Amplitude modulation antenna and associated process

Abstract

Amplitude Modulated Antenna and Associated Method. The present invention relates to an antenna comprising a plurality of sources and a beamforming module connected to the sources. Each source comprises a radiating element (110) with a respective principal radiation axis (Xi, Xj), the inclination of which varies within the antenna. The beamforming module is capable of generating and applying an amplitude modulation law to the radiating elements (110) depending on the beam to be formed. The amplitude modulation law includes an amplitude modulation coefficient for each radiating element (110), such that each radiating element (110) emits a signal having a respective amplitude equal to a given amplitude modulated by the corresponding amplitude modulation coefficient, or receives a signal having a respective amplitude, the corresponding amplitude modulation coefficient being applied to the respective amplitude after reception.The invention also relates to an associated method of use. Figure for the abstract: [Fig 2].

Description

Title of the invention: Amplitude modulation antenna and associated method

[0001] The present invention relates to an antenna comprising a plurality of sources, each source comprising a radiating element, each radiating element having a respective principal axis of radiation.

[0002] The antenna according to the invention is intended to be used within a satellite constellation, for example in an orbit around the Earth's surface strictly lower than the geostationary orbit.

[0003] The invention further relates to an associated method.

[0004] The use of active antennas in the form of planar arrays is particularly known for the implementation of telecommunications constellations. Each antenna element in the array has a radiation axis perpendicular to the plane of the array.

[0005] However, such antennas have several disadvantages.

[0006] To cover a wide field of view in low Earth orbit with such an active antenna, the size of the source is generally limited to a dimension on the order of 0.6 times the wavelength. In reception, for the Ka band and a frequency between 27.5 GHz and 31 GHz, this means that the source is approximately 6 mm in size. Manufacturing sources of this size, with satisfactory performance and suitable for industrial production, is complex.

[0007] Furthermore, in order to minimize any losses between an amplifier and the radiating element, it is preferable to plan the possible amplification chain as close as possible to the radiating element, so that the small size of the sources arranged in such a network complicates the realization of the amplification chain.

[0008] Furthermore, an antenna comprising a fine-mesh array of radiating elements is more likely to exhibit an active standing wave ratio. This can then create blinding directions, in which destructive recombination of the radiation patterns degrades the directivity. The finer the array mesh, the greater the risk of encountering this phenomenon.

[0009] Furthermore, such a flat antenna has its optimum directivity along its axis perpendicular to the plane. The greater the beam pointing angle, the lower the directivity. A loss of around -3 dB is typically observed at the edge of coverage. This is particularly problematic in the case of low or medium Earth orbit constellations, as the smallest terminals are often flat antennas that exhibit lower performance at low user elevation. Finally, from the satellite's perspective, the greater the pointing angle, the more The area covered by the beam is important. With a flat antenna, the worst performance is therefore over the largest areas and thus where there are potentially the most users.

[0010] Finally, to point a beam in a certain direction, the standard method consists of applying a phase law to the grating. However, since the law is calculated for a given frequency, it is observed that, at the edge of the band, the beam no longer points where it should, the performance in the direction of interest being degraded; this phenomenon is called strabismus.

[0011] In US document 2013 / 0234890 A1, an antenna system is described having an array of antenna elements, in which each antenna element is switchable between a plurality of phase-shift states.

[0012] However, such an antenna system does not allow precise control of the shape of the radiation pattern. Moreover, it is sensitive to the phenomenon of strabismus.

[0013] The aim of the invention is then to propose an antenna limiting the disadvantages presented above.

[0014] To this end, the invention relates to an antenna comprising a plurality of sources, each source comprising a radiating element, each radiating element having a respective principal radiation axis, each respective principal radiation axis having an inclination with a reference axis, the reference axis being common to the plurality of sources, the inclination of the respective principal radiation axes varying within the antenna, the antenna comprising a beamforming module connected to the sources, the beamforming module being capable of controlling the radiating elements to form at least one beam,

[0015] characterized in that the beamforming module is capable of generating and applying an amplitude modulation law to the radiating elements, the amplitude modulation law depending on the beam or beams to be formed, the amplitude modulation law comprising an amplitude modulation coefficient for each radiating element, so that each radiating element emits a signal having a respective amplitude equal to a given amplitude modulated by the corresponding amplitude modulation coefficient or receives a signal having a respective amplitude, the corresponding amplitude modulation coefficient being applied to the respective amplitude after reception.

