EP1407512B1 - Antenna - Google Patents

Description

The present invention relates to the field of antennas.

The document FR 2,668,859 describes a monopolar wire-plate antenna of the type shown on the figure 1 .

Such a structure is comparable to that of a conventional printed antenna. It consists of a metal pad 12 (capacitive roof of the antenna) of a predetermined arbitrary shape, placed on the upper face of a dielectric blade 13. The lower face of this blade 13 is conventionally entirely metallized and constitutes the ground plane 14 of the antenna.

The antenna feed is performed by a coaxial probe 17. The inner conductor 15 of this probe 17 traverses, without touching, the ground plane 14 and passes through the dielectric plate 13. It is connected to the metal roof 12. The external conductor of the probe 17 is connected to the ground plane 14.

The particularity of such an antenna is to have a wire 16 return to the ground plane 14 formed by the lower metallization. This wire 16 connects the capacitive roof 12 and the ground plane 14. It passes through the dielectric plate 13 parallel to the conductor 15 of the probe 17 and close to this conductor 15 so that this return wire 16 is coupled by inductive coupling to the wire 15 of the probe 17 and is traversed by a current at the working frequency. The presence of this wire 16 near the feed probe 15 is at the origin of the original operation of such an antenna.

The document FR 2 783 115 describes a coplanar wire-plate antenna, as shown in FIG. figure 2 . Such an antenna has been developed for the purpose of congestion reduction.

In this structure we find elements that are functionally comparable to those constituting the antenna presented in FR 2,668,859 that is: a ground plane 14, a central "capacitive roof" 12, a supply ribbon 15 connected to the capacitive roof 12, and a grounding strip 16 which connects the capacitive roof 12 and the ground plane 14 (by analogy respectively to the aforementioned feed and return son). However, in the case of the coplanar wire-plate antenna illustrated on the figure 2 , the capacitive roof 12 and the ground plane 14 are in the same plane, the ground plane 14 being placed at the periphery of the antenna, around the capacitive roof 12. The document FR 2 783 115 also discloses a reflective plane parallel to and near the coplanar antenna.

XP000688465 Kokotoff et al: 'An annular ring coupled to a shorter patch', IEEE Transactions on antennas and propagation, IEEE Inc. New York, US, vol. 45, No. 5, May 1, 1997 (1997-05-01), pp. 913-914 , describes a microstrip antenna.

We find in this structure elements functionally comparable to those constituting the antennas presented in the documents FR 2668 859 and FR 2 783 115 that is: a ground plane 14, a central "capacitive roof" 12, a supply ribbon 15 connected to the capacitive roof 12, and a grounding strip 16 which connects the capacitive roof 12 and the ground plane 14 (by analogy respectively to the aforementioned feed and return son). The plane of mass 14 is as in the document FR 2,668,859 located below the capacitive roof 12, but this capacitive roof 12 is split into two disjoint parts, one central 122 and the other peripheral 124. Only the central portion 122 is connected to the ground plane 14 via the elements 15 and 16.

The operating principle of these known antennas is mainly based on a complex coupling phenomenon between the supply probe 15 (or supply ribbon) and the wire 16 (or grounding tape). Without resumption of mass, these antennas behave like series resonant circuits due to the inductance of the supply probe 15 (L _alim ) and to the capacity (C _roof ) formed between the capacitive roof 12 and the ground plane 14 The addition of a return to ground 16 between roof 12 and ground plane 14 creates a parallel inductance (L _mass ) on the capacitance (C _roof ) causing the appearance of a parallel resonance.

An equivalent simplified diagram of these antennas is shown on the figure 3 . By a suitable choice of different physical parameters, it is possible to adapt these antennas to conventional microwave generators.

In each of these known cases, the mode of operation of these antennas is characterized by a high concentration of currents on the wire (or tape) back to mass 16, which gives these structures their monopolar type radiation for the wire-plate and dipolar antenna for coplanar wire-plate antenna.

The object of element 124 in XP000688465 is to increase the usable bandwidth around the resonance frequency of the antenna operating mode.

It is also known from the document US 6195048 , a PIFA type antenna according to the English terminology "Planar Inverted F-type Antenna", with which it is possible to transmit and receive according to several frequencies. For that, US 6195048 proposes an antenna in which the transmitting / receiving part has a particular disposition to the physical phenomena encountered in this type of antenna, which features can not be transposed to other types of antennas.

