EP0028185A1 - Antenne radar comportant des éléments rayonnant un diagramme pseudo-omnidirectionnel - Google Patents

Antenne radar comportant des éléments rayonnant un diagramme pseudo-omnidirectionnel Download PDF

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Publication number
EP0028185A1
EP0028185A1 EP80401480A EP80401480A EP0028185A1 EP 0028185 A1 EP0028185 A1 EP 0028185A1 EP 80401480 A EP80401480 A EP 80401480A EP 80401480 A EP80401480 A EP 80401480A EP 0028185 A1 EP0028185 A1 EP 0028185A1
Authority
EP
European Patent Office
Prior art keywords
dipoles
antenna
diagram
reflector
radiating
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Withdrawn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
EP80401480A
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German (de)
English (en)
French (fr)
Inventor
Albert Dupressoir
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 EP0028185A1 publication Critical patent/EP0028185A1/fr
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems

Definitions

  • the present invention relates to a radar antenna comprising elements radiating a pseudo-omnidirectional diagram.
  • the invention applies on the one hand to an antenna for primary radar ensuring the function of suppressing the lateral lobes of the directional diagram, known by the Anglo-Saxon name of Side Lobe Blanking (SLB), consisting of covering these lateral lobes of the Directional radiation pattern, emitted by the primary source of the radar, by a pseudo-omnidirectional type radiation pattern, higher than that of the side lobes to be covered.
  • SLB Side Lobe Blanking
  • the invention also applies to a common antenna for primary and secondary radars having an interrogation system of the IFF type and also ensuring the function of suppressing the lateral lobes of the directional diagram, known as the Side Lobe Suppressor (S.L.S.) in English.
  • An antenna performing the primary radar function has a reflector powered so that it radiates energy to detect a target.
  • this target has a sufficiently high interference level to cover the secondary lobes of the directional diagram radiated by the antenna, we are more particularly interested in the response of this target in the axis of the main lobe of the directional diagram, in trying to mask the interference from the target with a pseudo-omnidirectional diagram.
  • a source above the antenna reflector - a horn for example - radiating such a diagram but this kind of source has the disadvantage of being heavy and bulky.
  • common antenna for primary and secondary radars is meant a single reflector supplied for the detection function of a primary radar and also capable of transmitting an interrogation signal from said target and of receiving the response from its onboard transponder. , this is called the secondary radar function.
  • control means comprising radiating elements acting on the reception of the interrogation by the interrogated responder and on the reception of the latter's response by the receiver concerned. and which radiate according to an almost omni-directional diagram whose level is such that it covers the secondary lobes of the diagram radiated by the main antenna.
  • This arrangement makes it possible by comparison, made in the associated circuits, of the amplitude of the pulses received from the responder and those of control, to determine the pulse received in response to the interrogation by the main lobe.
  • control means intended to produce this control diagram must be such that the gain of the associated control channels is greater than that of the interrogation and reception channels in the angular zones comprising secondary lobes of the directive interrogation diagram but much lower in the direction of their main lobe.
  • control means are either physically independent of the main antenna, consisting of an omnidirectional antenna placed next to the main antenna, or dependent, the control function being carried out by the secondary radar antenna supplied for a determined time to cause a radiation type diagram to appear, whereas the diagram according to which the interrogation takes place is a sum type diagram.
  • the radiation pattern of the control means does not fully play its role, either because it is not completely omnidirectional, or because some high-level secondary lobes of the main directional diagram are not covered and also because in certain cases, the main lobe itself whose level is a little low may be suffocated by the omnidirectional diagram.
  • the control diagrams can be disturbed by certain exterior arrangements such as the radomes under which the antennas are placed.
  • the object of the invention is to remedy these drawbacks and to define an antenna comprising elements radiating a pseudo-omnidirectional diagram.
  • the radar antenna is constituted by a reflector illuminated by one or more emission-reception sources, one of them at least radiating a directional diagram and comprising a system of elements radiating a diagram of the type pseudo-omnidirectional with a crevice in the direction of the main lobe of the directional diagram radiated by one of the sources, characterized in that the system of radiating elements is constituted by one or more groups of two dipoles placed above and near the reflector , symmetrically with respect to the plane of symmetry thereof, the distance between two consecutive dipoles being between 0.5 and 0.8 times the wavelength at the central frequency of the operating band so that they radiate towards the front of it and independently of it a pseudo-omnidirectional diagram.
  • the invention can serve as an antenna for a primary radar ensuring the function of suppressing side lobes, (SLB), as it can also serve as a common antenna for primary and secondary radars, also ensuring the function of suppressing side lobes ( SLS).
  • SLB suppressing side lobes
  • the invention thus relates to a radar antenna comprising elements radiating a pseudo-omnidirectional diagram.
  • Figure 1 shows, schematically, such an antenna comprising a reflector 1 of any shape, illuminated by a primary source 2 placed in front of it and radiating a directional diagram.