[0016] Modulating the amplitude for each radiating element allows better control of the shape of the radiation pattern, while limiting the strabismus phenomenon and the disadvantages of a planar antenna, whose radiation axes of the radiating elements are perpendicular to the planar array.

[0017] According to other advantageous aspects of the invention, the antenna comprises one or more of the following features, taken individually or in all technically possible combinations:

[0018] - the radiating elements are arranged such that the principal radiation axes are each tangent to a unique three-dimensional curve exhibiting rotational symmetry about the reference axis, the three-dimensional curve being representative of a polynomial function in any plane passing through the reference axis, or

[0019] the radiating elements are arranged so that each radiating element is a translation image parallel to the reference axis of a corresponding fictitious radiating element, the fictitious radiating elements being such that their principal axes of radiation are each tangent to a single three-dimensional curve exhibiting rotational symmetry about the reference axis, the three-dimensional curve being representative of a polynomial function in any plane passing through the reference axis;

[0020] - the beamforming module is capable of generating the modulation law amplitude depending on the main direction of the beam(s) to be formed;

[0021] - the beamforming module is capable of generating and applying a law phase modulation at radiating elements, the phase modulation law depending on the beam(s) to be formed, the phase modulation law including a phase shift for each radiating element, so that each radiating element emits a signal with the corresponding phase shift or receives a signal to which the phase shift is applied;

[0022] - the beamforming module is digital;

[0023] - the antenna is capable of generating a beam with a frequency between 1 GHz and 44 GHz; and / or

[0024] - the antenna comprises a plurality of connectors, each connector connecting a respective source to a module, the sources and fittings being made by additive manufacturing.

[0025] The invention also relates to a method of using an antenna as defined above, comprising the following steps:

[0026] - generation of an amplitude modulation law by the training module of beams to form at least one beam,

[0027] - emission or reception of a signal by the radiating elements, and

[0028] - application of the amplitude modulation law generated to the signal received or transmitted at emitted by the radiating elements.

[0029] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations:

[0030] - the method of use includes the generation of a phase modulation law by the beamforming module to form at least one beam, and the application of the phase shift corresponding to the signal received or emitted by each radiating element; and / or

[0031] - a plurality of beams are formed simultaneously, the modulation law generated amplitude corresponding to the superposition of amplitude modulation sub-laws to form each beam.

[0032] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0033] [Fig-1] [Fig.1] is a schematic representation of an example of an antenna according to an embodiment of the invention,

[0034] [Fig.2] [Fig.2] is a three-dimensional view of a first example of an arrangement radiating elements of an antenna according to an embodiment of the invention,

[0035] [Fig.3] [Fig.3] is a three-dimensional view of a second example of the arrangement of radiating elements of an antenna according to an embodiment of the invention,

[0036] [Fig.4] [Fig.4] is a three-dimensional representation of an example of zones of an amplitude modulation law for the formation of an example beam, and

[0037] [Fig.5] [Fig.5] is a schematic view of an example of a beamforming module of an antenna according to an embodiment of the invention.

[0038] The invention relates to an antenna.

[0039] The antenna is, for example, adapted for use on the Earth's surface, mounted on an aircraft or used in space, for example for telecommunications or radar.

[0040] The antenna is capable of generating a beam with a frequency between 1 GHz and 44 GHz.

[0041] The antenna is, for example, adapted to be used in receive mode or in transmit mode or in transmit-receive mode.

[0042] Preferably, the antenna is adapted for use in receive mode.

[0043] Such an antenna is particularly advantageous for covering a wide angular range, especially with multiple beams.

[0044] The antenna is, for example, a satellite antenna in an orbit around the Earth's surface strictly lower than the geostationary orbit.

[0045] The antenna has, for example, an angular domain greater than or equal to ±50° with respect to an axis.

[0046] Alternatively, the antenna is, for example, used on the surface of the earth, so as to track several satellites on elevations from 10°.

[0047] An example of an antenna 10 according to the invention is shown in [Fig.1].

[0048] The antenna 10 comprises a plurality of sources 12 and a beamforming module 14.

