EP0017589A1 - Cassegrain antenna incorporated in a radome - Google Patents

Cassegrain antenna incorporated in a radome Download PDF

Info

Publication number
EP0017589A1
EP0017589A1 EP80400447A EP80400447A EP0017589A1 EP 0017589 A1 EP0017589 A1 EP 0017589A1 EP 80400447 A EP80400447 A EP 80400447A EP 80400447 A EP80400447 A EP 80400447A EP 0017589 A1 EP0017589 A1 EP 0017589A1
Authority
EP
European Patent Office
Prior art keywords
radome
reflector
fixed
cassegrain
antenna
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP80400447A
Other languages
German (de)
French (fr)
Inventor
François Gautier
Pierre Crochet
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.)
Thales SA
Original Assignee
Thomson CSF SA
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 Thomson CSF SA filed Critical Thomson CSF SA
Publication of EP0017589A1 publication Critical patent/EP0017589A1/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/42—Housings not intimately mechanically associated with radiating elements, e.g. radome
    • H01Q1/425—Housings not intimately mechanically associated with radiating elements, e.g. radome comprising a metallic grid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
    • H01Q19/18—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces
    • H01Q19/19—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface
    • H01Q19/195—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface wherein a reflecting surface acts also as a polarisation filter or a polarising device

Definitions

  • the present invention relates to microwave antennas of the Cassegrain type mounted inside a radome.
  • the antenna according to the invention aims to remedy these drawbacks according to the invention, the fixed curved reflector is fixed by one or more points of its periphery to the wall of the radome by any fixing means, this arrangement having the effect of reducing of the total weight and an increase of the useful surface the main result of which is an increase in total antenna gain.
  • Figure 1 shows a Cassegrain antenna mounted in a radome according to the prior art. It comprises a radome 3, inside which is located a source 1 radiating a polarized electromagnetic wave, oriented in such a way that its emission direction coincides with the axis of symmetry of the radome, a 2 plane reflector reflecting the waves. by rotating the polarization by 90 °, a second reflector 4 polarization filter and mounted on a support 5, itself rigidly positioned by a fixing means 6.
  • the reflector 4 is constituted by a network of parallel metallic wires which are bonded to a substrate 5 designed so as to avoid parasitic reflections. This is achieved by using a substrate of the "sandwich" type, that is to say composed of two films with high dielectric constant surrounding a plate of low dielectric constant and whose thickness is , celebrating the wavelength emitted by the source 1. Its shape, for example, is a hyperboloid or a paraboloid of revolution.
  • This reflector 4 has drawbacks due to both the material used and its physical design.
  • the material with a low dielectric constant is fragile and its precise machining is delicate and the bonding of the metallic wires constituting the reflector 4, which also requires great precision, can be the source of parasitic reflections due to the adhesive which can mismatch the substrate 5 due to slight variations in thickness.
  • the reflector 4 and substrate 5 assembly requires a particular support 6 which provides it with good mechanical rigidity.
  • This support is for example made up of a cylinder of revolution produced according to the same structure as the substrate 5.
  • Such a support has the disadvantage, in addition to its construction difficulties, of reducing the useful surface of the reflector and therefore the gain of the 'antenna.
  • the invention aims to remedy these defects of the prior art.
  • Figure 2 shows a Cassegrain mid-round antenna mounted in a radome. It takes up the elements of FIG. 1 by removing the support 6 from the fixed reflector 4 and possibly adding thereto means for absorbing or filtering 8 electromagnetic waves and means 9 for fixing the stationary reflector 4 on the radome 3.
  • the reflector 4 is directly fixed to the radome 3 thus giving a larger useful surface and therefore an increase in the gain.
  • Means 8 for absorbing or filtering electromagnetic waves can optionally be placed around the Cassegrain antenna, on the walls of the radome 3 limited by the reflector 4, in order to avoid parasitic reflected waves and waves whose polarization n is not in a defined direction.
  • the reflector 4 used in the device according to the invention is a metal polarization filter with slot, of which FIG. 3 shows an exemplary embodiment.
  • This type of filter is known and we will only quickly recall its use. We can usefully refer to the article on these filters published in the IEEE review on pages 1 to 6 of the January 1973 issue, by CHEN.
  • It consists of a metal plate pierced with slots 7 of width a and length b which determine the resonance frequency. These slots 7 are arranged in several parallel rows such that for two successive rows the slots are for example staggered. The interval between two slots in the same row is constant and denoted x and the interval between two rows is Ay.
  • An angle 6 determines the orientation of the diagonal alignment due to the staggered arrangement of the slots. This angle is for example chosen to be equal to .
  • the set of these slots determines a polarization filter such that the waves polarized in the direction Y'Y are fully reflected, and those in the direction X'X pass through the filter without attenuation.
  • this type of reflector comes from the ease of machining the slots, from the forming of the reflector, for example by stamping, and especially from its rigidity allowing the removal of the substrate 5 and thus the disadvantage of the stray reflections due to its presence and to the unevenness of the gluing of the metallic wires. This better adjustment precision and stability over time improves the characteristics of the antenna. In addition, its small thickness makes it possible to limit the effects of diffusion of the edges of this reflector 4. Finally, this type of filter is more selective in frequency and its use in Cassegrain antennas integrated into a radome 3 can contribute to reducing the interference coming from frequencies. neighbors.
  • metal polarization filters with slots constitutes a preferred example, which does not prevent the antenna from being produced with any type of reflector of equal rigidity giving the same results as polarization filters.
  • the fixing of the reflector 4 on the radome 3 can be carried out by any means 9 such as for example a screwing or direct bonding on the radome.

