EP1393411B1 - Omnidirectional resonant antenna - Google Patents

Description

The present invention relates to omnidirectional resonant antennas and more particularly omnidirectional resonant antennas in a half-space or all of the space.

It is known in the state of the art to make resonant antennas, that is to say, antennas whose dimensions have been determined so that they exhibit a resonance phenomenon for multiples of one frequency. predetermined. These antennas use the resonance phenomenon to increase the energy of the radiation emitted and / or received at the predetermined frequency and thus have a limited bandwidth. These antennas also have the advantage of having a small footprint compared to non-resonant antennas, that is to say antennas that do not have a resonance phenomenon for multiples of a predetermined frequency.

These antennas can be made using a single electrical conductor forming a dipole or a monopole, most often wired type. They are, for example, made using a metal roof printed on a dielectric substrate, the latter antennas being known as "patch antennas". Another embodiment consists in cutting slots in a ground plane, these antennas being known as "slot antennas". However, at best, it is known at the present time, to realize omnidirectional resonant antennas in a plane of space, that is to say that the electromagnetic radiation emitted or received is substantially uniform whatever the direction in this plan.

There are also in the state of the art systems comprising three resonant antennas each oriented in a different direction of space. These antennas are connected to the input of a signal processing computer. The computer is adapted to process the signals received at the input so as to output a single signal similar to that of an omnidirectional resonant antenna in all directions of space. The patent EP 0590671 K1 describes a broadband antenna with radiation pattern conservation.

However, these systems are difficult to integrate in industrial applications because of the presence of the computer.

Thus, there are currently no resonant antennas presenting the simplicity of antennas formed with a single electrical conductor while being omnidirectional in a half-space or the entire space.

The present invention therefore aims to fill this gap by creating an omnidirectional resonant antenna in a half-space or in the entire space.

It therefore relates to an omnidirectional resonant antenna as defined in claim 1.

• le conducteur électrique rayonnant comporte deux parties symétriques par rapport à un plan de symétrie pour obtenir un rayonnement du conducteur électrique, omnidirectionnel dans l'ensemble de l'espace ;
• le conducteur électrique rayonnant se compose d'un premier, d'un deuxième, d'un troisième, d'un quatrième et d'un cinquième brins, le quatrième et le cinquième brins étant respectivement les images par symétrie du deuxième et du premier brins par rapport au plan de symétrie médian du troisième brin ;
• un brin à l'extrémité du conducteur électrique rayonnant est positionné perpendiculairement à un plan de masse ;
• les dimensions du plan de masse sont inférieures à la longueur d'onde λ pour obtenir un rayonnement du conducteur électrique omnidirectionnel dans l'ensemble de l'espace ;
• les dimensions du plan de masse sont plusieurs fois supérieures à la longueur d'onde λ pour obtenir un rayonnement du conducteur électrique omnidirectionnel dans un demi-espace ;
• elle comporte des éléments de masse et en ce que les brins du conducteur électrique rayonnant sont respectivement coplanaires à ceux-ci ;
• le conducteur électrique rayonnant comporte une première extrémité raccordée à un émetteur/récepteur d'ondes et une seconde extrémité raccordée au plan de masse ;
• le conducteur électrique rayonnant comporte une première extrémité raccordée à un émetteur/récepteur d'ondes et une seconde extrémité raccordée aux éléments de masse ;
• le conducteur électrique rayonnant est raccordé à l'émetteur/récepteur d'ondes par l'intermédiaire d'une zone de couplage électromagnétique ;
• les dimensions de la zone de couplage électromagnétique déterminent en partie l'impédance réelle de l'antenne ;
• le conducteur électrique rayonnant se compose d'un premier, d'un deuxième et d'un troisième brins ;
• les brins consécutifs du conducteur électrique rayonnant sont orientés suivant deux directions orthogonales entre elles;
• les brins sont chacun formé par une bande dont la largeur est déterminée pour adapter, au moins en partie, l'impédance réelle de l'antenne à l'impédance d'un émetteur/récepteur d'ondes destiné à être raccordé à l'antenne ;
• le conducteur électrique rayonnant se compose de brins filaires ;
• le conducteur électrique rayonnant comporte une première extrémité raccordée à un émetteur / récepteur d'ondes et une seconde extrémité libre ;
• le conducteur électrique rayonnant est associé à un matériau diélectrique réduisant les dimensions de l'antenne ;
• le conducteur électrique rayonnant est noyé dans un matériau diélectrique réduisant les dimensions de l'antenne ; et
• le conducteur électrique rayonnant est positionné à la surface d'un matériau diélectrique réduisant les dimensions de l'antenne.

