Fully passive flat antenna with inclined beam with respect to normal

Abstract

Aflat antenna (10) configured to receive an electromagnetic radiation (R) having a wave number (k) associated with a frequency (f). The flat antenna (10) comprises a substantially flat body (11 ) comprising: - an upper surface (11a) having a plurality of elementary antennas (Axy) distributed according to an array pattern with a plurality of rows (Rx) and a plurality of columns (Cy), wherein each adjacent pair of rows (Rx) is spaced apart by a distance (d); - a combination network (15) comprising a plurality of transducers (Txy), each arranged at an elementary antenna and adapted to generate an electrical signal (Exy); - at least one output (20) configured to allow the acquisition of a combination of said plurality of electrical signals (Exy). The aforesaid distance (d) is defined by the formula (I) The plurality of transducers (Txy) comprises a first transducer (T11 ) and a second transducer (T21 ) connected in phase opposition to the first transducer (T11 ). The first transducer (T11 ) and the second transducer (T21 ) are adjacent and belong to a first column (C1 ) of the plurality of columns (Cy) and are configured to generate a first combined signal (Ea).

Description

[0001] FULLY PASSIVE FLAT ANTENNA WITH INCLINED BEAM WITH RESPECT TO NORMAL.

[0002] DESCRIPTION

[0003] The invention relates to a flat antenna and a hybrid antenna comprising a plurality of such flat antennas.

[0004] Today, flat antennas capable of receiving an electromagnetic radiation generated by a radio wave source along a propagation axis are known.

[0005] Such an antenna of known type comprises a substantially flat body configured to be constrained to a fixing surface.

[0006] This body comprises:

[0007] - an upper surface having a plurality of elementary antennas distributed according to an array pattern;

[0008] - a lower surface opposite said upper surface;

[0009] - a combination network that comprises a plurality of transducers which is distributed and fixed between said upper surface and said lower surface according to the aforesaid array pattern; in particular, each transducer of said plurality of transducers is arranged at a distinct opening of the aforesaid plurality of elementary antennas; furthermore, each transducer of said plurality of transducers is adapted to generate a distinct electrical signal of a plurality of electrical signals;

[0010] - at least one output configured to allow the acquisition of a combination of the aforesaid plurality of electrical signals.

[0011] Such a flat antenna, although well-known and appreciated, however, has an important limit.

[0012] In particular, such a flat antenna of known type requires that the aforesaid body be aligned orthogonally to the propagation axis of the electromagnetic radiation to be received.

[0013] The task of the present invention is to develop a flat antenna capable of overcoming this limit of the prior art.

[0014] In particular, it is an object of the present invention to realize a flat antenna that does not require the alignment of the body orthogonally to the propagation axis of the electromagnetic radiation to be received.

[0015] The above-mentioned task and object are achieved by a flat antenna according to claim 1.

[0016] Further characteristics of the flat antenna according to claim 1 are described in the dependent claims.

[0017] The aforesaid task and object, together with the advantages that will be mentioned hereinafter, are highlighted by the description of an embodiment of the invention, which is given by way of non-limiting example with reference to the attached drawings, where:

[0018] - figure 1 a represents a schematic side view of a flat antenna according to the invention;

[0019] - figure 1 b represents a perspective view of the flat antenna of figure 1 a;

[0020] - figure 1c represents a perspective exploded view of the flat antenna of figure 1a;

[0021] - figure 1 d represents a side view of the flat antenna of figure 1 a;

[0022] - figure 2 represents a perspective view of a detail of the flat antenna of figure 1b;

[0023] - figure 3a represents a perspective view of a first detail of the flat antenna of figure 1c;

[0024] - figure 3b represents a front view of figure 3a;

[0025] - figure 3c represents a rear view of figure 3a;

[0026] - figure 4a represents a front view of a second detail of the flat antenna of figure 1c;

[0027] - figure 4b represents a rear view of figure 4a;

[0028] - figure 5a represents a front view of a third detail of the flat antenna of figure 1c;

[0029] - figure 5b represents a rear view of figure 5a;

[0030] - figure 6a represents a front view of a fourth detail of the flat antenna of figure 1c;

[0031] - figure 6b represents a rear view of figure 6a;

[0032] - figure 7a represents a front view of a fifth detail of the flat antenna of figure 1c;

[0033] - figure 7b represents a rear view of figure 7a;

[0034] - figure 8 represents a perspective view of a detail of the flat antenna of figure 4a;

[0035] - figures 9a and 9b represent graphs relating to the operation of the flat antenna according to the invention;

[0036] - figure 10 represents a side view of a hybrid antenna according to the invention. With reference to the cited figures, a flat antenna according to the invention is indicated as a whole with the number 10, where such an antenna as a whole is clearly visible in figure 1b.