The aim of the invention is to improve the structures proposed up to now, both in terms of operating efficiency, in particular the possibilities of adaptation between the antenna and the generator, and at the same time in terms of bulk.

• l'une au moins de ces surfaces étant scindée en au moins deux parties concentriques consistant en une partie centrale et un ruban entourant cette partie centrale,
• ces au moins deux parties étant reliées entre elles par un ou plusieurs rubans ou fils conducteurs,
• les au moins deux surfaces superposées étant reliées entre elles par au moins un fil ou ruban conducteur,
• les au moins deux parties de la surface scindée incluant une partie reliée à une première borne du générateur, et une partie reliée à une deuxième borne du générateur, cette structure conférant à l'antenne un comportement multifonctions.

To achieve these objectives, the invention provides an antenna according to claim 1 comprising a generator and at least two parallel metal surfaces and substantially superimposed between them,

• at least one of these surfaces being split into at least two concentric parts consisting of a central part and a ribbon surrounding this central part,
• these at least two parts being interconnected by one or more ribbons or conductive wires,
• the at least two superposed surfaces being interconnected by at least one conductive wire or ribbon,
• the at least two parts of the split surface including a portion connected to a first terminal of the generator, and a portion connected to a second terminal of the generator, this structure conferring on the antenna a multifunctional behavior.

The antenna thus formed in accordance with the present invention groups together a plurality of radiating elements capable of each working in transmission or reception in their own mode at different independent frequencies, without increasing the volume bulkiness of the antenna, with respect to the known arrangements. of the prior art. The present invention thus makes it possible to obtain an antenna of relatively small size in front of the working length (s) of wavelength (s).

• les surfaces scindées en deux éléments donnent conjointement un mode de fonctionnement de type antenne fil-plaque formée par l'ensemble des deux surfaces métalliques ;
• chaque surface scindée en deux éléments reliés entre eux par au moins un ruban ou fil conducteur ajoute un nouveau mode de fonctionnement de type antenne fil-plaque coplanaire formée par les deux parties découpées ;
• l'antenne comprend une liaison électrique d'alimentation qui relie la première borne du générateur/récepteur à la partie centrale de la surface scindée en au moins deux parties, liaison électrique qui est formée d'un fil perpendiculaire aux deux surfaces ;
• la liaison électrique d'alimentation peut être formée par le conducteur central d'une liaison coaxiale qui traverse, sans la toucher, l'autre surface métallique ;
• la liaison électrique d'alimentation est reliée à un ruban lié à une partie centrale de la surface scindée en au moins deux parties.

According to other advantageous features of the present invention:

• the split surfaces into two elements together give a wire-plate antenna mode of operation formed by all of the two metal surfaces;
• each split surface into two elements interconnected by at least one ribbon or conductive wire adds a new operating mode of coplanar wire-plate antenna type formed by the two cut portions;
• the antenna comprises an electrical supply connection which connects the first terminal of the generator / receiver to the central part of the split surface into at least two parts, an electrical connection which is formed of a wire perpendicular to both surfaces;
• the electrical supply connection may be formed by the central conductor of a coaxial connection which passes through, without touching, the other metal surface;
• the electrical supply connection is connected to a ribbon bonded to a central part of the divided surface in at least two parts.

The dependent claims define more specific variants of the invention.

• la figure 1 représente une antenne fil-plaque monopolaire selon l'art antérieur ;
• la figure 2 représente une antenne fil-plaque coplanaire selon l'art antérieur ;
• la figure 3 est un schéma simplifié illustrant le comportement électrique des antennes des figures 1 et 2 ;
• la figure 4 est une vue de dessus d'une antenne selon un premier exemple;
• la figure 5 est une vue de côté de cette même antenne ;
• la figure 6 est une vue en perspective de cette même antenne ;
• la figure 7 est une vue de dessus d'une antenne selon une variante de l'invention, utilisée pour une simulation de comportement ci-après rapportée ;
• la figure 8 est une vue en perspective de cette même antenne ;
• les figures 8bis à 8 quinter représentent une antenne de type proche de celle de la figure 8 ;
• les figures 9 et 10 représentent l'impédance d'entrée et l'adaptation en fréquence (coefficient de réflexion) de l'antenne des figures 8 bis à 8 quinter ;
• les figures 11 et 11 bis sont des graphiques représentant des diagrammes de rayonnement réalisés pour une polarisation principale (verticale) dans un plan de coupe vertical (figure 11) et un plan de coupe