[0049] The antenna 10 further includes an amplification block 16 per source 12.

[0050] Each source 12 is connected to the beamforming module 14, for example by the intermediary of the respective amplification block 16.

[0051] The sources 12 together form an antenna array.

[0052] The antenna array has a mesh, the mesh size being between 0.6 and 1.4 times a nominal wavelength of the antenna. The nominal wavelength of the antenna corresponds to a preferred operating wavelength of the antenna, for example between 1 GHz and 44 GHz.

[0053] A source is arranged in each mesh of the network.

[0054] Antenna 10 includes, for example, between 128 and 512 sources.

[0055] Each source 12 is, for example, made of metal, here, for example, of aluminum.

[0056] Each source 12 comprises a radiating element.

[0057] Each source 12 includes, for example, in addition a polarizer and possibly a filter.

[0058] Each radiating element is capable of presenting radiation at the level of a front face 18 of the source.

[0059] Each radiating element is, for example, of the horn type, for example circular. Alternatively, the radiating elements are of the dipole, patch or helical type.

[0060] The radiating elements have, for example, different sizes within the antenna.

[0061] Alternatively, the radiating elements all have the same size.

[0062] Each radiating element has a respective principal radiation axis XI... Xn.

[0063] Each respective principal radiation axis XI.. .Xn has an inclination with a reference axis Y.

[0064] The reference axis Y is common to the plurality of sources.

[0065] Each respective principal radiation axis XI.. .Xn forms an angle of inclination with the reference axis Y.

[0066] The inclination of the respective principal radiation axes XI.. .Xn varies within the antenna, that is to say that the radiating elements do not all have the same inclination.

[0067] The arrangement of the radiating elements here exhibits a rotational symmetry around the reference axis Y.

[0068] Radiating elements placed at equal distances from the reference axis Y have, for example, angles of inclination of equal value.

[0069] The values ​​of the angles of inclination depend on the distance between the radiating elements and the reference axis Y.

[0070] More specifically, the further the radiating element is from the reference axis, the higher the angle of inclination has a value.

[0071] The inclination profile as a function of the distance with the reference axis depends here on the area to be covered and the size of the area to be covered by the beam.

[0072] A first example of the arrangement of radiating elements of an antenna according to an embodiment of the invention is shown in [Fig.2].

[0073] The radiating elements 110 are arranged such that the principal radiation axes Xi, Xj are each tangent to a single three-dimensional curve.

[0074] The three-dimensional curve exhibits rotational symmetry around the reference axis Y.

[0075] The three-dimensional curve is, for example, representative of a polynomial function in any plane passing through the reference axis Y.

[0076] More particularly, for any plane in space passing through the reference axis Y, there exists a frame of reference in which the curve represents a function f of the form:

[0077] [Math 1] (x) = ax11+b,

[0078] with a and b real numbers, a being non-zero, and n a natural number, more particularly an even natural number.

[0079] The numbers a, b and n are chosen according to the use and desired performance of the antenna.

[0080] For each source, the intersection between the radiation axis Xi, Xj and the representative curve is defined as the radiation center of said source. Said radiation center is arranged within the corresponding radiating element.

[0081] Here, the radiating elements 110 are arranged so that their radiation axes Xi, Xj converge with each other opposite the front face of the sources. Such an antenna is called a concave antenna.

[0082] Alternatively, the radiating elements 110 are arranged so that their radiation axes Xi, Xj diverge from each other at the front face of the sources (as in [Fig. 1]). Such an antenna is called a convex antenna.

[0083] A second example of the arrangement of radiating elements 210 of an antenna according to an embodiment of the invention is shown in [Fig.3].

[0084] The radiating elements 210 are arranged so that each radiating element is a translation image parallel to the reference axis Y of a corresponding fictitious radiating element.

[0085] The inclination of each radiating element with respect to the reference axis Y is maintained by translation of the fictitious radiating element.

[0086] The fictitious radiating elements are such that their principal radiation axes are each tangent to a single three-dimensional curve.

[0087] The three-dimensional curve exhibits rotational symmetry around the reference axis.

[0088] The three-dimensional curve is representative of a function f : x-> f(x) in any plane passing through the reference axis Y.

[0089] The three-dimensional curve is, for example, representative of a polynomial function in any plane passing through the reference axis Y.