[0037] Said flat antenna 10 is configured to receive an electromagnetic radiation R generated by a radio wave source S along a propagation axis P, as clearly schematized in figure 1a.

[0038] In particular, this electromagnetic radiation R has a wave number k associated with a frequency f.

[0039] In addition, this radio wave source S must be geostationary to ensure continuity of transmission with this flat antenna 10.

[0040] It is also important to point out that, although the wavefront of the electromagnetic radiation R is not flat near the radio wave source S, this wavefront is substantially flat near the flat antenna 10 due to the high distance from this radio wave source S.

[0041] This means that the electromagnetic radiation R affects the entire sensitive surface of the flat antenna 10 with constant angle.

[0042] The flat antenna 10 comprises a body 11, clearly visible in figures 1a, 1b, 1c and 1 d, substantially flat that develops in length according to a longitudinal axis X, in width according to a transverse axis Y orthogonal to the longitudinal axis X and in depth according to a sagittal axis Z orthogonal to the longitudinal axis X and to the transverse axis Y.

[0043] The aforesaid body 11 is configured to be constrained to a fixing surface W so that the propagation axis P is perpendicular to the transverse axis Y and inclined by an angle a with respect to the sagittal axis Z, where this operating condition of the antenna is well schematized in figure 1a.

[0044] This body 11 comprises:

[0045] - an upper surface 11a, clearly visible in figures 1b, 1c, 1 d, 2, 3a and 3b, orthogonal to the sagittal axis Z; this upper surface 11a has a plurality of elementary antennas Axy, visible in figures 3b and 3c, which is distributed according to an array pattern with a plurality of rows Rx parallel to the transverse axis Y and a plurality of columns Cy parallel to the longitudinal axis X; each antenna of this plurality of elementary antennas Axy is configured to convey the electromagnetic radiation R through the body 11; moreover, each adjacent pair of said plurality of rows Rx is spaced along the longitudinal axis X by a distance d, where this distance d is the same for each adjacent pair of the aforesaid plurality of rows Rx;

[0046] - a lower surface 11b, clearly visible in figures 1b, 1c, 1 d and 7b, opposite said upper surface 11a;

[0047] - a combination network 15, clearly visible in figures 4b, 5a, 6b and 7a, comprising a plurality of transducers Txy which is distributed and fixed between the upper surface 11a and the lower surface 11b according to the aforesaid array pattern; each transducer of said plurality of transducers Txy is arranged at a distinct opening of said plurality of elementary antennas Axy; in particular, each transducer of said plurality of transducers Txy is adapted to generate a distinct electrical signal of a plurality of electrical signals Exy; moreover, said plurality of transducers Txy is arranged so as to guarantee the conversion of the electromagnetic radiation R conveyed by said plurality of elementary antennas Axy;

[0048] - two outputs 20a and 20b, clearly visible in figures 4b, 5a, 5b, 6a, 6b, 7a and 7b, each of which is configured to allow the acquisition of a combination of said plurality of electrical signals Exy.

[0049] The aforesaid distance d between adjacent pairs of the aforesaid plurality of rows Rx is defined by the formula

[0050] 'll

[0051] ksina’

[0052] In the present embodiment of the invention, the electromagnetic radiation R with frequency f equal to 11.7 GHz corresponding to the wave number k equal to 245.29 rad / m has been taken into consideration.

[0053] The propagation axis P of the electromagnetic radiation R inclined by the angle a equal to 32° with respect to the sagittal axis Z has also been taken into consideration.

[0054] Therefore, the aforesaid distance d calculated according to the formula

[0055] 'll

[0056] ksina

[0057] is equal to 24 mm.