Landscapes

  • Aerials With Secondary Devices (AREA)

Abstract

The invention relates to Cassegrain antennas 1,4,2 mounted in a radome (3). Direct fixing of the main reflector (4) of the antenna which is fixed onto the radome permits an increase in the gain of the antenna and better reliability. The invention applies to all equipment using an antenna protected by a radome and comprising at least one reflector which is stationary relative to the radome. <IMAGE>

Description

La présente invention concerne les antennes microondes du type Cassegrain montées à l'intérieur d'un radome.The present invention relates to microwave antennas of the Cassegrain type mounted inside a radome.

Il est courant de protéger par un radome les antennes des dispositifs de détection électromagnétique. Ceci est le cas en particulier pour les radars équipant des missiles ou des avions. On utilise pour limiter l'encombrement de ces antennes des structures compactes du type Cassegrain qui comportent deux réflecteurs, dont l'un à rotation de polarisation, de structure généralement plane étant mobile autour de l'axe de symétrie défini par la direction de rayonnement de la source primaire et l'autre de structure courbe étant fixe par rapport à cette source primaire.It is common to protect the antennas of electromagnetic detection devices with a radome. This is particularly the case for radars fitted to missiles or aircraft. Compact structures of the Cassegrain type are used to limit the size of these antennas which comprise two reflectors, one of which with polarization rotation, of generally planar structure being movable around the axis of symmetry defined by the direction of radiation of the primary source and the other of curved structure being fixed relative to this primary source.

Un inconvénient dans l'utilisation de ce type d'antenne dans les équipements aéroportés nait de ce second réflecteur fixe. En effet celui-ci doit conserver dans le temps ses caractéristiques avec une grande précision et cette exigence a conduit à utiliser pour le maintenir en place un support spécial qui empêche toute déformation de sa structure pouvant altérer sa fiabilité. Cependant compte tenu de l'espace relativement restreint disponible dans le radome, ce support spécial tend à limiter la surface du réflecteur et donc également le gain de l'antenne. De plus il alourdit considérablement l'ensemble de l'antenne et du radar.A drawback in the use of this type of antenna in airborne equipment arises from this second fixed reflector. Indeed it must retain its characteristics over time with great precision and this requirement has led to use to keep it in place a special support which prevents any deformation of its structure which could affect its reliability. However, given the relatively limited space available in the radome, this special support tends to limit the surface of the reflector and therefore also the gain of the antenna. In addition, it considerably increases the overall antenna and radar.

