EP2889955B1 - Compact antenna structure for satellite telecommunication - Google Patents

Description

The present invention relates to an antenna structure for telecommunications, a platform comprising the antenna structure and a method for satellite communication between two stations using the antenna structure.

In the field of satellite communications, obtaining good quality communication implies specific performances for the electromagnetic waves produced by the antenna structure used in the communication in terms of gain and level of secondary lobes (ratio between the intensity of the secondary lobes and the intensity of the main lobe). This is all the more true for so-called “broadband” satellite communications, that is to say communications that do not only transmit voice.

In the particular case of the Ka electromagnetic band, two distinct frequency bands are involved. Indeed, in transmission, the electromagnetic waves of the Ka band have a frequency between 27 gigahertz (GHz) and 31 GHz while in reception, the electromagnetic waves of the Ka band have a frequency between 17.3 GHz and 21 GHz. .2GHz. In the remainder of the description, the Ka band for transmission is denoted Tx while the Ka band for reception is denoted Rx. Furthermore, the polarizations of the waves in transmission and in reception are generally of the opposite or non-opposing circular type.

These frequencies and these circular polarizations in reception and in transmission impose constraints on the antenna structure. Moreover, in the context of a satellite link, the antenna should be oriented in order to point the satellite making it possible to establish the link. In addition, to reduce the visual signature (physical clutter), parabolic antenna type solutions are generally not preferred. Especially since in this case, the depth of the antenna is constrained by the focal length of the source illuminating the parabola.

Among the antenna structures making it possible to respect these various constraints, it is known to use an electronic scanning antenna which can comprise two separate antenna panels respectively for the emission of a wave whose central frequency is around 30 GHz and for the reception. of a wave centered around 20 GHz.

However, the electronically scanned antenna obtained may have a large bulk corresponding to the radiating surfaces of each of the operating modes (transmission/reception). Furthermore, the efficiency of such an antenna can be insufficient as a function of the elementary antenna used and of the associated power supply circuit, in particular when it comes to patch-type antennas.

In addition, the implementation of a circular polarization in a first direction in the transmission part and a circular polarization in a second direction opposite or not to the first direction for the reception part proves to be difficult in the case of the use of a polarizer, which reduces the flexibility of use of the considered scanning antenna.

Other antennal structures are also known from documents US 6,441,800 B1 , from the article of DANIEL JP et al. entitled “Research on planar antennas and arrays: 'Radiant structures'” , from the article of SMITH D et al. titled “Dual Polarized Microstrip Antenna Design for a Polarization Shift Keying Microwave Transponder” , from the article of SHENG YE et al. titled “High-Gain Planar Antenna Arrays for Mobile Satellite Communications [Antenna Applications Corner]” and document DE 10 2011 066457 A1 .

There is therefore a need for an antenna structure for telecommunications, in particular satellite in the Ka band, having a reduced size in terms of depth and pointing capacity by using an electronic scanning principle while allowing the obtaining of a communication good quality broadband, particularly in terms of gain, ellipticity ratio and secondary lobes compatible with standard templates.

To this end, an antenna structure is proposed for telecommunications, in particular by satellite, according to claim 1.

According to particular embodiments, the antenna structure comprises one or more of the characteristics of claims 2 and 3 taken individually or in any technically possible combination.

Furthermore, the invention also relates to a platform, in particular aerial, comprising at least one antenna structure as described above.

The present invention also relates to a method of telecommunication, in particular by satellite, between two stations comprising at least one of the following steps: a step of emitting electromagnetic waves having a frequency of between 27 GHz and 31 GHz by a structure antenna as previously described and a step for receiving electromagnetic waves having a frequency between 17.3 GHz and 21.2 GHz by an antenna structure as previously described.

