EP0427654A1 - Tuned helical antennae consisting of two quadrifilar antennas fit into each other - Google Patents
Tuned helical antennae consisting of two quadrifilar antennas fit into each other Download PDFInfo
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- EP0427654A1 EP0427654A1 EP90460041A EP90460041A EP0427654A1 EP 0427654 A1 EP0427654 A1 EP 0427654A1 EP 90460041 A EP90460041 A EP 90460041A EP 90460041 A EP90460041 A EP 90460041A EP 0427654 A1 EP0427654 A1 EP 0427654A1
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- quadrifilar
- antenna
- helices
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- propellers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
- H01Q11/02—Non-resonant antennas, e.g. travelling-wave antenna
- H01Q11/08—Helical antennas
Definitions
- the present invention relates to a new antenna structure, having a quasi-hemispherical radiation pattern, and capable of having a relatively wide bandwidth, so for example that two neighboring transmission sub-bands can be released there.
- This type of antenna finds, for example, application in the context of satellite communications between fixed users and aeronautical, maritime or land mobiles.
- several satellite communication systems have been or are under development in L-band (INMARSAT, MSAT, PROSAT, NAVSTAR G.P.S, ).
- the first three systems mentioned correspond to links with geostationary satellites.
- the specifications of the antennas intended to equip the mobiles, in these systems, require that these antennas have a radiation pattern with quasi-hemispherical coverage, due to the very different incidences, or significant variations in the incidence of the signals received or transmitted.
- the polarization of the antennas must be circular with an ellipticity ratio better than 5 dB. (insulation 20 dB.) and special attention must be paid to the fight against multi-path phenomena for land and aeronautical mobiles. This latter specification also requires that for low elevations, the preponderant component of the electric field be vertical.
- the specifications impose that they are operational in a bandwidth of approximately 10%, or in two sub - neighboring bands.
- the only antenna structure compatible with type of specification is the resonant quadrifilar helix.
- This type of known antenna is formed by two two-wire helices 111, 112, arranged orthogonally and excited in phase quadrature.
- FIGS. 11A, 11B The exemplary embodiment represented in FIGS. 11A, 11B is cited in the work "UHF satellite array nulls adjacent signals" Microwaves & R.F., March 1984.
- the antenna is a resonant quadrifilar helix with strands 111A, 111B; 112A, 112B short-circuited at their unexcited end 113.
- the passband is of the order of 10% with an opening at -3 dB of 140 ° for a strand length equal to ⁇ 0 / 2 and a helical winding on a turn around.
- This type of antenna is not to be confused with certain helical antennas of the type disclosed for example in patent document US-4148030 (FOLDES) and which have the purpose of providing very directional axial radiation patterns (and not almost hemispherical as in the invention) and with great gain. Their operation is of the traveling wave type, and not in resonant mode.
- These known antennas moreover have a different structure. In particular, they have a length of several times the wavelength ⁇ of the antenna operating.
- each helical strand is cut into resonant dipoles to operate at a specific frequency.
- Quadrifilar helical antenna is also known, used in the mobile satellite communications system INMARSAT STANDARD-C where the antenna must operate correctly in two sub-bands (1530-1545 MHz) and (1631.5 -1646.5 MHz) corresponding respectively to reception and emission (KM KEEN "Developing a standard-C Antenna” (Development of an antenna in standard C) MSN Communication Technology, June 1988).
- the antenna is a resonant quadrifilar helix with printed strands open at their unexcited end.
- the power supply / adaptation module can be placed outside the antenna, around the working frequency. But when the antenna must operate in broadband, as discussed here, a power supply / internal adaptation module is generally used in the antenna structure. The most common is the so-called “balun” system (sometimes also called balun) or its “folded balun” variant with asymmetrical input and symmetrical output.
- balun sometimes also called balun
- balun folded balun
- FIG. 11 Such an arrangement is shown in FIG. 11, where, given the excitation and the symmetry of the antenna, the two orthogonal helices 111 and 112 have the same input impedance.
- Each two-wire propeller 111A, 111B; 112A, 112B is supplied by a coaxial balun of the "folded balun" type.
- the two two-wire are then excited in phase quadrature using a 115 hybrid coupler (90 °, -3 dB.).
- Each coaxial (asymmetrical) input therefore sees in parallel the impedance of the two-wire helix and an adapter of length close to ⁇ / 4.
- the balun / adapter assembly used in this type of antenna is produced for example by means of a coaxial section of length ⁇ / 4, the core and the sheath of which form a dipole; to avoid the problems due to the radiation of the sheath, the dipole can be closed between the core and an additional coaxial sheath (bazooka system) so as to avoid the circulation of a current on the sheath of the coaxial.
- the use of adaptation devices introduces losses and often limits the band of use of the antenna.
- the "folded balun" is placed in the body of the excited antenna at its upper end. This then produces a diffraction disturbance of the radiation patterns, particularly at high frequencies.
- the invention aims to overcome these drawbacks.
- the invention provides a new antenna structure having a quasi-hemispherical radiation pattern, and circular polarization, in particular (but not exclusively) in the L band.
- Another objective of the invention is to provide such a structure avoiding the introduction of complex adaptation devices between the antenna and its excitation.
- the invention also aims to provide an antenna having a widening of the bandwidth, or a dual band operation (dual frequency), in particular either in a bandwidth ⁇ 10%, or in two neighboring sub-bands.
- a complementary objective of the invention is to provide an antenna of low cost, and with energy consumption compatible with the constraints of on-board systems on land, sea, air or space mobiles.
- a resonant helical antenna with quasi-hemispherical radiation of the type comprising a quadrifilar helix made up of two bifilar helices arranged orthogonally and excited. in phase quadrature, this antenna comprising at least a second quadrifilar helix, coaxial and in electromagnetic coupling with said first quadrifilar helix, each of said quadrifilar helices being wound on a separate cylinder, of constant radius.
- the length of the strands is less than the wavelength ⁇ of operation of said antenna, and preferably between ⁇ / 2 and ⁇ , so as to obtain the desired hemispherical radiation pattern, with operation in standing waves.
- the strands of said second quadrifilar helix are in a situation of exact or close radial superposition with the strands of said first quadrifilar helix.
- said coupled quadrifilar propellers are connected in parallel to a common power supply.
- said common supply comprises, on the one hand, a coupler element, for excitation in phase quadrature of the two orthogonal bifilar helices of each quadrifilar helix, and on the other hand a balancing element for the supply in phase opposition of each of the strands of the two-wire propellers.
- the strands of at least one of the two quadrifilar propellers are open or short-circuited at their non-excited end.
- At least one of the quadrifilar helices is produced in technology printed on a dielectric support.
- the coupling of said quadrifilar propellers is controlled using at least one of the following means: - Control of the radial overlap of said quadrifilar propellers; - control of the angular offset between said quadrifilar propellers; - control of the propeller pitch of each of said propellers, so as in particular to adapt the impedance presented by each strand.
- said coupling of said quadrifilar helices is carried out so as to obtain radiation from the antenna in a single wide bandwidth.
- said coupling of said propellers quadrifilaires is performed so as to obtain radiation from the antenna in at least two disjoint bandwidths.