[0090] More particularly, for any plane in space passing through the reference axis, there exists a frame of reference in which the curve represents a function f of the form:

[0091] [Math 2] (x) = axa + b,

[0092] with a and b real numbers, a being non-zero, and n a natural number, more particularly an even natural number.

[0093] The numbers a, b and n are chosen according to the use and desired performance of the antenna.

[0094] The distance for each translation depends on the radiating element.

[0095] The respective translations of radiating elements placed at an equal distance from the reference axis Y have, for example, an equal translation distance between them.

[0096] The distance of the translation for each radiating element is, for example, equal to the absolute value of: Xf(x)+ q with X a number between 0 and 1 and q a real number, k and q each being a common number for all radiating elements, and f(x) the value of the function of the representative curve at the location of the corresponding fictitious radiating element.

[0097] The direction of the translation is such that the radiating elements are arranged on a three-dimensional image curve having locally a radius of curvature strictly greater than the radius of curvature of the three-dimensional curve at the level of the corresponding radiating element.

[0098] This makes it possible, in particular, to reduce the height of the radiating element array, while retaining the advantages associated with the inclination of the radiating elements. Specifically, the directivity performance of an antenna equipped with such an arrangement radiating elements are similar to those of an antenna with the radiating element arrangement described opposite [Fig.2].

[0099] The translation corresponds, for example, to a projection of each fictitious radiating element onto a reference plane, perpendicular to the reference axis Y. The reference plane is common to all the radiating elements 210.

[0100] Here, the radiating elements 210 are arranged so that their radiation axes Xi, Xj converge with each other opposite the front face of the sources. Such an antenna is called a concave antenna.

[0101] When the translations correspond to a projection of each fictitious radiating element onto a reference plane, it is, more particularly, called a concave plane antenna.

[0102] Alternatively, the radiating elements 210 are arranged so that their radiation axes Xi, Xj diverge from each other at the front face of the sources. Such an antenna is called a convex antenna.

[0103] When the translations correspond to a projection of each fictitious radiating element onto a reference plane, it is, more particularly, called a plane convex antenna.

[0104] The polarizer is connected to the corresponding radiating element upstream, so that the polarization of the signal of the radiating element is adapted according to the polarizer.

[0105] The filter is connected to the corresponding upstream polarizer, so as to apply a filter to the frequency spectrum of the radiating element.

[0106] Each source 12 is connected to the beamforming module 14, for example via the respective amplification block 16.

[0107] The antenna 10 comprises a plurality of connections 20, called a diverter network.

[0108] Each fitting 20 connects a respective source to a module, plus particularly a respective module connected to the beamforming module 14, more particularly to the respective amplification block 16.

[0109] Each connection 20 is such that the connection distance between the beamforming module 14 and the radiating element of each source 12 is equal for all sources 12.

[0110] The sources 12 and the fittings 20 are, for example, manufactured, for example together, by additive manufacturing, more particularly in metal, for example in aluminum.

[0111] Each amplification block 16 includes at least one low-noise amplifier, more particularly a low-noise bias amplifier.

[0112] Each amplification block 16 is connected to the beamforming module 14.

[0113] Each amplification block 16 is configured to amplify a signal passing through it, going from source 12 to beamforming module 14 and / or from beamforming module 14 to source 12.

[0114] The beamforming module 14 is capable of controlling the signals from the radiating elements in case of reception, or emitted by the radiating elements in case of emission, to form at least one beam.

[0115] The beamforming module 14 is capable of generating and applying an amplitude modulation law to the signals originating from or emitted by the radiating elements, the amplitude modulation law depending on the beam or beams to be formed.

[0116] The amplitude modulation law includes an amplitude modulation coefficient AA for each radiating element, such that each radiating element emits a signal having a respective amplitude equal to a given amplitude modulated by the corresponding amplitude modulation coefficient or receives a signal having a respective amplitude, the corresponding amplitude modulation coefficient being applied to the respective amplitude after reception.

[0117] A representation of an example of zones of an amplitude modulation law is visible in [Fig.4].

[0118] Each radiating element is associated with an amplitude modulation coefficient.

[0119] In the representation of [Fig.4], each zone relates to an interval of values ​​for the amplitude modulation coefficient.