• figure 1, un schéma d'une structure antennaire propre à fonctionner sur la bande Ka,
• figure 2, un schéma en perspective d'une antenne élémentaire fonctionnant sur la bande Tx ;
• figures 3 et 4, des graphiques montrant respectivement l'évolution du taux d'ellipticité et du taux d'ondes stationnaires de l'antenne élémentaire de la figure 2 sur la bande Tx en fonction de la fréquence de fonctionnement ;
• figure 5, un schéma d'un réseau comprenant un ensemble d'antennes élémentaires selon la figure 2 ;
• figures 6 et 7, des graphiques montrant l'évolution du taux d'ellipticité et du taux d'ondes stationnaires du réseau de la figure 5 en fonction de la fréquence de fonctionnement ;
• figure 8, un graphique montrant l'évolution du gain de la structure antennaire selon la figure 5 en fonction de l'angle d'élévation ;
• figure 9, un schéma d'un panneau fonctionnant sur la bande Tx et comprenant des réseaux selon la figure 5 ;
• figures 10 et 11, des graphiques montrant l'évolution du gain du panneau de la figure 9 en fonction de l'angle d'élévation et pour un angle d'azimut donné ;
• figure 12, un graphique montrant l'évolution du taux d'ellipticité du panneau de la figure 9 en fonction de la fréquence de fonctionnement ;
• figure 13, un graphique montrant l'évolution du gain du panneau de la figure 9 en fonction de l'angle d'azimut lorsqu'un dépointage est mis en oeuvre ;
• figure 14, un schéma en perspective d'une antenne élémentaire fonctionnant en bande Rx ;
• figures 15 et 16, des graphiques montrant l'évolution du taux d'ellipticité et du taux d'ondes stationnaires pour l'antenne élémentaire de la figure 14 sur la bande Rx en fonction de la fréquence de fonctionnement ;
• figure 17, un schéma d'un réseau comprenant un ensemble d'antennes élémentaires selon la figure 14 ;
• figures 18 et 19, des graphiques montrant l'évolution du taux d'ellipticité et du taux d'ondes stationnaires du réseau de la figure 17 en fonction de la fréquence de fonctionnement ;
• figure 20, un graphique montrant l'évolution du gain du réseau de la figure 17 en fonction de l'angle d'élévation ;
• figure 21, un schéma d'un panneau fonctionnant sur la bande Rx et comprenant des réseaux selon la figure 17 ;
• figures 22 et 23, des graphiques montrant l'évolution du gain du panneau de la figure 21 en fonction de l'angle d'élévation et respectivement de l'angle d'azimut, et
• figure 24, un graphique montrant l'évolution du taux d'ellipticité du panneau de la figure 21 en fonction de la fréquence de fonctionnement.

Other characteristics and advantages of the invention will appear on reading the following detailed description of embodiments of the invention, given by way of example only and with reference to the drawings which are:

• figure 1 , a diagram of an antenna structure capable of operating on the Ka band,
• figure 2 , a diagram in perspective of an elementary antenna operating on the Tx band;
• figures 3 and 4 , graphs showing respectively the evolution of the rate of ellipticity and the rate of stationary waves of the elementary antenna of the picture 2 on the Tx band depending on the operating frequency;
• figure 5 , a diagram of a network comprising a set of elementary antennas according to the picture 2 ;
• figure 6 and 7 , graphs showing the evolution of the ellipticity rate and the standing wave rate of the network of the figure 5 depending on the operating frequency;
• figure 8 , a graph showing the evolution of the gain of the antenna structure according to the figure 5 as a function of elevation angle;
• figure 9 , a diagram of a panel operating on the Tx band and including networks according to the figure 5 ;
• figure 10 and 11 , graphs showing the evolution of the gain of the panel of the figure 9 as a function of elevation angle and for a given azimuth angle;
• figure 12 , a graph showing the evolution of the ellipticity rate of the panel of the figure 9 depending on the operating frequency;
• figure 13 , a graph showing the evolution of the gain of the panel of the figure 9 as a function of the azimuth angle when depointing is implemented;
• figure 14 , a diagram in perspective of an elementary antenna operating in the Rx band;
• figures 15 and 16 , graphs showing the evolution of the ellipticity ratio and the standing wave ratio for the elementary antenna of the figure 14 on the Rx band depending on the operating frequency;
• figure 17 , a diagram of a network comprising a set of elementary antennas according to the figure 14 ;
• figures 18 and 19 , graphs showing the evolution of the ellipticity rate and the standing wave rate of the network of the figure 17 depending on the operating frequency;
• figure 20 , a graph showing the evolution of the network gain of the figure 17 as a function of elevation angle;
• figure 21 , a diagram of a panel operating on the Rx band and including networks according to the figure 17 ;
• figure 22 and 23 , graphs showing the evolution of the gain of the panel of the figure 21 as a function of elevation angle and azimuth angle respectively, and
• figure 24 , a graph showing the evolution of the ellipticity rate of the panel of the figure 21 depending on the operating frequency.

