EP3335268B1 - Surface wave antenna system - Google Patents

Surface wave antenna system Download PDF

Info

Publication number
EP3335268B1
EP3335268B1 EP16753413.0A EP16753413A EP3335268B1 EP 3335268 B1 EP3335268 B1 EP 3335268B1 EP 16753413 A EP16753413 A EP 16753413A EP 3335268 B1 EP3335268 B1 EP 3335268B1
Authority
EP
European Patent Office
Prior art keywords
antenna
antenna system
cover
wired
radiation
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.)
Active
Application number
EP16753413.0A
Other languages
German (de)
French (fr)
Other versions
EP3335268A1 (en
EP3335268C0 (en
Inventor
Mathilde Bellec
Sébastien PALUD
Pierre-Yves Jezequel
Franck Colombel
Stéphane AVRILLON
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Universite de Rennes 1
Telediffusion de France ets Public de Diffusion
Original Assignee
Universite de Rennes 1
Telediffusion de France ets Public de Diffusion
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Universite de Rennes 1, Telediffusion de France ets Public de Diffusion filed Critical Universite de Rennes 1
Publication of EP3335268A1 publication Critical patent/EP3335268A1/en
Application granted granted Critical
Publication of EP3335268B1 publication Critical patent/EP3335268B1/en
Publication of EP3335268C0 publication Critical patent/EP3335268C0/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/32—Vertical arrangement of element
    • H01Q9/36—Vertical arrangement of element with top loading
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/04—Adaptation for subterranean or subaqueous use
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/44—Details of, or arrangements associated with, antennas using equipment having another main function to serve additionally as an antenna, e.g. means for giving an antenna an aesthetic aspect
    • H01Q1/46—Electric supply lines or communication lines
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/10—Resonant antennas
    • H01Q5/15—Resonant antennas for operation of centre-fed antennas comprising one or more collinear, substantially straight or elongated active elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/30—Arrangements for providing operation on different wavebands
    • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
    • H01Q5/342—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes
    • H01Q5/357—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes using a single feed point
    • H01Q5/364—Creating multiple current paths
    • H01Q5/371—Branching current paths
    • 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
    • H01Q9/44—Resonant antennas with a plurality of divergent straight elements, e.g. V-dipole, X-antenna; with a plurality of elements having mutually inclined substantially straight portions
    • H01Q9/46—Resonant antennas with a plurality of divergent straight elements, e.g. V-dipole, X-antenna; with a plurality of elements having mutually inclined substantially straight portions with rigid elements diverging from single point