[0120] The radiating elements 260 of the same zone are likely to have different amplitude modulation coefficients within the corresponding range.

[0121] The more the interval corresponds to high amplitude modulation coefficients, the more the area is represented with a high density of points.

[0122] In the example shown, a beam is to be formed, the beam being directed generally according to the inclination of the darkest radiating elements.

[0123] More specifically, in the antenna's receive mode, each radiating element receives a signal with a respective amplitude. For each radiating element, the amplitude modulation coefficient is applied to the corresponding received signal.

[0124] The application of the amplitude modulation coefficient is carried out by the beamforming module, as described below.

[0125] In the transmission mode of the antenna, each radiating element emits a signal having a respective amplitude equal to a given amplitude modulated by the corresponding amplitude modulation coefficient.

[0126] The amplitude modulation law is, for example, a function of the main direction of the beam(s) to be formed, the size of the beam(s) to be formed and / or the purity of the beam(s) to be formed, the purity being the level of the side lobe.

[0127] If several beams are to be formed simultaneously in emission (or transmission), the generated amplitude modulation law corresponds to the superposition of amplitude modulation sub-laws to form each beam.

[0128] In addition, the beamforming module 14 is capable of generating and applying a phase modulation law to the signals coming from the radiating elements for reception or emitted towards the radiating elements for transmission, the phase modulation law depending on the beam(s) to be formed.

[0129] The phase modulation law of a beam includes a phase shift Aq> for each radiating element, so that for said beam each radiating element emits a signal having the corresponding phase shift or receives a signal to which the phase shift is applied.

[0130] The phase modulation law provides an additional degree, compared to amplitude modulation, to improve the accuracy of pointing or beam formation.

[0131] The phase modulation law has a precision, that is to say a maximum increment between the different possible values, less than or equal to 2°.

[0132] If several beams are to be formed simultaneously in emission (or transmission), the generated phase modulation law corresponds to the superposition of phase modulation sub-laws to form each beam.

[0133] More specifically, in the antenna's receive mode, each radiating element receives a signal having a respective phase. For each radiating element, the phase shift is applied to the corresponding received signal.

[0134] The phase shift application is carried out by the beamforming module.

[0135] In the antenna's transmit mode, each radiating element emits a signal with the corresponding phase shift.

[0136] The beamforming module 14 is likely to be digital or analog.

[0137] Here, the beamforming module 14 is, for example, digital.

[0138] An example of a beamforming module 310 is shown in [Fig.5].

[0139] The beamforming module 310 includes, for example, a processing sub-module 312.

[0140] The beamforming module 310 includes, for example, in addition, a conversion sub-module 314.

[0141] Each source is linked to the processing submodule 312, for example via the conversion submodule 314.

[0142] The conversion submodule 314 includes, for example, a frequency converter 316 and / or an analog-to-digital converter 318, more particularly a 316 frequency converter and / or a 318 analog-to-digital converter per source.

[0143] The conversion submodule 314 here comprises one channel per source, each channel comprising a frequency converter 316 and / or an analog-to-digital converter 318.

[0144] Each channel is connected, at one end, to the corresponding source, for example via the amplification block, and, at the other end, to the processing sub-module 312.

[0145] The frequency converter 316 and the analog-to-digital converter 318 are arranged in series.

[0146] The analog-to-digital converter 318 is arranged on the side of the processing sub-module 312 relative to the frequency converter.

[0147] Each source is connected to a respective frequency converter 316 and / or analog-to-digital converter 318, more particularly to a respective channel.

[0148] The frequency converter 316 performs, for example, a direct frequency conversion, more particularly in quadrature or I / Q.

[0149] The analog-to-digital converter 318 is capable of converting an analog signal from a source into a digital signal to the processing sub-module 312, more particularly in antenna reception mode, and / or vice versa, more particularly in antenna transmission mode.

[0150] The processing submodule 312 is capable of generating the amplitude modulation law, and where applicable the phase modulation law, for each beam bl, b2, b3.. .bn to be formed, and of applying the said law(s) to the signal received in reception, or alternatively to generate in transmission.

[0151] The processing submodule 312 includes, for example, an information processing unit formed, for example, of a memory and a processor associated with the memory.