In the context of a telecommunications application, in particular by satellites in the Ka band, an antenna structure 10 is proposed comprising a transmission surface 11Tx and a reception surface 11Rx as shown in figure 1 .

In the example presented, the emission surface 11Tx has a generally rectangular shape and the reception surface 11Rx also has a generally rectangular shape. Each surface for transmission 11Tx and reception 11Rx accommodates a plurality of elementary antennas 12Tx (for transmission) and 12Rx (for reception).

The whole of the emission surface 11Tx and of the plurality of elementary antennas 12Tx forms a emission panel 13Tx while the whole of the reception surface 11Rx and of the plurality of elementary antennas 12Rx forms a panel of 13Rx reception.

In the following, the structure of the 13Tx transmission panel is detailed by successively describing an elementary 12Tx antenna for transmission ( figures 2 to 4 ), a line comprising a plurality of elementary antennas 12Tx for transmission ( figure 5 to 8 ) and then the 13Tx transmit panel itself ( figures 9 to 13 ).A 12Tx elementary antenna for transmission is shown on the figure 2 . This implies that the elementary antenna 12Tx is capable of emitting an electromagnetic wave whose wavelength is denoted λ0, this wavelength λ0 corresponding to a central frequency of the band comprised between 27 GHz and 31 GHz.

The elementary antenna 12Tx comprises two patches 14Tx, 16Tx at least partially superimposed.

Each 14Tx, 16Tx patch is circular in shape.

The first patch 14Tx comprises a first metallized layer 18Tx and a first insulating layer 20Tx, the first metallized layer 18Tx being arranged on the insulating layer 20Tx.

The first metallized layer 18Tx is circular in shape and has a first diameter d1Tx.

The shape of the first metallized layer 18Tx gives the first patch 14Tx a circular shape.

The second patch 16Tx also comprises a second metallized layer and a second insulating layer 24Tx, the second metallized layer being arranged on the second insulating layer 24Tx.

The second metallized layer comprises a circular part 26Tx and two current supply ports 28Tx, 30Tx.

The circular part 26Tx is circular in shape and has a second diameter denoted d2Tx. The first access 28Tx comprises two first sections 32Tx and 34Tx, a first proximal section 32Tx in contact with the circular part 26Tx and a first section 34Tx distal with respect to the circular part 26Tx.

The first proximal section 32Tx is rectilinear and extends along a direction called the first proximal direction. The first proximal section 32Tx is normal with respect to the portion of the circular part 26Tx with which the first proximal section 32Tx is in contact.

The first distal section 34Tx is straight and extends in the extension of the proximal section 32Tx along a direction called the first distal direction. The first proximal and distal directions form an angle greater than 90° between them. Preferably, the angle between the first proximal direction and the first distal direction is between 120° and 145°.

Similarly, the second access 30Tx comprises two second sections 38Tx and 40Tx, a second proximal section 38Tx in contact with the circular part 26Tx and a second section 40Tx distal with respect to the circular part 26Tx.

The second proximal section 38Tx is rectilinear and extends along a direction called the second proximal direction. The second proximal section 38Tx is normal with respect to the portion of the circular part 26Tx with which the second proximal section 38Tx is in contact.

