unconnected strands not radiating or very weakly.
Le principe de fonctionnement est le suivant : soit une onde polarisée circulairement tombant sur une cellule déphaseuse dont deux des brins sont reliés pour former un dipole, on démontre que si le vecteur champ électrique représentant cette onde circulaire forme au niveau de la surface du dipole un angle de déphasage +θ avec la direction dudit dipole, alors le champ électrique réémis fera avec la direction du dipole un angle de déphasage -θ. En fonction des dipôles créés dans chaque cellule déphaseuse, il devient ainsi possible de contrôler le déphasage apporté et par conséquent l'angle de réémission du faisceau. L'avantage majeur de cette disposition est que le déphasage introduit est ainsi quasi-indépendant de la longueur d'onde du signal.The operating principle is as follows: either a circularly polarized wave falling on a phase shifting cell, two of whose strands are connected to form a dipole, we demonstrate that if the field vector electric representing this circular wave forms at the level of the surface of the dipole a phase shift angle + θ with the direction of said dipole, then the re-emitted electric field will make with the direction of the dipole a phase shift angle -θ. Depending on the dipoles created in each phase shifting cell, it thus becomes possible to control the phase shift provided and therefore the beam retransmission angle. The major advantage of this arrangement is that the phase shift introduced is thus almost independent of the wavelength of the signal.
Une des principales difficultés technologiques de ce type de cellule déphaseuse est la réalisation des dispositifs de commutation. Chaque réseau réflecteur peut comporter plusieurs dizaines de cellules déphaseuses et par conséquent plusieurs centaines de dispositifs de commutation. Ils doivent donc être fiables, de taille réduite, typiquement l'encombrement de chaque commutateur ne doit pas excéder quelques centaines de microns, avoir une consommation électrique faible, et ne pas parasiter le fonctionnement du dipole en hyperfréquence.One of the main technological difficulties with this type of phase shifting cell is the production of switching devices. Each reflective network can include several tens of phase-shifting cells and therefore several hundred switching devices. They must therefore be reliable, of reduced size, typically the size of each switch must not exceed a few hundred microns, have a low electrical consumption, and not interfere with the operation of the microwave dipole.
Le brevet US 5 835 062 (Fiat panel-configured electronically steerable phased array antenna having spatially distribued array of fanned dipole sub-array controlled by triode-configured field émission devices) propose de réaliser les commutateurs à partir de triodes électroniques. Cette solution nécessite la réalisation et l'implantation pour chaque triode de commutateur de micro-cathodes coniques et de micro-anodes annulaires. Ces dispositifs nécessitent également pour fonctionner une puissance électrique importante compte-tenu du grand nombre de commutateurs par réseau réflecteur.US patent 5,835,062 (Fiat panel-configured electronically steerable phased array antenna having spatially distribued array of fanned dipole sub-array controlled by triode-configured field emission devices) proposes to make the switches from electronic triodes. This solution requires the production and implantation for each triode of conical micro-cathode switches and annular micro-anodes. These devices also require significant electrical power to operate, given the large number of switches per reflector network.
L'invention propose, quant à elle, une solution alternative permettant de simplifier la réalisation du dispositif et de réduire la puissance électrique dissipée. L'objet de l'invention est de réaliser les commutateurs à partir de micro-dispositifs électro-mécaniques.The invention proposes, for its part, an alternative solution making it possible to simplify the production of the device and to reduce the dissipated electrical power. The object of the invention is to produce the switches from electro-mechanical micro-devices.
Le principe de fonctionnement de ce type de dispositif est décrit de façon schématique sur les figures 5 et 6 dans le cas le plus simple de l'utilisation en micro-interrupteur. Une membrane ou une poutre métallique 11 de très faible épaisseur est maintenue suspendue par des supports 14 au-dessus de surfaces conductrices 12 et 13 isolées entre elles. L'ensemble membrane - surfaces conductrices peut être soumis à une tension électrique T. En l'absence de tension appliquée, la membrane est suspendue au- dessus des surfaces conductrices et il n'y a aucun contact électrique entre celles-ci. Dans ce cas, un courant électrique ne peut passer entre 12 et 13 et on assimile l'ensemble membrane-surfaces conductrices à un interrupteur ouvert. Lorsque l'on soumet l'ensemble membrane-surfaces conductrices à une tension T croissante, la membrane est soumise à une force électrostatique qui la déforme jusqu'à ce que la membrane entre en contact avec les surfaces conductrices pour une tension Te- Le courant électrique peut alors passer de 12 à 13. L'ensemble membrane-surfaces conductrices est équivalent à un interrupteur fermé. On réalise ainsi un micro-interrupteur. Les principaux avantages de ce type de dispositif sont essentiellement :The operating principle of this type of device is described schematically in Figures 5 and 6 in the simplest case of use in microswitch. A very thin metal membrane or beam 11 is held suspended by supports 14 above conductive surfaces 12 and 13 isolated from each other. All membrane - conductive surfaces can be subjected to an electrical voltage T. In the absence of an applied voltage, the membrane is suspended above the conductive surfaces and there is no electrical contact between them. In this case, an electric current cannot pass between 12 and 13 and the membrane-conductive surfaces assembly is assimilated to an open switch. When the membrane-conductive surfaces assembly is subjected to an increasing voltage T, the membrane is subjected to an electrostatic force which deforms it until the membrane comes into contact with the conductive surfaces for a voltage Te- The current electric can then go from 12 to 13. The membrane-conductive surfaces assembly is equivalent to a closed switch. A micro-switch is thus produced. The main advantages of this type of device are essentially:
• les techniques de réalisation qui sont dérivées des technologies classiques de fabrication de circuits micro-électroniques en couches minces, qui permettent d'obtenir des coûts de réalisation faibles, en comparaison d'autres technologies tout en garantissant une fiabilité élevée ;• the production techniques which are derived from conventional technologies for manufacturing micro-electronic circuits in thin layers, which make it possible to obtain low production costs, in comparison with other technologies while guaranteeing high reliability;
• Les très faibles puissances électriques consommées, pratiquement nulles ;• The very low electrical powers consumed, practically zero;
• L'encombrement. On réalise ainsi un micro-commutateur dans une surface de l'ordre du dixième de millimètre carré ;• Congestion. A micro-switch is thus produced in a surface of the order of a tenth of a square millimeter;
• Les performances en utilisation hyperfréquence. Ce type de commutateur présente des pertes d'insertion très faibles, de l'ordre du dixième de déciBel, bien inférieures à celles de dispositifs assurant les mêmes fonctions.• Performance in microwave use. This type of switch has very low insertion losses, of the order of a tenth of deciBel, much lower than that of devices providing the same functions.