Other characteristics, objects and advantages of the invention will appear on reading the detailed description which follows, made with reference to the appended figures in which:

• the figure 1 represents a monopolar wire-plate antenna according to the prior art;
• the figure 2 represents a coplanar wire-plate antenna according to the prior art;
• the figure 3 is a simplified diagram illustrating the electrical behavior of antennas Figures 1 and 2 ;
• the figure 4 is a top view of an antenna according to a first example;
• the figure 5 is a side view of this same antenna;
• the figure 6 is a perspective view of this same antenna;
• the figure 7 is a top view of an antenna according to a variant of the invention, used for a behavior simulation hereinafter reported;
• the figure 8 is a perspective view of this same antenna;
• the figures 8bis to 8 quinter represent a type antenna similar to that of the figure 8 ;
• the Figures 9 and 10 represent the input impedance and the frequency adaptation (reflection coefficient) of the antenna of the figures 8 bis to 8 quinter;
• the Figures 11 and 11 bis are graphs representing radiation patterns made for a principal (vertical) polarization in a vertical section plane ( figure 11 ) and a cutting plane

• les figures 12 et 13 sont des diagrammes de rayonnement respectivement pour un plan de coupe vertical xoz et un plan de coupe azimutal xoy pour la polarisation principale (horizontale) dans un second mode de fonctionnement à 1,49 GHz de l'antenne des figures 8 bis à 8 quinter ;
• la figure 14 est une vue de dessus d'une antenne selon un second exemple ;
• la figure 15 est une vue de côté de cette même antenne ; et
• la figure 16 est une vue en perspective de cette antenne conforme à la présente invention.
• la figure 17 est une vue en coupe d'une antenne selon un autre mode de réalisation de l'invention ;
• la figure 18 est une vue de dessus d'une surface métallique de l'antenne de la figure 17 ;
• la figure 19 est une vue en coupe d'une antenne selon un autre mode de réalisation de l'invention ;
• la figure 20 est une vue de dessus d'une surface métallique de l'antenne de la figure 19 ;
• la figure 21 est une vue de dessus d'une autre surface métallique de l'antenne de la figure 19 ;
• la figure 22 est une vue de dessus d'une surface métallique d'antenne selon un autre exemple ;
• la figure 23 est une vue de dessus d'une surface métallique d'une antenne selon un autre mode de réalisation de l'invention, à diodes.
• la figure 24 est une coupe transversale d'une antenne selon un autre mode de réalisation, comportant une diode entre deux surfaces superposées.

horizontal ( figure 11 (bis) for a first mode of operation at 0,94 GHz;

• the Figures 12 and 13 are radiation diagrams respectively for a vertical sectional plane xoz and an azimuthal sectional plane xoy for the main (horizontal) polarization in a second mode of operation at 1.49 GHz of the antenna of figures 8 bis to 8 quinter;
• the figure 14 is a top view of an antenna according to a second example;
• the figure 15 is a side view of this same antenna; and
• the figure 16 is a perspective view of this antenna according to the present invention.
• the figure 17 is a sectional view of an antenna according to another embodiment of the invention;
• the figure 18 is a top view of a metal surface of the antenna of the figure 17 ;
• the figure 19 is a sectional view of an antenna according to another embodiment of the invention;
• the figure 20 is a top view of a metal surface of the antenna of the figure 19 ;
• the figure 21 is a top view of another metal surface of the antenna of the figure 19 ;
• the figure 22 is a top view of a metal antenna surface according to another example;
• the figure 23 is a top view of a metal surface of an antenna according to another embodiment of the invention, with diodes.
• the figure 24 is a cross section of an antenna according to another embodiment, having a diode between two superimposed surfaces.

The antenna of the first example ( Fig. 4 to 6 ) is composed, in the manner of a conventional wire-plate antenna, of two parallel plates of which one plate 140 is grounded and the other 120 is at the same time supplied by a current, via a probe 150, and both connected to the mass by a link 160 back to the ground plane 140, which link 160 is coupled by inductive coupling to the probe wire 150, to be traversed by a current at a working frequency.