According to the example of picture 2 , the two proximal directions form an angle between them of less than 180°. Thus, each access 28Tx, 30Tx is in an angular sector having an angle with respect to the center of the circular part less than 180°.

In other words, the distance between the two accesses 28Tx and 30Tx is less than 0.5*λ0 to allow the realization of the pointing function by phase shift with the least degradation of the secondary lobes in order to remain compatible with the normalization templates. Preferably, the distance between the two ports 28Tx and 30Tx is less than or equal to 0.42*λ0.

The second distal section 40Tx is straight and extends in the extension of the second proximal section 38Tx along a direction called the second distal direction. The second proximal and distal directions form an angle greater than 90° between them. Preferably, the angle between the second proximal direction and the second distal direction is between 120° and 145°.

The shape of the second metallized layer gives the second patch 16Tx a general circular shape so that it is considered in a simplified way in the following that the second patch 16Tx has a circular shape.

Thus, in particular, it is considered that the second diameter d2Tx of the circular part 26Tx is the diameter of the second patch 16Tx.

Preferably, the first diameter d1Tx and the second diameter d2Tx can be identical.

The two patches 14Tx and 16Tx are at least partially superimposed. This means that the two patches 14Tx and 16Tx are at least partially aligned along a first direction Z.

According to the particular example of figure 2 , the two patches 14Tx and 16Tx are superimposed. This means that the projection of the circular part 26Tx on the plane comprising the first metallized layer 18Tx coincides with the first metallized layer 18Tx.

Furthermore, the circular part 26Tx and the first metallized layer 18Tx are parallel. The two patches 14Tx and 16Tx are thus spaced apart along a first direction Z by a distance denoted ezTx.

Preferably, but not necessarily according to the invention, the spacing distance ezTx between the two patches 14Tx and 16Tx along the first direction Z is between 0.5 millimeters (mm) and 2.0 mm. According to the invention, the spacing distance ezTx between the two patches 14Tx and 16Tx along the first direction Z is between 0.75 mm and 1.5 mm.

In a manner known per se, the spacing distance ezTx between the two patches 14Tx and 16Tx along the first direction Z, the diameter d1Tx and d2Tx of the patches 14Tx and 16Tx make it possible to determine the frequency or frequencies at which (or at which) the elementary antenna 12Tx is capable of transmitting.

The elementary antenna 12Tx is dimensioned to emit frequencies comprised between 27 GHz and 31 GHz (Tx band). This means that such an elementary antenna 12Tx has first and second diameters d1Tx, d2Tx of between 2.5 mm and 4 mm. The upper limit corresponds to the product of 0.4 by the wavelength λ0 that the elementary antenna 12Tx is capable of transmitting.

Alternatively, instead of a condition on the diameters d1Tx, d2Tx, a constraint is imposed on the geometry of the second patch 16Tx. The second patch 16Tx is then writable in a rectangle whose extension exTx along a second X direction is between 4.0 mm and 4.4 mm and the extension eyTx along a third Y direction is between between 3.8mm and 4.2mm. The two directions X and Y are perpendicular to each other and to the first direction Z.

The performances of the elementary 12Tx antenna for transmission are now described with reference to the figures 3 and 4 .

The figures 3 and 4 show that over the entire band of interest (in this case, it is the Tx band), the ellipticity rate is relatively low as well as the standing wave rate (noted for simplicity by the corresponding acronym, i.e. TOS, in all the figures in which this rate appears).

The 12Tx elementary antenna therefore has a wide band, i.e. a band greater than 5% around the central operating frequency, with circular polarization and very good radiation efficiency (in particular the axial ratio for such a small antenna is better than in the state of the art and the apodization of the radiation pattern for the emitted wave is facilitated when networking).

It should be noted that in the illustrated embodiment, the two patches 14Tx and 16Tx are arranged so that the second metal layer faces the first insulating layer 20Tx.