- the coupling control can be optimized, without degrading any of the other characteristics of the antenna, and in particular the circular polarization and the radiation pattern.
- FIG. 1 A preferred embodiment of the antenna structure of the invention is shown in Figure 1. It is formed by two quadrifilar helices 11 and 12 concentric, wound on insulating cylindrical supports 13 and 14, coaxial, of diameters d1, d2 distinct. It is clear that the structure of the antenna of the invention can be generalized obviously to more than two concentric helices.
- Each quadrifilar propeller 11 and 12 has four strands 111, 112, 113, 114 and 121, 122, 123, 124 respectively, regularly spaced and wound on the cylindrical supports 13, 14.
- Each strand 111, 112, 113, 114; 121, 122, 123, 124 is formed by a continuous ribbon of electrically conductive material such as copper, of width W, printed on a kapton substrate, as shown in FIG. 2.
- the kapton substrate can have a thickness of 50 ⁇ m, for a width W of copper tape of 35 ⁇ m.
- each strand is advantageously between ⁇ / 2 and ⁇ and in all cases less than or equal to ⁇ , to operate in resonant mode and obtain a quasi-hemispherical radiation diagram.
- each propeller 11,12 are open at one end 15 (upper end in Figures 1 and 2) and electrically connected to the other end 16 (lower end in Figures 1 and 2) with conductive segments 31, 32, 33, 34, arranged on the base 30 of the lower part 16 of the support cylinders 13, 14 as shown diagrammatically in FIG. 3.
- These flat segments 31, 32, 33, 34 are advantageously made up of ribbons printed on kapton, in the form of portions of segments of decreasing width from the edge to near the center of the base 30 of the cylinders 13, 14.
- Each of these conductive segments is connected to the central core of one of the four 50 ⁇ coaxial cables for supplying the antenna structure.
- the two quadrifilar propellers 11,12 are thus fed in parallel, strand by strand (111, 121; 112, 122; 113, 123; 114, 124).
- each propeller 11,12 are excited across the segments 31, 32, 33, 34 according to the supply configuration shown diagrammatically in FIG. 4, using a conventional device consisting of a hybrid coupler module 41 (3 dB, 90 °) and two symmetrical modules 42,43 (3 dB, 180 °).
- a hybrid coupler module 41 (3 dB, 90 °) and two symmetrical modules 42,43 (3 dB, 180 °).
- One of the inputs 411, 421, 431, of each of these modules 41,42,43 is connected to ground through a 50 ⁇ resistor 44.
- the coupler module 41 is arranged so that the two outputs 413, 414 supply the other input 422, 432 of the two balancing modules 42.43.
- the outputs at 180 ° 423, 434 of the baluns are connected so as to supply two segments 31.34, the outputs at 0 ° 424 and 433 exciting the other two segments 33.34.
- This assembly can be made compactly in printed technology and placed directly at the base of the antenna structure.
- each antenna strand adapted in impedance for example to 50 ⁇ , is of course controlled, so as not to degrade, or as little as possible, the other characteristics of the antenna, and in particular the circular polarization and the radiation pattern.
- Dual-frequency antenna (or double band).
- the antenna parameters are presented in table I, (with C: circumference; Le: length of a radiating strand; Lax: axial length; with reference to the notations in FIG. 2 ) TABLE I interior propeller exterior propeller VS 0.5 ⁇ o 0.57 ⁇ o The 0.74 ⁇ o 0.76 ⁇ o Lax 0.58 ⁇ o 0.59 ⁇ o
- the impedance presented is the impedance calculated at the input of a radiating strand of the propeller in the presence of the others, this impedance being half that of a two-wire propeller.
- the curve marks a double resonance due to the coupling between the two quadrifilaries.
- the assembly functions as two coupled resonant circuits, the coupling of which deviates the resonant frequencies 61, 62.
- the ROS is less than 1.5 in two separate frequency bands: 1.54 Ghz ⁇ f ⁇ 1.5666 Ghz and 1.602 Ghz ⁇ f ⁇ 1.64 Ghz.
- the excitation device does not require any specific mounting of additional adaptation, which overcomes the antenna of the disadvantages of the simple quadrifilar antenna.
- FIG. 7 represents the radiation diagram of the coupled antenna, which differs little from the radiation diagrams of the quadrifilar propellers taken in isolation.
- This implementation can of course be generalized to more than two concentric quadrifilar propellers, so as to obtain as many distinct frequency bands as there are propellers.
- the electromagnetic coupling between the two superimposed quadrifilar propellers makes it possible to obtain a single passband wider than with a monolayer propeller of the same parameters.
- the initial bandwidth is 65 Mhz for an ROS ⁇ 2.5 for the indoor antenna, and 56 Mhz for an ROS ⁇ 2 for the outdoor antenna.
- the bandwidth for the bilayer antenna is equal to 86 MHz for an R.O.S ⁇ 2.
- the diagram of the R.O.S. and the SMITH chart of the corresponding impedance curve are shown in Figures 8 and 9.
- the R.O.S is less than 1.75 on a continuous frequency band from 1.535 to 1.595 GHz approximately, with a resonance frequency of 1.59 Ghz.
- the structure of the antenna of the invention thus makes it possible to "reduce” the imaginary part of the impedance and to bring back around 50 ⁇ s to the real part.
- FIG. 10 representing the diagram for the coupled two-layer antenna.
- the antenna structure of the invention finds numerous fields of application.
- MSAT Mobile Satellite System
- the ESA PROSAT program European Space Agency
- PRODAT European Space Agency
- the development low G / T terminals 24 dB / K
- air navigation elevation between 10 ° and 90 °
- maritime elevation between -25 ° and 90 ° to take account of the movements ⁇ 30 ° of the ship due roll and pitch
- terrestrial elevation between 15 ° and 90 °
Landscapes
- Variable-Direction Aerials And Aerial Arrays (AREA)
Abstract
Description
La présente invention concerne une nouvelle structure d'antenne, présentant un diagramme de rayonnement quasi hémisphérique, et susceptible de présenter une bande passante relativement large, de façon par exemple à pouvoir y dégager deux sous-bandes de transmission voisines.The present invention relates to a new antenna structure, having a quasi-hemispherical radiation pattern, and capable of having a relatively wide bandwidth, so for example that two neighboring transmission sub-bands can be released there.
Ce type d'antenne trouve par exemple application dans le cadre des communications par satellite entre des utilisateurs fixes et des mobiles aéronautiques, maritimes ou terrestres. Dans ce domaine, plusieurs systèmes de communication par satellite ont été ou sont en cours de développement en bande L (INMARSAT, MSAT, PROSAT, NAVSTAR G.P.S,...).This type of antenna finds, for example, application in the context of satellite communications between fixed users and aeronautical, maritime or land mobiles. In this area, several satellite communication systems have been or are under development in L-band (INMARSAT, MSAT, PROSAT, NAVSTAR G.P.S, ...).
Les trois premiers systèmes cités correspondent à des liaisons avec des satellites géostationnaires. Les spécifications des antennes destinées à équiper les mobiles, dans ces systèmes, imposent que ces antennes possèdent un diagramme de rayonnement à couverture quasi hémisphérique, du fait des incidences très différentes, ou variations d'incidence importantes des signaux reçus ou émis.The first three systems mentioned correspond to links with geostationary satellites. The specifications of the antennas intended to equip the mobiles, in these systems, require that these antennas have a radiation pattern with quasi-hemispherical coverage, due to the very different incidences, or significant variations in the incidence of the signals received or transmitted.