Plus précisément, l'invention a pour objet une cellule déphaseuse d'un réseau réflecteur reconfigurable pour antenne fonctionnant dans le domaine des hyperfréquences, ledit réseau comportant une pluralité de cellules déphaseuses, chacune desdites cellules déphaseuses comportant plusieurs brins électriquement conducteurs, caractérisé en ce qu'au moins deux desdits brins peuvent être reliés entre eux au moyen d'au moins un dispositif de commutation constitué d'un micro-système électromécanique comprenant une membrane flexible commandable électriquement, les brins ainsi reliés constituant un dipole rayonnant. Dans le cadre des réseaux réflecteurs dont la disposition géométrique des brins est en étoile, ladite cellule déphaseuse comporte deux faces planes et parallèles séparées d'une épaisseur représentant environ le quart de la longueur d'onde de la fréquence d'utilisation, ladite première face comportant un réseau en étoile constitué d'un nombre pair de brins électriquement conducteurs tous identiques disposés régulièrement autour d'un disque central également conducteur, chaque brin pouvant être électriquement relié au disque central par un dispositif à commutation dépendant d'une tension de commande, chaque paire de brins diamétralement opposés constituant ainsi, lorsque les deux dispositifs les reliant au disque central sont activés, un dipole résonnant dans le domaine des fréquences d'utilisation de l'antenne, la seconde face comprenant un plan de masse ; ladite cellule étant caractérisée en ce que le dispositif de commutation est constitué d'un micro-système électromécanique comprenant une membrane flexible soutenue par au moins deux piliers placés entre ladite membrane et la première face de la cellule, ladite membrane étant ainsi placée au-dessus de l'extrémité de chaque brin en regard du disque central et de la partie périphérique dudit disque placée vis- à-vis de cette extrémité ; ladite membrane, lorsque la tension de commande est appliquée, étant déformée par la force électrostatique résultante de façon suffisante pour assurer la liaison électrique entre l'extrémité du brin et la partie périphérique correspondante du disque central.More specifically, the subject of the invention is a phase-shifting cell of a reconfigurable reflective array for antenna operating in the microwave domain, said array comprising a plurality of phase-shifting cells, each of said phase-shifting cells comprising several electrically conductive strands, characterized in that 'at least two of said strands can be interconnected by means of at least one switching device consisting of an electromechanical micro-system comprising a flexible electrically controllable membrane, the strands thus connected constituting a radiating dipole. In the context of reflective arrays, the geometrical arrangement of the strands of which is in a star, said phase-shifting cell comprises two plane and parallel faces separated by a thickness representing approximately a quarter of the wavelength of the frequency of use, said first face comprising a star network made up of an even number of electrically conductive strands, all identical, regularly arranged around a central disc also conductive, each strand being able to be electrically connected to the central disc by a switching device dependent on a control voltage, each pair of diametrically opposite strands thus constituting, when the two devices connecting them to the central disc are activated, a dipole resonating in the range of frequencies of use of the antenna, the second face comprising a ground plane; said cell being characterized in that the switching device consists of an electromechanical micro-system comprising a flexible membrane supported by at least two pillars placed between said membrane and the first face of the cell, said membrane being thus placed above the end of each strand facing the central disc and the peripheral part of said disc placed opposite this end; said membrane, when the control voltage is applied, being deformed by the resulting electrostatic force sufficiently to ensure the electrical connection between the end of the strand and the corresponding peripheral part of the central disc.
Avantageusement, le dispositif de commutation est de type condensateur et la liaison électrique correspond à une forte augmentation de sa capacité. Un fonctionnement du micro-commutateur en simple interrupteur avec contact électrique entre la membrane flexible et les pièces du dipole présente l'inconvénient d'avoir une très faible fiabilité. Dans le domaine des fréquences d'utilisation considéré, l'utilisation d'un micro-condensateur à faible capacité, typiquement variant du femtoFarad en circuit ouvert au picoFarad en circuit fermé permet d'obtenir un excellent couplage en position fermée et une très bonne isolation en position ouverte tout en augmentant de façon considérable la fiabilité du dispositif.Advantageously, the switching device is of the capacitor type and the electrical connection corresponds to a large increase in its capacity. An operation of the micro-switch as a simple switch with electrical contact between the flexible membrane and the parts of the dipole has the disadvantage of having very low reliability. In the field of the frequencies of use considered, the use of a micro-capacitor with low capacity, typically varying from femtoFarad in open circuit to picoFarad in closed circuit allows to obtain an excellent coupling in closed position and a very good insulation in the open position while considerably increasing the reliability of the device.
Avantageusement, le rapport entre la valeur de la capacité du condensateur en l'absence de tension de commande et la valeur de la capacité lorsque la tension de commande est appliquée est de l'ordre du centième. Dans ce cas, les armatures du condensateur sont constituées d'une part de la membrane flexible et d'autre part de l'extrémité du brin et de la partie périphérique du disque correspondant placés sous cette membrane, l'isolement électrique étant assuré par une couche de matériau diélectrique recouvrant les brins et le disque. Ce matériau est preférentiellement du nitrure de silice. Les paramètres géométriques et mécaniques de la membrane sont dimensionnés de telle sorte que la tension de commande à appliquer pour assurer la commutation est grande devant les tensions parasites possibles. Cette tension de commande vaut typiquement trente volts. La fiabilité du dispositif, le temps de commutation et la tension de commande dépendent en partie des caractéristiques géométriques de la membrane. Le meilleur compromis est obtenu lorsque la membrane se présente sous la forme d'un parallélépipède rectangle de faible épaisseur, la largeur du rectangle valant typiquement cent microns, sa longueur trois cents microns et son épaisseur sept cents nanomètres. Les matériaux utilisés pour la réalisation de la membrane sont avantageusement l'Or, l'Aluminium ou des alliages de Tungstène et de Titane disposés en couches. En l'absence de tension de commande, les armatures du condensateur sont séparées d'environ trois microns.Advantageously, the ratio between the value of the capacitance of the capacitor in the absence of control voltage and the value of the capacity when the control voltage is applied is of the order of hundredth. In this case, the capacitor plates consist on the one hand of the flexible membrane and on the other hand of the end of the strand and of the peripheral part of the corresponding disc placed under this membrane, the electrical isolation being ensured by a layer of dielectric material covering the strands and the disc. This material is preferably silica nitride. The geometric and mechanical parameters of the membrane are dimensioned so that the control voltage to be applied to ensure the switching is large compared to the possible parasitic voltages. This control voltage is typically thirty volts. The reliability of the device, the switching time and the control voltage depend in part on the geometric characteristics of the membrane. The best compromise is obtained when the membrane is in the form of a thin rectangular parallelepiped, the width of the rectangle typically being worth one hundred microns, its length three hundred microns and its thickness seven hundred nanometers. The materials used for the production of the membrane are advantageously Gold, Aluminum or alloys of Tungsten and Titanium arranged in layers. In the absence of control voltage, the capacitor plates are separated by about three microns.
