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 antennal system.
• the invention relates to an antenna system with vertical and / or elliptical polarization adapted to emit and / or receive surface waves in a wide frequency band including in particular all or part of the low, medium and high frequencies between 30 kHz approximately 30 MHz, consisting of LF, MF and HF.
• Antennas using only a surface wave as propagation vector are very few.
• Current surface wave systems use whip or biconical antennas that are poorly suited for radar applications.
• space wave field also called ionospheric radiation
• the French patent application F 2965978 filed by the applicant, proposes a solution to significantly reduce the vertical size of the antenna, thus reducing implementation costs and improving the discretion of the antenna .
• the antenna provides improved surface wave propagation and decreased ionospheric radiation. Nevertheless, the ionospheric radiation remains important, 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, generate attenuation phenomena (fading in English), especially when the surface waves and the space waves interfere, at the surface of the Earth, after propagation in different environments and paths.
• the invention aims to overcome at least some of the disadvantages of known antennas.
• the invention aims to provide, in at least one embodiment of the invention, an antenna system whose preferential radiation is a surface wave radiation.
• the invention also aims to provide, in at least one embodiment, an antennal system whose ionospheric radiation is reduced.
• the invention also aims to provide, in at least one embodiment of the invention, a simple antenna system to achieve.
• the invention also aims to provide, in at least one embodiment, a discrete antennal system and whose vertical footprint is low.
• the invention also aims to provide, in at least one embodiment, an antenna system whose bandwidth can be easily modified.
• an antenna system with surface waves comprising:
• At least one vertical electrically short antenna with vertical or elliptical polarization and adapted to emit / receive radiation in at least one frequency band centered on a central frequency f 0 associated with a central wavelength ⁇ 0 , said antenna being connected to a conductive medium having a substantially horizontal surface,
• At least one wired cover of length greater than or equal to 0.8 ⁇ 0 electrically connected to at least one antenna at the center of the hood, and adapted to radiate at least the central frequency f 0 of the antenna.
• the term "electrically short antenna” in the vertical plane means an antenna emitting radiation in a preferential wavelength called central wavelength ⁇ 0 , and whose vertical space 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 center 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 antennal system therefore allows preferential radiation in surface waves, as well as the reduction of the ionospheric radiation of an antenna through the use of one or more wired hoods, so as to emit only surface waves.
• the wired hoods are electrically connected to the antenna, so that a power supply of the antenna also feeds the wired hoods.
• the wire hoods radiate at the center frequency f 0 and allow the modification of the antenna radiation pattern so as to reduce the ionospheric radiation of the antennal system.
• the wire covers are formed of a wire or a metal tube of small section.
• the vertical congestion of the antenna system is between 0.05 ⁇ 0 and 0.3 ⁇ 0 .
• the antennal system is therefore discreet. In addition, it is less sensitive to wind, blast, lightning, earthquakes, etc.
• the length of the wire cover is less than or equal to 2 ⁇ 0 .
• said at least one antenna is configured to emit / receive directional radiation in a radiation direction, and at least one wire cover extends in a main direction substantially parallel to the radiation direction.
• the ionospheric radiation of the antenna system is further reduced in the direction of radiation of the antenna when this one is a directional antenna.
• At least one wire 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 cap and the surface of the conductive medium between -5 ° and 5 °.
• the wired cover can also be strictly parallel to the surface of the conductive medium.
• the reduction of the ionospheric radiation and the directivity of the antenna are improved.
• an antenna system comprises at least two wire hoods extending in major directions different from each other.
• the presence of a plurality of wire hoods allows reduction of the enhanced 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 conducting medium if this conductivity is too low.
• at least one wire cover comprises at least one localized element adapted to allow the resonance of said cover at a multitude of frequencies.
• the localized elements which may 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 as well as current traps.
• the localized elements are thus adapted to obtain a multifrequency (i.e. multiple resonant) antenna system via said current traps.
• the localized elements may also make it possible to reproduce the LC resonance of the hood with a reduced physical cover length but an equivalent electrical length.
• the localized elements are thus adapted to modify the electrical length of the hood.
• At least one wire cover comprises a plurality of wire elements connected to each other so as to form a surface cover or a volume cover.
• the surface or volume covers allow to increase the bandwidth of the antennal system.