[0058] It is not excluded, however, that the sizing of this flat antenna 10 in terms of distance d may be different, compatibly with the frequency f and the angle a of the electromagnetic radiation R of interest and according to the aforementioned formula

[0059] 'll

[0060] ksina’

[0061] This ensures that each transducer of said plurality of transducers Txy receives an electrical signal of said plurality of electrical signals Exy in phase opposition with respect to any other transducer of said plurality of transducers Txy belonging to an adjacent row of the aforesaid plurality of rows Rx.

[0062] The aforesaid plurality of transducers Txy comprises a first transducer T11, clearly visible in figures 4a, 4b, 5a, 5b, 6a, 6b, 7a and 8 configured to generate a first electrical signal E11 of the plurality of electrical signals Exy.

[0063] This plurality of transducers Txy also comprises a second transducer T21, also clearly visible in figures 4a, 4b, 5a, 5b, 6a, 6b, 7a and 8, configured to generate a second electrical signal E21 of the plurality of electrical signals Exy.

[0064] This first transducer T11 is connected in phase opposition to this second transducer T21, where this connection is clearly shown in figure 8.

[0065] It is also noted that said first transducer T11 and said second transducer T21 are adjacent and both belong to a first column C1 of the aforesaid plurality of columns Cy.

[0066] For the sake of clarity, the adjacency of two transducers Txy just defined is to be understood as the two transducers Txy belonging to two rows Rx adjacent to a same column Cy.

[0067] This connection in phase opposition between the first transducer T11 and the second transducer T21 compensates for the 180° electrical phase shift between the first electrical signal E11 and the second electrical signal E21 linked to the particular choice of the distance d.

[0068] Moreover, this 180° phase shift is advantageously obtained in a totally passive way.

[0069] Therefore, this configuration of the flat antenna 10 advantageously allows to receive the electromagnetic radiation R with propagation axis P inclined with angle a equal to 32° with respect to the sagittal axis Z.

[0070] More precisely, this flat antenna 10 does not require the alignment of the body 11 orthogonally to the propagation axis P of the electromagnetic radiation R to be received.

[0071] Said first transducer T11 and said second transducer T21 form a first adjacent pair Ta of said plurality of transducers Txy, as can be seen from figures 4b, 5a, 6b, 7a and 8.

[0072] Furthermore, said first adjacent pair Ta is configured to generate a first combined signal Ea obtained by combining said first signal E11 and said second signal E21.

[0073] In the present embodiment of the invention, each transducer of said plurality of transducers Txy is connected in phase opposition to a single and adjacent transducer of said plurality of transducers Txy belonging to a same column of said plurality of columns Cy.

[0074] More precisely, the combination network 15 comprises a plurality of adjacent pairs Tn of the aforesaid plurality of transducers Txy, where each pair of said plurality of adjacent pairs Tn is configured as the first adjacent pair Ta previously described.

[0075] For example, the aforesaid plurality of transducers Txy also comprises a third transducer T31 and a fourth transducer T41 , also connected in phase opposition forming a second adjacent pair Tb represented in figures 4a, 4b, 5a, 5b, 6a, 6b and 7a.

[0076] Said third transducer T31 is configured to generate a third electrical signal E31 of the plurality of electrical signals Exy, while said fourth transducer T41 is configured to generate a fourth electrical signal E41 of the plurality of electrical signals Exy.

[0077] Furthermore, the aforesaid second adjacent pair Tb is configured to generate a second combined signal Eb obtained by combining said third signal E31 and said fourth signal E41.

[0078] It is important to point out that, given the distance d between each adjacent pair of the plurality of rows Rx, the first combined signal Ea is 360° electrically phase-shifted by the second combined signal Eb.

[0079] More precisely, the aforesaid plurality of adjacent pairs Tn does not require any type of phase alignment to correctly transduce the electromagnetic radiation R at the predetermined frequency f and with angle a.

[0080] In the present embodiment of the invention, the first adjacent pair Ta and the second adjacent pair Tb are connected by means of a beam stabilizer 16, clearly visible in figures 4b, 5a, 6b and 7a.