Avantageusement, l'extrémité du brin et la partie du disque central en regard placés sous la membrane composent un peigne de doigts interdigités, le nombre total de doigts est preférentiellement de cinq. La forme en peignes interdigités des deux surfaces de l'extrémité du brin et du disque central en regard permettent d'optimiser l'effet capacitif.Advantageously, the end of the strand and the part of the central disc opposite placed under the membrane compose a comb of interdigitated fingers, the total number of fingers is preferably five. The interdigitated comb shape of the two surfaces of the end of the strand and of the central disc opposite make it possible to optimize the capacitive effect.
Les tensions de commande des dispositifs à commutation passent par les brins au moyen de lignes résistives internes et les membranes flexibles sont toutes reliées à la masse électrique au moyen également d'autres lignes résistives internes. Le matériau utilisé pour réaliser les différentes liaisons électriques est preférentiellement de l'or. La valeur de l'impédance des lignes résistives à la fréquence d'utilisation est suffisamment élevée pour isoler l'ensemble des brins, du disque central et des dispositifs de commutation de l'extérieur.The control voltages of the switching devices pass through the strands by means of internal resistive lines and the flexible membranes are all connected to the electrical ground by means of other internal resistive lines as well. The material used to make the various electrical connections is preferably gold. The value of the impedance of the resistive lines at the frequency of use is high enough to isolate all the strands, the central disc and the switching devices from the outside.
Avantageusement, la cellule est de forme hexagonale et comporte douze brins, chaque brin ayant preférentiellement une forme évasée, l'angle d'évasement étant voisin de 20 degrés. La forme hexagonale de la cellule permet un pavage complet et uniforme de l'espace du réseau réflecteur. Par principe, le déphasage introduit par chaque cellule est discret, l'angle minimal de déphasage étant inversement proportionnel au nombre de brins. Il est, bien entendu intéressant de diminuer cet angle en augmentant le nombre de brins. Cependant, celui-ci est limité par la complexité des systèmes d'interconnexion lorsque le nombre de brins à commander s'accroît, la nécessaire limite de miniaturisation des commutateurs et les interférences possibles entre brins si leur espacement se resserre. En pratique, douze brins par cellule sont un bon compromis entre la complexité technologique et l'angle minimal de déphasage. Le coefficient de réflexion de l'onde par le dipole dépend de sa taille qui doit être classiquement voisine d'une demi-longueur d'onde, mais également de sa forme, les formes faiblement évasées étant bien adaptées pour obtenir une bonne résonance du dipole.Advantageously, the cell is hexagonal in shape and has twelve strands, each strand preferably having a flared shape, the flare angle being close to 20 degrees. The hexagonal shape of the cell allows a complete and uniform tiling of the space of the reflecting network. In principle, the phase shift introduced by each cell is discrete, the minimum phase shift angle being inversely proportional to the number of strands. It is, of course, advantageous to reduce this angle by increasing the number of strands. However, this is limited by the complexity of the interconnection systems when the number of strands to be controlled increases, the necessary limit of miniaturization of the switches and the possible interference between strands if their spacing is tightened. In practice, twelve strands per cell are a good compromise between technological complexity and the minimum phase shift angle. The coefficient of reflection of the wave by the dipole depends on its size which must be conventionally close to half a wavelength, but also on its shape, the slightly flared shapes being well adapted to obtain a good resonance of the dipole .
Avantageusement, l'ensemble électronique de ladite cellule formé par les brins, le disque central, les dispositifs de commutation et les différentes lignes résistives amenant les tensions de commande et la masse électrique est implanté sur un substrat transparent aux ondes hyperfréquences, le matériau utilisé peut être du silicium, du quartz ou du verre, notamment de marque Pyrex. Ledit substrat se présente sous la forme d'un cylindre droit à faces planes et parallèles, de base circulaire ou hexagonale et est centré sur le disque central de la cellule.Advantageously, the electronic assembly of said cell formed by the strands, the central disc, the switching devices and the various resistive lines bringing the control voltages and the electrical ground is implanted on a substrate transparent to microwave waves, the material used can be silicon, quartz or glass, in particular of the Pyrex brand. Said substrate is in the form of a straight cylinder with flat and parallel faces, of circular or hexagonal base and is centered on the central disc of the cell.
Avantageusement, les parties supérieures des substrats qui comportent les disques centraux et les différents dispositifs de commutation sont protégées par un ou plusieurs capots de protection. Chaque cellule peut disposer de son propre capot de protection ou le capot peut être unique, commun à l'ensemble du réseau réflecteur. Les dispositifs de commutation qui sont des pièces mécaniques de très faibles dimensions, de l'ordre de quelques microns à quelques centaines de microns nécessitent un capot permettant de les protéger des éléments extérieurs comme les fluides ou la poussière qui risqueraient de dégrader fortement leurs performances. En particulier, les performances des membranes métalliques peuvent être gravement altérées par l'oxydation.Advantageously, the upper parts of the substrates which comprise the central disks and the various switching devices are protected by one or more protective covers. Each cell can have its own protective cover or the cover can be unique, common to the entire reflecting network. Switching devices which are mechanical parts of very small dimensions, of the order of a few microns to a few hundred microns require a cover making it possible to protect them from external elements such as fluids or dust which would risk seriously degrading their performance. In particular, the performance of metal membranes can be seriously affected by oxidation.
Avantageusement, le substrat commun à l'ensemble du réseau réflecteur comporte deux faces planes et parallèles, la face supérieure portant les différents substrats en verre correspondant à chaque cellule, et la face opposée comportant un plan de masse, le matériau de ce substrat étant un matériau transparent aux ondes hyperfréquences et électriquement isolant. Preférentiellement, ce matériau est réalisé à base de fibres de verre et de téflon. La société NELTEC commercialise un matériau de ce type sous la marque METCLAD.Advantageously, the substrate common to the whole of the reflective grating comprises two flat and parallel faces, the upper face carrying the various glass substrates corresponding to each cell, and the opposite face comprising a ground plane, the material of this substrate being a material transparent to microwave waves and electrically insulating. Preferably, this material is made from glass fibers and teflon. The NELTEC company markets a material of this type under the METCLAD brand.