L'antenne selon l'invention vise à remédier à ces inconvénients selon l'invention, le réflecteur courbe fixe est fixé par un ou plusieurs points de son pourtour sur la paroi du radome par tout moyen de fixation, cette disposition ayant pour effet une diminution du poids total et une augmentation de la surface utile dont le résultat principal est une augmentation du gain total de l'antenne.The antenna according to the invention aims to remedy these drawbacks according to the invention, the fixed curved reflector is fixed by one or more points of its periphery to the wall of the radome by any fixing means, this arrangement having the effect of reducing of the total weight and an increase of the useful surface the main result of which is an increase in total antenna gain.

D'autres avantages et caractéristiques de la présente invention apparaîtront dans la description qui suit donnée à l'aide des figures qui représentent :

  • - la figure 1, une antenne Cassegrain montée dans un radome selon l'art antérieur ;
  • - la figure 2, une antenne Cassegrain montée dans un radome selon l'invention ;
  • - et la figure 3, le schéma d'un exemple de réflecteur métallique du type filtre de polarisation à fentes.
Other advantages and characteristics of the present invention will appear in the following description given with the aid of the figures which represent:
  • - Figure 1, a Cassegrain antenna mounted in a radome according to the prior art;
  • - Figure 2, a Cassegrain antenna mounted in a radome according to the invention;
  • - And Figure 3, the diagram of an example of a metal reflector type polarization filter slits.

La figure 1 montre une antenne Cassegrain montéé dans un radome selon l'art antérieur. Elle comporte un radome 3, à l'intérieur duquel se trouve, une source 1 rayonnant une onde électromagnétique polarisée, orientée de telle façon que sa direction d'émission coïncide avec l'axe de symétrie du radome, un réflecteur 2 plan réfléchissant les ondes en faisant tourner la polarisation de 90°, un second réflecteur 4 filtre de polarisation et monté sur un support 5, lui-même positionné rigidement par un moyen de fixation 6.Figure 1 shows a Cassegrain antenna mounted in a radome according to the prior art. It comprises a radome 3, inside which is located a source 1 radiating a polarized electromagnetic wave, oriented in such a way that its emission direction coincides with the axis of symmetry of the radome, a 2 plane reflector reflecting the waves. by rotating the polarization by 90 °, a second reflector 4 polarization filter and mounted on a support 5, itself rigidly positioned by a fixing means 6.

Le réflecteur 4 est constitué par un réseau de fils métalliques parallèles qui sont collés sur un substrat 5 conçu de manière à éviter les réflexions parasites. On arrive à ce résultat en utilisant un substrat du type "sandwich", c'est-à-dire composé de deux pellicules à forte constante diélectrique entourant une plaque de faible constante diélectrique et dont l'épaisseur est de

Figure imgb0001
, fêtant la longueur d'onde émise par la source 1. Sa forme, est par exemple un hyperboloide ou un paraboloïde de révolution. Ce réflecteur 4 présente des inconvénients dus à la fois au matériau utilisé et à sa conception physique.The reflector 4 is constituted by a network of parallel metallic wires which are bonded to a substrate 5 designed so as to avoid parasitic reflections. This is achieved by using a substrate of the "sandwich" type, that is to say composed of two films with high dielectric constant surrounding a plate of low dielectric constant and whose thickness is
Figure imgb0001
 , celebrating the wavelength emitted by the source 1. Its shape, for example, is a hyperboloid or a paraboloid of revolution. This reflector 4 has drawbacks due to both the material used and its physical design.