However, in the context of this example, the plate 120 is split into two elements 122, 124: a central surface 122 and a peripheral strip 124 which remotely surrounds the central surface 122.

The central surface 122 and the ribbon 124 are separated from each other by a circumferential recess 123 at the central surface 122.

In addition, the central surface 122 and the ribbon 124 are interconnected by a link 126 which is coplanar with them.

The geometry of the central surface 122, the ribbon 124 and the lower plate 140 is not critical.

However preferably the central surface 122, the ribbon 124 and the lower plate 140 have contours of the same geometry, for example rectangular, square, circular, oval, etc. The upper plate 120 is advantageously centered on the lower plate 140. The upper plate 120 further advantageously has a smaller surface area than the lower plate 140.

Furthermore, the tape 126 preferably extends in a generally radial direction relative to the center of the central surface 122.

More precisely still, according to the illustrated example on Figures 4 to 6 , the central surface 122 is of square geometry, while the ribbon 124 comprises four sections respectively parallel and perpendicular to each other, and to the edges of the central surface 122, two by two. The link 126 is itself perpendicular to an edge 121 of the central surface 122 and to a portion constituting the ribbon 124.

• un plan de masse 140,
• un plan supérieur 120 scindé en deux éléments concentriques 122, 124, reliés entre eux par une liaison coplanaire 126, qui constitue à la fois, par son élément central 122, un toit capacitif, et par son élément périphérique 124, un élément de masse,
• une sonde coaxiale dont le blindage externe 154 est relié à la masse d'un générateur / récepteur, tandis que son conducteur central 150 est relié à la borne active du générateur / récepteur, le blindage 154 de la sonde étant relié au plan de masse 140, tandis que le conducteur central 150 traverse, sans le toucher, le plan de masse 140 et est relié à l'élément central 122 du plan supérieur 120, et
• une liaison conductrice 160 couplée par couplage inductif au conducteur central de la sonde 150, et qui relie l'élément périphérique 124 du plan supérieur et le plan de masse 140.

So the antenna illustrated on the Figures 4 to 6 annexed includes:

• a plan of mass 140,
• an upper plane 120 divided into two concentric elements 122, 124, interconnected by a coplanar connection 126, which constitutes, by its central element 122, a capacitive roof, and by its peripheral element 124, a ground element,
• a coaxial probe whose outer shield 154 is connected to the ground of a generator / receiver, while its central conductor 150 is connected to the active terminal of the generator / receiver, the shielding 154 of the probe being connected to the ground plane 140 , while the central conductor 150 passes, without touching, the ground plane 140 and is connected to the central element 122 of the upper plane 120, and
• a conductive link 160 coupled by inductive coupling to the central conductor of the probe 150, and which connects the peripheral element 124 of the upper plane and the ground plane 140.

The conductive connection 160 provides both the connection between the ground elements 124 and 140 and the grounding of the wire-plate antenna.

According to the particular example illustrated on Figures 4 to 6 appended, the supply conductor 150 of the probe is placed, perpendicularly to the two planes 120 and 140, near an edge 121 of the central element 122. The conductive connection 160 is placed parallel to the conductor 150, on one edge outer ribbon 124, placed opposite said edge 121.

• un plan de masse inférieur 140,
• un plan supérieur 120 scindé en deux éléments concentriques 122, 124, reliés entre eux, qui constitue à la fois, par son élément central 122, un toit capacitif, et par son élément périphérique 124, un élément de masse,
• une sonde coaxiale dont le blindage externe 154 est relié à la masse d'un générateur / récepteur, tandis que son conducteur central 150 est relié à la borne active du générateur / récepteur, le blindage 154 de la sonde étant relié au plan de masse 140, tandis que le conducteur central 150 traverse, sans le toucher, le plan de masse 140 et est relié à l'élément central 122 du plan supérieur 120, et
• une liaison conductrice 160 couplée par couplage inductif au conducteur central de la sonde 150, et qui relie l'élément périphérique 124 du plan supérieur et le plan de masse 140. La taille du plan inférieur 140 est de 70mm* 70mm, celle du plan supérieur (120) est de 60mm*60mm et la hauteur de 7mm. Cette antenne possède un fil vertical d'alimentation 150.