Avantageusement, la connectique de chaque cellule est assurée par un pavage en nid d'abeille de trous de connexion circulaires réalisés dans le substrat commun et disposés en hexagone, chacun des hexagones étant centré sur un disque central de cellule, chacune des lignes résistives internes d'une cellule issues des brins ou des membranes étant reliée à ces trous par d'autres liaisons résistives de connection externes implantées sur le substrat commun, les lignes résistives internes implantés sur les substrats en verre de chaque cellule étant reliées aux lignes résistives externes implantées sur le substrat du réseau réflecteur au moyen de fils de connexion câblés.Advantageously, the connection of each cell is provided by a honeycomb paving of circular connection holes made in the common substrate and arranged in hexagon, each of the hexagons being centered on a central cell disc, each of the internal resistive lines d '' a cell from the strands or membranes being connected to these holes by other resistive external connection links implanted on the common substrate, the internal resistive lines implanted on the glass substrates of each cell being connected to the external resistive lines implanted on the substrate of the reflective network by means of cabled connection wires.
Avantageusement, les lignes de trous de connexion sont communes à deux cellules adjacentes et chaque hexagone de plots de connexion comporte alors un nombre de plots égal à au moins deux fois le nombre total de brins de chaque cellule augmenté de deux de façon à pouvoir assurer la connexion de deux cellules adjacentes.Advantageously, the lines of connection holes are common to two adjacent cells and each hexagon of connection pads then comprises a number of pads equal to at least twice the total number of strands of each cell increased by two so as to be able to ensure the connection of two adjacent cells.
Il est nécessaire d'assurer l'isolation de chaque cellule de façon qu'une configuration de cellule donnée ne parasite pas les cellules environnantes. Cette isolation est assurée de deux façons ; d'une part par les trous de connexion qui vont jouer un rôle de barrière électromagnétique si leur espacement est suffisamment faible devant la longueur d'onde et d'autre part par des ensembles de parois métalliques de séparation disposées en hexagone au-dessus des trous de connexion, lesdites parois étant reliées entre elles et reliées à la masse par des pions de centrage métalliques situés d'une part dans les parois et d'autre part dans certains trous de connexion réservés à cet effet. L'ensemble des parois des cellules forme alors une grille en nid d'abeille située au-dessus du réseau réflecteur.It is necessary to insulate each cell so that a given cell configuration does not interfere with the surrounding cells. This insulation is ensured in two ways; on the one hand by the connection holes which will act as an electromagnetic barrier if their spacing is sufficiently small compared to the wavelength and on the other hand by sets of metal separation walls arranged in hexagon above the holes of connection, said walls being connected together and connected to ground by metal centering pins located on the one hand in the walls and on the other hand in certain connection holes reserved for this purpose. The set of cell walls then forms a honeycomb grid located above the reflective grating.
Avantageusement, l'ensemble du réseau réflecteur est recouvert d'un traitement diélectrique multicouches permettant d'augmenter l'efficacité de la cellule lorsque l'incidence du rayonnement incident ou réfléchi est importante.Advantageously, the entire reflecting network is covered with a multilayer dielectric treatment making it possible to increase the efficiency. of the cell when the incidence of incident or reflected radiation is significant.
De façon générale, le procédé de réalisation du réseau réflecteur comprend les étapes suivantes :In general, the method of making the reflecting array comprises the following steps:
• Réalisation du substrat circuit imprimé commun aux cellules• Realization of the printed circuit substrate common to the cells
• Dépôt du plan de masse• Deposit of the ground plan
• Réalisation des plots de connexion électrique : trous et plages métallisés• Realization of electrical connection pads: holes and metallized areas
• Réalisation des substrats micro-électroniques centraux des cellules• Realization of the central micro-electronic substrates of the cells
• Dépôts sur ces substrats des différents dispositifs électroniques• Deposits on these substrates of various electronic devices
• Réalisation des brins, du disque central et des lignes résistives• Realization of strands, central disc and resistive lines
• Réalisation des dispositifs de commutation• Realization of switching devices
• Protection des dispositifs de commutation par la mise en place de capots.• Protection of switching devices by fitting covers.
• Mise en place des substrats centraux sur le substrat commun• Installation of central substrates on the common substrate
• Raccordement électrique des lignes résistives aux plots de connexion• Electrical connection of resistive lines to connection pads
• Mise en place des pions de centrage• Installation of centering pins
• Pose des grilles d'isolation sur les pions de centrage Avantageusement, le procédé de réalisation des commutateurs comprend les sous-étapes suivantes :• Installation of isolation grids on the centering pins Advantageously, the process for producing the switches includes the following sub-steps:
• Dépôt d'une couche de matériau diélectrique à l'emplacement des peignes interdigités ;• Deposition of a layer of dielectric material at the location of the interdigitated combs;
• Dépôt d'une couche de résine photosensible couvrant au moins l'emplacement de la membrane et de ses piliers supports ;• Deposit of a layer of photosensitive resin covering at least the location of the membrane and its support pillars;
• Retrait de ladite résine à l'emplacement de chaque pilier ;• Removal of said resin at the location of each pillar;
• Création des piliers et de la membrane par dépôt d'une couche métallique au moins aux emplacements desdits piliers et de la membrane.• Creation of the pillars and the membrane by depositing a metal layer at least at the locations of said pillars and of the membrane.
• Retrait de la résine au moins sous la membrane de façon à laisser libre la membrane sur ces piliers. L'invention sera mieux comprise et d'autres avantages apparaîtront à la lecture de la description qui va suivre, donnée à titre non limitatif et grâce aux figures annexées parmi lesquelles :• Removal of the resin at least under the membrane so as to leave the membrane free on these pillars. The invention will be better understood and other advantages will appear on reading the description which follows, given without limitation and thanks to the appended figures among which:
• La figure 1 représente le schéma de principe d'une antenne selon l'invention.• Figure 1 shows the block diagram of an antenna according to the invention.
• La figure 2 représente une vue de dessus du réseau réflecteur montrant le pavage hexagonal des cellules déphaseuses.• Figure 2 shows a top view of the reflective network showing the hexagonal tiling of the phase shifting cells.