As a variant, the two patches 14Tx and 16Tx are arranged so that the second metallic layer faces the first metallic layer 18Tx.

It is also proposed a 50Tx network as illustrated by the figure 5 , comprising a plurality of elementary antennas 12Tx for transmission.

According to the particular example of figure 5 , the 50Tx network comprises twenty-four elementary 12Tx antennas.

In general, a combination of a larger number of 12Tx elementary antennas is possible depending on the overall dimensions and the desired performance, in particular at the gain level of the 50Tx network.

Each 12Tx elementary antenna of the figure 5 is identical to the elementary 12Tx antenna described with reference to picture 2 .

Alternatively, some antennas are different.

The 12Tx elementary antennas are arranged regularly along a line thus forming the 50Tx array. In addition, the 12Tx elementary antennas are connected together to form the 50Tx network. The connection is made via two straight lines which ensure the supply of the unitary network. The 50Tx network as well formed on transmission has two ports which allow, depending on the power supply, to radiate an electromagnetic wave in the desired frequency band according to the desired circular polarization.

In the example of the figure 5 , the 50Tx grating exhibits an extension ex2Tx along the second X direction of between 4 mm and 6 mm. Preferably, the extension ex2Tx along the second direction X is between 4.5 mm and 5.5 mm.

In the example of the figure 5 , the 50Tx grating also exhibits an extension ey2Tx along the third Y direction between 160 mm and 190 mm. Preferably, the extension ey2Tx along the third direction Y is between 165 mm and 185 mm.

In operation, each elementary antenna 12Tx of the 50Tx array is powered by an electromagnetic wave. Each elementary antenna 12Tx picks up the electric field resulting from this electromagnetic wave so that the 50Tx network emits a wave in the desired frequency band.

The performances in terms of ellipticity ratio and standing wave ratio and advantages granted by the 50Tx network are similar to the performances and advantages granted by the 12Tx elementary antenna of the figure 2 as shown by the study of figure 6 and 7 .

Also, it appears on the figure 8 that the 50Tx network has a gain of the order of 20 dB, which testifies to the good radiation efficiency of the antenna structure with regard to its dimensions, that is to say the ex2Tx extension along the second direction X and the extension ey2Tx along the third direction Y.

The figure 9 illustrates the 13Tx transmit panel of the figure 1 . The elements identical to the embodiment of the figure 5 are not described again. Only the differences are highlighted.

The 13Tx transmit panel has eight 50Tx arrays instead of a single 50Tx array.

In general, an association of a larger number of 50Tx gratings is possible depending on the overall dimensions and the desired performance, particularly in terms of gain and radiation aperture.

In this case, the number of antennas for the 50Tx array is chosen according to a dimensional constraint applied along the third direction Y.

Each 50Tx network is parallel to the other 50Tx networks.

The 12Tx elementary antennas are staggered. Such an arrangement makes it possible to maintain the performance in terms of stability of the rate of ellipticity during the networking of the overall structure as well as during the realization of pointing by phase shift.

Also, in the example of the figure 9 , the emission panel 13Tx has an extension ex3Tx along the second direction X between 40 mm and 50 mm. Preferably, the extension ex3Tx along the second direction X is between 45 mm and 48 mm. The extension ex3Tx along the second direction X is linked to the number of 50Tx array antennas considered. In the case presented on the figure 9 , the extension ex3Tx along the second direction X corresponds to approximately nine times the size of an elementary antenna.

In the example of the figure 9 , the 13Tx emission panel also has an extension ey3Tx along the third Y direction between 160 mm and 190 mm. Preferably, the extension ey3Tx along the third Y direction is between 165 mm and 185 mm. The extension ey3Tx along the third direction Y is linked to the number of elementary antennas 12Tx considered.

The performances in terms of ellipticity rate and advantages granted by the 13Tx emission panel are similar to the performances and advantages granted by the 12Tx elementary antenna of the figure 2 as shown by the study of figure 12 .