De plus la polarisation des antennes doit être circulaire avec un rapport d'ellipticité meilleur que 5 dB. (isolation 20 dB.) et une attention particulière doit être portée à la lutte contre les phénomènes de multitrajets pour les mobiles terrestres et aéronautiques. Cette dernière spécification nécessite d'ailleurs que pour les faibles élévations, la composante prépondérante du champ électrique soit verticale.In addition, the polarization of the antennas must be circular with an ellipticity ratio better than 5 dB. (insulation 20 dB.) and special attention must be paid to the fight against multi-path phenomena for land and aeronautical mobiles. This latter specification also requires that for low elevations, the preponderant component of the electric field be vertical.
Pour ce qui est des antennes utilisables à la réception de signaux par des satellites à défilement utilisés dans des systèmes du type du système américain NAVSTAR, les spécifications imposent qu'elles soient opérationnelles dans une bande passante d'environ 10 %, ou dans deux sous-bandes voisines.As regards the antennas usable for the reception of signals by traveling satellites used in systems of the type of the American NAVSTAR system, the specifications impose that they are operational in a bandwidth of approximately 10%, or in two sub - neighboring bands.
Dans l'état actuel des connaissances, la seule structure d'antenne compatible avec de type de spécification (essentiellement diagramme de rayonnement quasi hémisphérique et polarisation circulaire) est l'hélice quadrifilaire résonnante.In the current state of knowledge, the only antenna structure compatible with type of specification (essentially quasi-hemispherical radiation diagram and circular polarization) is the resonant quadrifilar helix.
Ce type d'antenne connu, comme représenté en figures 11A, 11B, est formé de deux hélices bifilaires 111, 112, disposées orthogonalement et excitées en quadrature de phase.This type of known antenna, as shown in FIGS. 11A, 11B, is formed by two two-
L'exemple de réalisation représenté en figures 11A, 11B est cité dans l'ouvrage "UHF satellite array nulls adjacent signals" Microwaves & R.F., Mars 1984.The exemplary embodiment represented in FIGS. 11A, 11B is cited in the work "UHF satellite array nulls adjacent signals" Microwaves & R.F., March 1984.
L'antenne est une hélice quadrifilaire résonnante à brins 111A,111B ; 112A,112B court-circuités à leur extrémité non excitée 113. La bande passante est de l'ordre de 10 % avec une ouverture à -3 dB de 140° pour une longueur de brin égale à λ₀/2 et un enroulement hélicoïdal sur un demi tour. Ce type d'antennes n'est pas à confondre avec certaines antennes hélicoïdales du type divulgué par exemple dans le document de brevet US-4148030 (FOLDES) et qui ont elles pour finalité de fournir des diagrammes de rayonnement axiaux très directifs (et non quasi-hémisphérique comme dans l'invention) et à grand gain. Leur fonctionnement est du type à ondes progressives, et non en mode résonnant. Ces antennes connues présentent d'ailleurs une structure différente. Elles ont notamment une longueur de plusieurs fois la longueur d'onde λ de fonctionnement de l'antenne. Par ailleurs, chaque brin hélicoïdal est découpé en dipoles résonnants pour fonctionner à une fréquence spécifique.The antenna is a resonant quadrifilar helix with
On connaît également un autre mode de réalisation d'antenne hélicoïdale quadrifilaire, utilisée dans le système de communications mobiles par satellite INMARSAT STANDARD-C où l'antenne doit fonctionner correctement dans deux sous-bandes (1530-1545 MHz) et (1631,5-1646,5 MHz) correspondant respectivement à la réception et à l'émission (K.M. KEEN "Developing a standard-C Antenna" (Développement d'une antenne en standard C) M.S.N. Communication Technology, juin 1988).Another embodiment of a quadrifilar helical antenna is also known, used in the mobile satellite communications system INMARSAT STANDARD-C where the antenna must operate correctly in two sub-bands (1530-1545 MHz) and (1631.5 -1646.5 MHz) corresponding respectively to reception and emission (KM KEEN "Developing a standard-C Antenna" (Development of an antenna in standard C) MSN Communication Technology, June 1988).
Dans ce mode de réalisation connu, l'antenne est une hélice quadrifilaire résonnante à brins imprimés ouverts à leur extrémité non excitée.In this known embodiment, the antenna is a resonant quadrifilar helix with printed strands open at their unexcited end.
Bien que remplissant les spécifications requises, les antennes quadrifilaires résonnantes présentent un certain nombre d'inconvénients.Although meeting the required specifications, resonant quadrifilar antennas have a number of drawbacks.
Les problèmes principaux posés par ce type connu de structure tiennent aux contraintes d'adaptation des impédances de l'antenne avec celles des coaxiaux d'alimentation, tout en réalisant une excitation adéquate des hélices bifilaires orthogonales.The main problems posed by this known type of structure are due to the constraints of adapting the impedances of the antenna with those of the feed coaxials, while achieving adequate excitation of the two-wire helices. orthogonal.
Dans les systèmes à bande étroite, le module d'alimentation/adaptation peut être disposé extérieurement à l'antenne, autour de la fréquence de travail. Mais lorsque l'antenne doit fonctionner en large bande, comme discuté ici, on utilise généralement un module d'alimentation/adaptation interne à la structure d'antenne. Le plus courant est le système dit "balun" (parfois également appelé symétriseur) ou sa variante "folded balun" (balun replié) à entrée dissymétrique et sortie symétrique.In narrow band systems, the power supply / adaptation module can be placed outside the antenna, around the working frequency. But when the antenna must operate in broadband, as discussed here, a power supply / internal adaptation module is generally used in the antenna structure. The most common is the so-called "balun" system (sometimes also called balun) or its "folded balun" variant with asymmetrical input and symmetrical output.
Un tel montage est représenté en fig. 11, où, compte tenu de l'excitation et de la symétrie de réalisation de l'antenne, les deux hélices orthogonales 111, et 112 présentent la même impédance d'entrée. Chaque hélice bifilaire 111A,111B ; 112A,112B est alimentée par un symétriseur coaxial de type "balun replié". Les deux bifilaires sont ensuite excitées en quadrature de phase grâce à un coupleur hybride 115 (90°, -3 dB.). Chaque entrée (dissymétrique) coaxiale voit donc en parallèle l'impédance de l 'hélice bifilaire et un adaptateur de longueur voisine de λ/4.Such an arrangement is shown in FIG. 11, where, given the excitation and the symmetry of the antenna, the two
Le montage symétriseur/adaptateur utilisé dans ce type d'antenne est réalisé par exemple au moyen d'un tronçon de coaxial de longueur λ/4, dont l'âme et la gaine forment dipole ; pour éviter les problèmes dûs au rayonnement de la gaine, le dipole peut être fermé entre l'âme et une gaine supplémentaire coaxiale (système bazooka) de façon à éviter la circulation d'un courant sur la gaine du coaxial.The balun / adapter assembly used in this type of antenna is produced for example by means of a coaxial section of length λ / 4, the core and the sheath of which form a dipole; to avoid the problems due to the radiation of the sheath, the dipole can be closed between the core and an additional coaxial sheath (bazooka system) so as to avoid the circulation of a current on the sheath of the coaxial.