• La figure 3 représente le principe général des cellules déphaseuse à dipôles en étoile en vue de dessus. Sur cette vue, les commutateurs sont représentés par de simples interrupteurs. En configuration d'utilisation normale, seulement deux interrupteurs diamétralement opposés sont fermés, les autres étant laissés ouverts.FIG. 3 represents the general principle of the phase-shifting cells with star dipoles in top view. In this view, the switches are represented by simple switches. In normal use configuration, only two diametrically opposite switches are closed, the others being left open.
• La figure 4 représente le même schéma que la figure précédente, mais en coupe.• Figure 4 shows the same diagram as the previous figure, but in section.
• La figure 5 représente le principe de fonctionnement d'un commutateur à dispositif électromécanique lorsqu'il est en position OFF, c'est-à-dire qu'il n'existe aucune différence de potentiel entre la membrane et les surfaces conductrices situées au-dessous.FIG. 5 represents the operating principle of a switch with an electromechanical device when it is in the OFF position, that is to say that there is no difference in potential between the membrane and the conductive surfaces located at the -Dessous.
• La figure 6 représente le principe de fonctionnement d'un commutateur à dispositif électromécanique lorsqu'il est en position ON, c'est- à-dire qu'il existe une différence de potentiel suffisante entre la membrane et les surfaces conductrices situées au-dessous pour que le contact mécanique soit réalisé.FIG. 6 represents the operating principle of a switch with an electromechanical device when it is in the ON position, that is to say that there is a sufficient potential difference between the membrane and the conductive surfaces situated above it. below so that mechanical contact is made.
• La figure 7 représente une vue de dessus de deux ensembles de commutation selon l'invention. Sur cette figure, seules sont représentées l'extrémité de deux brins en regard du disque central, la partie du disque central leur faisant face, les liaisons résistives et la membrane de chaque commutateur.• Figure 7 shows a top view of two switching assemblies according to the invention. In this figure, only the end of two strands opposite the central disc are represented, the part of the central disc facing them, the resistive connections and the membrane of each switch.
• La figure 8 représente une vue de l'extrémité du brin et de la partie du disque central en regard, montrant les peignes interdigités situés sous la membrane. Seuls les contours de la membrane ont été représentés en pointillés dans un souci de clarté.• Figure 8 shows a view of the end of the strand and the part of the central disc opposite, showing the interdigitated combs located under the membrane. Only the contours of the membrane have been shown in dotted lines for the sake of clarity.
• La figure 9 représente une vue en perspective des deux commutateurs de la figure 7, l'un des deux commutateurs est en position OFF(membrane droite), l'autre en position ON (membrane courbe). • La figure 10 représente une vue de dessus de la cellule selon l'invention. Dans un souci de clarté, les commutateurs sont représentés par des pointillés en position OFF et par un trait plein en position ON.• Figure 9 shows a perspective view of the two switches of Figure 7, one of the two switches is in the OFF position (straight membrane), the other in the ON position (curved membrane). • Figure 10 shows a top view of the cell according to the invention. For the sake of clarity, the switches are represented by dotted lines in the OFF position and by a solid line in the ON position.
• La figure 11 représente une première vue en coupe de la cellule selon l'invention passant par le centre de la cellule. Les commutateurs ne sont pas représentés sur cette figure par un souci de clarté.• Figure 11 shows a first sectional view of the cell according to the invention passing through the center of the cell. The switches are not shown in this figure for the sake of clarity.
• La figure 12 représente une seconde vue en coupe de la cellule selon l'invention passant par la périphérie de la cellule, montrant le raccordement d'une paroi métallique sur le substrat commun.• Figure 12 shows a second sectional view of the cell according to the invention passing through the periphery of the cell, showing the connection of a metal wall on the common substrate.
• La figure 13 représente la disposition générale de trois cellules voisines en vue de dessus.• Figure 13 shows the general arrangement of three neighboring cells in top view.
La figure 7 représente une vue de dessus des dispositifs de commutation selon l'invention. Deux brins conducteurs 7 adjacents d'une cellule déphaseuse 4 sont représentés ainsi que la partie du disque central 8 leur faisant face. La zone de commutation de chaque brin est constituée par l'extrémité du brin située en regard du disque central. Le dispositif de commutation comprend essentiellement une membrane 11 disposée au- dessus de la zone de commutation. Les tensions de commande et les mises à la masse sont réalisées au moyen de lignes résistives 151 , 154 et 155.FIG. 7 represents a top view of the switching devices according to the invention. Two conductive strands 7 adjacent to a phase shifting cell 4 are shown as well as the part of the central disc 8 facing them. The switching zone of each strand is formed by the end of the strand located opposite the central disc. The switching device essentially comprises a membrane 11 arranged above the switching zone. Control voltages and grounding are carried out using resistive lines 151, 154 and 155.
La figure 8 représente une vue détaillée de la zone de commutation. L'extrémité 71 de chaque brin placé du côté du disque central et la partie correspondante 81 du disque placée en regard de cette extrémité composent un peigne de doigts interdigités. La zone de ce peigne constitue la zone de commutation. L'intérêt de cette disposition géométrique est qu'elle permet de répartir la tension de commande venant du brin de façon homogène dans la zone de commutation. Sur la figure 8, à titre d'exemple, cinq doigts sont interdigités, deux appartenant au disque central et trois appartenant à chaque brin. L'ensemble de la zone de commutation est recouvert d'une couche de matériau isolant comme par exemple le nitrure de silice, non représenté sur la figure.Figure 8 shows a detailed view of the switching area. The end 71 of each strand placed on the side of the central disc and the corresponding part 81 of the disc placed opposite this end make up a comb of interdigital fingers. The area of this comb constitutes the switching area. The advantage of this geometrical arrangement is that it makes it possible to distribute the control voltage coming from the strand evenly in the switching zone. In FIG. 8, by way of example, five fingers are interdigitated, two belonging to the central disc and three belonging to each strand. The entire switching area is covered with a layer of insulating material such as, for example, silica nitride, not shown in the figure.