• the surface or volume covers are adapted for use with broadband antennas.
• the wire elements are, for example, strands made 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.
• FIG. 1 is a schematic perspective view of an antenna system according to a first embodiment of the invention
• FIG. 2 is a schematic perspective view of an antenna system according to a second embodiment of the invention.
• FIG. 3 is a radiation diagram along the yOz plane of the antenna system according to the second embodiment of the invention.
• FIG. 4 is a schematic perspective view of an antenna system according to a third embodiment of the invention.
• FIG. 5 is a schematic perspective view of an antenna system according to a fourth embodiment of the invention.
• FIG. 6 is a schematic perspective view of an antenna system according to a fifth embodiment of the invention.
• FIG. 7 is a schematic perspective view of an antenna system according to a sixth embodiment of the invention.
• FIG. 8 is a schematic perspective view of an antenna system according to a seventh embodiment of the invention.
• FIG. 9 is a radiation diagram according to the yOz plane of the antenna system according to the seventh embodiment of the invention.
• FIG. 10 is a schematic perspective view of an antenna system according to an eighth embodiment of the invention.
• FIG. 11 is a schematic perspective view of an antenna system according to a ninth embodiment of the invention.
• FIG. 12 is a schematic perspective view of an antenna system according to a tenth embodiment of the invention.
• FIG. 13 is a schematic perspective view of an antenna system according to an eleventh embodiment of the invention.
• Figure 14 is a schematic perspective view of an antenna system according to a twelfth embodiment of the invention.
• Figure 1 shows schematically in perspective an antenna system according to a first embodiment of the invention.
• the antenna system 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 electric ground symbol connected to the ground.
• Conductive medium 28 is an imperfect conductive medium, for example soil (earth, sand, etc.) or water (sea, salt marsh, lake, etc.).
• the antenna is fed at the level of the vertical radiating element 26b by a generator 29.
• the antenna system further includes a wire hood 30 electrically connected to the antenna 22 at the center of the hood.
• the wire hood 30 is connected to the antenna 22 at the center of the vertical radiating element 24.
• the wired cap 30 is single stranded (i.e. 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 the earth and sand have low electrical conductivity.
• the antenna system 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 may be formed of a plate, or a set of conductive wires forming a grid, etc.
• the ground plane can take many forms, for example a circle, a polygon (regular or not), etc.
• the ground plane extends below the entire antennal system, i.e., the projection of the antenna system onto the conductive medium 28 along the Oz axis is included in the surface occupied by the mass plan.
• Figure 2 schematically shows in perspective an antenna system according to a second embodiment of the invention.
• the antenna system comprises an antenna 22 as described in the French patent application FR2965978 filed by the applicant.
• the antenna system includes a wire hood 30 electrically connected to the antenna 22 at the center of the hood.
• the wired cap 30 is single strand, and is composed of two sub-strands 32a, 32b of equal lengths, connected to one of their ends and arranged in the same plane.
• the two sub-strands are connected at an angle, due to the difference between the height h1 at which the sub-strands are connected and at 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, as the hood described above in the first mode of realization.
• FIG. 3 represents a radiation pattern according to the yOz plane (referred to as the zenith radiation pattern) of the antenna system according to the second embodiment of the invention, in which the wired cap has a length of 0.8 ⁇ 0 , the height hl is equal to 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 of the antennal system is therefore mainly surface-wave radiation, and the ionospheric radiation of the antenna system is greatly reduced with respect to an antenna 22 without a hood.
• the gain of the antenna system (expressed in dB relative to the maximum radiation of the antennal system) is between 0 and -5 dB for radiation angles in the ranges [-90 °, -60 °] and [60 °, 90 °], and is less than -10 dB in the range [-50 °, 50 °].
• Figure 4 schematically shows in perspective an antenna system according to a third embodiment of the invention.
• the antenna system comprises a PIFA-type antenna 22 (for Planar Inverted F-Shaped Antenna in English).
• the antenna 22 is composed of two vertical radiating elements 34a, 34b connected to a horizontal radiating element 36.
• the antennal system includes a single-wire wired cap 30 electrically connected to the antenna 22 at the center of the wire hood.
• Figure 5 schematically shows in perspective an antenna system according to a fourth embodiment of the invention.
• the antenna system comprises an antenna 22 of shortened whip antenna type.
• the antenna 22 is a monopole antenna comprising a single radiating wire, and the antennal system comprises a single-wire wired cap 30 electrically connected to one end of the antenna 22 at the center of the wire hood 30.
• FIGS 6, 7, 8, 10 and 11 show schematically in perspective an antenna system according to different embodiments comprising an antenna 22 in the form of M as described above with reference to the first embodiment.