De fait le matériau à faible constante diélectrique est fragile et son usinage précis est délicate et le collage des fils métalliques constituant le réflecteur 4, qui lui aussi nécessite une grande précision, peut être à l'origine de réflexions parasites dues à la colle qui peut désadapter le substrat 5 du fait de légères variations d'épaisseur.In fact, the material with a low dielectric constant is fragile and its precise machining is delicate and the bonding of the metallic wires constituting the reflector 4, which also requires great precision, can be the source of parasitic reflections due to the adhesive which can mismatch the substrate 5 due to slight variations in thickness.

L'ensemble réflecteur 4 et substrat 5 selon la réalisation de l'art antérieur, exige un support particulier 6 qui lui assure une bonne rigidité mécanique. Ce support est par exemple constitué d'un cylindre de révolution réalisé selon la même structure que le substrat 5. Cependant un tel support présente l'inconvénient, outre ses difficultés de construction, de réduire la surface utile du réflecteur et donc le gain de l'antenne.The reflector 4 and substrate 5 assembly according to the embodiment of the prior art, requires a particular support 6 which provides it with good mechanical rigidity. This support is for example made up of a cylinder of revolution produced according to the same structure as the substrate 5. However, such a support has the disadvantage, in addition to its construction difficulties, of reducing the useful surface of the reflector and therefore the gain of the 'antenna.

L'invention a pour but de remédier à ces défauts de l'art antérieur.The invention aims to remedy these defects of the prior art.

La figure 2 présente une antenne Cassegrain mi- croonde montée dans un radome. Elle reprend les éléments de la figure 1 en supprimant le support 6 du réflecteur fixe 4 et en y ajoutant éventuellement des moyens d'absorption ou de filtrage 8 des ondes électromagnétiques et des moyens 9 de fixation du réflecteur immobile 4 sur le radome 3.Figure 2 shows a Cassegrain mid-round antenna mounted in a radome. It takes up the elements of FIG. 1 by removing the support 6 from the fixed reflector 4 and possibly adding thereto means for absorbing or filtering 8 electromagnetic waves and means 9 for fixing the stationary reflector 4 on the radome 3.

Selon l'invention le réflecteur 4 est directement fixé sur le radome 3 donnant ainsi une plus grande surface utile et donc une augmentation du gain. Des moyens 8 d'absorption ou de filtrage des ondes électromagnétiques peuvent éventuellement être placés autour de l'antenne Cassegrain, sur les parois du radome 3 limitées par le réflecteur 4, afin d'éviter les ondes réfléchies parasites et les ondes dont la polarisation n'est pas dans une direction définie.According to the invention the reflector 4 is directly fixed to the radome 3 thus giving a larger useful surface and therefore an increase in the gain. Means 8 for absorbing or filtering electromagnetic waves can optionally be placed around the Cassegrain antenna, on the walls of the radome 3 limited by the reflector 4, in order to avoid parasitic reflected waves and waves whose polarization n is not in a defined direction.

De façon préférentielle, le réflecteur 4 utilisé dans le dispositif selon l'invention est un filtre de polarisation métallique à fente dont la figure 3 montre un exemple de réalisation. Ce type de filtre est connu et on ne rappellera que rapidement son utilisation. On pourra se reporter utilement à l'article sur ces filtres publié dans la revue IEEE aux pages 1 à 6 du numéro de janvier 1973, par CHEN.Preferably, the reflector 4 used in the device according to the invention is a metal polarization filter with slot, of which FIG. 3 shows an exemplary embodiment. This type of filter is known and we will only quickly recall its use. We can usefully refer to the article on these filters published in the IEEE review on pages 1 to 6 of the January 1973 issue, by CHEN.