Toutefois, ce type de montage présente l'inconvénient de former une sorte de filtre passe-bande à bande encore trop étroite.However, this type of arrangement has the drawback of forming a sort of bandpass filter with a band which is still too narrow.
On a alors imaginé des systèmes plus complexes dans lesquels on utilise une ligne compensée au moyen d'un conducteur plein, ou encore d'un câble coaxial mort, formant circuit bouchon (voir C.C KILGUS "Resonant quadrifilar helix" (hélice quadrifilaire rayonnante) Microwave Journal, décembre 1970).We then imagined more complex systems in which a compensated line is used by means of a solid conductor, or even a dead coaxial cable, forming a plug circuit (see CC KILGUS "Resonant quadrifilar helix" Microwave quadrifilar helix) Journal, December 1970).
Dans tous les cas, un dispositif d'adaptation doit être ajouté entre le coupleur hybride et les "baluns" pour adapter l'antenne. Ceci ressort clairement notamment de l'abaque de SMITH de la figure 12, où l'on constate clairement pour deux modes de réalisations, que les fenêtres de fonctionnement 121,122 se trouvent essentiellement en dehors de la zone d'adaptation 123.In all cases, an adaptation device must be added between the hybrid coupler and the "baluns" to adapt the antenna. This is clear in particular from the abacus of SMITH in FIG. 12, where we clearly see for two embodiments, that the
Or, l'utilisation de dispositifs d'adaptation introduit des pertes et limite souvent la bande d'utilisation de l'antenne. De plus, dans ces exemples de réalisations, et sans doute pour des problèmes d'encombrement, le "balun replié" est placé dans le corps même de l'antenne excitée à son extrémité supérieure. Ceci produit alors une perturbation par diffraction des diagrammes de rayonnement, particulièrement aux fréquences élevées.However, the use of adaptation devices introduces losses and often limits the band of use of the antenna. In addition, in these exemplary embodiments, and no doubt for reasons of space, the "folded balun" is placed in the body of the excited antenna at its upper end. This then produces a diffraction disturbance of the radiation patterns, particularly at high frequencies.
L'invention a pour objectif de pallier ces inconvénients.The invention aims to overcome these drawbacks.
Plus précisément, l'invention fournit une nouvelle structure d'antenne présentant un diagramme de rayonnement quasi hémisphérique, et de polarisation circulaire, notamment (mais non exclusivement) en bande L.More specifically, the invention provides a new antenna structure having a quasi-hemispherical radiation pattern, and circular polarization, in particular (but not exclusively) in the L band.
Un autre objectif de l'invention est de fournir une telle structure évitant l'introduction de dispositifs complexes d'adaptation entre l'antenne et son excitation.Another objective of the invention is to provide such a structure avoiding the introduction of complex adaptation devices between the antenna and its excitation.
L'invention a également pour objectif de fournir une antenne présentant un élargissement de la bande passante, ou un fonctionnement double bande (dual frequency), notamment soit dans une bande passante ≈ 10 %, soit dans deux sous-bandes voisines.The invention also aims to provide an antenna having a widening of the bandwidth, or a dual band operation (dual frequency), in particular either in a bandwidth ≈ 10%, or in two neighboring sub-bands.
Un objectif complémentaire de l'invention est de fournir une antenne de faible coût, et à consommation d'énergie compatible avec les contraintes des systèmes embarqués sur mobiles terrestres, maritimes, aériens ou spatiaux.A complementary objective of the invention is to provide an antenna of low cost, and with energy consumption compatible with the constraints of on-board systems on land, sea, air or space mobiles.
Ces objectifs ainsi que d'autres qui apparaîtront par la suite, sont atteints selon l'invention à l'aide d'une antenne hélicoïdale résonnante à rayonnement quasi-hémisphérique, du type comprenant une hélice quadrifilaire constituée de deux hélices bifilaires disposées orthogonalement et excitées en quadrature de phase, cette antenne comportant au moins une seconde hélice quadrifilaire, coaxiale et en couplage électromagnétique avec ladite première hélice quadrifilaire, chacune desdites hélices quadrifilaires étant enroulée sur un cylindre distinct, de rayon constant.These objectives, as well as others which will appear subsequently, are achieved according to the invention using a resonant helical antenna with quasi-hemispherical radiation, of the type comprising a quadrifilar helix made up of two bifilar helices arranged orthogonally and excited. in phase quadrature, this antenna comprising at least a second quadrifilar helix, coaxial and in electromagnetic coupling with said first quadrifilar helix, each of said quadrifilar helices being wound on a separate cylinder, of constant radius.
La superposition de ces deux hélices quadrifilaires résonnantes permet d'obtenir un diagramme de rayonnement quasi-hémisphérique sur une large bande de fréquence, ou sur deux bandes de fréquence voisines, selon les réglages choisis pour leur couplage électromagnétique.The superposition of these two resonant quadrifilar propellers allows to obtain a quasi-hemispherical radiation pattern over a wide frequency band, or over two neighboring frequency bands, depending on the settings chosen for their electromagnetic coupling.
Avantageusement, la longueur des brins est inférieure à la longueur d'onde λ de fonctionnement de ladite antenne, et de préférence comprise entre λ/2 et λ, de façon à obtenir le diagramme de rayonnement hémisphérique recherché, avec un fonctionnement en ondes stationnaires.Advantageously, the length of the strands is less than the wavelength λ of operation of said antenna, and preferably between λ / 2 and λ, so as to obtain the desired hemispherical radiation pattern, with operation in standing waves.
Selon une caractéristique préférentielle de l'invention, les brins de ladite seconde hélice quadrifilaire sont en situation de superposition radiale exacte ou proche avec les brins de ladite première hélice quadrifilaire.According to a preferred characteristic of the invention, the strands of said second quadrifilar helix are in a situation of exact or close radial superposition with the strands of said first quadrifilar helix.
Selon une autre caractéristique de l'invention lesdites hélices quadrifilaires couplées sont connectées en parallèle à une alimentation commune. Avantageusement, ladite alimentation commune comporte, d'une part, un élément coupleur, pour l'excitation en quadrature de phase des deux hélices bifilaires orthogonales de chaque hélice quadrifilaire, et d'autre part un élément symétriseur pour l'alimentation en opposition de phase de chacun des brins des hélices bifilaires.According to another characteristic of the invention, said coupled quadrifilar propellers are connected in parallel to a common power supply. Advantageously, said common supply comprises, on the one hand, a coupler element, for excitation in phase quadrature of the two orthogonal bifilar helices of each quadrifilar helix, and on the other hand a balancing element for the supply in phase opposition of each of the strands of the two-wire propellers.
De façon préférentielle, les brins d'au moins une des deux hélices quadrifilaires sont ouverts ou courts-circuités à leur extrémité non excitée.Preferably, the strands of at least one of the two quadrifilar propellers are open or short-circuited at their non-excited end.
Avantageusement, au moins une des hélices quadrifilaires est réalisée en technologie imprimée sur support diélectrique.Advantageously, at least one of the quadrifilar helices is produced in technology printed on a dielectric support.