Definitions

  • the invention relates to an antenna system.
  • the invention relates to an antenna system with vertical and/or elliptical polarization suitable for transmitting and/or receiving surface waves in a wide frequency band including in particular all or part of the low, medium and high frequencies between 30 kHz and about 30 MHz, i.e. LF, MF and HF.
  • Antennas using only a surface wave as a propagation vector are very few in number.
  • Current surface wave systems use whip or biconical type antennas which are poorly suited for radar applications.
  • space wave field also called ionospheric radiation
  • the invention aims to overcome at least some of the drawbacks of known antennas.
  • the invention aims to provide, in at least one embodiment of the invention, an antenna system whose preferential radiation is surface wave radiation.
  • the invention also aims to provide, in at least one embodiment, an antenna system whose ionospheric radiation is reduced.
  • the invention also aims to provide, in at least one embodiment of the invention, an antenna system that is simple to produce.
  • the invention also aims to provide, in at least one embodiment, a discrete antenna system whose vertical bulk is small.
  • the invention also aims to provide, in at least one embodiment, an antenna system whose bandwidth can be easily modified.
  • electrically short antenna in the vertical plane is meant an antenna emitting radiation in a preferential wavelength called the central wavelength ⁇ 0 , and whose vertical size is less than a quarter of the central wavelength. If the antenna transmits on a frequency band, the central wavelength corresponds to the wavelength associated with the central frequency of the frequency band.
  • the antenna is for example an antenna as described in the French patent application FR2965978 , a whip antenna, a PIFA type antenna (for Planar Inverted F-Shaped Antenna in English), M-shaped antenna, etc.
  • An antenna system therefore allows preferential radiation in surface waves, as well as the reduction of the ionospheric radiation of an antenna thanks to the use of one or more wire covers, so as to emit only surface waves.
  • the wired covers are electrically connected to the antenna, so that a power supply from the antenna also supplies the wired covers.
  • the wired covers radiate at the central frequency f 0 and allow modification of the radiation pattern of the antenna so as to reduce the ionospheric radiation of the antenna system.
  • the wired covers are formed from a metal wire or a small section metal tube.
  • the vertical size of the antenna system is between 0.05 ⁇ 0 and 0.3 ⁇ 0 .
  • the antenna system is therefore discreet. In addition, it is less sensitive to wind, blast, lightning, earthquakes, etc.
  • the length of the wired cover is less than or equal to 2 ⁇ 0 .
  • said at least one antenna is configured to transmit/receive directional radiation along a direction of radiation, and at least one wired cover extends along a main direction substantially parallel to the direction of radiation.
  • the ionospheric radiation of the antenna system is further reduced in the radiation direction of the antenna when this is a directional antenna.
  • At least one wired cover extends in a direction forming an angle of between ⁇ 10° and 10° with the surface of the conductive medium.
  • the wired cover extends in a direction substantially parallel to the surface of the conductive medium. “Substantially parallel” means an angle between the direction of each cover and the surface of the conductive medium comprised between ⁇ 5° and 5°.
  • the wired cover can also be strictly parallel to the surface of the conductive medium.
  • the reduction of ionospheric radiation and the directivity of the antenna are improved.
  • an antenna system comprises at least two wire covers extending in main directions different from each other.
  • the presence of a plurality of wired covers allows an improved reduction of ionospheric radiation in several azimuths.
  • the conductive medium comprises a ground plane, to which each antenna is connected.
  • the ground plane makes it possible to improve the conductivity of the conductive medium if this conductivity is too low.
  • At least one wired cowl comprises at least one localized element adapted to allow the resonance of said cowl at a multitude of frequencies.
  • the localized elements which can be resistive, capacitive or inductive elements, make it possible to form on the cover(s) open circuits (or high impedance) or closed circuits according to the operating frequencies, forming thus current traps.
  • the localized elements are thus adapted to obtain a multifrequency antenna system (that is to say with multiple resonances) via said current traps.
  • the localized elements can also make it possible to reproduce the RLC resonance of the cowl with a reduced physical length of the cowl but an equivalent electrical length.
  • the localized elements are thus adapted to modify the electrical length of the cover.
  • At least one wired cover comprises a plurality of wired elements connected to each other so as to form a surface cover or a volume cover.
  • the surface or volume covers make it possible to increase the bandwidth of the antenna system.
  • surface or volume covers are suitable for use with broadband antennas.
  • the wired elements are, for example, strands composed of tubes or metal wires.
  • the invention also relates to an antenna system characterized in combination by all or some of the characteristics mentioned above or below.
  • An orthogonal marker Oxyz is used in each figure representing antenna systems according to the different embodiments of the invention.
  • FIG. 1 schematically represents in perspective an antenna system according to a first embodiment of the invention.
  • the antenna system 20 comprises an antenna 22, here an M-shaped antenna comprising a horizontal radiating element 24 connected to three vertical radiating elements 26a, 26b, 26c, themselves connected to a conductive medium 28.
  • the conductive medium 28 is represented by an electrical ground symbol connected to the ground.
  • the conductive medium 28 is an imperfect conductive medium, for example soil (earth, sand, etc.) or water (sea, salt marsh, lake, etc.).
  • the antenna is powered at the level of the vertical radiating element 26b by a generator 29.
  • the antenna system 20 further comprises a wire cover 30 electrically connected to the antenna 22 at the level of the center of the cover.
  • the wire cover 30 is connected to the antenna 22 at the level of the center of the vertical radiating element 24 .
  • the wire cover 30 is single-stranded (that is to say it is composed of a single radiating wire), has a length greater than 0.8 ⁇ 0 and extends in a direction substantially parallel to the surface of the middle 28 conductor.
  • the conductive medium 28 has an electrical conductivity which varies according to its composition.
  • the sea, salt marshes or salt lakes have high electrical conductivity, and earth and sand have low electrical conductivity.
  • the antenna system 20 is completed by a ground plane, connected to the antenna 22, and buried below or on the surface of the conductive medium 28.
  • the ground plane can be formed of a plate, or of a set of conductive wires forming a mesh, etc.
  • the ground plane can take several shapes, for example a circle, a polygon (regular or not), etc.
  • the ground plane extends under the whole of the antenna system 20, that is to say that the projection of the antenna system 20 on the conductive medium 28 along the axis Oz is included in the surface occupied by the ground plane.
  • FIG. 2 schematically represents in perspective an antenna system according to a second embodiment of the invention.
  • the antenna system 20 comprises an antenna 22 as described in the French patent application FR2965978 filed by the applicant.
  • the antenna system 20 comprises a wire cover 30 electrically connected to the antenna 22 at the level of the center of the cover.
  • the wire cover 30 is single-stranded, and is composed of two sub-strands 32a, 32b of equal lengths, connected at one of their ends and arranged in the same plane.
  • the two sub-strands are connected by forming an angle, due to the difference between the height h1 at which the sub-strands are connected and the height of the other two ends of the sub-strands.
  • the angle is equal to 180° and therefore the sub-strands are aligned and the cover is parallel to the surface of the conductive medium 28, like the cover previously described in the first embodiment of achievement.
  • FIG. 3 represents a radiation diagram according to the yOz plane (known as the zenithal radiation diagram) of the antenna system according to the second embodiment of the invention, in which the wired cover has a length of 0.8 ⁇ 0 , the height h1 is equal at 0.06 ⁇ 0 , the height h2 is equal to 0.05 ⁇ 0 and the length L of the antenna is equal to 0.3 ⁇ 0 .
  • the radiation from the antenna system is therefore mainly surface wave radiation, and the ionospheric radiation from the antenna system is greatly reduced compared to an antenna 22 without cover.
  • the gain of the antenna system (expressed in dB relative to the maximum radiation of the antenna system) is between 0 and -5 dB for radiation angles included in the intervals [-90°, -60°] and [60 °, 90°], and is less than -10dB in the interval [-50°, 50°].
  • FIG. 4 schematically represents in perspective an antenna system according to a third embodiment of the invention.
  • the antenna system 20 comprises an antenna 22 of the PIFA type (for Planar Inverted F-Shaped Antenna ).
  • the antenna 22 is composed of two vertical radiating elements 34a, 34b connected to a horizontal radiating element 36.
  • the antenna system 20 comprises a single-strand wire cover 30 electrically connected to the antenna 22 at the level of the center of the wire cover 30.
  • FIG. 5 schematically represents in perspective an antenna system according to a fourth embodiment of the invention.
  • the antenna system 20 comprises an antenna 22 of the shortened whip antenna type.
  • the antenna 22 is a monopole antenna comprising a single radiating wire, and the antenna system 20 comprises a single-strand wire cover 30 electrically connected to one end of the antenna 22 at the level of the center of the wire cover 30.
  • FIG. 6 , 7 , 8 , 10 and 11 schematically represent in perspective an antenna system 20 according to different embodiments comprising an M-shaped antenna 22 as described above with reference to the first embodiment.
  • THE figure 6 And 7 represent respectively a fifth and a sixth embodiment of the invention, in which the wire cover 30 is single-stranded and is connected to the antenna according to different arrangements, in particular connected to any point of the horizontal radiating element 24 in the fifth embodiment ( figure 6 ) or at one of the ends of the horizontal radiating element 24 in the sixth embodiment ( figure 7 ).
  • wired cover 30 make it possible in particular to adapt the antenna system 20 according to different configurations so as to adapt to the constraints of the environment in which the antenna system 20 is arranged, the configurations having identical operations.
  • THE figure 8 , 10 and 11 respectively represent a seventh, an eighth and a ninth embodiment of the invention, in which the wired cover 30 is a so-called multi-strand cover, comprising a plurality of wire elements, here two strands 38a, 38b connected at their center and s extending in different directions so as to form an angle ⁇ .
  • the strands are of the same length greater than 0.8 ⁇ 0 .
  • the cover is connected to the antenna according to different arrangements, in particular connected to the center of the horizontal radiating element 24 in the seventh embodiment ( figure 8 ), at any point of the horizontal radiating element 24 in the eighth embodiment ( figure 10 ) or at one of the ends of the horizontal radiating element 24 in the ninth embodiment ( figure 11 ).
  • FIG 9 represents a radiation diagram according to the yOz plane (known as the zenithal radiation diagram) of the antenna system according to the seventh embodiment of the invention, in which each strand of the cover has a length of 1.1 ⁇ 0 , the element 24 horizontal radiating from the antenna 22 has a length of 0.7 ⁇ 0 and the antenna has a height h of 0.08 ⁇ 0 .
  • the radiation from the antenna system is therefore mainly surface wave radiation, and the ionospheric radiation from the antenna system is greatly reduced compared to an antenna 22 without cover.
  • the gain of the antenna system (expressed in dB relative to the maximum radiation of the antenna system) is between 0 and -5 dB for radiation angles included in the intervals [-90°, -60°] and [60 °, 90°], is less than -10dB in the interval [-50°, 50°], and less than -15dB in the interval [-40°, 40°].
  • FIG 12 , 13 and 14 schematically represent in perspective an antenna system 20 respectively according to a tenth, an eleventh and a twelfth embodiment.
  • Each antenna system comprises an M-shaped antenna 22 according to different particular embodiments.
  • the antenna 22 comprises three horizontal radiating elements 24a, 24b, 24c of the same lengths, each connected at their ends to a vertical radiating element and all connected at their center to a single vertical radiating element 26b.
  • This embodiment of the antenna allows a widening of the radiation frequency band of the antenna.
  • the system 22 antenna comprises a multi-stranded wire cover 30 composed of two strands 38a, 38b, as described above, the ends of the strands being connected two by two by wire connections 40a, 40b so as to form a surface cover, that is to say say equivalent to a radiating surface.
  • This surface cover therefore has a widened operating frequency band in connection with the widening of the operating band of the antenna 22.
  • the antenna 22 comprises two horizontal radiating elements 24, 124 of different lengths each connected at their ends to a vertical radiating element and all connected at their center to a single vertical radiating element.
  • a first horizontal radiating element 24 is of suitable length to radiate at a first central frequency f 0 (associated with the wavelength ⁇ 0 ) and a second horizontal element 124 is of suitable length to radiate at a second central frequency f bis ( associated with the wavelength ⁇ bis ).
  • the antenna is said to be double resonant.
  • the antenna system 22 comprises a wire cover 30 composed of several strands, here three strands 38a, 38b, 38c, arranged in parallel, of different lengths and connected at their ends.
  • a first strand 38b has a length greater than 0.8 ⁇ 0 and is suitable for radiating at the first central frequency f 0
  • two second and third strands 38a, 38c have a length greater than 0.8 ⁇ bis and are suitable for radiate at the central frequency f bis .
  • the wire cover 30 is thus double resonant and allows the reduction of the ionospheric radiation for the central frequencies f 0 and f bis .
  • the antenna 22 comprises five vertical radiating elements 26a, 26b, 26c, 26d, 26e connected to the horizontal radiating element 24.
  • the antenna 22 comprises localized elements 42a, 42b, 42c, 42d arranged on two of the vertical radiating elements and on the horizontal radiating element 24, allowing the formation of current traps and/or allowing the electrical lengths to be modified. of the antenna 22.
  • the localized elements can be resistive, capacitive (capacitors) or inductive (coils). These localized elements are commonly called " load " in English.
  • the antenna system 22 comprises two multi-strand covers 30a, 30b connected to the horizontal radiating element of the antenna, each of the covers comprising two strands.
  • the covers further comprise localized elements 42e, 42f, 42g, 42h, 42i, 42j, 42k, 421 allowing the formation of current traps and/or allowing the electrical lengths of the covers to be modified.
  • the lumped elements are resistive (eg a resistor), capacitive (eg a capacitor) or inductive (eg a coil).
  • At least one cover can be a volume type cover so as to further broaden the bandwidth of the antenna system
  • the antenna system can comprise more than two covers, several antennas, etc.