[0152] The processing submodule 312 is implemented as a software program, or a software component, executable by the processor. The memory is then capable of storing the software.

[0153] Alternatively, the processing submodule 312 is implemented as a programmable logic component, such as an FPGA (Field Programmable Gate Array), or as an integrated circuit, such as an ASIC (Application-Specific Integrated Circuit).

[0154] When the processing submodule 312 is implemented as one or more software programs, i.e., as a computer program, also called a computer program product, it is also capable of being stored on a computer-readable medium, not shown. The computer-readable medium is, for example A readable medium is a device capable of storing electronic instructions and being connected to a computer system bus. Examples of such a medium include optical discs, magneto-optical discs, ROMs, RAM, any type of non-volatile memory (such as FLASH or NVRAM), or magnetic cards. A computer program containing software instructions is then stored on this readable medium.

[0155] The conversion submodule 314 is linked to the processing submodule 312.

[0156] In reception mode, the conversion sub-module 314 is capable of receiving the received signals by the sources, for example amplified and / or filtered, to digitize them and transmit them to the processing sub-module 312.

[0157] In reception, the processing sub-module 312 is capable of receiving the signals received by the sources, here converted by the conversion sub-module 314, and of applying to them the amplitude modulation law, and where applicable the phase modulation law, corresponding to the beam(s) to be formed.

[0158] During transmission, the processing sub-module 312 is capable of generating the amplitude modulation law, and where applicable the phase modulation law, corresponding to the beam(s) to be formed and emitting a corresponding signal to which the amplitude modulation law, and where applicable the phase modulation law, has been applied. The signal emitted by the processing sub-module 312 is transmitted to the sources, more specifically here to the conversion sub-module 314.

[0159] In transmission, the conversion sub-module 314 is capable of receiving the signal emitted by the processing sub-module, converting it into an analog signal and transmitting it to the sources, here via an amplification block.

[0160] A method of using an antenna 10 according to the invention will now be described.

[0161] The method of use comprises the following steps:

[0162] - generation of an amplitude modulation law by the training module of 14 beams to form at least one beam,

[0163] - emission or reception of a signal by the radiating elements, and

[0164] - application of the generated amplitude modulation law to the received or to be transmitted signal by the radiating elements.

[0165] The method of use includes, for example, further the generation of a phase modulation law by the beamforming module to form at least one beam, and the application of the phase shift corresponding to the signal received or to be emitted by the radiating elements.

[0166] When a plurality of beams are formed simultaneously, the generated amplitude modulation law, and where applicable the generated phase modulation law, correspond(s) to the superposition of amplitude modulation sub-laws, and where applicable phase modulation sub-laws, to form each beam

[0167] More particularly, in reception, the sources 12 receive a signal and transmit it to the beam generation module 14, for example via the amplification block 16.

[0168] The beam generation module 14 applies the generated amplitude modulation law, and where applicable the generated phase modulation law, to the received signal.

[0169] More specifically, the conversion sub-module 314 receives the signal transmitted by the sources, for example amplified and / or filtered, digitizes it and transmits it to the processing sub-module 312.

[0170] The processing sub-module 312 receives the signal transmitted by the sources, here converted by the conversion sub-module 314, and applies to them the amplitude modulation law, and where applicable the phase modulation law, corresponding to the beam(s) to be formed.

[0171] During transmission, the beamforming module 14 generates the amplitude modulation law, and where applicable the phase modulation law, corresponding to the beam(s) to be formed, and transmits to the sources the signal to which the law(s) are applied. Each source 12 then emits a signal with an amplitude to which the corresponding amplitude modulation coefficient is applied, and where applicable with the corresponding phase shift.

[0172] More particularly, the processing submodule 312 generates the amplitude modulation law, and where applicable the phase modulation law, corresponding to the beam(s) to be formed and emits a corresponding signal to which the amplitude modulation law, and where applicable the phase modulation law, has been applied.

[0173] The signal emitted by the processing submodule 312 is emitted to the sources, more particularly here to the conversion submodule 314.

[0174] The conversion sub-module 314 receives the signal emitted by the processing sub-module, converts it into an analog signal and transmits it to each source, here via the corresponding amplification block.

[0175] Each source 12 then emits radiation with an amplitude to which the corresponding amplitude modulation coefficient is applied, and where appropriate with the corresponding phase shift.