Additionally, it appears on the figure 10 and 11 that the emission panel 13Tx has a gain of the order of 28 dB, which corresponds to an effective compact antenna structure at the operating frequency considered.

In addition, when a depointing is performed, it can be shown by comparing, in particular, the figure 11 and 13 that the 26 dB gain is obtained in a relatively distant direction determined by an azimuth angle of 30°. The proposed 13Tx transmission panel is therefore robust to misalignment with very low rise in the secondary lobes.

In the following, the structure of the 13Rx reception panel of the figure 1 is detailed by successively describing an elementary antenna 12Rx for reception ( figures 14 to 16 ), a line comprising a plurality of elementary antennas 12Rx for reception ( figures 17 to 20 ) and then the 13Rx receiving panel itself ( figures 21 to 24 ).

The figure 14 illustrates a 12Rx elementary antenna for reception. The elements identical to the elementary 12Tx antenna for transmitting the picture 2 are not described again. Only the differences are highlighted.

The reference signs of the elements of the elementary antenna 12Rx for reception are followed by a suffix Rx instead of the suffix Tx for the corresponding elements of the elementary antenna 12Rx.

A 12Rx elementary antenna for reception is shown on the figure 14 . This implies that the elementary antenna 12Rx is capable of receiving an electromagnetic wave whose wavelength is denoted λ0, this wavelength λ0 corresponding to a frequency comprised between 17.3 GHz and 21.2 GHz.

Also, the elementary antenna 12Rx is sized to receive frequencies between 17.3 GHz and 21.2 GHz (Rx band). This means that such an elementary antenna 12Rx has first and second diameters d1Rx, d2Rx of between 4.5 mm and 7 mm.

Alternatively, instead of a condition on the diameters d1Rx, d2Rx, a constraint is imposed on the second patch 16Rx. The second patch 16Rx is then writable in a rectangle whose extension exRx along the second direction X is between 6.6 mm and 7.0 mm and the extension eyRx along the third direction Y is between 6 .0mm and 6.4mm.

The performances of the 12Rx elementary antenna for reception are now described with reference to the figures 15 and 16 .

The performances and advantages granted by the elementary antenna 12Rx for reception are similar to the performances and advantages granted by the elementary antenna 12Tx for transmission as shown by the study of the figures 15 and 16 .

The figure 17 illustrates a 50Rx network for reception according to the invention. According to the particular example of figure 17 , the 50Rx network comprises eighteen elementary antennas 12Rx.

In general, a combination of a larger number of elementary antennas 12Rx is possible depending on the overall dimensions and the desired performance, in particular at the gain level of the 50Rx network.

In this case, the number of antennas for the 50Rx array is chosen according to a dimensional constraint applied along the third direction Y.

Each 12Rx elementary antenna of the figure 17 is identical to the elementary antenna 12Rx described with reference to the figure 14 .

Alternatively, some antennas are different.

The elementary antennas 12Rx are arranged regularly along a line thus forming the network 50Rx. Furthermore, the elementary antennas 12Rx are connected together to form the network 50Rx. The connection is made via a straight line which supplies the unit network. The 50Rx network thus formed on reception has two ports which make it possible, depending on the power supply, to receive an electromagnetic wave in the desired frequency band according to the desired circular polarization.

In the example of the figure 17 , the 50Rx grating exhibits an ex2Rx extension along the second X direction of between 6 mm and 8.5 mm. Preferably, the ex2Rx extension along the second X direction is between 7.6 mm and 8.0 mm.

In the example of the figure 17 , the 50Rx grating also exhibits an extension ey2Rx along the third Y direction between 180 mm and 200 mm. Preferably, the extension ey2Rx along the third Y direction is between 185 mm and 195 mm. The extension ey2Rx along the third direction Y is linked to the number of elementary antennas 12Rx considered.

The performance in terms of ellipticity rate and standing wave rate granted by the 50Rx network are similar to the performance and advantages granted by the elementary antenna 12Rx according to the example of the figure 14 as shown by the study of figures 18 and 19 .