Landscapes

  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Details Of Aerials (AREA)
  • Aerials With Secondary Devices (AREA)

Description

1. Domaine technique de l'invention1. Technical field of the invention

L'invention concerne un système antennaire. En particulier, l'invention concerne un système antennaire à polarisation verticale et/ou elliptique adapté pour émettre et/ou recevoir des ondes de surface dans une large bande de fréquence incluant notamment tout ou partie des fréquences basses, moyennes et hautes comprises entre 30 kHz environ et 30 MHz environ, soit des ondes kilométriques, hectométriques et décamétriques.The invention relates to an antenna system. In particular, the invention relates to an antenna system with vertical and/or elliptical polarization suitable for transmitting and/or receiving surface waves in a wide frequency band including in particular all or part of the low, medium and high frequencies between 30 kHz and about 30 MHz, i.e. LF, MF and HF.

2. Arrière-plan technologique2. Technological background

Actuellement, des pylônes rayonnants de grandes dimensions sont utilisés pour émettre de fortes puissances dans les bandes hectométriques. Ces pylônes présentent l'inconvénient d'être coûteux, de nécessiter un important terrain de sécurité pour leur installation, et d'être peu esthétiques et discrets. Ils ne sont pas optimisés pour une diffusion essentiellement par ondes de surface.Currently, large radiating pylons are used to transmit high power in the hectometric bands. These pylons have the drawback of being expensive, of requiring a large amount of safety ground for their installation, and of being unsightly and unobtrusive. They are not optimized for diffusion essentially by surface waves.

Les antennes utilisant uniquement une onde de surface comme vecteur de propagation sont très peu nombreuses. Les systèmes à ondes de surface actuels utilisent des antennes de type fouet ou biconique qui sont mal adaptées pour des applications radar.Antennas using only a surface wave as a propagation vector are very few in number. Current surface wave systems use whip or biconical type antennas which are poorly suited for radar applications.

Les pylônes rayonnants et en général toutes les antennes à polarisation verticale par exemple de type fouet ou biconique génèrent essentiellement un champ d'onde d'espace (aussi appelé rayonnement ionosphérique) et sont coûteux et/ou très peu discrets.Radiating pylons and in general all antennas with vertical polarization, for example of the whip or biconical type, essentially generate a space wave field (also called ionospheric radiation) and are expensive and/or very inconspicuous.

Des solutions ont été proposées pour résoudre ces problèmes. La demande de brevet français FR2965978 , déposée par le demandeur, propose une solution permettant de réduire de façon importante l'encombrement vertical de l'antenne, permettant ainsi une réduction des coûts d'implantation et une amélioration de la discrétion de l'antenne. En outre, l'antenne permet une amélioration de la propagation par ondes de surface et une diminution du rayonnement ionosphérique. Néanmoins, le rayonnement ionosphérique reste toutefois important, notamment pour des angles compris entre ±[20° ; 80°] autour de la normale au plan de sol sur lequel est disposé l'antenne. Ce rayonnement ionosphérique restant peut, dans certaines bandes de fréquences, engendrer des phénomènes d'atténuation (fading en anglais), notamment lorsque les ondes de surface et les ondes d'espace interfèrent, au niveau de la surface de la Terre, après propagation dans des milieux et par des chemins différents.Solutions have been proposed to solve these problems. The request for French patent FR2965978 , filed by the applicant, proposes a solution making it possible to significantly reduce the vertical bulk of the antenna, thus allowing a reduction in installation costs and an improvement in the discretion of the antenna. In addition, the antenna allows an improvement of the propagation by surface waves and a reduction of the ionospheric radiation. Nevertheless, the However, ionospheric radiation remains significant, especially for angles between ±[20°; 80°] around the normal to the ground plane on which the antenna is placed. This remaining ionospheric radiation can, in certain frequency bands, cause attenuation phenomena ( fading in English), in particular when surface waves and space waves interfere, at the level of the surface of the Earth, after propagation in different places and through different paths.

3. Objectifs de l'invention3. Objects of the invention

L'invention vise à pallier au moins certains des inconvénients des antennes connus.The invention aims to overcome at least some of the drawbacks of known antennas.

En particulier, l'invention vise à fournir, dans au moins un mode de réalisation de l'invention, un système antennaire dont le rayonnement préférentiel est un rayonnement d'ondes de surface.In particular, the invention aims to provide, in at least one embodiment of the invention, an antenna system whose preferential radiation is surface wave radiation.

L'invention vise aussi à fournir, dans au moins un mode de réalisation, un système antennaire dont le rayonnement ionosphérique est diminué.The invention also aims to provide, in at least one embodiment, an antenna system whose ionospheric radiation is reduced.

L'invention vise aussi à fournir, dans au moins un mode de réalisation de l'invention, un système antennaire simple à réaliser.The invention also aims to provide, in at least one embodiment of the invention, an antenna system that is simple to produce.

L'invention vise aussi à fournir, dans au moins un mode de réalisation, un système antennaire discret et dont l'encombrement vertical est faible.The invention also aims to provide, in at least one embodiment, a discrete antenna system whose vertical bulk is small.

L'invention vise aussi à fournir, dans au moins un mode de réalisation, un système antennaire dont la bande passante peut être facilement modifiée.The invention also aims to provide, in at least one embodiment, an antenna system whose bandwidth can be easily modified.

4. Exposé de l'invention4. Disclosure of Invention

Pour ce faire, l'invention concerne un système antennaire à ondes de surface selon la revendication 1 comprenant :

  • au moins une antenne électriquement courte dans le plan vertical, à polarisation verticale ou elliptique et adapté pour émettre/recevoir un rayonnement dans au moins une bande de fréquence centrée sur une fréquence centrale f0 associée à une longueur d'onde centrale λ0, ladite antenne étant reliée à un milieu conducteur présentant une surface sensiblement horizontale,
le système antennaire étant caractérisé en ce qu'il comprend en outre :
  • au moins un capot filaire de longueur supérieure ou égale à 0,8 λ0, électriquement lié à au moins une antenne au niveau du centre du capot, et adaptée pour rayonner au moins à la fréquence centrale f0 de l'antenne.
To do this, the invention relates to a surface wave antenna system according to claim 1 comprising:
  • at least one electrically short antenna in the vertical plane, with vertical or elliptical polarization and suitable for transmitting/receiving radiation in at least one frequency band centered on a central frequency f 0 associated with a central wavelength λ 0 , said antenna being connected to a conductive medium having a substantially horizontal surface,
the antenna system being characterized in that it further comprises:
  • at least one wired cover of length greater than or equal to 0.8 λ 0 , electrically linked to at least one antenna at the level of the center of the cover, and adapted to radiate at least at the central frequency f 0 of the antenna.

On entend par antenne électriquement courte dans le plan vertical une antenne émettant un rayonnement dans une longueur d'onde préférentielle dite longueur d'onde centrale λ0, et dont l'encombrement vertical est inférieur à un quart de la longueur d'onde centrale. Si l'antenne émet sur une bande de fréquence, la longueur d'onde centrale correspond à la longueur d'onde associée à la fréquence centrale de la bande de fréquence. L'antenne est par exemple une antenne telle que décrite dans la demande de brevet français FR2965978 , une antenne fouet, une antenne de type PIFA (pour Planar Inverted F-Shaped Antenna en anglais), antenne en forme de M, etc.By electrically short antenna in the vertical plane is meant an antenna emitting radiation in a preferential wavelength called the central wavelength λ 0 , and whose vertical size is less than a quarter of the central wavelength. If the antenna transmits on a frequency band, the central wavelength corresponds to the wavelength associated with the central frequency of the frequency band. The antenna is for example an antenna as described in the French patent application FR2965978 , a whip antenna, a PIFA type antenna (for Planar Inverted F-Shaped Antenna in English), M-shaped antenna, etc.