[0081] Said stabilizer 16 is configured to phase shift said first combined signal Ea with respect to said second combined signal Eb by an electrical phase shift <p.

[0082] This electrical phase shift <p varies as the frequency f of the electromagnetic radiation R varies.

[0083] More precisely, in the present embodiment of the invention, this electrical phase shift <p is zero when the frequency f is equal to 11.7 GHz.

[0084] In addition, the electrical phase shift <p varies linearly from electrical -30° to electrical 30° as the frequency f varies from 10.7 GHz to 12.75 GHz. This electrical phase shift <p allows the flat antenna 10 to compensate for phase misalignments that arise between the plurality of adjacent pairs Tn at a deviation of frequency f from the value of 11.7 GHz.

[0085] This advantageously allows the flat antenna 10 to receive electromagnetic radiations of frequency f comprised between 10.7 GHz and 12.75 GHz along the propagation axis P inclined with angle a equal to 32° with respect to the sagittal axis Z.

[0086] However, it cannot be excluded that the linearity range of the electrical phase shift <p as the frequency f varies may differ from what is described in terms of the amplitude of the phase shift and the band with linear characteristic.

[0087] Figure 9a shows a first graph of the grating lobes of the antenna 10 where the gain of the flat antenna 10 is highlighted as the angle a of incidence of the aforesaid electromagnetic radiation R varies, which however does not use any stabilizer 16.

[0088] This first graph shows a first local maximum for the angle a equal to 30° at a main lobe 30a when the frequency f equals 11.7 GHz.

[0089] In addition, the graph also shows a second local maximum at a secondary lobe 31a for the angle a equal to -32° when the frequency f equals 11.7 GHz.

[0090] It can also be observed that, as the frequency f varies, the main lobe 30a no longer shows a maximum gain at the angle a equal to 32°.

[0091] In order to illustrate the effect of the aforesaid stabilizer 16, a second graph of the grating lobes of the antenna 10, where the gain of the flat antenna 10 is highlighted as the angle a of incidence of the aforesaid electromagnetic radiation R varies, is presented in figure 9b.

[0092] This second graph shows a first local maximum for the angle a equal to 32° at a main lobe 30b when the frequency f equals 11.7 GHz.

[0093] In addition, this second graph shows a second local maximum for the angle a equal to -32° at a secondary lobe 31b when the frequency f equals 11.7 GHz. However, it can be observed that, as the frequency f varies between 10.7 GHz and 12.75 GHz, the main lobe 30b advantageously shows a maximum gain always at the angle a equal to 32°.

[0094] Said first adjacent pair Ta and said second adjacent pair Tb form a first adjacent quadruplet of the aforesaid plurality of transducers Txy, as can be seen from figures 4b, 5a, 6b and 7a.

[0095] Furthermore, said first adjacent quadruplet is configured to generate a third combined signal obtained by combining said first combined signal Ea and said second combined signal Eb.

[0096] In the present embodiment of the invention, each pair of said plurality of adjacent pairs Tn is connected to a single and adjacent further pair of said plurality of adjacent pairs Tn belonging to the same column of said plurality of columns Cy.

[0097] More precisely, the combination network 15 comprises a plurality of adjacent quadruplets of the aforesaid plurality of transducers Txy, wherein each adjacent quadruplet of said plurality of adjacent quadruplets is configured as the first adjacent quadruplet previously described.

[0098] In the present embodiment of the invention, this stabilizer 16 is a waveguide phase shifter whose cross-sectional area varies along its longitudinal development.

[0099] In particular, the aforesaid waveguide phase shifter has an impedance value that is variable as a function of the frequency f of the electromagnetic radiation R

[0100] More precisely, a different linearity range can be obtained by suitably modifying the discontinuity of the aforesaid cross-sectional area of the longitudinal development of the stabilizer 16.

[0101] Each transducer of the aforesaid plurality of transducers Txy is an orthomodal transducer, clearly visible in figure 8, adapted to acquire both orthogonally polarized components of the electromagnetic radiation R by combining them into a distinct electrical signal of the plurality of electrical signals Exy.

[0102] In the present embodiment of the invention, the aforesaid plurality of elementary antennas Axy is a plurality of openings and the plurality of transducers Txy is a plurality of waveguide transducers.