Selon une caractéristique avantageuse de l'invention, le couplage desdites hélices quadrifilaires est contrôlé à l'aide d'au moins un des moyens suivants :
- contrôle de l'écart radial de superposition desdites hélices quadrifilaires;
- contrôle du décalage angulaire entre lesdites hélices quadrifilaires ;
- contrôle du pas d'hélice de chacune desdites hélices,
de façon notamment à adapter l'impédance présentée par chaque brin.According to an advantageous characteristic of the invention, the coupling of said quadrifilar propellers is controlled using at least one of the following means:
- Control of the radial overlap of said quadrifilar propellers;
- control of the angular offset between said quadrifilar propellers;
- control of the propeller pitch of each of said propellers,
so as in particular to adapt the impedance presented by each strand.
Selon un premier mode de réalisation, ledit couplage desdites hélices quadrifilaires est effectué de façon à obtenir un rayonnement de l'antenne dans une unique large bande passante.According to a first embodiment, said coupling of said quadrifilar helices is carried out so as to obtain radiation from the antenna in a single wide bandwidth.
Selon un second mode de réalisation, ledit couplage desdites hélices quadrifilaires est effectué de façon à obtenir un rayonnement de l'antenne dans au moins deux bandes passantes disjointes.According to a second embodiment, said coupling of said propellers quadrifilaires is performed so as to obtain radiation from the antenna in at least two disjoint bandwidths.
Il est clair que grâce à l'invention le contrôle du couplage peut être optimisé, sans dégrader aucune des autres caractéristiques de l'antenne, et en particulier la polarisation circulaire et le diagramme de rayonnement.It is clear that, thanks to the invention, the coupling control can be optimized, without degrading any of the other characteristics of the antenna, and in particular the circular polarization and the radiation pattern.
D'autres caractéristiques et avantages de l'invention apparaîtront à la lecture de la description d'un mode de réalisation préférentiel de l'invention, donné à titre illustratif et non limitatif, et des dessins annexés dans lesquels :
- - la figure 1 est une vue en perspective d'un mode de réalisation avantageux d'une structure d'antenne à double hélice quadrifilaire selon l'invention;
- - la figure 2 est une vue en développé d'une des deux hélices quadrifilaires superposées, réalisée sous forme de rubans de cuivre imprimés sur substrat de kapton ;
- - la figure 3 est une vue en plan de la base des cylindres supports de l'antenne des figures 1 et 2, portant des segments conducteurs de connexion des brins rayonnants ;
- - la figure 4 schématise une structure d'alimentation classique pour l'antenne des figures 1 à 3 ;
- - les figures 5, 6, 7 représentent respectivement le diagramme de SMITH, la valeur du ROS et le diagramme de rayonnement en polarisation circulaire copolaire et contrapolaire d'un prototype de l'invention dimensionné pour fonctionner en double bande (antenne bifréquence) ;
- - les figures 8, 9, 10 représentent respectivement le diagramme de SMITH, la valeur du ROS et le diagramme de rayonnement en polarisation circulaire copolaire et contrapolaire d'un prototype de l'invention dimensionné pour fonctionner à large bande.
- - les figures 11A, 11B et 12 illustrent respectivement une vue de face et de dessus, et l'abaque de SMITH de la courbe d'impédance d'une hélice quadrifilaire monocouche de type connu.
- - Figure 1 is a perspective view of an advantageous embodiment of an antenna structure with a quadrifilar double helix according to the invention;
- - Figure 2 is a developed view of one of the two superimposed quadrifilar propellers, produced in the form of copper ribbons printed on kapton substrate;
- - Figure 3 is a plan view of the base of the antenna support cylinders of Figures 1 and 2, carrying conductive connection segments of the radiating strands;
- - Figure 4 shows schematically a conventional feed structure for the antenna of Figures 1 to 3;
- - Figures 5, 6, 7 respectively represent the SMITH diagram, the ROS value and the radiation diagram in co-polar and cross-polar polarization of a prototype of the invention dimensioned to operate in double band (dual-frequency antenna);
- - Figures 8, 9, 10 respectively represent the SMITH diagram, the ROS value and the radiation diagram in co-polar and cross-polar polarization of a prototype of the invention sized to operate at broadband.
- - Figures 11A, 11B and 12 respectively illustrate a front view and from above, and the SMITH chart of the impedance curve of a single-layer quadrifilar propeller of known type.
Un mode de réalisation préférentiel de la structure d'antenne de l'invention est représenté en figure 1. Elle est formée de deux hélices quadrifilaires 11 et 12 concentriques, enroulées sur des supports cylindriques isolants 13 et 14, coaxiaux, de diamètres d₁, d₂ distincts. Il est clair que la structure de l'antenne de l'invention peut être généralisée de façon évidente à plus de deux hélices concentriques.A preferred embodiment of the antenna structure of the invention is shown in Figure 1. It is formed by two
Chaque hélice quadrifilaire 11 et 12 comporte quatre brins 11₁, 11₂, 11₃, 11₄ et 12₁, 12₂, 12₃, 12₄ respectivement, régulièrement espacés et enroulés sur les supports cylindriques 13, 14.Each
Chaque brin 11₁, 11₂, 11₃, 11₄ ; 12₁, 12₂, 12₃, 12₄ est formé d'un ruban continu de matériau conducteur électrique tel que le cuivre, de largeur W, imprimé sur un substrat de kapton, comme représenté en figure 2. Le substrat de kapton peut présenter une épaisseur de 50 µm, pour une largeur W de ruban de cuivre de 35 µm.Each
La longueur de chaque brin est avantageusement comprise entre λ/2 et λ et dans tous les cas inférieure ou égale à λ, pour fonctionner en mode résonnant et obtenir un diagramme de rayonnement quasi-hémisphérique.The length of each strand is advantageously between λ / 2 and λ and in all cases less than or equal to λ, to operate in resonant mode and obtain a quasi-hemispherical radiation diagram.
Dans le cas où les sont brins de longueur légèrement supérieure à on obtient un diagramme de rayonnement radial, et non plus quasi-hémisphérique. Ce type de fonctionnement peut toutefois présenter un intérêt dans certaines applications particulières.In the case where the are strands of length slightly greater than a radial radiation diagram is obtained, and no longer quasi-hemispherical. This type of operation can however be of interest in certain particular applications.