To the Figures 7 and 8 , according to this variant, there is an antenna which comprises:

• a lower ground plane 140,
• an upper plane 120 divided into two concentric elements 122, 124, interconnected, which constitutes, by its central element 122, a capacitive roof, and by its peripheral element 124, a mass element,
• a coaxial probe whose outer shield 154 is connected to the ground of a generator / receiver, while its central conductor 150 is connected to the active terminal of the generator / receiver, the shielding 154 of the probe being connected to the ground plane 140 , while the central conductor 150 passes, without touching, the ground plane 140 and is connected to the central element 122 of the upper plane 120, and
• a conductive link 160 coupled by inductive coupling to the central conductor of the probe 150, and which connects the peripheral element 124 of the upper plane and the ground plane 140. The size of the lower plane 140 is 70mm * 70mm, that of the upper plane (120) is 60mm * 60mm and the height of 7mm. This antenna has a vertical feed wire 150.

However according to this variant, the central element 122 is connected to the peripheral element 124, not by a single connection, but by two links 126, 127. These are parallel to each other, perpendicular to an edge 121 of the central element 122 and connected to this edge, about a quarter of the length of this edge 121, counted respectively from its first and second end.

On the other hand, the feed wire 150 is not connected directly to the central surface 122, but to an additional ribbon 128 which extends outwardly from the central surface 122, in the direction of the peripheral band 124, but The supply conductor 150, which extends perpendicularly to the planes 120 and 140, is placed at the end of this strip 128. The supply is, in this case, deported via this horizontal ribbon 128, offset to optimize the adaptation of the antenna.

The mass return wire 160 is placed on the edge of the outer ribbon 124 placed opposite the edge 121 of the central surface 122, substantially between the supply ribbon 128 and the mass return ribbon 127.

It should be noted that as illustrated in Figures 7 and 8 the ribbons 126 and 127 may have different widths.

It will thus be noted that the presence of the two return tapes 126 and 127, and the slight offset of the feed wire 150 thanks to the ribbon 128, make it possible to optimize the characteristics of the input impedance in order to improve the adaptation. of the antenna.

Thus, not only does such an antenna convert the energy received in an adaptation band into a radiated energy in a given direction with a preferred bias, but it also allows adaptation to a generator having a given input impedance (in general 50 Ohm) on one or more frequency bands.

The geometrical parameters of the antenna can differ according to the needs of the user (operating frequencies, adaptation, bandwidth ...) and can easily be developed by those skilled in the art depending on the adaptation to the desired frequencies.

• Les figures 8 bis à 8 quinter présentent la géométrie de l'antenne, la taille du plan inférieur 140 est de 100mm*100mm, celle du plan supérieur 120 est de 60mm*60mm et la hauteur de 22mm. Cette antenne possède deux rubans de liaison 160 et un fil vertical d'alimentation 150.

The antenna of figures 8 bis to 8 quinter is still a variant, which has two mass recovery tapes 160:

• The figures 8 bis to 8 quinter present the geometry of the antenna, the size of the lower plane 140 is 100mm * 100mm, that of the upper plane 120 is 60mm * 60mm and the height of 22mm. This antenna has two connecting strips 160 and a vertical supply wire 150.

The results presented on Figures 9 and 10 At the input impedance, two parallel resonances appear at 0.83 GHz and 1.37 GHz. The first corresponds to the mode of the wire-plate antenna and the second to that of the coplanar wire-plate antenna cut in the surface 120. For each of the modes, the adaptation takes place when the real part of the impedance d The input is close to 50 ohms and the imaginary part of 0. The adaptation of the first mode is therefore -15dB and takes place at 0.94 GHz and that of the second is -18 dB at 1.49 GHz.

Gain charts ( Figures 11 to 13 ) are represented in two section planes for each operating mode (note: only the main polarization of the electric field is represented, E0 for the first mode and Eφ for the second one).

The first mode (at 0.94 GHz) presents a diagram ( Figures 11 and 11bis ) with symmetry of revolution around the axis OZ (omnidirectional in azimuth with a maximum gain on the horizon).

The second ( Figures 12 and 13 ) has a hemispherical coverage with maximum gain in the axis of the antenna.

A second example is shown in Figures 14, 15 and 16 .