Il est constitué d'une plaque métallique percée de fentes 7 de largeur a et de longueur b qui en déterminent la fréquence de résonnance. Ces fentes 7 sont disposées selon plusieurs rangées parallèles telles, que pour deux rangées successives les fentes sont par exemple en quinconce. L'intervalle entre deux fentes d'une même rangée est constant et notédx et l'intervalle entre deux rangées estAy.It consists of a metal plate pierced with slots 7 of width a and length b which determine the resonance frequency. These slots 7 are arranged in several parallel rows such that for two successive rows the slots are for example staggered. The interval between two slots in the same row is constant and denoted x and the interval between two rows is Ay.

Un angle 6 détermine l'orientation de l'alignement diagonal dû à la disposition en quinconce des fentes cet angle est par exemple choisi égal à

Figure imgb0002
. L'ensemble de ces fentes détermine un filtre de polarisation tel que les ondes polarisées selon la direction Y'Y sont entièrement réfléchies, et celles selon la direction X'X traversent le filtre sans atténuation.An angle 6 determines the orientation of the diagonal alignment due to the staggered arrangement of the slots. This angle is for example chosen to be equal to
Figure imgb0002
 . The set of these slots determines a polarization filter such that the waves polarized in the direction Y'Y are fully reflected, and those in the direction X'X pass through the filter without attenuation.

Les avantages de l'utilisation de ce type de réflecteur. proviennent de la facilité d'usinage des fentes, du formage du réflecteur par exemple par emboutissage, et surtout de sa rigidité permettant la suppression du substrat 5 et ainsi l'inconvénient des réflexions parasites dû à sa présence et aux inégalités de l'encollage des fils métalliques. Cette meilleure précision de réglage et cette stabilité dans le temps améliorent les caractéristiques de l'antenne. De plus sa faible épaisseur permet de limiter les effets de diffusion des bords de ce réflecteur 4. Enfin ce type de filtre est plus sélectif en fréquence et son utilisation dans les antennes Cassegrain intégrées à un radome 3 peut contribuer à réduire le brouillage provenant de fréquences voisines.The advantages of using this type of reflector. come from the ease of machining the slots, from the forming of the reflector, for example by stamping, and especially from its rigidity allowing the removal of the substrate 5 and thus the disadvantage of the stray reflections due to its presence and to the unevenness of the gluing of the metallic wires. This better adjustment precision and stability over time improves the characteristics of the antenna. In addition, its small thickness makes it possible to limit the effects of diffusion of the edges of this reflector 4. Finally, this type of filter is more selective in frequency and its use in Cassegrain antennas integrated into a radome 3 can contribute to reducing the interference coming from frequencies. neighbors.

On notera que l'utilisation des filtres de polarisation métalliques à fentes pour réaliser le réflecteur 4 constitue un exemple préférentiel, qui n'empêche pas que l'antenne soit réalisée avec tout type de réflecteur d'égale rigidité donnant les mêmes résultats que des filtres de polarisation.Note that the use of metal polarization filters with slots to make the reflector 4 constitutes a preferred example, which does not prevent the antenna from being produced with any type of reflector of equal rigidity giving the same results as polarization filters.

La fixation du réflecteur 4 sur le radome 3 pourra être réalisée par un moyen quelconque 9 comme par exemple un vissage ou un collage direct sur le radome.The fixing of the reflector 4 on the radome 3 can be carried out by any means 9 such as for example a screwing or direct bonding on the radome.

On a ainsi décrit une structure d'antenne Cassegrain montée dans un radome permettant d'obtenir un gain maximum compte tenu des dimensions intérieures de ce radome.We have thus described a Cassegrain antenna structure mounted in a radome making it possible to obtain maximum gain taking into account the interior dimensions of this radome.