Un système antennaire selon l'invention permet donc un rayonnement préférentiel en ondes de surfaces, ainsi que la réduction du rayonnement ionosphérique d'une antenne grâce à l'utilisation d'un ou plusieurs capots filaires, de façon à émettre uniquement des ondes de surface. Les capots filaires sont reliés électriquement à l'antenne, de façon à ce qu'une alimentation de l'antenne alimente aussi les capots filaires. De cette façon et grâce à leurs dimensions, les capots filaires rayonnent à la fréquence centrale f0 et permettent la modification du diagramme de rayonnement de l'antenne de façon à réduire le rayonnement ionosphérique du système antennaire. Les capots filaires sont formés d'un fil métallique ou d'un tube métallique de faible section.An antenna system according to the invention therefore allows preferential radiation in surface waves, as well as the reduction of the ionospheric radiation of an antenna thanks to the use of one or more wire covers, so as to emit only surface waves. . The wired covers are electrically connected to the antenna, so that a power supply from the antenna also supplies the wired covers. In this way and thanks to their dimensions, the wired covers radiate at the central frequency f 0 and allow modification of the radiation pattern of the antenna so as to reduce the ionospheric radiation of the antenna system. The wired covers are formed from a metal wire or a small section metal tube.

De préférence, l'encombrement vertical du système antennaire est compris entre 0,05 λ0 et 0,3 λ0. Le système antennaire est donc discret. En outre, il est moins sensible au vent, au souffle, à la foudre, aux séismes, etc.Preferably, the vertical size of the antenna system is between 0.05 λ 0 and 0.3 λ 0 . The antenna system is therefore discreet. In addition, it is less sensitive to wind, blast, lightning, earthquakes, etc.

De préférence, la longueur du capot filaire est inférieure ou égale à 2 λ0.Preferably, the length of the wired cover is less than or equal to 2 λ 0 .

Avantageusement et selon l'invention, ladite au moins une antenne est configurée pour émettre/recevoir un rayonnement directif selon une direction de rayonnement, et au moins un capot filaire s'étend selon une direction principale sensiblement parallèle à la direction de rayonnement.Advantageously and according to the invention, said at least one antenna is configured to transmit/receive directional radiation along a direction of radiation, and at least one wired cover extends along a main direction substantially parallel to the direction of radiation.

Selon cet aspect de l'invention, le rayonnement ionosphérique du système antennaire est réduit davantage dans la direction de rayonnement de l'antenne lorsque celle-ci est une antenne directive.According to this aspect of the invention, the ionospheric radiation of the antenna system is further reduced in the radiation direction of the antenna when this is a directional antenna.

Avantageusement et selon l'invention, au moins un capot filaire s'étend selon une direction formant un angle compris entre -10° et 10° avec la surface du milieu conducteur.Advantageously and according to the invention, at least one wired cover extends in a direction forming an angle of between −10° and 10° with the surface of the conductive medium.

De préférence, le capot filaire s'étend selon une direction sensiblement parallèle à la surface du milieu conducteur. On entend par sensiblement parallèle un angle entre la direction de chaque capot et la surface du milieu conducteur compris entre -5° et 5°. Le capot filaire peut aussi être strictement parallèle à la surface du milieu conducteur.Preferably, the wired cover extends in a direction substantially parallel to the surface of the conductive medium. “Substantially parallel” means an angle between the direction of each cover and the surface of the conductive medium comprised between −5° and 5°. The wired cover can also be strictly parallel to the surface of the conductive medium.

Selon cet aspect de l'invention, la réduction du rayonnement ionosphérique et la directivité de l'antenne sont améliorées.According to this aspect of the invention, the reduction of ionospheric radiation and the directivity of the antenna are improved.

Avantageusement, un système antennaire selon l'invention comprend au moins deux capots filaires s'étendant dans des directions principales différentes l'une de l'autre.Advantageously, an antenna system according to the invention comprises at least two wire covers extending in main directions different from each other.

Selon cet aspect de l'invention, la présence d'une pluralité de capots filaires permet une réduction du rayonnement ionosphérique améliorée dans plusieurs azimuts.According to this aspect of the invention, the presence of a plurality of wired covers allows an improved reduction of ionospheric radiation in several azimuths.

Avantageusement et selon l'invention, le milieu conducteur comprend un plan de masse, auquel est reliée chaque antenne.Advantageously and according to the invention, the conductive medium comprises a ground plane, to which each antenna is connected.

Selon cet aspect de l'invention, le plan de masse permet d'améliorer la conductivité du milieu conducteur si cette conductivité est trop faible.According to this aspect of the invention, the ground plane makes it possible to improve the conductivity of the conductive medium if this conductivity is too low.

Avantageusement et selon l'invention, au moins un capot filaire comprend au moins un élément localisé adapté pour permettre la résonance dudit capot à une multitude de fréquence.Advantageously and according to the invention, at least one wired cowl comprises at least one localized element adapted to allow the resonance of said cowl at a multitude of frequencies.

Selon cet aspect de l'invention, les éléments localisés, qui peuvent être des éléments résistifs, capacitifs ou inductifs, permettent de former sur le ou les capots des circuits ouverts (ou haute impédance) ou des circuits fermés selon les fréquences de fonctionnement, formant ainsi des pièges de courant. Les éléments localisés sont ainsi adaptés pour obtenir un système antennaire multifréquence (c'est-à-dire à multiples résonances) via lesdits pièges de courant.According to this aspect of the invention, the localized elements, which can be resistive, capacitive or inductive elements, make it possible to form on the cover(s) open circuits (or high impedance) or closed circuits according to the operating frequencies, forming thus current traps. The localized elements are thus adapted to obtain a multifrequency antenna system (that is to say with multiple resonances) via said current traps.

En outre, les éléments localisés peuvent aussi permettre de reproduire la résonance RLC du capot avec une longueur physique de capot réduite mais une longueur électrique équivalente. Les éléments localisés sont ainsi adaptés pour modifier la longueur électrique du capot.In addition, the localized elements can also make it possible to reproduce the RLC resonance of the cowl with a reduced physical length of the cowl but an equivalent electrical length. The localized elements are thus adapted to modify the electrical length of the cover.

Avantageusement et selon l'invention, au moins un capot filaire comprend une pluralité d'éléments filaires reliés les uns aux autres de sorte à former un capot surfacique ou un capot volumique.Advantageously and according to the invention, at least one wired cover comprises a plurality of wired elements connected to each other so as to form a surface cover or a volume cover.

Selon cet aspect de l'invention, les capots surfaciques ou volumiques permettent d'augmenter la largeur de bande passante du système antennaire. Ainsi, les capots surfaciques ou volumiques sont adaptés pour être utilisés avec des antennes à large bande. Les éléments filaires sont par exemple des brins composés de tubes ou de fils métalliques.According to this aspect of the invention, the surface or volume covers make it possible to increase the bandwidth of the antenna system. Thus, surface or volume covers are suitable for use with broadband antennas. The wired elements are, for example, strands composed of tubes or metal wires.

L'invention concerne également un système antennaire caractérisé en combinaison par tout ou partie des caractéristiques mentionnées ci-dessus ou ci-après.The invention also relates to an antenna system characterized in combination by all or some of the characteristics mentioned above or below.