According to other features of the invention, it may further comprise one or more of the following features:

• the radiating electrical conductor comprises two parts symmetrical with respect to a plane of symmetry to obtain a radiation of the electrical conductor, omnidirectional in the whole of the space;
• the radiating electrical conductor is composed of a first, a second, a third, a fourth and a fifth strand, the fourth and fifth strands respectively being symmetrical images of the second and first strands; relative to the median plane of symmetry of the third strand;
• a strand at the end of the radiating electrical conductor is positioned perpendicular to a ground plane;
• the dimensions of the ground plane are less than the wavelength λ to obtain an omnidirectional electrical conductor radiation in the whole of the space;
• the dimensions of the ground plane are several times greater than the wavelength λ to obtain a radiation of the omnidirectional electrical conductor in a half-space;
• it comprises mass elements and in that the strands of the radiating electrical conductor are respectively coplanar with them;
• the radiating electrical conductor has a first end connected to a wave transmitter / receiver and a second end connected to the ground plane;
• the radiating electrical conductor has a first end connected to a wave transmitter / receiver and a second end connected to the ground elements;
• the radiating electrical conductor is connected to the wave transmitter / receiver via an electromagnetic coupling zone;
• the dimensions of the electromagnetic coupling area partly determine the actual impedance of the antenna;
• the radiating electrical conductor consists of first, second and third strands;
• the consecutive strands of the radiating electrical conductor are oriented in two directions orthogonal to each other;
• the strands are each formed by a band whose width is determined to adapt, at least in part, the actual impedance of the antenna to the impedance of a wave transmitter / receiver intended to be connected to the antenna ;
• the radiating electrical conductor consists of wire strands;
• the radiating electrical conductor has a first end connected to a wave transmitter / receiver and a second free end;
• the radiating electrical conductor is associated with a dielectric material reducing the dimensions of the antenna;
• the radiating electrical conductor is embedded in a dielectric material reducing the dimensions of the antenna; and
• the radiating electrical conductor is positioned on the surface of a dielectric material reducing the dimensions of the antenna.

The invention also relates to a device for receiving and emitting electromagnetic radiation in a half-space or in the entire space, characterized in that it comprises a plurality of omnidirectional resonant antennas according to any one of the preceding claims.

• la figure 1 représente schématiquement un conducteur électrique raccordé par une première extrémité à un émetteur / récepteur d'ondes et par une seconde extrémité à une masse, ainsi qu'un graphique illustrant la répartition de la densité surfacique de courant le long de ce conducteur.
• la figure 2 représente schématiquement, en perspective, un premier mode de réalisation d'une antenne résonante omnidirectionnelle dans l'espace conforme à l'invention, dimensionnée à partir du graphique de la figure 1.
• la figure 3 représente en perspective un second mode de réalisation d'une antenne résonante omnidirectionnelle dans l'espace conforme à l'invention.
• la figure 4 représente un conducteur électrique raccordé par une première extrémité à un émetteur / récepteur d'ondes et dont une seconde extrémité est libre, ainsi qu'un graphique illustrant la répartition de la densité surfacique de courant le long de ce conducteur.
• la figure 5 représente en perspective un troisième mode de réalisation d'une antenne résonante omnidirectionnelle dans l'espace conforme à l'invention, dimensionnée à partir du graphique de la figure 4; et
• la figure 6 représente en perspective un quatrième mode de réalisation d'une antenne résonante omnidirectionnelle dans l'espace selon l'invention.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings in which:

• the figure 1 schematically represents an electrical conductor connected by a first end to a wave transmitter / receiver and a second end to a ground, and a graph illustrating the distribution of the current surface density along that conductor.
• the figure 2 represents schematically, in perspective, a first embodiment of an omnidirectional resonant antenna in the space according to the invention, sized from the graph of the figure 1 .
• the figure 3 represents in perspective a second embodiment of an omnidirectional resonant antenna in the space according to the invention.
• the figure 4 represents an electrical conductor connected at one end to a wave transmitter / receiver and a second end of which is free, and a graph illustrating the distribution of the surface flux density along that conductor.
• the figure 5 represents in perspective a third embodiment of an omnidirectional resonant antenna in the space according to the invention, dimensioned from the graph of the figure 4 ; and
• the figure 6 represents in perspective a fourth embodiment of an omnidirectional resonant antenna in the space according to the invention.

The figure 1 represents extending along the x-axis of the graph, an electrical conductor 4 forming a monopole. In a classic way, it is a "quarter-wave" electrical conductor, that is to say an electrical conductor whose total length is equal to a quarter of a wavelength, denoted by λ, of a frequency predetermined. The predetermined frequency is subsequently called "working frequency". A constructive resonance phenomenon occurs in the electrical conductor 4 when emitting and / or receiving electromagnetic radiation whose wavelength is λ. The electrical conductor 4 is here formed of a current conducting band of constant width. The electrical conductor 4 has a first end 6 connected to a ground and a second end 8 connected to a wave transmitter / receiver 10 such as a conventional microwave transmitter / receiver. In the remainder of the description, a transceiver capable of emitting and / or receiving electromagnetic radiation at a given frequency when it is connected to an electrical conductor is called a transceiver. Curve 12 represents the distribution of the surface density of current along the electrical conductor at the working frequency. This curve is determined, for example, using conventional software for electromagnetic radiation simulation of electrical conductors. The area between the curve 12 and the electrical conductor 4 is divided into three areas 14, 16 and 18 of equal area and whose interest will appear in the following description. A point 20 on the electrical conductor 4 marks the boundary separating the area 14 from the area 16; likewise a point 22 on the electrical conductor 4 marks the boundary separating the area 16 from the area 18. The points 20 and 22 thus delimit three strands placed end to end on the electrical conductor 4.

The areas 14, 16 and 18 are respectively proportional to the level of radiation of the electrical conductor strands 4 between the end 8 and the point 20, between the points 20 and 22 and between the point 22 and the end 6. conceives, therefore, that with the help of figure 1 it is possible to determine the length of a strand of electrical conductor so that it has a predetermined level of radiation.

The figure 2 represents a first embodiment of an omnidirectional resonant antenna in the space dimensioned from the graph of the figure 1 . This comprises an electrical conductor 26 forming a monopole similar to that of the figure 1 . The electrical conductor 26 possesses and a current density distribution of current per unit length similar to that of the figure 1 . It consists of three strands 28, 30 and 32 placed end to end and orthogonal two by two between them. The strand 28 has a length equal to that of the strand between the end 8 and the point 20 of the figure 1 . The strand 30 has a length equal to that strand between the points 20 and 22 of the figure 1 . The strand 32 has a length equal to that of the strand between the point 22 and the end 6 of the figure 1 . The free end of the strand 28 is connected via an electromagnetic coupling zone 34 to a terminal 36 of a wave transmitter / receiver 37. The length of the coupling zone 34, that is to say say the gap between the free end of the strand 28 and the terminal 36 is determined by simulation or experimentally to match the actual impedance of the antenna to the impedance of the wave transmitter / receiver 37. Note that it is also possible to play on the width of each strand of the electrical conductor 26 to adapt the actual impedance of the antenna to the impedance of the wave transmitter / receiver 37 so as to limit the phenomena at the interface of these two devices 26 and 37. The free end of the strand 32 is connected perpendicular to a ground plane 38 whose dimensions are smaller than the wavelength λ of the working frequency. Under these conditions, the ground plane 38 does not form a radiation shield of the electrical conductor 26. On the other hand, the various parameters of the strands (length, width, orientation, etc.) must be adjusted to compensate for the edge effects of the plane. of mass 38.