La figure 9 représente une vue en perspective des deux commutateurs représentés en figure 7. Chaque membrane est soutenue par au moins deux piliers 14 disposés de part et d'autre de la zone de commutation. La membrane se trouve ainsi isolée à une certaine distance au-dessus de la zone de commutation. Cette distance vaut typiquement quelques microns. Ladite membrane métallique a une forme grossièrement parallélépipédique. Cette forme représente un bon compromis entre la résistance mécanique de la membrane qui conditionne sa durée de vie et sa fiabilité et les tensions nécessaires à mettre en œuvre pour obtenir la commutation qui ne doivent pas être trop importantes. Ainsi, pour une membrane de longueur typique trois cents microns, de largeur typique cent microns et d'épaisseur sept cents nanomètres, les tensions de commande sont de l'ordre de trente volts. La membrane est également percée d'une multitude de trous 110 au cours de sa réalisation. Ces trous permettent le passage du solvant permettant la libération de la membrane au cours du processus de réalisation. Par souci de clarté, ces trous ne sont pas représentés sur les différentes figures représentant la membrane, hormis sur la vue de détail de la figure 7. La membrane est métallique. Les métaux et alliages possibles sont preférentiellement l'or, l'aluminium, le tungstène ou le titane.FIG. 9 represents a perspective view of the two switches represented in FIG. 7. Each membrane is supported by at least two pillars 14 arranged on either side of the switching zone. The membrane is thus isolated at a certain distance above the switching area. This distance is typically worth a few microns. Said metal membrane has a roughly parallelepiped shape. This form represents a good compromise between the mechanical resistance of the membrane which conditions its service life and its reliability and the voltages necessary to be implemented to obtain the switching which should not be too great. Thus, for a membrane of typical length three hundred microns, of typical width one hundred microns and of thickness seven hundred nanometers, the control voltages are of the order of thirty volts. The membrane is also pierced with a multitude of holes 110 during its production. These holes allow the passage of the solvent allowing the release of the membrane during the production process. For the sake of clarity, these holes are not shown in the various figures representing the membrane, except in the detailed view of FIG. 7. The membrane is metallic. The possible metals and alloys are preferably gold, aluminum, tungsten or titanium.
L'ensemble constitué par la membrane et l'extrémité du brin et la partie du disque central située dessous forment les armatures d'un condensateur dont la capacité au repos vaut quelques femtofarads. Lorsque la membrane est sollicitée, elle se déforme, rapprochant les deux armatures du condensateur. Sa capacité augmente et vaut alors quelques picofarads.The assembly constituted by the membrane and the end of the strand and the part of the central disc located below form the reinforcements of a capacitor whose capacity at rest is worth a few femtofarads. When the membrane is stressed, it deforms, bringing the two plates of the capacitor closer together. Its capacity increases and is then worth a few picofarads.
Les figures 10, 11 et 12 représentent la vue de dessus et deux vues en coupe d'une cellule du réseau selon l'invention.Figures 10, 11 and 12 show the top view and two sectional views of a network cell according to the invention.
La figure 10 représente la vue de dessus de la cellule. La partie centrale de la cellule 4 comprend un substrat 61 sur lequel est implanté le réseau en étoile des brins 7 électriquement conducteurs constituant les différents dipôles, ledit réseau étant centré sur un disque central 8 électriquement conducteur. Le substrat est électriquement isolant et transparent aux ondes hyperfréquences. Il doit être compatible des technologies d'implantation des différents composants électroniques de la cellule. Ce substrat est, par exemple, du silicium ou du quartz ou du verre, notamment de marque pyrex. Les brins sont nécessairement en nombre pair et disposés symétriquement de façon que chaque brin est un vis-à-vis diamétralement opposé. Chaque paire de brins diamétralement opposé constitue ainsi un dipole lorsqu'elle est reliée au disque central par les dispositifs de commutation représentés sur les figures 7, 8 et 9.Figure 10 shows the top view of the cell. The central part of the cell 4 comprises a substrate 61 on which is installed the star network of the electrically conductive strands 7 constituting the different dipoles, said network being centered on a central electrically conductive disc 8. The substrate is electrically insulating and transparent to microwave waves. It must be compatible with the implantation technologies of the various electronic components of the cell. This substrate is, for example, silicon or quartz or glass, in particular of the pyrex brand. The strands are necessarily in even number and arranged symmetrically so that each strand is a diametrically opposite vis-à-vis. Each pair of diametrically opposite strands thus constitutes a dipole when it is connected to the central disc by the switching devices shown in FIGS. 7, 8 and 9.
Les tensions de commande et les mises à la masse sont réalisées au moyen de lignes résistives 151 , 154 et 155 reliées d'une part aux différents brins et aux membranes de commutation et d'autre part à des plots de connexion 161 disposés sur le pourtour du substrat central. Une première série de lignes de commande 151 est connectée à l'extrémité de chaque brin comme il est montré sur la figure 10. Deux lignes de mise à la masse diamétralement opposées 154 relient deux membranes à la masse, les autres membranes et le disque central sont reliées à ces deux membranes par d'autres lignes résistives 155 comme il est montré sur la figure 10. Les lignes résistives 151 , 154 et 155 ont une résistance suffisante pour obtenir un isolement électrique complet aux ondes hyperfréquences de l'ensemble des brins et des dispositifs de commutation. Typiquement, les dépôts résistifs ont une résistance ohmique de quelques centaines d'Ohm carré.The control voltages and grounding are carried out by means of resistive lines 151, 154 and 155 connected on the one hand to the different strands and to the switching membranes and on the other hand to connection pads 161 arranged on the periphery of the central substrate. A first series of control lines 151 is connected to the end of each strand as shown in FIG. 10. Two diametrically opposite grounding lines 154 connect two membranes to ground, the other membranes and the central disc are connected to these two membranes by other resistive lines 155 as shown in FIG. 10. The resistive lines 151, 154 and 155 have sufficient resistance to obtain complete electrical isolation from the microwave of all the strands and switching devices. Typically, resistive deposits have an ohmic resistance of a few hundred square ohms.
Les brins son preférentiellement de forme évasée de façon à augmenter le rendement du dipole. L'angle d'évasement fait environ vingt degrés. La longueur de chaque brin vaut environ le quart de la longueur d'onde hyperfréquence d'utilisation. Les substrats centraux correspondant à une cellule donné sont implantés de façon régulière sur un substrat commun 62 à l'ensemble des cellules 4 du réseau réflecteur. Ce substrat est également électriquement isolant et transparent aux ondes hyperfréquences. Il doit être compatible des technologies d'implantation des différents composants électroniques de la cellule. Ce substrat est réalisé notamment à partir d'un composite à base de fibres de verre et de téflon. Ce type de matériau est commercialisé par la société NELTEC sous la marque METCLAD. L'épaisseur totale du substrat commun et de chaque substrat central vaut environ le quart de la longueur d'onde hyperfréquence d'utilisation, soit de l'ordre de un à deux millimètres compte-tenu des fréquences d'utilisation. Ce substrat comporte sur la face opposée à celle des substrats centraux un plan de masse 10.The strands are preferably flared so as to increase the yield of the dipole. The flare angle is about twenty degrees. The length of each strand is approximately one quarter of the microwave wavelength of use. The central substrates corresponding to a given cell are regularly implanted on a common substrate 62 for all of the cells 4 of the reflective network. This substrate is also electrically insulating and transparent to microwave waves. It must be compatible with the implantation technologies of the various electronic components of the cell. This substrate is produced in particular from a composite based on glass fibers and Teflon. This type of material is marketed by the company NELTEC under the brand METCLAD. The total thickness of the common substrate and of each central substrate is approximately one quarter of the microwave wavelength of use, that is to say of the order of one to two millimeters taking into account the frequencies of use. This substrate comprises on the face opposite to that of the central substrates a ground plane 10.