5. Liste des figures5. List of Figures

D'autres buts, caractéristiques et avantages de l'invention apparaîtront à la lecture de la description suivante donnée à titre uniquement non limitatif et qui se réfère aux figures annexées dans lesquelles :

  • la figure 1 est une vue schématique en perspective d'un système antennaire selon un premier mode de réalisation de l'invention,
  • la figure 2 est une vue schématique en perspective d'un système antennaire selon un deuxième mode de réalisation de l'invention,
  • la figure 3 est un diagramme de rayonnement selon le plan yOz du système antennaire selon le deuxième mode de réalisation de l'invention,
  • la figure 4 est une vue schématique en perspective d'un système antennaire selon un troisième mode de réalisation de l'invention,
  • la figure 5 est une vue schématique en perspective d'un système antennaire selon un quatrième mode de réalisation de l'invention,
  • la figure 6 est une vue schématique en perspective d'un système antennaire selon un cinquième mode de réalisation de l'invention,
  • la figure 7 est une vue schématique en perspective d'un système antennaire selon un sixième mode de réalisation de l'invention,
  • la figure 8 est une vue schématique en perspective d'un système antennaire selon un septième mode de réalisation de l'invention,
  • la figure 9 est un diagramme de rayonnement selon le plan yOz du système antennaire selon le septième mode de réalisation de l'invention,
  • la figure 10 est une vue schématique en perspective d'un système antennaire selon un huitième mode de réalisation de l'invention,
  • la figure 11 est une vue schématique en perspective d'un système antennaire selon un neuvième mode de réalisation de l'invention,
  • la figure 12 est une vue schématique en perspective d'un système antennaire selon un dixième mode de réalisation de l'invention,
  • la figure 13 est une vue schématique en perspective d'un système antennaire selon un onzième mode de réalisation de l'invention,
  • la figure 14 est une vue schématique en perspective d'un système antennaire selon un douzième mode de réalisation de l'invention.
Other aims, characteristics and advantages of the invention will appear on reading the following description given solely by way of non-limiting and which refers to the appended figures in which:
  • there figure 1 is a schematic perspective view of an antenna system according to a first embodiment of the invention,
  • there figure 2 is a schematic perspective view of an antenna system according to a second embodiment of the invention,
  • there picture 3 is a radiation pattern along the yOz plane of the antenna system according to the second embodiment of the invention,
  • there figure 4 is a schematic perspective view of an antenna system according to a third embodiment of the invention,
  • there figure 5 is a schematic perspective view of an antenna system according to a fourth embodiment of the invention,
  • there figure 6 is a schematic perspective view of an antenna system according to a fifth embodiment of the invention,
  • there figure 7 is a schematic perspective view of an antenna system according to a sixth embodiment of the invention,
  • there figure 8 is a schematic perspective view of an antenna system according to a seventh embodiment of the invention,
  • there figure 9 is a radiation pattern along the yOz plane of the antenna system according to the seventh embodiment of the invention,
  • there figure 10 is a schematic perspective view of an antenna system according to an eighth embodiment of the invention,
  • there figure 11 is a schematic perspective view of an antenna system according to a ninth embodiment of the invention,
  • there figure 12 is a schematic perspective view of an antenna system according to a tenth embodiment of the invention,
  • there figure 13 is a schematic perspective view of an antenna system according to an eleventh embodiment of the invention,
  • there figure 14 is a schematic perspective view of an antenna system according to a twelfth embodiment of the invention.

6. Description détaillée d'un mode de réalisation de l'invention6. Detailed description of an embodiment of the invention

Les réalisations suivantes sont des exemples. Bien que la description se réfère à un ou plusieurs modes de réalisation, ceci ne signifie pas nécessairement que chaque référence concerne le même mode de réalisation, ou que les caractéristiques s'appliquent seulement à un seul mode de réalisation. De simples caractéristiques de différents modes de réalisation peuvent également être combinées pour fournir d'autres réalisations. Sur les figures, les échelles et les proportions ne sont pas strictement respectées et ce, à des fins d'illustration et de clarté.The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments can also be combined to provide other realizations. In the figures, scales and proportions are not strictly adhered to, for purposes of illustration and clarity.

Un repère orthogonal Oxyz est utilisé sur chaque figure représentant des systèmes antennaires selon les différents modes de réalisation de l'invention.An orthogonal marker Oxyz is used in each figure representing antenna systems according to the different embodiments of the invention.

Les notions de « horizontal » et « vertical » sont utilisées en correspondance avec une antenne une fois installée, en situation opérationnelle, comme représenté figure 1. En outre, un élément est horizontal si sa direction principale est parallèle au plan xOy et est vertical si sa direction principale est parallèle à l'axe Oz.The notions of “horizontal” and “vertical” are used in correspondence with an antenna once installed, in an operational situation, as shown figure 1 . Also, an element is horizontal if its main direction is parallel to the xOy plane and is vertical if its main direction is parallel to the Oz axis.

La figure 1 représente schématiquement en perspective un système 20 antennaire selon un premier mode de réalisation de l'invention.There figure 1 schematically represents in perspective an antenna system according to a first embodiment of the invention.

Le système 20 antennaire comprend une antenne 22, ici une antenne en forme de M comprenant un élément 24 rayonnant horizontal relié à trois éléments 26a, 26b, 26c rayonnants verticaux, eux-mêmes reliés à un milieu 28 conducteur. Sur cette figure et sur les figures suivantes, le milieu 28 conducteur est représenté par un symbole de masse électrique reliée à la terre. Le milieu 28 conducteur est un milieu conducteur imparfait, par exemple un sol (en terre, sable, etc.) ou de l'eau (mer, marais salant, lac, etc.). L'antenne est alimentée au niveau de l'élément 26b rayonnant vertical par un générateur 29.The antenna system 20 comprises an antenna 22, here an M-shaped antenna comprising a horizontal radiating element 24 connected to three vertical radiating elements 26a, 26b, 26c, themselves connected to a conductive medium 28. In this figure and in the following figures, the conductive medium 28 is represented by an electrical ground symbol connected to the ground. The conductive medium 28 is an imperfect conductive medium, for example soil (earth, sand, etc.) or water (sea, salt marsh, lake, etc.). The antenna is powered at the level of the vertical radiating element 26b by a generator 29.

Le système 20 antennaire comprend en outre un capot 30 filaire relié électriquement à l'antenne 22 au niveau du centre du capot. En outre, dans ce mode de réalisation, le capot 30 filaire est relié à l'antenne 22 au niveau du centre de l'élément 24 rayonnant vertical.The antenna system 20 further comprises a wire cover 30 electrically connected to the antenna 22 at the level of the center of the cover. In addition, in this embodiment, the wire cover 30 is connected to the antenna 22 at the level of the center of the vertical radiating element 24 .

Le capot 30 filaire est monobrin (c'est-à-dire qu'il est composé d'un seul fil rayonnant), a une longueur supérieure à 0,8 λ0 et s'étend dans une direction sensiblement parallèle à la surface du milieu 28 conducteur.The wire cover 30 is single-stranded (that is to say it is composed of a single radiating wire), has a length greater than 0.8 λ 0 and extends in a direction substantially parallel to the surface of the middle 28 conductor.

Le milieu 28 conducteur a une conductivité électrique qui varie en fonction de sa composition. Par exemple, la mer, les marais salants ou les lacs salés ont une forte conductivité électrique, et la terre et le sable ont une faible conductivité électrique. Selon un mode de réalisation non représenté, si la conductivité électrique est trop faible, c'est-à-dire inférieure à 1 S/m, le système 20 antennaire est complété par un plan de masse, relié à l'antenne 22, et enfoui en dessous ou à la surface du milieu 28 conducteur. Le plan de masse peut être formé d'une plaque, ou d'un ensemble de fils conducteurs formant un grillage, etc. Le plan de masse peut prendre plusieurs formes, par exemple un cercle, un polygone (régulier ou non), etc. Le plan de masse s'étend sous l'ensemble du système 20 antennaire, c'est-à-dire que la projection du système 20 antennaire sur le milieu 28 conducteur selon l'axe Oz est comprise dans la surface occupée par le plan de masse.The conductive medium 28 has an electrical conductivity which varies according to its composition. For example, the sea, salt marshes or salt lakes have high electrical conductivity, and earth and sand have low electrical conductivity. According to an embodiment not shown, if the electrical conductivity is too low, that is to say less than 1 S/m, the antenna system 20 is completed by a ground plane, connected to the antenna 22, and buried below or on the surface of the conductive medium 28. The ground plane can be formed of a plate, or of a set of conductive wires forming a mesh, etc. The ground plane can take several shapes, for example a circle, a polygon (regular or not), etc. The ground plane extends under the whole of the antenna system 20, that is to say that the projection of the antenna system 20 on the conductive medium 28 along the axis Oz is included in the surface occupied by the ground plane.

La figure 2 représente schématiquement en perspective un système 20 antennaire selon un deuxième mode de réalisation de l'invention.There figure 2 schematically represents in perspective an antenna system according to a second embodiment of the invention.