These figures show an antenna which has the general shape of a wire-plate antenna, that is to say which has two parallel main metallic planes 120 and 140.

However, here, it is the lower metal plane 140 forming the ground plane of the assembly, which is split into two elements, one central 142 connected to the first active terminal of the generator / receiver via a ribbon 148, the other 144 device connected to the second terminal, ground, the generator / receiver.

Thus, the metal plate 140 has a peripheral ribbon 144 which is connected to ground while a central surface 142 is connected to the positive terminal of a power source.

These two elements 142 and 144 are interconnected by a mass recovery ribbon 146 which is coplanar with them.

The geometry of the upper plate 120, the central surface 142 and the ribbon 144 is not critical.

Preferably, however, the upper plate 120 is centered on the lower plate 140. In addition, the central surface 142 and the ribbon 144 have contours of the same geometry, for example rectangular, square, circular, oval, etc.

The upper plate 120 further advantageously has a smaller surface area than the lower plate 140.

Furthermore, the ribbon 146 preferably extends in a generally radial direction with respect to the center of the central surface 142.

More precisely still, according to the illustrated example on Figures 14 to 16 , the central surface 142 is of square geometry, while the ribbon 144 comprises four sections (one of which is formed of two segments aligned to allow the passage of the supply ribbon 148) respectively parallel and perpendicular, to each other, and to the edges of the central surface 142, two by two. The link 146 is itself perpendicular to an edge of the central surface 142 and to a portion constituting the ribbon 144. It is parallel and coplanar with the supply ribbon 148.

The upper plate 120 is connected to the central surface 142 of the plate 140, so that it is also fed.

For this, a feed link 150 formed by a single wire connects the central surface 142 to the plate 120.

More specifically, the peripheral strip 144 has the general shape of a C. The central surface 142 is extended by a coplanar track forming a supply ribbon 148 which opens outwards, via the opening of this C. And the wired link 150, which extends perpendicular to the planes of the plates 120 and 140, connects the supply ribbon 148 to the plate 120.

Furthermore, a ground return wire 160 connects the two plates 120 and 140. This return wire connects the plate 120 to the plate 140 at its grounding strip 146 between the central surface 142 and the peripheral strip 144. The ground return wire 160 extends perpendicularly to the planes 120 and 140.

• un plan de masse 140, scindé en deux éléments concentriques 142, 144, reliés entre eux par une liaison 146,
• un plan supérieur 120,
• une sonde coaxiale dont le blindage externe 154 est relié à la masse d'un générateur / récepteur, tandis que son conducteur central 151 est relié à la borne active du générateur / récepteur, le blindage 154 de la sonde étant relié au ruban 144, tandis que le conducteur central 151 est relié à l'élément central 142 du plan inférieur 140, par l'intermédiaire du ruban d'alimentation 148,
• une liaison conductrice 150 qui relie le ruban d'alimentation 148, à proximité de l'élément central 142, et la plaque supérieure 120 et
• une liaison conductrice 160 couplée par couplage inductif au conducteur 150, et qui relie l'élément périphérique 144 du plan inférieur 140 (plus précisément son ruban 146) et le plan supérieur 120.

So the antenna illustrated on the Figures 14 to 16 annexed includes:

• a ground plane 140, divided into two concentric elements 142, 144, interconnected by a link 146,
• a top plane 120,
• a coaxial probe whose outer shield 154 is connected to the ground of a generator / receiver, while its central conductor 151 is connected to the active terminal of the generator / receiver, the shielding 154 of the probe being connected to the ribbon 144, while that the central conductor 151 is connected to the central element 142 of the lower plane 140, via the supply ribbon 148,
• a conductive link 150 which connects the supply ribbon 148, near the central element 142, and the upper plate 120 and
• a conductive link 160 coupled by inductive coupling to the conductor 150, and which connects the peripheral element 144 of the lower plane 140 (more precisely its ribbon 146) and the upper plane 120.

On the figure 14 , the return wire connects the plate 120 to the plate 140 at its ground ribbon. In general, the return wire connects the plate 120 to the peripheral element 144 of the plate 140.

The capacitive roof of this general structure is thus formed by the plate 120, which behaves in the manner of a capacitive roof of traditional wire-plate antenna in that it is fed by a current and connected to a plane of parallel mass, here the plate 140, more precisely the ribbon 144 thereof.