Claims (7)

1. Antenne du type Cassegrain montée à l'intérieur d'un radome (3), comportant deux réflecteurs dont l'un (2) est mobile, et l'autre (4) est fixe, les deux réflecteurs (2 et 4) ainsi que la source émettrice (1) étant enfermés dans un radome (3), caractérisée en ce que le réflecteur fixe (4) est fixé directement sur le radome (3) par des moyens de fixation (9).1. Cassegrain type antenna mounted inside a radome (3), comprising two reflectors, one of which (2) is mobile, and the other (4) is fixed, the two reflectors (2 and 4) as well as the emitting source (1) being enclosed in a radome (3), characterized in that the fixed reflector (4) is fixed directly to the radome (3) by fixing means (9). 2. Antenne du type Cassegrain montée dans un radome selon la revendication 1, caractérisée en ce que le réflecteur fixe (4) fixé sur le radome (3) est un filtre métallique de polarisation à fentes.2. A Cassegrain type antenna mounted in a radome according to claim 1, characterized in that the fixed reflector (4) fixed on the radome (3) is a metal polarization filter with slits. 3. Antenne du type Cassegrain montée dans un radome selon la revendication 1, caractérisée en ce que les moyens de fixation (9) du réflecteur fixe (4) sur le radome sont recouverts d'un moyen absorbant les ondes électromagnétiques émises par la source (1).3. Cassegrain type antenna mounted in a radome according to claim 1, characterized in that the fixing means (9) of the fixed reflector (4) on the radome are covered with a means absorbing the electromagnetic waves emitted by the source ( 1). 4. Antenne du type Cassegrain montée dans un radome selon la revendication 1, caractérisée en ce que le réflecteur fixe (4) a sa forme adaptée de façon que tous les points de son périmètre sont en contact avec le périmètre interne de la section du radome (3) sur lequel il est fixé.4. Cassegrain type antenna mounted in a radome according to claim 1, characterized in that the fixed reflector (4) has its shape adapted so that all the points of its perimeter are in contact with the internal perimeter of the section of the radome (3) on which it is fixed. 5. Antenne du type Cassegrain montée dans un radome selon la revendication 1, caractérisée en ce que la partie du radome (3) entourant le réflecteur mobile (2) limitée par le périmètre du réflecteur fixe (4) est recouverte d'un moyen (8) absorbant et/ou filtrant les ondes électromagnétiques reçues.5. Cassegrain type antenna mounted in a radome according to claim 1, characterized in that the part of the radome (3) surrounding the movable reflector (2) limited by the perimeter of the fixed reflector (4) is covered with a means ( 8) absorbing and / or filtering the electromagnetic waves received. 6. Antenne du type Cassegrain montée dans un radome selon la revendication 1, caractérisée en ce que les moyens de fixation (9) du réflecteur fixe (4) sur le radome (3) consistent en un collage dudit réflecteur (4) sur le radome (3).6. Antenna of the Cassegrain type mounted in a radome according to claim 1, characterized in that the fixing means (9) of the fixed reflector (4) on the radome (3) consist of bonding of said reflector tor (4) on the radome (3). 7. Radome caractérisé en ce qu'il comporte une antenne Cassegrain selon l'une quelconque des revendications précédentes.7. Radome characterized in that it comprises a Cassegrain antenna according to any one of the preceding claims.
EP80400447A 1979-04-09 1980-04-03 Cassegrain antenna incorporated in a radome Withdrawn EP0017589A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7908966 1979-04-09
FR7908966A FR2454190A1 (en) 1979-04-09 1979-04-09 CASSEGRAIN ANTENNA MOUNTED IN A RADOME

Publications (1)

Publication Number Publication Date
EP0017589A1 true EP0017589A1 (en) 1980-10-15

Family

ID=9224141

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80400447A Withdrawn EP0017589A1 (en) 1979-04-09 1980-04-03 Cassegrain antenna incorporated in a radome

Country Status (2)

Country Link
EP (1) EP0017589A1 (en)
FR (1) FR2454190A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003026065A1 (en) * 2001-09-14 2003-03-27 The Boeing Company Reflector assembly disposed within a radome

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1584348A (en) * 1968-07-16 1969-12-19
US4070678A (en) * 1976-04-02 1978-01-24 Raytheon Company Wide angle scanning antenna assembly
NL7809306A (en) * 1977-09-13 1979-03-15 Marconi Co Ltd ANTENNA SYSTEMS FOR GROUND-INSTALLED RADAR EQUIPMENT.