Le système 20 antennaire comprend une antenne 22 telle que décrite dans la demande de brevet français FR2965978 déposée par le demandeur. Le système 20 antennaire comprend un capot 30 filaire relié électriquement à l'antenne 22 au niveau du centre du capot.The antenna system 20 comprises an antenna 22 as described in the French patent application FR2965978 filed by the applicant. The antenna system 20 comprises a wire cover 30 electrically connected to the antenna 22 at the level of the center of the cover.

Le capot 30 filaire est monobrin, et est composé de deux sous-brins 32a, 32b de longueurs égales, reliés à une de leurs extrémités et disposés dans un même plan. Les deux sous-brins sont reliés en formant un angle, dû à la différence entre la hauteur h1 à laquelle les sous-brins sont connectés et à la hauteur des deux autres extrémités des sous-brins. En particulier, lorsque les hauteurs h1 et h2 sont égales, l'angle est égal à 180° et donc les sous-brins sont alignés et le capot est parallèle à la surface du milieu 28 conducteur, comme le capot décrit précédemment dans le premier mode de réalisation.The wire cover 30 is single-stranded, and is composed of two sub-strands 32a, 32b of equal lengths, connected at one of their ends and arranged in the same plane. The two sub-strands are connected by forming an angle, due to the difference between the height h1 at which the sub-strands are connected and the height of the other two ends of the sub-strands. In particular, when the heights h1 and h2 are equal, the angle is equal to 180° and therefore the sub-strands are aligned and the cover is parallel to the surface of the conductive medium 28, like the cover previously described in the first embodiment of achievement.

La figure 3 représente un diagramme de rayonnement selon le plan yOz (dit diagramme de rayonnement zénithal) du système antennaire selon le deuxième mode de réalisation de l'invention, dans lequel le capot filaire a une longueur de 0,8 λ0, la hauteur h1 est égale à 0,06 λ0, la hauteur h2 est égale à 0,05 λ0 et la longueur L de l'antenne est égale à 0,3 λ0.There picture 3 represents a radiation diagram according to the yOz plane (known as the zenithal radiation diagram) of the antenna system according to the second embodiment of the invention, in which the wired cover has a length of 0.8 λ 0 , the height h1 is equal at 0.06 λ 0 , the height h2 is equal to 0.05 λ 0 and the length L of the antenna is equal to 0.3 λ 0 .

Le rayonnement du système antennaire est donc principalement un rayonnement en ondes de surfaces, et le rayonnement ionosphérique du système antennaire est fortement réduit par rapport à une antenne 22 sans capot. En particulier, le gain du système antennaire (exprimé en dB par rapport au rayonnement maximal du système antennaire) est compris entre 0 et -5 dB pour des angles de rayonnement compris dans les intervalles [-90°, -60°] et [60°, 90°], et est inférieur à -10dB dans l'intervalle [-50°, 50°].The radiation from the antenna system is therefore mainly surface wave radiation, and the ionospheric radiation from the antenna system is greatly reduced compared to an antenna 22 without cover. In particular, the gain of the antenna system (expressed in dB relative to the maximum radiation of the antenna system) is between 0 and -5 dB for radiation angles included in the intervals [-90°, -60°] and [60 °, 90°], and is less than -10dB in the interval [-50°, 50°].

La figure 4 représente schématiquement en perspective un système 20 antennaire selon un troisième mode de réalisation de l'invention.There figure 4 schematically represents in perspective an antenna system according to a third embodiment of the invention.

Le système 20 antennaire comprend une antenne 22 de type PIFA (pour Planar Inverted F-Shaped Antenna en anglais). L'antenne 22 est composée de deux éléments 34a, 34b rayonnants verticaux reliés à un élément 36 rayonnant horizontal.The antenna system 20 comprises an antenna 22 of the PIFA type (for Planar Inverted F-Shaped Antenna ). The antenna 22 is composed of two vertical radiating elements 34a, 34b connected to a horizontal radiating element 36.

Le système 20 antennaire comprend un capot 30 filaire monobrin relié électriquement à l'antenne 22 au niveau du centre du capot 30 filaire.The antenna system 20 comprises a single-strand wire cover 30 electrically connected to the antenna 22 at the level of the center of the wire cover 30.

La figure 5 représente schématiquement en perspective un système 20 antennaire selon un quatrième mode de réalisation de l'invention.There figure 5 schematically represents in perspective an antenna system according to a fourth embodiment of the invention.

Le système 20 antennaire comprend une antenne 22 de type antenne fouet raccourcie. L'antenne 22 est une antenne monopôle comprenant un unique fil rayonnant, et le système 20 antennaire comprend un capot 30 filaire monobrin relié électriquement à une extrémité de l'antenne 22 au niveau du centre du capot 30 filaire.The antenna system 20 comprises an antenna 22 of the shortened whip antenna type. The antenna 22 is a monopole antenna comprising a single radiating wire, and the antenna system 20 comprises a single-strand wire cover 30 electrically connected to one end of the antenna 22 at the level of the center of the wire cover 30.

Les figures 6, 7, 8, 10 et 11 représentent schématiquement en perspective un système 20 antennaire selon différents modes de réalisation comprenant une antenne 22 en forme de M telle que décrite précédemment en référence au premier mode de réalisation.THE figure 6 , 7 , 8 , 10 and 11 schematically represent in perspective an antenna system 20 according to different embodiments comprising an M-shaped antenna 22 as described above with reference to the first embodiment.

Les figures 6 et 7 représentent respectivement un cinquième et un sixième mode de réalisation de l'invention, dans lesquels le capot 30 filaire est monobrin et est relié à l'antenne selon différentes dispositions, notamment relié à un point quelconque de l'élément 24 rayonnant horizontal dans le cinquième mode de réalisation (figure 6) ou à une des extrémités de l'élément 24 rayonnant horizontal dans le sixième mode de réalisation (figure 7).THE figure 6 And 7 represent respectively a fifth and a sixth embodiment of the invention, in which the wire cover 30 is single-stranded and is connected to the antenna according to different arrangements, in particular connected to any point of the horizontal radiating element 24 in the fifth embodiment ( figure 6 ) or at one of the ends of the horizontal radiating element 24 in the sixth embodiment ( figure 7 ).

Ces différentes dispositions du capot 30 filaire permettent notamment d'adapter le système 20 antennaire selon différentes configurations de façon à s'adapter aux contraintes de l'environnement dans lequel est disposé le système 20 antennaire, les configurations ayant des fonctionnements identiques.These different arrangements of the wired cover 30 make it possible in particular to adapt the antenna system 20 according to different configurations so as to adapt to the constraints of the environment in which the antenna system 20 is arranged, the configurations having identical operations.

Les figures 8, 10 et 11 représentent respectivement un septième, un huitième et un neuvième mode de réalisation de l'invention, dans lequel le capot 30 filaire est un capot dit multibrins, comprenant une pluralité d'éléments filaires, ici deux brins 38a, 38b reliés en leur centre et s'étendant dans des directions différentes de façon à former un angle α. Les brins sont de même longueur supérieure à 0,8 λ0.THE figure 8 , 10 and 11 respectively represent a seventh, an eighth and a ninth embodiment of the invention, in which the wired cover 30 is a so-called multi-strand cover, comprising a plurality of wire elements, here two strands 38a, 38b connected at their center and s extending in different directions so as to form an angle α. The strands are of the same length greater than 0.8 λ 0 .

Selon les modes de réalisation, le capot est relié à l'antenne selon différentes dispositions, notamment relié au centre de l'élément 24 horizontal rayonnant dans le septième mode de réalisation (figure 8), à un point quelconque de l'élément 24 horizontal rayonnant dans le huitième mode de réalisation (figure 10) ou à une des extrémités de l'élément 24 rayonnant horizontal dans le neuvième mode de réalisation (figure 11).According to the embodiments, the cover is connected to the antenna according to different arrangements, in particular connected to the center of the horizontal radiating element 24 in the seventh embodiment ( figure 8 ), at any point of the horizontal radiating element 24 in the eighth embodiment ( figure 10 ) or at one of the ends of the horizontal radiating element 24 in the ninth embodiment ( figure 11 ).