In this case, the supply of the assembly is through the ribbon 148 and the wire 150.

Note that the grounding wire 160 connecting the two plates 120 and 140 joins the bottom plate 140 at its grounding strip 147.

It is recalled that it is important in the context of the present invention that the ground return wire 160, whatever the embodiment, or close to the supply wire 150, to be coupled, by inductive coupling to the latter , so that the ground return wire 160 is traversed by a current at the working frequency. Typically the distance between the supply wire 150 and the ground return wire is less than 1/10 λ, where λ represents the working wavelength.

The multifunctional radiating devices that have just been described are only examples among various possible possibilities, the geometric configurations of the various elements remaining variable and depending on the functions to be performed or the working frequency.

The size of the side of the surface 120 and of average λ / 6 for the first mode of operation and λ / 4 for the second.

The small volume requirement of these antennas (on average λ _0/4 ) facilitates their integration into current communication systems. In addition, the use of a dielectric substrate makes it possible to further reduce this bulk.

The present invention can thus be envisaged for different modes of operation according to its geometric configuration.

For example: the application to a multilobe antenna (favoring different directions of radiation) at the same frequency (for example for telemetry applications).

One can also consider for example a multifunction antenna, combining the functions GSM, GPS, ...

Such antennas also make it possible to miniaturize aerials in mobile communication systems.

The plates 120 and 140 may be supported in their relative position by any suitable means. Preferably the plates 120 and 140 are thus disposed respectively on either side of a substrate dielectric of small thickness compared to the dimensions of the plates 120 and 140. The substrate may be formed of a homogeneous layer. However, if necessary, the substrate may be formed of several adjacent stacked layers having different dielectric properties. Alternatively the dielectric medium placed between the two plates 120 and 140 may even be formed by air.

Preferably, the plates 120 and 140 are thus formed by etching metallizations formed on either side of a substrate, or by deposition of contours controlled on this substrate.

Of course, the present invention is not limited to the particular embodiments which have just been described, but extends to all embodiments according to the claims.

Thus, for example, the antenna according to the present invention may comprise several upper plates 120 parallel to each other and of identical geometry.

In the context of Figures 4-8 , the different plates 120 may each comprise a central element 122 and an outer ribbon 124 interconnected by a mass recovery tape 126. The central elements 122 of the various plates 120 may be interconnected by means of wires extending the feed wire 150, while the various external ribbons 124 may be interconnected via wires extending the ground return wire 160.

In the context of Figures 14-16 the different plates 120 can be full. These plates 120 are interconnected via wires comparable to the wire 150. However, in this case the links existing between two adjacent plates 120 are preferably formed of multiple links arranged in a symmetrical arrangement.

According to yet another variant, the antenna according to the present invention may be associated with a proximity reflector to form the radiation, for example to concentrate the radiation in a desired direction.

Other embodiments of the invention are shown in Figures 17 to 24 . The assembly of the figure 17 has a higher level consisting of two parallel conductive surfaces connected by at least one vertical conductor (called wire or tape recovery "mass").

This upper level is referenced 120 and divides into two plates 125 and 127. The plate 125, lower plate of this upper level, is shown in plan view at the figure 18 . It is cut into three concentric elements connected by conductive ribbons (or son according to a variant).

Each cut gives rise to a second type of operation providing an axial radiation (maximum gain in the axis of the antenna). The smaller the cut metal part, the higher the resonance frequency of the second type of operation.

Each level gives rise to an operating mode of wire-plate antenna type: input impedance having a resonance parallel to a given frequency, and rotationally symmetrical radiation around the vertical axis (omnidirectional) and having a maximum gain at the horizon.

To the figure 19 another embodiment of the invention is shown. In this embodiment, the lower level comprises three metal surfaces 145, 146 and 147, the levels 146 and 147 of which are shown in plan view respectively. figures 20 and 21 . The three metal surfaces of this lower level are connected by at least one conductive wire.

As can be seen at figure 20 , the plate 146 has two concentric elements connected to one another by two ribbons and, as can be seen in FIG. figure 21 , the plate 147 has three concentric surfaces, the two outer concentric surfaces are interconnected by two ribbons. The inner concentric surface is connected to the intermediate concentric surface by a single ribbon.