• FIGS. 6 and 7 respectively represent a fifth and a sixth embodiment of the invention, in which the wired cap 30 is single-stranded and is connected to the antenna in various arrangements, in particular connected to any point of the element 24 radiating horizontally in the fifth embodiment ( Figure 6) or at one end of the horizontal radiating element 24 in the sixth embodiment ( Figure 7).
• wired cover 30 makes it possible in particular to adapt the antenna system in different configurations so as to adapt to the constraints of the environment in which the antenna system is arranged, the configurations having identical operations.
• FIGS. 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 wired elements, here two strands 38a, 38b connected in their center and extending in different directions so as to form an angle a.
• the strands are of the same length greater than 0.8 ⁇ 0 .
• the cover is connected to the antenna in various arrangements, in particular connected to the center of the horizontal radiating element 24 in the seventh embodiment (FIG. 8), at any point of the horizontal element 24. radiating in the eighth embodiment ( Figure 10) or at one end of the horizontal radiating element 24 in the ninth embodiment ( Figure 11).
• FIG. 9 represents a radiation pattern according to the yOz plane (referred to as the zenith radiation pattern) of the antenna system according to the seventh embodiment of the invention, in which each strand of the hood has a length of 1.1 ⁇ 0 , 1 horizontal radiating element of the antenna 22 has a length of 0.7 ⁇ 0 and the antenna has a height h of 0.08 ⁇ 0 .
• the radiation of the antennal system is therefore mainly surface-wave radiation, and the ionospheric radiation of the antenna system is greatly reduced with respect to an antenna 22 without a hood.
• the gain of the antenna system (expressed in dB relative to the maximum radiation of the antennal system) is between 0 and -5 dB for radiation angles in the ranges [-90 °, -60 °] and [60 °, 90 °], is less than -10 dB in the range [-50 °, 50 °], and less than -15 dB in the range [-40 °, 40 °].
• FIGS 12, 13 and 14 show schematically in perspective an antenna system respectively according to a tenth, an eleventh and a twelfth embodiment.
• Each antenna system comprises an M-shaped antenna 22 according to various particular embodiments.
• the antenna 22 comprises three horizontal radiating elements 24a, 24b, 24c of the same length, each connected at their ends to a vertical radiating element and all connected at their center to a single radiating element 26b. vertical.
• This embodiment of the antenna allows a broadening of the radiation frequency band of the antenna.
• the system 22 antenna comprises a multi-strand wired cap 30 composed of two strands 38a, 38b, as described above, the ends of the strands being connected in pairs by connections 40a, 40b wired so as to form a surface cover, that is to say to say equivalent to a radiant surface.
• This surface cover therefore has an enlarged 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 length adapted to radiate at a first central frequency f 0 (associated with the wavelength ⁇ 0 ) and a second horizontal element 124 is of length adapted to radiate at a second central frequency f bis ( associated with the wavelength ⁇ bis ).
• the antenna is called double resonance.
• the antennal system comprises a wired cap 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 adapted to radiate at the first center frequency f 0
• two second and third strands 38a, 38c have a length greater than 0.8 and are adapted to radiate to the central frequency f bis .
• the wired cap 30 is thus double resonance and allows the reduction of the ionospheric radiation for the center 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 disposed on two of the vertical radiating elements and on the horizontal radiating element 24, allowing the formation of current traps and / or for modifying the electrical lengths. of the antenna 22.
• the localized elements may be resistive, capacitive (capacitors) or inductive (coils) elements. These Localized elements are commonly called "load" in English.
• the antennal system 22 comprises two multi-stranded covers 30a, 30b connected to the horizontal radiating element of the antenna, each of the covers comprising two strands.
• the hoods further comprise localized elements 42e, 42f, 42g, 42h, 42i, 42j, 42k, 421 allowing the formation of current traps and / or making it possible to modify the electrical lengths of the hoods.
• the localized elements are resistive elements (for example a resistor), capacitive (for example a capacitor) or inductive elements (for example a coil).
• the invention is not limited to the embodiments described.
• at least one cover may be a volume type cover so as to further widen the bandwidth of the antennal system, the antenna system may comprise more than two covers, several antennas, etc.

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

Applications Claiming Priority (2)

Publications (3)

Family

ID=54937233

Family Applications (1)

Country Status (4)

Family Cites Families (4)

• 2015
  • 2015-08-10 FR FR1557655A patent/FR3040109B1/fr active Active
• 2016
  • 2016-07-22 EP EP16753413.0A patent/EP3335268B1/de active Active
  • 2016-07-22 ES ES16753413T patent/ES2958409T3/es active Active
  • 2016-07-22 WO PCT/FR2016/051916 patent/WO2017025674A1/fr active Application Filing

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