La figure 9 représente un diagramme de rayonnement selon le plan yOz (dit diagramme de rayonnement zénithal) du système antennaire selon le septième mode de réalisation de l'invention, dans lequel chaque brin du capot a une longueur de 1,1 λ0, l'élément 24 rayonnant horizontal de l'antenne 22 a une longueur de 0,7 λ0 et l'antenne a une hauteur h de 0,08 λ0.There figure 9 represents a radiation diagram according to the yOz plane (known as the zenithal radiation diagram) of the antenna system according to the seventh embodiment of the invention, in which each strand of the cover has a length of 1.1 λ 0 , the element 24 horizontal radiating from the antenna 22 has a length of 0.7 λ 0 and the antenna has a height h of 0.08 λ 0 .

Le rayonnement du système antennaire est donc principalement un rayonnement en ondes de surfaces, et le rayonnement ionosphérique du système antennaire est fortement réduit par rapport à une antenne 22 sans capot. En particulier, le gain du système antennaire (exprimé en dB par rapport au rayonnement maximal du système antennaire) est compris entre 0 et -5 dB pour des angles de rayonnement compris dans les intervalles [-90°, -60°] et [60°, 90°], est inférieur à -10dB dans l'intervalle [-50°, 50°], et inférieur à -15dB dans l'intervalle [-40°, 40°].The radiation from the antenna system is therefore mainly surface wave radiation, and the ionospheric radiation from the antenna system is greatly reduced compared to an antenna 22 without cover. In particular, the gain of the antenna system (expressed in dB relative to the maximum radiation of the antenna system) is between 0 and -5 dB for radiation angles included in the intervals [-90°, -60°] and [60 °, 90°], is less than -10dB in the interval [-50°, 50°], and less than -15dB in the interval [-40°, 40°].

Les figures 12, 13 et 14 représentent schématiquement en perspective un système 20 antennaire respectivement selon un dixième, un onzième et un douzième mode de réalisation. Chaque système antennaire comprend une antenne 22 en forme de M selon différents modes de réalisation particuliers.THE figure 12 , 13 and 14 schematically represent in perspective an antenna system 20 respectively according to a tenth, an eleventh and a twelfth embodiment. Each antenna system comprises an M-shaped antenna 22 according to different particular embodiments.

Dans le dixième mode de réalisation représenté figure 12, l'antenne 22 comprend trois éléments 24a, 24b, 24c rayonnants horizontaux de mêmes longueurs, chacun reliés à leurs extrémités à un élément rayonnant vertical et tous reliés en leur centre à un unique élément 26b rayonnant vertical. Ce mode de réalisation de l'antenne permet un élargissement de la bande de fréquence de rayonnement de l'antenne.In the tenth embodiment shown figure 12 , the antenna 22 comprises three horizontal radiating elements 24a, 24b, 24c of the same lengths, each connected at their ends to a vertical radiating element and all connected at their center to a single vertical radiating element 26b. This embodiment of the antenna allows a widening of the radiation frequency band of the antenna.

Pour être adapté à cet élargissement de la bande de fréquence, le système 22 antennaire comprend un capot 30 filaire multibrin composé de deux brins 38a, 38b, tel que décrit précédemment, les extrémités des brins étant reliées deux à deux par des connexions 40a, 40b filaires de façon à former un capot surfacique, c'est-à-dire équivalent à une surface rayonnante. Ce capot surfacique a donc une bande de fréquence de fonctionnement élargie en lien avec l'élargissement de la bande de fonctionnement de l'antenne 22.To be adapted to this widening of the frequency band, the system 22 antenna comprises a multi-stranded wire cover 30 composed of two strands 38a, 38b, as described above, the ends of the strands being connected two by two by wire connections 40a, 40b so as to form a surface cover, that is to say say equivalent to a radiating surface. This surface cover therefore has a widened operating frequency band in connection with the widening of the operating band of the antenna 22.

Dans le onzième mode de réalisation représenté figure 13, l'antenne 22 comprend deux éléments 24, 124 rayonnants horizontaux de longueurs différentes chacun reliés à leurs extrémités à un élément rayonnant vertical et tous reliés en leur centre à un unique élément rayonnant vertical. Un premier élément 24 rayonnant horizontal est de longueur adaptée pour rayonner à une première fréquence centrale f0 (associée à la longueur d'onde λ0) et un deuxième élément 124 horizontal est de longueur adaptée pour rayonner à une deuxième fréquence centrale fbis (associée à la longueur d'onde λbis). L'antenne est dite à double résonance.In the eleventh embodiment shown figure 13 , the antenna 22 comprises two horizontal radiating elements 24, 124 of different lengths each connected at their ends to a vertical radiating element and all connected at their center to a single vertical radiating element. A first horizontal radiating element 24 is of suitable length to radiate at a first central frequency f 0 (associated with the wavelength λ 0 ) and a second horizontal element 124 is of suitable length to radiate at a second central frequency f bis ( associated with the wavelength λ bis ). The antenna is said to be double resonant.

Pour être adapté à cette double résonance, le système 22 antennaire comprend un capot 30 filaire composés de plusieurs brins, ici trois brins 38a, 38b, 38c, disposés parallèlement, de longueurs différentes et reliés à leurs extrémités. Un premier brin 38b a une longueur supérieure à 0,8 λ0 et est adapté pour rayonner à la première fréquence centrale f0, et deux seconds et troisième brins 38a, 38c ont une longueur supérieure à 0,8 λbis et sont adaptés pour rayonner à la fréquence centrale fbis. Le capot 30 filaire est ainsi à double résonance et permet la réduction du rayonnement ionosphérique pour les fréquences centrales f0 et fbis.To be adapted to this double resonance, the antenna system 22 comprises a wire cover 30 composed of several strands, here three strands 38a, 38b, 38c, arranged in parallel, of different lengths and connected at their ends. A first strand 38b has a length greater than 0.8 λ 0 and is suitable for radiating at the first central frequency f 0 , and two second and third strands 38a, 38c have a length greater than 0.8 λ bis and are suitable for radiate at the central frequency f bis . The wire cover 30 is thus double resonant and allows the reduction of the ionospheric radiation for the central frequencies f 0 and f bis .

Dans le douzième mode de réalisation représenté figure 14, l'antenne 22 comprend cinq éléments 26a, 26b, 26c, 26d, 26e rayonnants verticaux reliés à l'élément 24 rayonnant horizontal. En outre, l'antenne 22 comprend des éléments 42a, 42b, 42c, 42d localisés disposés sur deux des éléments rayonnants verticaux et sur l'élément 24 rayonnant horizontal, permettant la formation de pièges de courant et/ou permettant de modifier les longueurs électriques de l'antenne 22. Les éléments localisés peuvent être des éléments résistifs, capacitifs (condensateurs) ou inductifs (bobines). Ces éléments localisés sont couramment appelés « load » en anglais.In the twelfth embodiment shown figure 14 , the antenna 22 comprises five vertical radiating elements 26a, 26b, 26c, 26d, 26e connected to the horizontal radiating element 24. In addition, the antenna 22 comprises localized elements 42a, 42b, 42c, 42d arranged on two of the vertical radiating elements and on the horizontal radiating element 24, allowing the formation of current traps and/or allowing the electrical lengths to be modified. of the antenna 22. The localized elements can be resistive, capacitive (capacitors) or inductive (coils). These localized elements are commonly called " load " in English.

Le système 22 antennaire comprend deux capots 30a, 30b multibrins reliés à l'élément rayonnant horizontal de l'antenne, chacun des capots comprenant deux brins. Les capots comprennent en outre des éléments 42e, 42f, 42g, 42h, 42i, 42j, 42k, 421 localisés permettant la formation de pièges de courant et/ou permettant de modifier les longueurs électriques des capots.The antenna system 22 comprises two multi-strand covers 30a, 30b connected to the horizontal radiating element of the antenna, each of the covers comprising two strands. The covers further comprise localized elements 42e, 42f, 42g, 42h, 42i, 42j, 42k, 421 allowing the formation of current traps and/or allowing the electrical lengths of the covers to be modified.