It should be noted that, in general, any number of concentric elements can be adopted in the same conductive surface, connecting two of these concentric elements to a different terminal of a generator.

On the figures 20 and 21 , the different concentric elements do not have symmetry of revolution, according to an embodiment where the surfaces are selected specifically adapted to the intended application.

• Le premier type d'excitation (figure 17) est effectué par un fil vertical d'alimentation entre deux surfaces. Le fil d'alimentation vertical peut parcourir plusieurs niveaux en connectant l'élément central de chaque niveau. Ce fil constitue l'âme centrale d'un guide coaxial connecté à l'une des deux surfaces précitées et traverse la seconde sans la toucher. Cette dernière est alors connectée au blindage extérieur du guide coaxial (les autres niveaux sont alors alimentés par couplage).

Two types of excitation can be envisaged:

• The first type of excitation ( figure 17 ) is performed by a vertical feed wire between two surfaces. The vertical feed wire can traverse several levels by connecting the center element of each level. This wire constitutes the central core of a coaxial guide connected to one of the two aforementioned surfaces and passes through the second without touching it. The latter is then connected to the outer shield of the coaxial guide (the other levels are then supplied by coupling).

In the context of the first excitation, the outer shield of the coaxial guide may constitute the return wire to the vertical mass mentioned above.

The second type of excitation is carried out in the plane of one of the surfaces by a coplanar line, this surface possibly having three concentric elements, as represented in FIG. figure 22 , where, in this figure, it is the innermost concentric element which is connected to a first terminal of the generator, and it is the outermost concentric element which is connected to the second terminal of the generator, the intermediate concentric element being connected to the generator only through one or the other of the internal or external concentric elements.

In the case of the second type of excitation, it is preferable to connect the internal elements of each surface by a vertical connection.

As represented in Figures 23 and 24 , the electrical connections, whether they are coplanar between two concentric or transverse elements between two superposed elements, may be provided with a link diode that suppresses or adds operating modes depending on the bias voltage applied to the diode.

Claims (7)

1. Antenna of the wire-and-patch type comprising a generator and at least two parallel metal surfaces (120, 140) and mutually substantially superposed, wherein:

   - at least one of these surfaces is split into at least two concentric portions (122, 124) and constituting a central portion (122) and a strip (124) surrounding this central portion;

   - these at least two portions are interconnected by one (126) or more conductive strips or wires;

   - the at least two superposed surfaces (120, 140) are interconnected by at least one conductive wire or strip (160);

   - the at least two portions of the split surface include a portion connected to a first terminal of the generator and a portion connected to a second terminal of the generator;

   this structure imparting multifunctional behaviour to the antenna, characterised in that said antenna comprises an electrical feed connection (150) connecting the first terminal of the generator/receiver to the central portion (122) of the surface (120) split into at least two portions, which electrical connection is formed by a wire extending perpendicularly to the two surfaces (120, 140), the electrical feed connection (150) being connected to a strip (128) connected to the central portion (122) of the surface that is split into at least two portions (120).
2. Antenna according to claim 1, characterised in that the electrical feed connection (150) is formed by the central conductor of a coaxial connection which passes through, without touching it, the surface that is parallel and substantially superposed to the split surface (140).
3. Antenna according to one of claims 1 to 2, characterised in that the conductive wire or strip (160) connects an outer zone (124) of the split surface (120) : and the surface (140) parallel and substantially superposed to the split surface (120).
4. Antenna according to one of claims 1 to 3, characterised in that it includes a plurality of mutually parallel top plates (120) of identical shape.
5. Antenna according to any one of claims 1 to 4, characterised in that it includes a plurality of metal parallel surfaces (120) each split into a central element (122) and a strip peripheral to the central element (124) and interconnected by a ground return strip or connection (126), the central elements (122) of the various plates (120) being interconnected by wires extending a free wire (150), while the various peripheral strips (124) are interconnected by wires extending a ground return wire (160).
6. Antenna according to one of claims 1 to 4, characterised in that it includes a plurality of solid metal parallel surfaces (120) interconnected by at least one wire (150), and preferably via multiple connections disposed in a symmetrical arrangement.
7. Antenna according to one of claims 1 to 6, characterised in that it comprises three surfaces (122, 124, 140) arranged in series between two terminals of a generator/receiver.

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