$\frac{\lambda }{10}$

et $\frac{\lambda }{80},$

où X est la longueur d'onde de la fréquence de travail.Alternatively, the ground plane 38 is a plane whose width and length are several times greater than the wavelength λ of the working frequency of the electrical conductor 26. It is said that the ground plane is infinite. It will be appreciated that an infinite ground plane forms a shield to the electromagnetic radiation of an electrical conductor such as the conductor 26 and therefore the resonant antenna is omnidirectional in a half space. In this case, the lengths of the strands such as the strands 28, 30 and 32 are respectively less than $\frac{\lambda }{5},$

$\frac{\mathrm{<figure-callout\; id="10"\; label="\lambda "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\lambda </figure-callout>}}{10}$

and $\frac{\mathrm{<figure-callout\; id="80"\; label="\lambda "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\lambda </figure-callout>}}{80},$

where X is the wavelength of the working frequency.

Thus, for example, for a wavelength λ = 314 mm and for an electrical conductor formed with a band 5 mm wide, the lengths of each of the strands corresponding to the strands 28, 30 and 32 are respectively 53 mm, 30 mm and 3 mm. In addition, in this example, the width of the coupling zone such as zone 34 is 1 mm, terminal 36 is 4 mm long and the diameter of the connecting wire with the emitter / receiver is 0.2 mm.

The figure 3 represents a second embodiment of an omnidirectional resonant antenna in the space according to the invention in which the resonant antenna is formed by an electrical conductor 50 forming a monopole. This electrical conductor comprises five strands 52, 54, 56, 58 and 60 placed end to end and arranged to form a first and a second image portions of each other with respect to a plane of symmetry 62. The strands 52, 54, and 56 are rectilinear and orthogonal pairwise to each other. The first part consists of the strands 52, 54 and a half-strand 64. The half-strand 64 represents the upper half of the strand 56. The strands 52, 54 and 64 form an electrical conductor similar to the electrical conductor 26 described next to the figure 2 . The total length of the electrical conductor formed by the strands 52, 54 and the half-strand 64 is equal to the wavelength of the working frequency divided by four. More precisely, the length of the strand 52 is equal to that of the strand between the end 8 and the point 20 of the figure 1 . The length of the strand 54 is equal to that of the strand between the points 20 and 22 of the figure 1 . The length of the half-strand 64 is equal to that of the strand between the point 22 and the end 6 of the figure 1 . The second part of the electrical conductor 50 consists of the strands 58, 60 and a half-strand 66. The half-strand 66 represents the lower half of the strand 56. The dimensions of the strands 58, 60 and the half-strand 66 are respectively the same as those of the strands 54, 52 and the half-strand 64. The second part of the electrical conductor 50 is intended to make an electrical image of the first part in ways to simulate the existence of a ground plane. The second part thus fulfills the functions of a mass plan such as the plane of mass 38 of the figure 2 for the first part, and vice versa. This is why the strand dimensions of the first part are determined in the same way as in the embodiment of the figure 2 . The free end of the strand 52 is connected to a first terminal of a wave transmitter / receiver 68 and the free end of the strand 60 is connected to a second terminal of the wave transmitter / receiver 68. This first and second terminals are also the image of one another with respect to the plane of symmetry 62 so as not to introduce a phase shift between the signals transmitted / received by the transmitter / receiver of waves 68.