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1584348A (en) * 1968-07-16 1969-12-19
US4070678A (en) * 1976-04-02 1978-01-24 Raytheon Company Wide angle scanning antenna assembly
NL7809306A (en) * 1977-09-13 1979-03-15 Marconi Co Ltd ANTENNA SYSTEMS FOR GROUND-INSTALLED RADAR EQUIPMENT.

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003026065A1 (en) * 2001-09-14 2003-03-27 The Boeing Company Reflector assembly disposed within a radome
US6570540B2 (en) 2001-09-14 2003-05-27 The Boeing Company Reflector assembly for minimizing reflections of electromagnetic energy from an antenna disposed within a radome
US6856295B2 (en) 2001-09-14 2005-02-15 The Boeing Company Attenuation apparatus for minimizing reflections of electromagnetic energy from an antenna disposed within a radome

Also Published As

Publication number Publication date
FR2454190B1 (en) 1983-05-20
FR2454190A1 (en) 1980-11-07

Similar Documents

Publication Publication Date Title
EP3547450B1 (en) Radiating element with circular polarisation implementing a resonance in a fabry-perot cavity
EP0899814B1 (en) Radiating structure
EP1241733B1 (en) PIFA antenna with slots
FR2843238A1 (en) MULTI-SOURCE ANTENNA IN PARTICULAR FOR A REFLECTOR SYSTEM
EP0145597A2 (en) Plane periodic antenna
CA2682273A1 (en) Antenna with resonator having a filtering coating and system including such antenna
CA2310125C (en) Antenna
EP0147325A2 (en) Antenna with two orthogonal parabolic cylindrical reflectors and process for making it
EP2658032B1 (en) Corrugated horn antenna
FR2704358A1 (en) Waveguide polarisation duplexer
EP0074295A1 (en) Passive microwave duplexer using semi-conductors
EP0045254B1 (en) Compact dual-frequency microwave feed
CA2800952C (en) Very thin linear orthogonal dual-polarised wide band compact antenna operating in v/uhf bands
EP2817850B1 (en) Electromagnetic band gap device, use thereof in an antenna device, and method for determining the parameters of the antenna device
FR2687013A1 (en) AIR FOR RADAR.
EP0017589A1 (en) Cassegrain antenna incorporated in a radome
FR2518828A1 (en) Frequency spatial filter for two frequency microwave antenna - comprising double sandwich of metallic grids and dielectric sheets
FR2814614A1 (en) DIVERGENT DOME LENS FOR MICROWAVE WAVES AND ANTENNA COMPRISING SUCH A LENS
FR2919432A1 (en) ANTENNA MODULE HAVING AN INTEGRATED RADOME.
FR3003700A1 (en) ANTENNA RADAR SIGNATURE REDUCTION DEVICE AND ASSOCIATED ANTENNA SYSTEM
EP0520908A1 (en) Linear antenna array
FR2472279A1 (en) HYPERFREQUENCY WINDOW AND WAVEGUIDE HAVING SUCH A WINDOW
EP0466579A1 (en) Double reflector with grids
FR3013909A1 (en) CORNET, ELEMENTARY ANTENNA, ANTENNA STRUCTURE AND TELECOMMUNICATION METHOD THEREOF
EP0762534B1 (en) Method for enlarging the radiation diagram of an antenna array with elements distributed in a volume

Legal Events

Date Code Title Description
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

AK Designated contracting states

Designated state(s): DE GB IT

17P Request for examination filed

Effective date: 19801029

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

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19830820

RIN1 Information on inventor provided before grant (corrected)

Inventor name: GAUTIER, FRANCOIS

Inventor name: CROCHET, PIERRE