[0103] In particular, each antenna of this plurality of elementary antennas Axy consists of a through hole obtained on the upper surface 11a and whose longitudinal development crosses the body 11 parallel to the sagittal axis Z.

[0104] It should also be highlighted that each pair of said plurality of adjacent pairs Tn is connected to a single and adjacent further pair of said plurality of adjacent pairs Tn belonging to the same rows of said plurality of rows Rx, as can be seen from figure 8.

[0105] However, it is important to emphasize that this connection between said plurality of adjacent pairs Tn is not essential for obtaining the desired technical effect. The flat antenna 10 also comprises a plurality of trumpet-like directional elements Dxy, clearly visible in figures 1 d, 2, 3a and 3b, which is distributed and fixed on the upper surface 11a according to the aforesaid array pattern.

[0106] In particular, each element of said plurality of directional elements Dxy is arranged at a distinct opening of the plurality of openings and is inclined by the angle a with respect to the sagittal axis Z.

[0107] More precisely, this plurality of directional elements Dxy is configured to make the flat antenna 10 selective to incident electromagnetic radiations with angle a with respect to the sagittal axis Z.

[0108] The flat antenna 10 also comprises a plurality of directional strips Sx, clearly visible in figures 1 b, 1 d and 2, which is distributed and fixed on the upper surface 11a

[0109] Each strip of said plurality of directional strips Sx is fixed to the upper surface 11a by means of a pair of angular brackets 23a and 23b, also visible in figures 1b, 1d and 2.

[0110] Each strip of said plurality of directional strips Sx is arranged at a row of the aforesaid plurality of rows Rx and is inclined by the angle a with respect to the sagittal axis Z.

[0111] Like the aforesaid plurality of directional elements Dxy, this plurality of directional strips Sx is configured to make the flat antenna 10 selective to incident electromagnetic radiations with angle a with respect to the sagittal axis Z.

[0112] The flat antenna 10 still comprises support means 19, schematized in figure 1a, configured to constrain the lower surface 11b parallel to the fixing surface W. It is important to point out that both the aforesaid plurality of directional elements Dxy and the plurality of directional strips Sx are not indispensable for the operation of the flat antenna 10, but they advantageously allow to have maximum gain with incident electromagnetic radiations with angle a with respect to the sagittal axis Z.

[0113] In particular, these support means 19 allow only the rotation of the body 11 around a scanning axis parallel to the sagittal axis Z.

[0114] In the present embodiment of the invention, the aforesaid support means 19 correspond to a rotation pin constrained at a first end to the lower surface 11b and at a second end to the fixing surface W.

[0115] The flat antenna 10 can be obtained by means of an additive manufacturing procedure, but it is not excluded that different techniques can be used, such as for example an injection moulding procedure.

[0116] The flat antenna 10 according to the present embodiment of the invention is made by implementing the following steps in sequence:

[0117] a) arranging a plate from which to obtain the aforesaid body 11 of the flat antenna 10;

[0118] b) obtaining, at the upper surface 11a of the body 11 , the aforesaid plurality of elementary antennas Axy which is distributed according to the array pattern in such a way that each adjacent pair of the plurality of rows Rx is spaced along the longitudinal axis X by a distance d defined by the formula

[0119] 71

[0120] ksina’

[0121] c) defining the aforesaid combination network 15 with the plurality of waveguide transducers Txy which is distributed and fixed between the upper surface 11a and the lower surface 11b according to the array pattern. Still with reference to the present embodiment of the invention, the flat antenna 10 is made of a metallic material, but it is not excluded that different materials can be used for its realization, such as for example metallized plastic.

[0122] For the sake of completeness, it should be point out that the installation of this flat antenna 10 comprises the following sequential steps:

[0123] - arranging the aforesaid flat antenna 10 at a fixing surface W;

[0124] - constraining the body 11 of said flat antenna 10 to said fixing surface W so that the propagation axis P of the electromagnetic radiation R is perpendicular to the transverse axis Y and inclined by the angle a with respect to the sagittal axis Z.