Les quatre brins de chaque hélice 11,12 sont ouverts à une extrémité 15 (extrémité supérieure sur les figures 1 et 2) et connectés électriquement à l'autre extrémité 16 (extrémité inférieure sur les figures 1 et 2) avec des segments conducteurs 31, 32, 33, 34, disposés sur la base 30 de la partie inférieure 16 des cylindres supports 13, 14 comme schématisé en figure 3. Ces segments plans 31, 32, 33, 34 sont avantageusement constitués de rubans imprimés sur kapton, sous forme de portions de segments de largeur décroissante depuis le bord jusqu'à proximité du centre de la base 30 des cylindres 13, 14. Chacun de ces segments conducteur est relié à l'âme centrale d'un des quatre câbles coaxiaux 50 Ω d'alimentation de la structure d'antenne. Les deux hélices quadrifilaires 11,12 sont ainsi alimentées en parallèle, brin à brin (11₁,12₁ ; 11₂,12₂ ; 11₃,12₃ ; 11₄,12₄).The four strands of each
Les quatre brins de chaque hélice 11,12 sont excités à travers les segments 31,32,33,34 selon la configuration d'alimentation schématisée en figure 4, à l'aide d'un dispositif classique constitué d'un module coupleur hybride 41 (3 dB, 90°) et de deux modules symétriseurs 42,43 (3 dB, 180°). Une des entrées 41₁, 42₁, 43₁, de chacun de ces modules 41,42,43 est reliée à la masse à travers une résistance 50 Ω 44. Le module coupleur 41 est disposé de façon que les deux sorties 41₃,41₄ alimentent l'autre entrée 42₂,43₂ des deux modules symétriseurs 42,43. Les sorties à 180° 42₃,43₄ des symétriseurs sont connectées de façon à alimenter deux segments 31,34, les sorties à 0° 42₄ et 43₃ excitant les deux autres segments 33,34. De cette façon, on obtient une excitation en quadrature de phase des deux hélices bifilaires 31,33 et 32,34 de chaque hélice quadrifilaire 11,12, et une excitation en opposition de phase de chacun des brins 31 et 33 d'une part, 32 et 34 d'autre part, de chaque hélice bifilaire.The four strands of each
Cet ensemble peut être réalisé de façon compacte en technologie imprimée et placé directement à la base de la structure d'antenne.This assembly can be made compactly in printed technology and placed directly at the base of the antenna structure.
Compte tenu de la valeur voisine de 50 Ω de l'impédance d'entrée de chacun des brins de la double structure hélicoïdale quadrifilaire, aucune adaptation d'impédance supplémentaire n'est nécessaire.Given the value close to 50 Ω of the input impedance of each of the strands of the double helical quadrifilar structure, no additional impedance adjustment is necessary.
Bien entendu, d'autres configurations d'alimentation sont envisageables, ainsi que d'autres moyens techniques de mise en oeuvre, comme il apparaîtra à l'homme du métier. Ainsi, dans un autre mode de réalisation de l'excitation de la structure d'antenne, non représenté, il est possible de ne pas alimenter une des deux hélices quadrifilaires, qui fonctionne alors comme un élément parasite vis à vis de la seconde.Of course, other supply configurations can be envisaged, as well as other technical means of implementation, as will be apparent to those skilled in the art. Thus, in another embodiment of the excitation of the antenna structure, not shown, it is possible not to supply one of the two quadrifilar propellers, which then functions as a parasitic element with respect to the second.
Le contrôle du couplage entre les deux hélices quadrifilaires peut s'effectuer de plusieurs façons. Il est notamment possible d'agir sur l'écart radial entre les deux hélices, sur le décalage angulaire des antennes autour de l'axe de révolution de l'antenne, par rapport à une position d'exacte superposition radiale brin à brin, ou encore sur le pas d'hélice de chacune des hélices.There are several ways to check the coupling between the two quadrifilar propellers. It is in particular possible to act on the radial difference between the two helices, on the angular offset of the antennas around the axis of revolution of the antenna, with respect to an exact position, radial strand by strand superposition, or still on the propeller pitch of each of the propellers.
Le couplage électromagnétique de chaque brin d'antenne adapté en impédance, par exemple à 50 Ω, est bien sûr contrôlé, de façon à ne pas dégrader, ou le moins possible, les autres caractéristiques de l'antenne, et notamment la polarisation circulaire et le diagramme de rayonnement.The electromagnetic coupling of each antenna strand adapted in impedance, for example to 50 Ω, is of course controlled, so as not to degrade, or as little as possible, the other characteristics of the antenna, and in particular the circular polarization and the radiation pattern.
On va maintenant présenter les résultats obtenus avec deux prototypes de mise en oeuvre de la structure d'antenne de l'invention, correspondant respectivement à une configuration en double bande (fig. 5, 6, 7) à large bande (fig. 8, 9, 10).We will now present the results obtained with two prototypes of implementation of the antenna structure of the invention, corresponding respectively to a double-band configuration (fig. 5, 6, 7) with wide band (fig. 8, 9, 10).
Dans le premier mode de réalisation calculé et testé, les paramètres de l'antenne sont présentés en table I, (avec C : circonférence ; Le : longueur d'un brin rayonnant ; Lax : longueur axiale ; en référence aux notations de la figure 2)
Une série de relevés de mesures a été effectuée sur chaque hélice prise séparément, puis en alimentation simultanée en parallèle. Dans ce qui suit, l'impédance présentée est l'impédance calculée à l'entrée d'un brin rayonnant de l'hélice en présence des autres, cette impédance étant la moitié de celle d'une hélice bifilaire.A series of measurement readings was taken on each propeller taken separately, then in simultaneous supply in parallel. In what follows, the impedance presented is the impedance calculated at the input of a radiating strand of the propeller in the presence of the others, this impedance being half that of a two-wire propeller.
Dans le cas des mesures des antennes quadrifilaires prises isolément, on a relevé une bande passante pour un R.O.S < 2 égale à 60 Mhz (Antenne intérieure) et à 50 Mhz (Antenne extérieure).In the case of measurements of the quadrifilar antennas taken in isolation, a bandwidth was noted for an R.O.S <2 equal to 60 Mhz (indoor antenna) and 50 Mhz (outdoor antenna).
L'alimentation en parallèle des deux hélices conduit à la courbe d'impédance de l'abaque de SMITH de la figure 5 où la courbe représentée pour F1 = 1,480 à Ff = 1,730 présente deux bandes de fréquence 51,52 disjointes dans le domaine d'adaptation de l'antenne. Il est possible, en outre, à l'aide d'un transformateur d'impédance, de recentrer la courbe d'impédance sur l'abaque. Un dimensionnement adapté du paramètre de l'antenne permet aussi d'obtenir une coïncidence des portions 51 et 52. La courbe marque une double résonance due au couplage entre les deux quadrifilaires. Comme il apparaît sur le diagramme de R.O.S de la fig. 6, l'ensemble fonctionne comme deux circuits résonants couplés dont le couplage écarte les fréquences de résonance 61,62. Le R.O.S est inférieure à 1,5 dans deux bandes de fréquence distinctes : 1,54 Ghz < f < 1,5666 Ghz et 1,602 Ghz < f < 1,64 Ghz.The parallel supply of the two helices leads to the impedance curve of the SMITH abacus of FIG. 5 where the curve represented for F1 = 1.480 to Ff = 1.730 has two frequency bands 51.52 disjoint in the domain d adaptation of the antenna. It is also possible, using an impedance transformer, to center the impedance curve on the chart. A suitable dimensioning of the antenna parameter also makes it possible to obtain a coincidence of the
De plus, l'antenne étant pratiquement adaptée à 50 Ω autour des deux fréquences de résonance, le dispositif d'excitation ne nécessite aucun montage spécifique d'adaptation supplémentaire, ce qui affranchit l'antenne des inconvénients de l'antenne quadrifilaire simple.In addition, the antenna being practically adapted to 50 Ω around the two resonant frequencies, the excitation device does not require any specific mounting of additional adaptation, which overcomes the antenna of the disadvantages of the simple quadrifilar antenna.