The figure 4 represents, extending along the x-axis of a graph, an electrical conductor 68 forming a monopole. This electrical conductor is here formed by a band of constant current-conducting width, however other forms may be used in other embodiments. A first end of this electrical conductor is connected to a wave transmitter / receiver 69. The second end remains free. A curve 70 represents the surface density of current along the electrical conductor 68 at the working frequency. This curve is obtained, for example, using conventional simulation software. In this example, and similarly to what has been described with regard to the figure 1 , the area between the curve 12 and the electrical conductor 68 is divided into three areas 72, 74 and 76 of equal area. Once these areas are defined, a point 78 is placed on the electrical conductor 68 to mark the boundary between the area 72 and the area 74. Similarly, a point 80, on the electrical conductor 68, marks the boundary between the Area 74 and area 76. Points 78 and 80 cut the electrical conductor 68 into three strands of respective length L1, L2 and L3. The areas of areas 72, 74 and 76 are respectively proportional to the radiation levels of the length of strands L1, L2 and L3.

The figure 5 represents a resonant antenna sized according to the graph of the figure 4 . This antenna comprises an electrical conductor 86 forming a monopole similar to the electrical conductor 68 of the figure 4 . The electrical conductor 86 is connected at one end to a terminal 87 of a wave transmitter / receiver 88. A second end of the electrical conductor 68 remains free. This electrical conductor 86 consists of three strands 90, 92 and 94 placed end to end. These strands are rectilinear and orthogonal two by two between them. The length of each of these strands is determined in accordance with figure 4 that is, the strand 94 has a length L1, the strand 92 has a length L2 and the strand 90 has a length L3. The free end of the strand 94 is connected to the transceiver 88 while being perpendicular to a ground plane 96 whose dimensions are smaller than the wavelength λ of the working frequency. The assembly of the antenna formed by the electrical conductor 86 and the ground plane 96 is embedded in a dielectric material 98 to reduce the dimensions of the antenna. In fact, embedding the electrical conductor of an antenna in a dielectric material or placing it on the surface of a dielectric material makes it possible to reduce the dimensions required for the electrical conductor and therefore the antenna.

The resonant antenna of the figure 6 comprises an electrical conductor 110 formed of a band of current-conducting material of constant width. This electrical conductor consists of three strands 112, 114 and 116 placed end to end and orthogonal two by two between them. The antenna also comprises two ground elements 120 and 122. These ground elements 120 and 122 are each formed by a current-conducting strip of constant width. The first element 120 comprises three strands 124, 126 and 128 placed end to end. The second mass element 122 also has three strands 130, 132 and 134 placed end to end. These two ground elements 120 and 122 are respectively disposed to the right and left of the electrical conductor 110. The strands 124 and 130 of the ground elements are parallel and coplanar with the strand 112 of the electrical conductor 110. Similarly the strands 126 and 132 and the strands 128 and 134 are respectively parallel and coplanar with the strands 114 and 116 of the electrical conductor 110. The ends of the strands 128, 116 and 134 opposite the strands 126, 114 and 132 are interconnected by a current-conducting element 136. The The free end of the strand 112 is connected to a wave transmitter / receiver 138. The lengths of the strands 112, 114 and 116 are determined according to the distribution of the current surface density along the electrical conductor 110 in a manner similar to what has been described with regard to Figures 1 and 2 . The width of the gaps 140, 142 separating the strands of the ground elements, the strands of the electrical conductor 110, as well as the width of the bands forming the ground elements are determined by simulation or experimentation to adapt the actual impedance of the antenna. that of the wave transmitter / receiver 138. Such an antenna is typically made by cutting slots of constant width in a sheet which is then bent at right angles.

The operation of the omnidirectional resonant antenna in space will now be described using the Figures 1 and 2 .

When emitting electromagnetic radiation at the working frequency using the antenna of the figure 2 , the wave transmitter / receiver 37 generates electromagnetically coupled in the electromagnetic coupling zone 34 a surface density of current in the electrical conductor 26. The surface density thus created is distributed along the electrical conductor 26 as illustrated on the graph of the figure 1 .