Le substrat commun comporte un pavage de plots de connexion électrique 171 et 172 disposés régulièrement suivant un motif hexagonal. Chaque hexagone est centré sur un substrat central de cellule comme il est indiqué sur les figures 7 et 13 et est composé de six lignes d'au moins six plots de connexion. Les plots de chaque ligne sont régulièrement espacés entre eux. Ils traversent complètement le substrat commun (figure 12).The common substrate comprises a paving of electrical connection pads 171 and 172 regularly arranged in a hexagonal pattern. Each hexagon is centered on a central cell substrate as it is indicated in Figures 7 and 13 and is composed of six lines of at least six connection pads. The pads of each line are regularly spaced between them. They completely cross the common substrate (Figure 12).
Chaque cellule est surmontée d'un ensemble de six parois métalliques 18 (figure 12) également disposées en hexagone et placées au- dessus des lignes de plots de connexion, l'ensemble formant une grille en nid d'abeille (figures 10 et 13).Each cell is surmounted by a set of six metal walls 18 (FIG. 12) also arranged in hexagon and placed above the lines of connection pads, the assembly forming a honeycomb grid (FIGS. 10 and 13) .
Il existe deux types de plots. Le premier type est utilisé pour relier les lignes résistives de commande à l'extérieur du réseau réflecteur vers le module électronique de commande et sont isolés du plan de masse. Le second type est utilisé d'une part pour fixer mécaniquement les parois métalliques sur le substrat commun au moyen de pions de fixation 172 et d'autre part, pour relier ces parois au plan de masse comme il est indiqué sur la figure 12.There are two types of studs. The first type is used to connect the resistive control lines outside the reflective network to the electronic control module and are isolated from the ground plane. The second type is used on the one hand to mechanically fix the metal walls on the common substrate by means of fixing pins 172 and on the other hand to connect these walls to the ground plane as indicated in FIG. 12.
Les plots du premier type sont reliés aux lignes résistives 151 et 154 des substrats communs par d'autres lignes résistives 153 interconnectées au moyen de fils de connexion câblés 152 comme il est indiqué sur la figure 10. Lesdites lignes résistives 153 ont une résistance suffisante pour obtenir un isolement électrique complet aux ondes hyperfréquences de l'ensemble des brins et des dispositifs de commutation. Typiquement, les dépôts résistifs ont une résistance ohmique d'environ un kiloOhm carré. Les plots sont isolés des parois métalliques par des pastilles isolantes 173. La disposition des lignes résistives reliées aux plots d'interconnexion est indiquée sur les figures 10 et 13. Cette disposition permet à la fois d'avoir la même disposition géométrique pour toutes les cellules du réseau et d'autre part de minimiser les longueurs des lignes résistives.The pads of the first type are connected to the resistive lines 151 and 154 of the common substrates by other resistive lines 153 interconnected by means of cabled connection wires 152 as indicated in FIG. 10. Said resistive lines 153 have sufficient resistance to obtain complete electrical isolation from microwave waves of all the strands and switching devices. Typically, resistive deposits have an ohmic resistance of about one square kiloOhm. The pads are isolated from the metal walls by insulating pads 173. The arrangement of the resistive lines connected to the interconnection pads is indicated in FIGS. 10 and 13. This arrangement makes it possible both to have the same geometrical arrangement for all the cells. of the network and on the other hand to minimize the lengths of the resistive lines.
II est nécessaire de protéger les dispositifs de commutation qui sont mécaniquement fragiles. Cette protection est assurée soit au niveau de chaque cellule par un capot de protection 19 comme il est indiqué sur la figure 11 qui représente une vue en coupe de la cellule. Ce capot 19 doit également être transparent aux ondes hyperfréquences. Ce capot peut également être commun à l'ensemble du réseau réflectif. Les substrats centraux peuvent également être recouvert d'un traitement diélectrique multicouches de façon à augmenter le rendement des cellules sous forte incidence angulaire.It is necessary to protect the switching devices which are mechanically fragile. This protection is provided either at the level of each cell by a protective cover 19 as indicated in FIG. 11 which represents a sectional view of the cell. This cover 19 must also be transparent to microwave waves. This cover can also be common to the entire reflective network. The central substrates can also be covered with a multilayer dielectric treatment so as to increase the yield of the cells at high angular incidence.
Le principe de fonctionnement du réseau réflecteur est le suivant :The operating principle of the reflective network is as follows:
• Pour obtenir la réflexion des ondes hyperfréquences fournies par l'émetteur dans une direction déterminée, le module électronique calcule pour chaque cellule la disposition géométrique des dipôles à activer.• To obtain the reflection of the microwave waves supplied by the transmitter in a determined direction, the electronic module calculates for each cell the geometric arrangement of the dipoles to be activated.
• Pour chaque cellule, le module électronique génère les tensions de commande qui sont envoyées aux deux brins diamétralement opposés à activer.• For each cell, the electronic module generates the control voltages which are sent to the two diametrically opposite strands to be activated.
• Sous l'effet de la tension, les deux membranes placées au- dessus des brins activés se déforment (figure 9). La capacité existant entre les armatures augmente fortement. L'ordre de grandeur entre les rapports des capacités des deux états du commutateur est environ cent. L'impédance du dispositif de commutation devient négligeable et les deux brins sollicités sont connectés au disque central formant ainsi un dipole.• Under the effect of the tension, the two membranes placed above the activated strands become deformed (figure 9). The capacity existing between the reinforcements greatly increases. The order of magnitude between the capacity ratios of the two states of the switch is about one hundred. The impedance of the switching device becomes negligible and the two stressed strands are connected to the central disc thus forming a dipole.