La figure 7 représente le diagramme de rayonnement de l'antenne couplée, qui diffère peu des diagrammes de rayonnement des hélices quadrifilaires prises isolément.FIG. 7 represents the radiation diagram of the coupled antenna, which differs little from the radiation diagrams of the quadrifilar propellers taken in isolation.
Cette mise en oeuvre peut bien sûr être généralisée à plus de deux hélices quadrifilaires concentriques, de façon à obtenir autant de bandes de fréquence distinctes qu'il y a d'hélices.This implementation can of course be generalized to more than two concentric quadrifilar propellers, so as to obtain as many distinct frequency bands as there are propellers.
En modifiant les paramètres des antennes et la distance entre les couches, le couplage électromagnétique entre les deux hélices quadrifilaires superposées permet d'obtenir une bande passante unique plus large qu'avec une hélice monocouche de mêmes paramètres.By modifying the parameters of the antennas and the distance between the layers, the electromagnetic coupling between the two superimposed quadrifilar propellers makes it possible to obtain a single passband wider than with a monolayer propeller of the same parameters.
Une telle configuration est obtenue par exemple en choisissant les valeurs des paramètres de la Table II.
Pour ces valeurs de paramètres, la bande passante initiale est de 65 Mhz pour un R.O.S. < 2,5 pour l'antenne intérieure, et de 56 Mhz pour un R.O.S. < 2 pour l'antenne extérieure.For these parameter values, the initial bandwidth is 65 Mhz for an ROS <2.5 for the indoor antenna, and 56 Mhz for an ROS < 2 for the outdoor antenna.
En fonctionnement couplé, la bande passante pour l'antenne bicouche est égale à 86 MHz pour un R.O.S < 2. Le diagramme du R.O.S. et l'abaque de SMITH de la courbe d'impédance correspondants sont représentés en figures 8 et 9.In coupled operation, the bandwidth for the bilayer antenna is equal to 86 MHz for an R.O.S <2. The diagram of the R.O.S. and the SMITH chart of the corresponding impedance curve are shown in Figures 8 and 9.
Le R.O.S est inférieur à 1,75 sur une bande de fréquence continue de 1,535 à 1,595 GHz environ, avec une fréquence de résonance de 1,59 Ghz. La courbe d'impédance de la fig.9 s'étend pour F1 = 1,5 Ghz à Ff = 1,63 Ghz pratiquement intégralement dans la zone d'adaptation de l'abaque (avec possibilité de centrage plus exact sur l'abaque comme pour le mode de réalisation précédent).The R.O.S is less than 1.75 on a continuous frequency band from 1.535 to 1.595 GHz approximately, with a resonance frequency of 1.59 Ghz. The impedance curve in fig. 9 extends for F1 = 1.5 Ghz to Ff = 1.63 Ghz almost entirely in the adaptation zone of the abacus (with the possibility of more exact centering on the abacus as for the previous embodiment).
D'une manière générale, la structure de l'antenne de l'invention permet ainsi de "réduire" la partie imaginaire de l'impédance et de ramener autour de 50 Ω sà partie réelle.In general, the structure of the antenna of the invention thus makes it possible to "reduce" the imaginary part of the impedance and to bring back around 50 Ω s to the real part.
On ne constate pas de modifications sensibles des diagrammes de rayonnements, la figure 10 représentant le diagramme pour l'antenne bicouche couplée.There are no significant modifications to the radiation diagrams, FIG. 10 representing the diagram for the coupled two-layer antenna.
Du fait de ces caractéristiques, et de la possibilité de mode de réalisation bifréquence et à large bande, la structure d'antenne de l'invention trouve de nombreux domaines d'application.Because of these characteristics, and the possibility of a dual-frequency and broadband embodiment, the antenna structure of the invention finds numerous fields of application.
Ainsi, elle s'applique aux systèmes de communication par satellite en cours de développement en bande L, par exemple ceux utilisés par "l'International Maritime Satellite Organisation (INMARSAT)" dans le domaine des communications maritimes à l'échelle mondiale.Thus, it applies to satellite communication systems under development in L-band, for example those used by the "International Maritime Satellite Organization (INMARSAT)" in the field of maritime communications on a global scale.
On peut également citer, aux Etats-Unis, le "Mobile Satellite System (MSAT)" qui poursuit le développement de son propre service de communication pour véhicules terrestres ; de même différents concepts ont été proposés pour les communications et le contrôle de trafic aéronautique. (voir J. HUANG and D. BELL "L-Band satellite communication antennas for U.S coast boats, land vehicles and aircraft" IEEE, AP-S INT.SYMP. Digest 1987 (AP 22-1)).We can also cite, in the United States, the "Mobile Satellite System (MSAT)" which pursues the development of its own communication service for land vehicles; similarly, different concepts have been proposed for communications and aeronautical traffic control. (see J. HUANG and D. BELL "L-Band satellite communication antennas for U.S coast boats, land vehicles and aircraft" IEEE, AP-S INT.SYMP. Digest 1987 (AP 22-1)).
En Europe, le programme PROSAT de l'ESA (Agence Spatiale Européenne) prévoit, pour la transmission de données (PRODAT), le développe ment de terminaux de faible G/T (-24 dB/K) pour la navigation aérienne (élévation entre 10° et 90°), maritime (élévation entre -25° et 90° pour tenir compte des mouvements ± 30° du navire dûs au roulis et au tangage), et terrestre (élévation entre 15° et 90°) dans lesquels la structure d'antenne de l'invention trouve une application avantageuse.In Europe, the ESA PROSAT program (European Space Agency) provides for the transmission of data (PRODAT), the development low G / T terminals (-24 dB / K) for air navigation (elevation between 10 ° and 90 °), maritime (elevation between -25 ° and 90 ° to take account of the movements ± 30 ° of the ship due roll and pitch), and terrestrial (elevation between 15 ° and 90 °) in which the antenna structure of the invention finds an advantageous application.
La mise en oeuvre de l'invention ne se limite bien entendu pas à ces exemples d'utilisation, et l'homme de métier concevra de lui-même d'autres modes de réalisation de l'antenne que ceux décrits ici sans sortir du cadre de l'invention.The implementation of the invention is of course not limited to these examples of use, and those skilled in the art will conceive of themselves other embodiments of the antenna than those described here without departing from the scope of the invention.
Claims (10)
caractérisée en ce qu'elle comporte au moins une seconde hélice quadrifilaire (12), co-axiale et en couplage electromagnétique avec ladite première hélice quadrifilaire (11), chacune desdites hélices quadrifilaires (11,12) étant enroulée sur un cylindre de rayon constant distinct.1. Resonant helical antenna with quasi-hemispherical radiation, of the type comprising a quadrifilar helix (11) consisting of two bifilar helices (11₁, 11₂; 11₃, 11₄) arranged orthogonally and excited in phase quadrature,
characterized in that it comprises at least a second quadrifilar helix (12), co-axial and in electromagnetic coupling with said first quadrifilar helix (11), each of said quadrifilar helices (11,12) being wound on a cylinder of constant radius separate.