The length of the strands 28, 30 and 32 is determined so that the areas 14, 16 and 18 have an equal area. Therefore, the radiation levels of each of the strands of the electrical conductor 26 are the same.

Furthermore, the level of radiation emitted at a point in any space is practically the vector sum of the radiation emitted by each of the strands 28, 30 and 32. These strands are orthogonal to one another and the radiation emitted by a strand being parallel to its direction, it is conceivable that the radiation emitted by one strand does not interfere with that of the others. Thus it will be noted that orthogonal strands optimize the gain of the antenna by avoiding destructive interference phenomena. It is realized, therefore, that no particular direction of space is privileged by this antenna, since the strands are orthogonal and the level of radiation of each strand is the same. Therefore, the antenna thus produced is practically omnidirectional. It is considered here that the radiation is practically omnidirectional in a predetermined region of space, if the level of radiation emitted / received by the antenna in any two directions of this region of space does not vary by more than 50% .

It will be noted that the ground plane 38 does not constitute a screen with electromagnetic radiation and that consequently the radiation of the preceding antenna is omnidirectional in the whole of the space.

When receiving electromagnetic radiation at the working frequency using the antenna of the figure 2 , the radiation levels received along the directions of the strands 28, 30 and 32 are respectively proportional to the areas 14, 16 and 18 and thus determined by the respective lengths of each strand. In the particular case of the first embodiment, the length each strand was chosen so that areas 14, 16 and 18 are equal. Consequently, the level of radiation received for a given radiation parallel to a strand will be the same whether this radiation is parallel to the strands 28, 30 or 32. Any directional radiation can always be decomposed into three components respectively parallel to the three strands 28, 30 and 32 the overall level of radiation received by the antenna is unchanged regardless of the direction of this radiation. It will be noted that, as the emission, the reception is not limited by the ground plane 38 to a half-space, if the width and length dimensions thereof are less than λ.

The operation of the antenna shown in figure 3 follows from the one just described.

Indeed, the second portion of the electrical conductor 50 of the antenna formed by the strands 58, 60 and the half-strand 66 performs the functions of a ground plane extending along the plane of symmetry 62 for the first part formed by the strands 52, 54 and the half-strand 64. Therefore the study of the operation of the first part of the antenna is reduced to the study of the operation of an electrical conductor connected perpendicularly to a ground plane se confusing with the plane of symmetry 62. The operation of such a structure has already been described with regard to the figure 2 .

Conversely, the first part of the antenna performs the functions of ground plane merging with the plane of symmetry 62 for the second part of the antenna. Therefore, similar to what has just been described above, the operation of the second part of the antenna is reduced to the study of an antenna whose structure is similar to that described with respect to the figure 2 .

The operation of the resonant antennas represented respectively in Figures 5 and 6 can be deduced easily from the operation of the antenna described with reference to figure 2 .

As a variant, the electrical conductor of the preceding embodiments consists of strands formed with wire elements instead of strands in the form of a strip. The diameter of the wire forming each strand is determined to adjust the actual impedance of such an antenna to that of the wave transmitter / receiver.

As a variant, the electrical conductor of the preceding examples of embodiment consists of strands of any shape, the distribution of the surface density of the current at the working frequency being known to be calculated.

Advantageously, a device for receiving and transmitting electromagnetic radiation comprises a plurality of omnidirectional resonant antennas in a half space or in the whole of the space such as those described above each adapted to receive and emit a predetermined wavelength. . Thus, the receiving and transmitting device is both omnidirectional in a half-space or in the whole of the space, and able to receive and transmit at different wavelengths.