Les dispositifs de commutation sont mis en œuvre simultanément pour deux brins opposés par deux commandes en tension séparées, la géométrie du dispositif ne permettant pas de relier les deux brins simultanément au disque central par une commande commune.The switching devices are implemented simultaneously for two opposite strands by two separate voltage commands, the geometry of the device not making it possible to connect the two strands simultaneously to the central disk by a common command.
De façon générale, le procédé de réalisation du réseau réflecteur comprend les étapes suivantes :In general, the method of making the reflecting array comprises the following steps:
• Réalisation du substrat circuit imprimé commun aux cellules• Realization of the printed circuit substrate common to the cells
• Dépôt du plan de masse• Deposit of the ground plan
• Réalisation des plots de connexion électrique : trous et plages métallisés• Realization of electrical connection pads: holes and metallized areas
• Réalisation des substrats micro-électroniques centraux des cellules• Realization of the central micro-electronic substrates of the cells
• Dépôts sur ces substrats des différents dispositifs électroniques• Deposits on these substrates of various electronic devices
• Réalisation des brins, du disque central et des lignes résistives• Realization of strands, central disc and resistive lines
• Réalisation des dispositifs de commutation • Protection des dispositifs de commutation par la mise en place de capots.• Realization of switching devices • Protection of switching devices by fitting covers.
• Mise en place des substrats centraux sur le substrat commun• Installation of central substrates on the common substrate
• Raccordement électrique des lignes résistives aux plots de connexion• Electrical connection of resistive lines to connection pads
• Mise en place des pions de centrage• Installation of centering pins
• Pose des grilles d'isolation sur les pions de centrage• Installation of insulating grids on the centering pins
Le procédé de réalisation des commutateurs comprend les sous- étapes suivantes :The method for producing the switches comprises the following substeps:
• Dépôt d'une couche de matériau diélectrique à l'emplacement des peignes interdigités ;• Deposition of a layer of dielectric material at the location of the interdigitated combs;
• Dépôt d'une couche de résine photosensible couvrant au moins l'emplacement de la membrane et de ses piliers supports ;• Deposit of a layer of photosensitive resin covering at least the location of the membrane and its support pillars;
• Retrait de ladite résine à l'emplacement de chaque pilier ;• Removal of said resin at the location of each pillar;
• Création des piliers et de la membrane par dépôt d'une couche métallique au moins aux emplacements desdits piliers et de la membrane.• Creation of the pillars and the membrane by depositing a metal layer at least at the locations of said pillars and of the membrane.
• Retrait de la résine au moins sous la membrane de façon à laisser libre la membrane sur ces piliers. • Removal of the resin at least under the membrane so as to leave the membrane free on these pillars.
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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FR0207743 | 2002-06-21 | ||
FR0207743A FR2841389B1 (en) | 2002-06-21 | 2002-06-21 | PHASE CELL FOR ANTENNA REFLECTIVE ARRAY |
PCT/FR2003/001803 WO2004001899A1 (en) | 2002-06-21 | 2003-06-13 | Phase-shifting cell for antenna reflector |
Publications (1)
Publication Number | Publication Date |
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EP1522121A1 true EP1522121A1 (en) | 2005-04-13 |
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Application Number | Title | Priority Date | Filing Date |
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EP03760729A Withdrawn EP1522121A1 (en) | 2002-06-21 | 2003-06-13 | Phase-shifting cell for antenna reflector |
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US (1) | US7042397B2 (en) |
EP (1) | EP1522121A1 (en) |
FR (1) | FR2841389B1 (en) |
WO (1) | WO2004001899A1 (en) |
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FR2952048B1 (en) * | 2009-11-03 | 2011-11-18 | Thales Sa | CAPACITIVE MICRO-SWITCH COMPRISING A LOAD DRAIN BASED ON NANOTUBES BASED ON THE LOW ELECTRODE AND METHOD FOR MANUFACTURING THE SAME |
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CN106067601B (en) * | 2016-05-20 | 2019-03-15 | 北京邮电大学 | Pattern Reconfigurable Microstrip Antenna |
KR102245947B1 (en) * | 2017-04-26 | 2021-04-29 | 한국전자통신연구원 | Transceiver in a wireless communication system |
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US3718935A (en) * | 1971-02-03 | 1973-02-27 | Itt | Dual circularly polarized phased array antenna |
US5835062A (en) * | 1996-11-01 | 1998-11-10 | Harris Corporation | Flat panel-configured electronically steerable phased array antenna having spatially distributed array of fanned dipole sub-arrays controlled by triode-configured field emission control devices |
US6081235A (en) * | 1998-04-30 | 2000-06-27 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | High resolution scanning reflectarray antenna |
US6046659A (en) | 1998-05-15 | 2000-04-04 | Hughes Electronics Corporation | Design and fabrication of broadband surface-micromachined micro-electro-mechanical switches for microwave and millimeter-wave applications |
DE19833271A1 (en) * | 1998-07-24 | 2000-01-27 | Werner Arnold | Satellite transmission receiver for digital control of aerial reception plane contains control portion and reception unit in aerial unit |
US6195047B1 (en) * | 1998-10-28 | 2001-02-27 | Raytheon Company | Integrated microelectromechanical phase shifting reflect array antenna |
US6396368B1 (en) | 1999-11-10 | 2002-05-28 | Hrl Laboratories, Llc | CMOS-compatible MEM switches and method of making |
US6404401B2 (en) * | 2000-04-28 | 2002-06-11 | Bae Systems Information And Electronic Systems Integration Inc. | Metamorphic parallel plate antenna |
US6653985B2 (en) * | 2000-09-15 | 2003-11-25 | Raytheon Company | Microelectromechanical phased array antenna |
US6642889B1 (en) * | 2002-05-03 | 2003-11-04 | Raytheon Company | Asymmetric-element reflect array antenna |
-
2002
- 2002-06-21 FR FR0207743A patent/FR2841389B1/en not_active Expired - Fee Related
-
2003
- 2003-06-13 EP EP03760729A patent/EP1522121A1/en not_active Withdrawn
- 2003-06-13 WO PCT/FR2003/001803 patent/WO2004001899A1/en not_active Application Discontinuation
- 2003-06-13 US US10/517,706 patent/US7042397B2/en not_active Expired - Fee Related
Non-Patent Citations (1)
Title |
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See references of WO2004001899A1 * |
Also Published As
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WO2004001899A1 (en) | 2003-12-31 |
US20050219125A1 (en) | 2005-10-06 |
FR2841389A1 (en) | 2003-12-26 |
FR2841389B1 (en) | 2004-09-24 |
US7042397B2 (en) | 2006-05-09 |
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