Also, it appears on the figure 20 that the 50Rx network has a gain of the order of 18 dB, which corresponds to an effective compact antenna structure at the operating frequency considered.

The figure 21 illustrates the 13Rx receiving panel of the figure 1 . The elements identical to the embodiment of the figure 17 are not described again. Only the differences are highlighted.

The 13Rx receiving panel has eight 50Rx arrays instead of a single 50Rx array.

In general, an association of a larger number of 50Rx gratings is possible depending on the overall dimensions and the desired performance, particularly in terms of gain and radiation aperture.

Each 50Rx array is parallel to the other 50Rx arrays.

The elementary antennas 12Rx are arranged in staggered rows. Such an arrangement makes it possible to maintain the performance in terms of stability of the ellipticity rate during the networking of the overall structure as well as the realization of the pointing by phase shift.

Also, in the example of the figure 21 , the 13Rx receiving panel has an ex3Rx extension along the second X direction of between 60 mm and 80 mm. Preferably, the ex3Rx extension along the second direction X is between 65 mm and 75 mm. The ex3Rx extension along the second X direction is related to the number of 50Tx networks considered.

In the example of the figure 21 , the 13Rx receiving panel also has an extension ey3Rx along the third Y direction between 190 mm and 210 mm. Preferably, the ey3Rx extension along the third Y direction is comprised between 195mm and 205mm. The extension ey3Rx along the third direction Y is linked to the number of elementary antennas 12Tx considered.

The performance in terms of ellipticity rate and gain and benefits afforded by the 13Rx receiver panel are similar to the performance and benefits afforded by the 50Rx array of the figure 17 as shown by the study of figures 22 to 24 .

In all the embodiments, because the elementary antenna 12 is broadband, of circular polarization and has good radiation efficiency, the antenna structure 10 has a reduced size as well as a reduced weight compared to the antenna structures of the state of the art for identical performance in terms of radiation. This reduced weight makes it possible to reduce the constraints in particular in the case where the complete antenna is accompanied by a mechanical positioner.

In addition, the production of this antenna structure 10 on a single-layer substrate makes it easy to insert on the rear side at the ground plane level, with the least constraint and impact on the radiation performance, the coupler devices, power supply and phase shift to ensure the control and choice of polarization as well as of phase and amplitude law making it possible to orient the radiation diagram in the desired direction in electronic scanning configuration.

The antenna structure 10 is also capable of transmitting or receiving circularly polarized electromagnetic waves without using an additional polarizer. This improved compactness is accompanied by a gain in lightness and a gain in radiation performance over a wide frequency band compatible with the targeted application. Furthermore, the antenna structure 10 is easy to make and can be manufactured at low cost.

Thus, the proposed antenna structure 10 can be used for telecommunications applications between two stations, in particular by satellite. It should be noted that in this case, the radiation pattern of the antenna structure 10 thus produced complies with the templates specified for use with certain satellites.

Such an antenna structure 10 can advantageously be used in a platform, in particular aerial of the helicopter or drone type. In the context of this use, the compactness of the antenna structure 10 makes it possible to reduce the constraints on the installation of equipment in the platform.

The antenna structure 10 presented with reference to the figure 1 is an example of antenna structure 10 exhibiting the compactness properties described above. Other similar antenna structures 10 can also be envisaged, in particular with a different number of elementary reception 12Rx and/or transmission 12Tx antennas and a different arrangement thereof.

These different antenna structures 10 are antenna structures for telecommunications, in particular satellite, having a reduced size in terms of depth and pointing capabilities by using an electronic scanning principle while allowing high-speed communication of good quality to be obtained. quality, in particular in terms of gain, ellipticity rate and secondary lobes compatible with normative templates.