[0176] An antenna according to the invention makes it possible to orient the beam without implementing a phase shift to adjust the beam pointing. Indeed, the pointing is achieved first by activating the radiating elements of the array differently in amplitude. This avoids the disadvantages noted for a conventional planar antenna array.

[0177] The mesh can be expanded without creating a lattice lobe, which allows, for example, the same directivity for a reduced number of radiating elements.

[0178] The conformation also allows for a larger surface area to be presented in the desired direction. Thus, for a high elevation, the projection of the antenna surface allows for greater directivity.

[0179] Finally, not applying a first-order phase-shift law to orient the beam limits the effect of strabismus at the edge of the band.

Claims

Demands

1. An antenna (10) comprising a plurality of sources (12), each source (12) comprising a radiating element (110; 210), each radiating element (110; 210) having a respective principal radiation axis (XI, Xn, Xi, Xj), each respective principal radiation axis (XI, Xn, Xi, Xj) having an inclination with a reference axis (Y), the reference axis (Y) being common to the plurality of sources (12), the inclination of the respective principal radiation axes (XI, Xn, Xi, Xj) varying within the antenna (10), the antenna (10) comprising a beamforming module (14) connected to the sources (12), the beamforming module (14) being capable of controlling the radiating elements to form at least one beam, characterized in that the beamforming module (14) is capable of generating and applying an amplitude modulation law to the radiating elements (110;210), the amplitude modulation law depending on the beam(s) to be formed, the amplitude modulation law including an amplitude modulation coefficient for each radiating element (110; 210), so that each radiating element (110; 210) emits a signal with a respective amplitude equal to a given amplitude modulated by the corresponding amplitude modulation coefficient or receives a signal with a respective amplitude, the corresponding amplitude modulation coefficient being applied to the respective amplitude after reception.

2. An antenna according to claim 1, wherein the radiating elements (110) are arranged such that the principal radiation axes (XI, Xn, Xi, Xj) are each tangent to a single three-dimensional curve exhibiting rotational symmetry about the reference axis (Y), the three-dimensional curve being representative of a polynomial function in any plane passing through the reference axis (Y), or wherein the radiating elements (210) are arranged such that each radiating element (210) is a translational image parallel to the reference axis (Y) of a corresponding fictitious radiating element, the fictitious radiating elements being such that their principal radiation axes are each tangent to a single three-dimensional curve exhibiting rotational symmetry around the reference axis (Y), the three-dimensional curve being representative of a polynomial function in any plane passing through the reference axis (Y).

3. Antenna according to claim 1 or 2, wherein the beamforming module (14) is capable of generating the amplitude modulation law as a function of the main direction of the beam(s) to be formed.

4. Antenna according to any one of claims 1 to 3, wherein the beamforming module (14) is capable of generating and applying a phase modulation law to the radiating elements (110; 210), the phase modulation law depending on the beam or beams to be formed, the phase modulation law including a phase shift for each radiating element (110; 210), so that each radiating element (110; 210) emits a signal having the corresponding phase shift or receives a signal to which the phase shift is applied.

5. Antenna according to any one of claims 1 to 4, wherein the beamforming module (14) is digital.

6. Antenna according to any one of claims 1 to 5, wherein the antenna (10) is capable of generating a beam having a frequency between 1 GHz and 44 GHz.

7. Antenna according to any one of claims 1 to 6, comprising a plurality of connectors (20), each connector (20) connecting a respective source (12) to a module, the sources (12) and the connectors (20) being made by additive manufacturing.

8. A method of using an antenna (10) according to any one of claims 1 to 7, comprising the following steps: - generating an amplitude modulation law by the beamforming module (14) to form at least one beam, - emitting or receiving a signal by the radiating elements (110; 210), and - applying the generated amplitude modulation law to the signal received or to be emitted by the radiating elements (110; 210).

9. A method of use according to claim 8, comprising generating a phase modulation law by the beamforming module (14) to form at least one beam, and

10. the application of the phase shift corresponding to the signal received or emitted by each radiating element (110; 210). A method of use according to claim 8 or 9, wherein a plurality of beams are formed simultaneously, the generated amplitude modulation law corresponding to the superposition of amplitude modulation sub-laws to form each beam.

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