Claims (18)

1. An omnidirectional resonant antenna in half or whole of space including a single radiating electric conductor (26; 50; 86; 110) forming a monopole with a total length resonating at a predetermined frequency and a predetermined current surface density distribution along the electric conductor formed with at least three strands (28, 30, 32; 52, 54, 56, 58, 60; 90; 92; 94; 112; 114; 116) put end to end, the length of each strand and the orientation of the strands relatively to each other, contributing to determining the global radiation of the electric conductor, the strands being oriented along at least three different directions in space and being orthogonal two by two with each other, characterized in that the integral of the current surface density along each strand has a same value.
2. The resonant antenna according to claim 1, characterized in that the radiating electric conductor (50) includes two symmetrical portions relatively to a plane of symmetry (62) in order to obtain omnidirectional radiation of the electric conductor in the whole of space.
3. The resonant antenna according to claim 2, characterized in that the radiating electric conductor (50) consists of first, second, third, fourth and fifth strands (52, 54, 56, 58, 60), the fourth and the fifth strands (58, 62) respectively being images by symmetry of the second and first strands (52, 54) relatively to the middle plane of symmetry (62) of the third strand (56).
4. The antenna according to claim 1, characterized in that a strand at the end of the radiating electric conductor (26; 86) is positioned, and perpendicularly to a ground plane (38; 96).
5. The antenna resonating at a wavelength λ according to claim 4, characterized in that the dimensions of the ground plane (38; 96) are less than the X wavelength in order to obtain omnidirectional radiation of the electric conductor in the whole of space.
6. The antenna resonating at a wavelength λ according to claim 4, characterized in that the dimensions of the ground plane are several times greater than the wavelength λ in order to obtain directional radiation of the electric conductor in a half space.
7. The resonant antenna according to claim 6, characterized in that it includes ground elements (124, 126, 128, 130, 132, 134), and in that the strands (112, 114, 116) of the radiating electric conductor (110) are respectively coplanar with the latter.
8. The resonant antenna according to any of claims 4 to 7, characterized in that the radiating electric conductor (26) includes a first end connected to a wave transmitter/receiver (37) and a second end connected to the ground plane (38).
9. The resonant antenna according to any of claims 4 to 7, characterized in that the radiating electric conductor (110) includes a first end connected to a wave transmitter/receiver (138) and a second end connected to the ground elements (120, 122).
10. The resonant antenna according to claim 8 or 9, characterized in that the radiating electric conductor (26) is connected to the wave transmitter/receiver (37) via an electromagnetic coupling zone (34).
11. The resonant antenna according to claim 10, characterized in that the dimensions of the electromagnetic coupling zone (34) partly determine the real impedance of the antenna.
12. The resonant antenna according to any of claims 4 to 11, characterized in that the radiating electric conductor (26; 86; 110) consists of first, second and third strands (28, 30, 32; 90, 92, 94; 112, 114, 116).
13. The resonant antenna according to any of the preceding claims, characterized in that the consecutive strands (28, 30, 32; 52, 54, 56, 58, 60; 90, 92, 94; 112, 114, 116) of the radiating electric conductor are oriented along two directions orthogonal to each other.
14. The resonant antenna according to any of the preceding claims, characterized in that the strands (28, 30, 32; 52, 54, 56, 58, 60; 90, 92, 94; 112, 114, 116) are each formed with a strip, the width of which is determined so as to adapt, at least partly, the real impedance of the antenna to the impedance of a wave transmitter/receiver intended to be connected to the antenna.
15. The resonant antenna according to any of the preceding claims, characterized in that the radiating electric conductor (26; 50; 86; 110) consists of wire strands.
16. The resonant antenna according to one of claims 1 to 7 and 12 to 15, characterized in that the radiating electric conductor (86) includes a first end connected to a wave transmitter/receiver and a second free end.
17. The resonant antenna according to any of the preceding claims, characterized in that the radiating electric conductor (86) is associated with a dielectric material (98), reducing the dimensions of the antenna.
18. A device for receiving and transmitting electromagnetic radiation in half or in the whole of space, characterized in that it includes several omnidirectional resonant antennas according to any of the preceding claims.

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