Claims (5)

1. An antenna structure (10) for telecommunications, in particular by satellite, comprising:

   • an emitting surface (11Tx) comprising at least one set of a plurality of elementary emitting antennas (12Tx) forming an array (50Tx), and

   • a receiving surface (11Rx) comprising at least one set of a plurality of elementary receiving antennas (12Rx) forming an array (50Rx),

   the antenna structure (10) being characterized in that it is electronically-scanned and that it is realized on single-layer substrate comprising a rear side at the ground plane and that it comprises coupling, power supplying and phase shifting devices inserted on the rear side, and

   • at least one elementary emit antenna (12Tx) comprising two generally circular patches (14Tx, 16Tx) that are at least partially superimposed, said at least one elementary emitting antenna (12Tx) being dimensioned to emit at least one electromagnetic wave having a frequency comprised between 27 GHz and 31 GHz, and

   • at least one elementary receiving antenna (12Rx) comprising two generally circular patches (14Rx, 16Rx) that are at least partially superimposed, said at least one elementary receiving antenna (12Rx) being dimensioned to receive at least one electromagnetic wave having a frequency comprised between 17.3 GHz and 21.2 GHz;

   and in that the emitting surface (11Tx) is for circular polarization in a first direction, and the receiving surface (11Rx) is for circular polarization in a second direction opposed to the first direction,
   and in that:

   • each patch (14Tx, 16Tx) of said at least one elementary emitting antenna (12Tx) has a center, said elementary emitting antenna (12Tx) comprising two power supply ports (28Tx, 30Tx) able to power one of the two patches (14Tx, 16Tx), each port (28Tx, 30Tx) being in an angular sector having an angle relative to the center of the powered patch (14Tx, 16Tx) smaller than 180°, and/or

   • each patch (14Rx, 16Rx) of said at least one elementary receiving antenna (12Rx) has a center, said elementary receiving antenna (12Rx) comprising two power supply ports (28Rx, 30Rx) able to power one of the two patches (14Rx, 16Rx), each port (28Rx, 30Rx) being in an angular sector having an angle relative to the center of the powered patch (14Rx, 16Rx) smaller than 180°,

   and in that

   • the two patches (14Tx, 16Tx) of said at least one elementary emitting antenna (12Tx) are spaced apart in a first direction (Z) by a distance (ezTx) comprised between 0.75 millimeters (mm) and 1.5 mm, and/or

   • the two patches (14Rx, 16Rx) of said at least one elementary receiving antenna (12Rx) are spaced apart in a first direction (Z) by a distance (ezRx) comprised between 0.75 millimeters (mm) and 1.5 mm, and

   in that

   • the diameters (d1Tx, d2Tx) of the two patches (14Tx, 16Tx) of said at least one elementary emitting antenna (12Tx) are identical, and/or

   • the diameters (d1Rx, d2Rx) of the two patches (14Rx, 16Rx) of said at least one elementary receiving antenna (12Rx) are identical.
2. The antenna structure according to claim 1, wherein the elementary emitting antennas (12Tx) and the elementary receiving antennas (12Rx) are arranged in staggered rows.
3. The antenna structure according to claim 1 or 2, wherein:

   • the emitting surface (11Tx) is generally rectangular and comprises at least two sets of a plurality of elementary emitting antennas (12Tx) each forming an array (50Tx), the elementary emitting antennas (12Tx) of each set (50Tx) being along a line specific to that set, each line being parallel to the other specific lines, and/or

   • the receiving surface (11Rx) is generally rectangular and comprises at least two sets of a plurality of elementary receiving antennas (12Rx) each forming an array (50Rx), the elementary receiving antennas (12Rx) of each set being along a line specific to that set, each line being parallel to the other specific lines.
4. A platform, in particular aerial, comprising at least one antenna structure (10) according to any one of claims 1 to 3.
5. A telecommunications method, in particular by satellite, between two stations comprising at least one of the following steps:

   - a step for emitting electromagnetic waves having a frequency comprised between 27 GHz and 31 GHz via an antenna structure (10) according to any one of claims 1 to 4, and

   - a step for receiving electromagnetic waves having a frequency comprised between 17.3 GHz and 21.2 GHz via an antenna structure (10) according to any one of claims 1 to 3.

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