  • the elements radiating a pseudo-omnidirectional control diagram are formed by a group of two removable dipoles 3, of the whole or half-wave type placed side by side, just above the antenna reflector 1 in the median plane of this one.
  • the position of the dipoles is such that they release the reflector both to radiate correctly without being disturbed by it and so as not to shade the radiation from the primary source 2. It is however admitted that they can obscure the reflector 1 only by half of their lower strands 9, as shown in FIG. 1.
  • the distance between the two dipoles 3 is between 0.5 and 0.8 times the wavelength at the central frequency of the strip of operation so as to obtain the desired pseudo-omnidirectional diagram, that is to say covering the secondary lobes of the directional diagram but having a crevice centered on the direction of the main lobe of this same diagram.
  • the crevice of the pseudo-omnidirectional diagram having to coincide with the direction of the main lobe of the associated directional diagram, the two dipoles are placed symmetrically with respect to the plane of symmetry TT of the reflector. They are supplied in phase opposition via dividers 4 of power by two removable also and radiate directly without reflector to cover the secondary lobes of the directive diagram on 360 ° of opening. This is why their pseudo-omnidirectional radiation pattern presents a symmetrical crevice of the main crevice in the direction of the main lobe of the directional diagram.
  • the function of suppressing the side lobes may also be provided by several groups of two dipoles distributed symmetrically on either side of the plane of symmetry ri of the reflector 1 according to a linear network.
  • the same remarks made previously as to their position remain valid and the distance between two consecutive dipoles is between 0.5 and 0.8 times the wavelength at the central frequency of the operating band.
  • An antenna thus formed can be used for a primary radar having a lateral lobe suppression function (SLB) provided by the dipoles 3, which radiate a pseudo-omnidirectional diagram having a crevice centered on the main lobe of the directive diagram of the primary source 2 .
  • SLB lateral lobe suppression function
  • a source 5 next to it constituted for example by two dipoles of the whole or half-wave type provided with conformed reflectors. These dipoles are supplied in phase via a conventional power divider, not shown, and two coaxial connecting cables 7. These dipoles radiate the directional diagram of the interrogation reception path of the secondary radar.
  • the dipoles 3 radiating the pseudo-omnidirectional diagram of the control channel, the crevice of which coincides with the main lobe of the directive diagram of the interrogation channel, provide the side lobe suppression (SLS) function of the secondary radar insofar as their diagram covers the entire interrogation diagram except in the direction of the main lobe.
  • SLS side lobe suppression
  • FIG. 1 is represented a radome 8 and devices stabilization 80 of the antenna reflector 1.
  • This reflector 1 is fixed on the removable part 81 of a frame 82 comprising a fixing system 83. This makes it possible to fold the antenna by tilting the reflector 1 towards the frame 82. This is why the fact that the dipoles 3 as the dividers 4 are removable have the advantage of retracting or folding them when one wishes to fold the antenna in the case of transport for example.
  • FIG. 2 represents an example of elements radiating a diagram. pseudo-omnidirectional, used in an antenna according to the invention.
  • This element comprises two conventional dipoles 3, of the full wave or half wave type, placed side by side parallel on a fixing rod 10. They are composed of a coaxial base 11, of an open coaxial line 12 serving as an adapter and of a balun and two radiating strands 13 of length generally equal to a quarter or half of the operating wavelength of the system. These two dipoles are connected to a conventional power divider 14 by coaxial cables 15, while another coaxial connecting cable 16 connects the power divider to the antenna reflector.
  • the power divider 14 is fixed on a rod 17 forming a tee with the rod 10.
  • Three fixing means 18, such as screws, can be provided in order to fix the radiating element to the antenna reflector.
  • These radiating elements are produced independently of the reflector, and provided with means for fixing to the latter, makes it possible to deposit or retract them during movements of the antenna which then has a reduced bulk.
  • dipoles which has just been given is only a nonlimiting example and it is possible to envisage using dipoles obtained by photoengraving of a copper plate on a dielectric wafer, according to a technique analogous to that of the circuits. prints.
  • FIG. 3 shows the pseudo-omnidirectional radiation diagram emitted by the elements associated with the antenna according to the invention, as well as a typical directional diagram, both being plotted in the bearing plane marked by the abscissa axes O - bearing angle - and ordinate G - gain in dB.
  • the directional diagram 19 is that emitted by an antenna for primary radar or that emitted by the interrogation - reception channel of a common antenna for primary and secondary radars.
  • the pseudo-omnidirectional diagram 20, radiated by the elements according to the invention covers well the lateral lobes 22 of the directional diagram except in the direction of the main lobe of the latter where it has a crevice 21. As has already been said, a crevasse also exists, but with a less marked amplitude, in the axis of the main lobe but in the opposite direction, due to the supply of the dipoles.
  • an IFF antenna according to the invention must have a good coverage rate and widths of processing arc compatible with the large angular opening generally required on site. This requirement requires a great omni-directionality of the diagram, except in the axial region.
  • a radar antenna has thus been described comprising elements radiating a pseudo-omnidirectional diagram.