[0125] As anticipated above, the present invention also relates to a hybrid antenna 100, schematically represented in figure 10, which comprises at least a first flat antenna 10a and at least a second flat antenna 10b, each of which is defined as described above.

[0126] The aforesaid first flat antenna 10a and second flat antenna 10b are associated respectively with a first output 20a and with a second output 20b.

[0127] In addition, these first flat antenna 10a and second flat antenna 10b are coplanar, adjacent and aligned along the longitudinal axis X.

[0128] In this configuration, the hybrid antenna 100 comprises an electrical combiner 140, also schematized in figure 10, connected to the first output 20a and to the second output 20b in such a way as to combine and electronically phase shift the electrical signal relative to the first output 20a and the electrical signal relative to the second output 20b into an overall electrical signal E.

[0129] This advantageously allows to obtain a reconfigurability margin of the antenna thus defined in terms of alignment with the propagation axis P of the electromagnetic radiation R.

[0130] Practically, it has been established that the invention achieves the intended task and object.

[0131] In particular, with the invention, a flat antenna has been developed that does not require the body to be aligned orthogonally to the propagation axis of the electromagnetic radiation to be received.

[0132] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; moreover, all the details may be replaced by other technically equivalent elements.

[0133] In practice, the components and the materials used could be of any type, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, according to requirements and the state of the art.

[0134] Where the features and techniques mentioned in any claim are followed by reference marks, such reference marks are intended to be affixed solely for the purpose of increasing the intelligibility of the claims and consequently such reference marks have no limiting effect on the interpretation of each element identified by way of example by such reference marks.