Les éléments localisés sont des éléments résistifs (par exemple une résistance), capacitifs (par exemple un condensateur) ou inductifs (par exemple une bobine).The lumped elements are resistive (eg a resistor), capacitive (eg a capacitor) or inductive (eg a coil).

L'invention ne se limite pas aux seuls modes de réalisation décrits. En particulier, au moins un capot peut être un capot de type volumique de façon à élargir davantage la bande passante du système antennaire, le système antennaire peut comprendre plus de deux capots, plusieurs antennes, etc.The invention is not limited to the embodiments described. In particular, at least one cover can be a volume type cover so as to further broaden the bandwidth of the antenna system, the antenna system can comprise more than two covers, several antennas, etc.

Claims (7)

  1. A surface wave antenna system (20), comprising :
    - at least one antenna (22), vertically or elliptically polarised and adapted to transmit/receive radiation in at least one frequency band centred on a central frequency f0 associated with a central wavelength λ0, said at least one antenna (22) being electrically short in the vertical plane, such that the antenna (22) has a vertical footprint of less than 0.25λ0, said antenna (22) being configured to be connected to a conductive medium (28) having a substantially horizontal surface,
    the antenna system (20) being characterised in that it further comprises :
    - at least one wired cover (30; 30a, 30b; 38a, 38b; 38a, 38b, 38c) of length greater than or equal to 0.8λ0, electrically linked to at least one antenna (22) at the centre of the cover (30; 30a, 30b; 38a, 38b), and adapted to radiate at least at the central frequency f0 of the antenna (22).
  2. The antenna system according to claim 1, characterised in that at least one wired cover (30; 30a, 30b) extends in a direction forming an angle of between -10° and 10° with the surface of the conductive medium (28).
  3. The antenna system according to claim 2, characterized in that said at least one wired cover (30; 30a, 30b; 38a, 38b; 38a, 38b, 38b) extends in a direction substantially parallel to the surface of the conductive medium (28).
  4. The antenna system according to one of claims 1 to 3, characterised in that it comprises at least two wired covers (30a, 30b; 38a, 38b) extending in different main directions from each other.
  5. The antenna system according to one of claims 1 to 4, characterised in that it further comprises a ground plane, to which each antenna (22) is connected.
  6. The antenna system according to one of claims 1 to 5, characterised in that at least one wired cover (30; 30a, 30b) comprises at least one localised element (42e-42l) adapted to allow the resonance of said cover (30; 30a, 30b) at a multitude of frequencies.
  7. The antenna system according to one of claims 1 to 6, characterised in that at least one wired cover (30; 30a, 30b; 38a, 38b; 38a, 38b, 38c) comprises a plurality of wired elements connected to each other so as to form a surface cover or a volume cover.
EP16753413.0A 2015-08-10 2016-07-22 Surface wave antenna system Active EP3335268B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1557655A FR3040109B1 (en) 2015-08-10 2015-08-10 SURFACE WAVE ANTENNA SYSTEM
PCT/FR2016/051916 WO2017025674A1 (en) 2015-08-10 2016-07-22 Surface wave antenna system

Publications (3)

Publication Number Publication Date
EP3335268A1 EP3335268A1 (en) 2018-06-20
EP3335268B1 true EP3335268B1 (en) 2023-07-19
EP3335268C0 EP3335268C0 (en) 2023-07-19

Family

ID=54937233

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16753413.0A Active EP3335268B1 (en) 2015-08-10 2016-07-22 Surface wave antenna system

Country Status (4)

Country Link
EP (1) EP3335268B1 (en)
ES (1) ES2958409T3 (en)
FR (1) FR3040109B1 (en)
WO (1) WO2017025674A1 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR608523A (en) * 1925-12-04 1926-07-28 Materiel Telephonique Antenna system
GB474384A (en) * 1936-04-29 1937-10-29 Marconi Wireless Telegraph Co Improvements in or relating to wireless aerials
DE869650C (en) * 1941-05-01 1953-03-05 Telefunken Gmbh Trap-shaped antenna
GB2241384A (en) * 1990-02-02 1991-08-28 British Broadcasting Corp T-shaped antenna

Also Published As

Publication number Publication date
ES2958409T3 (en) 2024-02-08
EP3335268A1 (en) 2018-06-20
FR3040109A1 (en) 2017-02-17
WO2017025674A1 (en) 2017-02-16
EP3335268C0 (en) 2023-07-19
FR3040109B1 (en) 2018-10-05

Similar Documents

Publication Publication Date Title
CA2985023C (en) Surface wave antenna system
EP2625741B1 (en) Large-area broadband surface-wave antenna
EP0327965A2 (en) Multi-frequency antenna for satellite communications
FR2709833A1 (en) Broadband and low band listening instrument for space applications.
EP3335267B1 (en) Surface-wave antenna, antenna array and use of an antenna or an antenna array
EP1594186B1 (en) Earth antenna with loop radiating kilometric or hectometric waves
EP3335268B1 (en) Surface wave antenna system
FR2644937A1 (en) Omnidirectional antenna with transverse circular polarisation and maximum gain beneath the horizon
EP2449629B1 (en) Omnidirectional, broadband compact antenna system comprising two highly decoupled separate transmission and reception access lines
KR102228184B1 (en) Tower based antenna including multiple sets of elongate antenna elements and related methods
EP2779304B1 (en) Wire antenna for the transmission of HF radiowaves on a submarine
EP2610965B1 (en) Compact broad-band antenna with double linear polarisation
WO2016139403A1 (en) Omnidirectional wideband antenna structure
EP1532713B1 (en) Hectometric wave transmission antenna
EP0792528B1 (en) Half-wave dipole antenna
FR2842025A1 (en) RADIANT BI-BAND DEVICE WITH COPLANAR POLARIZATIONS
FR2940531A1 (en) OMNIDIRECTIONAL ANTENNA VERY BROADBAND
EP0604304A1 (en) Multi-polorized omnidirectionnal antenna
FR2996686A1 (en) Electromagnetic method for decoupling of antenna systems, involves arranging set of electromagnetic decoupling devices to electrically cut support mast between antenna system and another antenna system by blocking currents
FR3019385A1 (en) BEAM ORIENTATION ANTENNA
EP2736118A1 (en) Nested-loop antenna system and vehicle including such an antenna system

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20180307

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20210429

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20220712

GRAJ Information related to disapproval of communication of intention to grant by the applicant or resumption of examination proceedings by the epo deleted

Free format text: ORIGINAL CODE: EPIDOSDIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

INTC Intention to grant announced (deleted)
GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20230228

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602016081155

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: FRENCH

U01 Request for unitary effect filed

Effective date: 20230817

U07 Unitary effect registered

Designated state(s): AT BE BG DE DK EE FI FR IT LT LU LV MT NL PT SE SI

Effective date: 20230823

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: UNIVERSITE DE RENNES

Owner name: TDF

U1K Transfer of rights of the unitary patent after the registration of the unitary effect

Owner name: UNIVERSITE DE RENNES; FR

Owner name: TDF; FR

U20 Renewal fee paid [unitary effect]

Year of fee payment: 8

Effective date: 20230914

REG Reference to a national code

Ref country code: NO

Ref legal event code: T2

Effective date: 20230719

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20230828

Year of fee payment: 8

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20231019 AND 20231025

REG Reference to a national code

Ref country code: BE

Ref legal event code: PD

Owner name: UNIVERSITE DE RENNES; FR

Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), MERGE

Effective date: 20231017

REG Reference to a national code

Ref country code: NL

Ref legal event code: PD

Owner name: UNIVERSITE DE RENNES; FR

Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), MERGE; FORMER OWNER NAME: UNIVERSITE DE RENNES 1

Effective date: 20231110

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20230401715

Country of ref document: GR

Effective date: 20231113

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231119

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231119

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: TR

Payment date: 20231005

Year of fee payment: 8

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2958409

Country of ref document: ES

Kind code of ref document: T3

Effective date: 20240208

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602016081155

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230731

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230719

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20240422

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230722

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20240620

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GR

Payment date: 20240620

Year of fee payment: 9

U20 Renewal fee paid [unitary effect]

Year of fee payment: 9

Effective date: 20240619

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230722

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NO

Payment date: 20240620

Year of fee payment: 9