- contrôle de l'écart radial de superposition desdites hélices quadrifilaires (11,12) ;
- contrôle du décalage angulaire entre lesdites hélices quadrifilaires (11,12);
- contrôle du pas d'hélice de chacune desdites hélices quadrifilaires (11,12).8. Antenna according to any one of claims 1 to 7 characterized in that the coupling of said quadrifilar propellers (11,12) is controlled using at least one of the following means:
- control of the radial overlap of said quadrifilar propellers (11,12);
- control of the angular offset between said quadrifilar propellers (11,12);
- control of the propeller pitch of each of said quadrifilar propellers (11,12).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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FR8914952A FR2654554B1 (en) | 1989-11-10 | 1989-11-10 | ANTENNA IN PROPELLER, QUADRIFILAIRE, RESONANT BICOUCHE. |
FR8914952 | 1989-11-10 |
Publications (2)
Publication Number | Publication Date |
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EP0427654A1 true EP0427654A1 (en) | 1991-05-15 |
EP0427654B1 EP0427654B1 (en) | 1995-02-08 |
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ID=9387403
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP90460041A Expired - Lifetime EP0427654B1 (en) | 1989-11-10 | 1990-11-07 | Tuned helical antennae consisting of two quadrifilar antennas fit into each other |
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Country | Link |
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US (1) | US5255005A (en) |
EP (1) | EP0427654B1 (en) |
JP (1) | JPH03274808A (en) |
CA (1) | CA2029290A1 (en) |
DE (1) | DE69016746T2 (en) |
FR (1) | FR2654554B1 (en) |
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US5298910A (en) * | 1991-03-18 | 1994-03-29 | Hitachi, Ltd. | Antenna for radio apparatus |
EP0715369A1 (en) * | 1994-12-01 | 1996-06-05 | Indian Space Research Organisation | A multiband antenna system |
WO1997006579A1 (en) * | 1995-08-09 | 1997-02-20 | Qualcomm Incorporated | Quadrifilar helix antenna and feed network |
WO1997006575A1 (en) * | 1995-08-09 | 1997-02-20 | Qualcomm Incorporated | 180° power divider for a helix antenna |
WO1997011507A1 (en) * | 1995-09-22 | 1997-03-27 | Qualcomm Incorporated | Dual-band octafilar helix antenna |
EP0777293A1 (en) * | 1995-12-06 | 1997-06-04 | Murata Manufacturing Co., Ltd. | Chip antenna having multiple resonance frequencies |
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- 1990-11-05 US US07/609,383 patent/US5255005A/en not_active Expired - Lifetime
- 1990-11-07 EP EP90460041A patent/EP0427654B1/en not_active Expired - Lifetime
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US5298910A (en) * | 1991-03-18 | 1994-03-29 | Hitachi, Ltd. | Antenna for radio apparatus |
EP0715369A1 (en) * | 1994-12-01 | 1996-06-05 | Indian Space Research Organisation | A multiband antenna system |
US5572227A (en) * | 1994-12-01 | 1996-11-05 | Indian Space Research Organisation | Multiband antenna system for operating at L-band, S-band and UHF-band |
US5793338A (en) * | 1995-08-09 | 1998-08-11 | Qualcomm Incorporated | Quadrifilar helix antenna and feed network |
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WO1997006575A1 (en) * | 1995-08-09 | 1997-02-20 | Qualcomm Incorporated | 180° power divider for a helix antenna |
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WO1997011507A1 (en) * | 1995-09-22 | 1997-03-27 | Qualcomm Incorporated | Dual-band octafilar helix antenna |
US5828348A (en) * | 1995-09-22 | 1998-10-27 | Qualcomm Incorporated | Dual-band octafilar helix antenna |
EP0777293A1 (en) * | 1995-12-06 | 1997-06-04 | Murata Manufacturing Co., Ltd. | Chip antenna having multiple resonance frequencies |
US5870066A (en) * | 1995-12-06 | 1999-02-09 | Murana Mfg. Co. Ltd. | Chip antenna having multiple resonance frequencies |
WO1997035357A1 (en) * | 1996-03-19 | 1997-09-25 | France Telecom | Helical antenna with built-in duplexing means, and manufacturing methods therefor |
WO1997035356A1 (en) * | 1996-03-19 | 1997-09-25 | France Telecom | Helix antenna with a built-in broadband power supply, and manufacturing methods therefor |
US6608604B1 (en) | 1996-03-19 | 2003-08-19 | France Telecom | Helical antenna with built-in duplexing means, and manufacturing methods therefor |
US6181295B1 (en) | 1996-03-19 | 2001-01-30 | France Telecom | Helix antenna with a built-in broadband power supply, and manufacturing methods therefor |
FR2746547A1 (en) * | 1996-03-19 | 1997-09-26 | France Telecom | PROPELLER ANTENNA WITH INTEGRATED BROADBAND SUPPLY, AND MANUFACTURING METHODS THEREOF |
FR2746548A1 (en) * | 1996-03-19 | 1997-09-26 | France Telecom | HELICAL ANTENNA WITH INTEGRATED DUPLEXING MEANS, AND MANUFACTURING METHODS THEREOF |
US5909196A (en) * | 1996-12-20 | 1999-06-01 | Ericsson Inc. | Dual frequency band quadrifilar helix antenna systems and methods |
US5920292A (en) * | 1996-12-20 | 1999-07-06 | Ericsson Inc. | L-band quadrifilar helix antenna |
WO1998028815A1 (en) * | 1996-12-20 | 1998-07-02 | Ericsson, Inc. | L-band quadrifilar helix antenna |
WO1998028817A1 (en) * | 1996-12-20 | 1998-07-02 | Ericsson, Inc. | Dual frequency band quadrifilar helix antenna systems and methods |
EP0856906A3 (en) * | 1997-02-04 | 1999-04-07 | ICO Services Ltd. | Antenna and fabrication method |
EP0856906A2 (en) * | 1997-02-04 | 1998-08-05 | ICO Services Ltd. | Antenna and fabrication method |
KR100299886B1 (en) * | 1997-05-08 | 2001-09-06 | 가네꼬 히사시 | Helical antenna |
WO1999034476A1 (en) * | 1997-12-31 | 1999-07-08 | Ericsson, Inc. | Retractable radiotelephone antennas with extended feeds |
US6097934A (en) * | 1997-12-31 | 2000-08-01 | Ericsson Inc. | Retractable radiotelephone antennas with extended feeds |
US7903044B2 (en) | 2007-01-08 | 2011-03-08 | Sarantel Limited | Dielectrically-loaded antenna |
US8089421B2 (en) | 2008-01-08 | 2012-01-03 | Sarantel Limited | Dielectrically loaded antenna |
CN110518370A (en) * | 2019-08-06 | 2019-11-29 | 西安电子科技大学 | A kind of wide angle covering array antenna of multiband Shared aperture |
Also Published As
Publication number | Publication date |
---|---|
FR2654554B1 (en) | 1992-07-31 |
CA2029290A1 (en) | 1991-05-11 |
DE69016746T2 (en) | 1995-09-14 |
EP0427654B1 (en) | 1995-02-08 |
US5255005A (en) | 1993-10-19 |
FR2654554A1 (en) | 1991-05-17 |
JPH03274808A (en) | 1991-12-05 |
DE69016746D1 (en) | 1995-03-23 |
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