Claims

CLAIMS1) Flat antenna (10) configured to receive an electromagnetic radiation (R) generated by a radio wave source (S) along a propagation axis (P), said electromagnetic radiation (R) having a wave number (k) associated with a frequency (f), said flat antenna (10) comprising a substantially flat body (11) that develops in length according to a longitudinal axis (X), in width according to a transverse axis (Y) orthogonal to said longitudinal axis (X) and in depth according to a sagittal axis (Z) orthogonal to said longitudinal axis (X) and to said transverse axis (Y), said body (11) being configured to be constrained to a fixing surface (W) so that said propagation axis (P) is perpendicular to said transverse axis (Y) and inclined by an angle (a) with respect to said sagittal axis (Z), said body (11 ) comprising:- an upper surface (11 a) orthogonal to said sagittal axis (Z), said upper surface (11a) having a plurality of elementary antennas (Axy) distributed according to an array pattern with a plurality of rows (Rx) parallel to said transverse axis (Y) and a plurality of columns (Cy) parallel to said longitudinal axis (X), each antenna of said plurality of elementary antennas (Axy) being configured to convey said electromagnetic radiation (R) through said body (11), each adjacent pair of said plurality of rows (Rx) being spaced along said longitudinal axis (X) by a distance (d), said distance (d) being the same for each adjacent pair of said plurality of rows (Rx);- a lower surface (11 b) opposite said upper surface (11a);- a combination network (15) comprising a plurality of transducers (Txy) which is distributed and fixed between said upper surface (11a) and said lower surface (11 b) according to said array pattern, each transducer of said plurality of transducers (Txy) being arranged at a distinct elementary antenna of said plurality of elementary antennas (Axy), each transducer of said plurality of transducers (Txy) being adapted to generate a distinct electrical signal of a plurality of electrical signals (Exy);- at least one output (20) configured to allow the acquisition of a combination of said plurality of electrical signals (Exy);characterized in that said distance (d) is defined by the formula:'llksinasaid plurality of transducers (Txy) comprising a first transducer (T11 ) configured to generate a first electrical signal (E11) of said plurality of electrical signals(Exy) and a second transducer (T21 ) configured to generate a second electrical signal (E21 ) of said plurality of electrical signals (Exy), said first transducer (T11 ) being connected in phase opposition to said second transducer (T21), said first transducer (T11) and said second transducer (T21) being adjacent and both belonging to a first column (C1) of said plurality of columns (Cy), said first transducer (T11) and said second transducer (T21) forming a first adjacent pair (Ta) of said plurality of transducers (Txy), said first adjacent pair (Ta) being configured to generate a first combined signal (Ea) obtained from the combination of said first signal (E11 ) and said second signal (E21 ).2) Flat antenna (10) according to claim 1, characterized in that said combination network (15) comprises a plurality of adjacent pairs (Tn) of said plurality of transducers (Txy), each pair of said plurality of adjacent pairs (Tn) being configured as said first adjacent pair (Ta).3) Flat antenna (10) according to claim 2, characterized in that said plurality of adjacent pairs (Tn) comprises a second adjacent pair (Tb), said first adjacent pair (Ta) and said second adjacent pair (Tb) being connected by means of a beam stabilizer (16), said stabilizer (16) being configured to phase shift said first combined signal (Ea) with respect to said second combined signal (Eb) by an electrical phase shift (q>), said electrical phase shift (cp) varying as said frequency (f) of said electromagnetic radiation (R) varies, said first adjacent pair (Ta) and said second adjacent pair (Tb) forming a first adjacent quadruplet of said plurality of adjacent pairs (Tn), said first adjacent quadruplet being configured to generate a third combined signal obtained by the combination of said first combined signal (Ea) and said second combined signal (Eb).4) Flat antenna (10) according to claim 3, characterized in that said combination network (15) comprises a plurality of adjacent quadruplets of said plurality of transducers (Txy), each of said plurality of adjacent quadruplets being configured as said first adjacent quadruplet.5) Flat antenna (10) according to claim 3 or 4, characterized in that said stabilizer (16) is a waveguide phase shifter whose cross-sectional area varies along its longitudinal development, said waveguide phase shifter having an impedance value that is variable as a function of said wave number (k).6) Flat antenna (10) according to any one of the preceding claims, characterized in that each transducer of said plurality of transducers (Txy) is an orthomodal transducer adapted to acquire both orthogonally polarizedcomponents of said electromagnetic radiation (R) by combining them into a distinct electrical signal of said plurality of electrical signals (Exy).7) Flat antenna (10) according to any one of the preceding claims, characterized in that said plurality of elementary antennas (Axy) is a plurality of openings and that said plurality of transducers (Txy) is a plurality of waveguide transducers.8) Flat antenna (10) according to claim 7, characterized in that it comprises a plurality of trumpet-like directional elements (Dxy) which is distributed and fixed on said upper surface (11a) according to said array pattern, each element of said plurality of directional elements (Dxy) being arranged at a distinct opening of said plurality of openings, each element of said plurality of directional elements (Dxy) being inclined by said angle (a) with respect to said sagittal axis (Z), said plurality of directional elements (Dxy) being configured to make said flat antenna (10) selective to incident electromagnetic radiations with angle (a) with respect to said sagittal axis (Z).9) Flat antenna (10) according to any one of the preceding claims, characterized in that it comprises a plurality of directional strips (Sx) which is distributed and fixed on said upper surface (11a), each strip of said plurality of directional strips (Sx) being arranged at a row of said plurality of rows (Rx), each strip of said plurality of directional strips (Sx) being inclined by said angle (a) with respect to said sagittal axis (Z), said plurality of directional strips (Sx) being configured to make said flat antenna (10) selective to incident electromagnetic radiations with angle (a) with respect to said sagittal axis (Z).10) Flat antenna (10) according to any one of the preceding claims, characterized in that it comprises support means (19) configured to constrain said lower surface (11b) parallel to said fixing surface (W).11) Flat antenna (10) according to claim 10, characterized in that said support means (19) only allow the rotation of said body (11) around a scanning axis parallel to said sagittal axis (Z).12) Hybrid antenna (100), characterized in that it comprises at least a first flat antenna (10a) and at least a second flat antenna (10b) each of which is defined according to any one of the preceding claims, said first flat antenna (10a) and said second flat antenna (10b) being associated respectively with a first output (20a) and with a second output (20b), said first flat antenna (10a) and said second flat antenna (10b) being coplanar, adjacent and aligned alongsaid longitudinal axis (X), said hybrid antenna (100) comprising an electrical combiner (140) connected to said first output (20a) and to said second output (20b) in such a way as to combine and electronically phase shift the electrical signal relative to said first output (20a) and the electrical signal relative to said second output (20b) into an overall electrical signal (E).

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