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  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Aerials With Secondary Devices (AREA)
EP80401480A 1979-10-26 1980-10-17 Antenne radar comportant des éléments rayonnant un diagramme pseudo-omnidirectionnel Withdrawn EP0028185A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7926609A FR2469015A1 (fr) 1979-10-26 1979-10-26 Antenne radar comportant des elements rayonnant un diagramme pseudo-omnidirectionnel
FR7926609 1979-10-26

Publications (1)

Publication Number Publication Date
EP0028185A1 true EP0028185A1 (fr) 1981-05-06

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP80401480A Withdrawn EP0028185A1 (fr) 1979-10-26 1980-10-17 Antenne radar comportant des éléments rayonnant un diagramme pseudo-omnidirectionnel

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US (1) US4388624A (enExample)
EP (1) EP0028185A1 (enExample)
FR (1) FR2469015A1 (enExample)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19859120C1 (de) * 1998-12-21 2000-03-23 Howaldtswerke Deutsche Werft Antennenanordnung
US6067051A (en) * 1998-12-23 2000-05-23 Terk Technologies, Inc. Apparatus and method of mounting VHF/UHF antenna assembly on satellite dish antenna
US6366252B1 (en) 2000-07-24 2002-04-02 Neil D. Terk Method and apparatus for mounting an auxiliary antenna to a reflector antenna
US20170323239A1 (en) 2016-05-06 2017-11-09 General Electric Company Constrained time computing control system to simulate and optimize aircraft operations with dynamic thermodynamic state and asset utilization attainment

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2653238A (en) * 1945-10-26 1953-09-22 Kenneth T Bainbridge Dual frequency antenna
US2846678A (en) * 1955-06-09 1958-08-05 Sanders Associates Inc Dual frequency antenna
US2966675A (en) * 1957-10-23 1960-12-27 Stewart Warner Corp Radar beacon system with side lobe suppression
US3213446A (en) * 1961-09-06 1965-10-19 Cossor Ltd A C Interrogation radar systems
DE2139216A1 (de) * 1971-08-05 1973-02-15 Siemens Ag Richtantennenanordnung
FR2284997A1 (fr) * 1974-09-13 1976-04-09 Thomson Csf Antenne commune pour radar primaire et radar secondaire avec moyens de controle de l'interrogation
DE2513611A1 (de) * 1975-03-27 1976-10-07 Licentia Gmbh Kombinierte radarantenne fuer primaer- und sekundaer-radarbetrieb

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3445850A (en) * 1965-11-08 1969-05-20 Canoga Electronics Corp Dual frequency antenna employing parabolic reflector
FR2315181A1 (fr) * 1975-06-20 1977-01-14 Thomson Csf Dipole rayonnant pour reflecteur, plus particulierement utilise dans une antenne commune pour radar primaire et radar secondaire avec moyens de controle de l'interrogation

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2653238A (en) * 1945-10-26 1953-09-22 Kenneth T Bainbridge Dual frequency antenna
US2846678A (en) * 1955-06-09 1958-08-05 Sanders Associates Inc Dual frequency antenna
US2966675A (en) * 1957-10-23 1960-12-27 Stewart Warner Corp Radar beacon system with side lobe suppression
US3213446A (en) * 1961-09-06 1965-10-19 Cossor Ltd A C Interrogation radar systems
DE2139216A1 (de) * 1971-08-05 1973-02-15 Siemens Ag Richtantennenanordnung
FR2284997A1 (fr) * 1974-09-13 1976-04-09 Thomson Csf Antenne commune pour radar primaire et radar secondaire avec moyens de controle de l'interrogation
DE2513611A1 (de) * 1975-03-27 1976-10-07 Licentia Gmbh Kombinierte radarantenne fuer primaer- und sekundaer-radarbetrieb

Also Published As

Publication number Publication date
FR2469015A1 (fr) 1981-05-08
FR2469015B1 (enExample) 1983-12-23
US4388624A (en) 1983-06-14

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Inventor name: DUPRESSOIR, ALBERT