Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
  • H01Q3/24—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
  • H01Q3/245—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching in the focal plane of a focussing device
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
  • H01Q15/02—Refracting or diffracting devices, e.g. lens, prism
  • H01Q15/08—Refracting or diffracting devices, e.g. lens, prism formed of solid dielectric material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
  • H01Q19/06—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens
  • H01Q19/062—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens for focusing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
  • H01Q25/007—Antennas or antenna systems providing at least two radiating patterns using two or more primary active elements in the focal region of a focusing device

Definitions

• Antenna system whose radiation pattern is reconfigurable among sectoral and directive radiation patterns, and corresponding transmitter and / or receiver device.
• the field of the invention is that of radiating antennas and more particularly antenna systems whose radiation pattern is reconfigurable among a set of radiation patterns.
• Such antenna systems can switch from a directional radiation pattern (i.e. radiating in a preferred direction) to a sectoral radiation pattern (i.e. radiating in an angular sector with a constant power density) and vice versa.
• a sector diagram is a diagram whose beam shape has a uniform radiation (on a given sector of space) and zero side lobes.
• corrugations smaller than 3dB and also secondary lobes (within a certain limit) are acceptable.
• a conventional technique consists in implementing several source antennas arranged so as to form a network which is generally realized by means of a planar network technology. printed.
• an active module comprising a phase-shifter and an amplifier or an attenuator
• the amplitude and phase laws applied to the network it is possible to go from a sectoral radiation pattern to a directional radiation pattern, and vice versa.
• a directional radiation pattern is obtained by choosing a network comprising a large number of source antennas (the larger this number is, the more directional the radiation pattern is);
• a sectoral radiation pattern is obtained by playing both on the amplitude and the phase of each source antenna of the network as illustrated by Figures IA and IB (from the doctoral thesis document of the University of Rennes 1 supported by Olivier LAFOND in December 2000 and entitled "60GHz multilayer printed antenna design and technologies") which show a sectorial radiation pattern (figure IA) obtained at 58.5 GHz when applying the value pairs indicated by Figure IB has six source antennas 101, 102, 13, 104, 105, 106 of an antenna system.
• the invention in at least one embodiment, is intended in particular to overcome these disadvantages of the prior art.
• an object of the invention in at least one of its embodiments, is to provide an antennal system whose radiation is reconfigurable, more easily than with the systems of the prior art, among a set of radiation patterns comprising at least one directional radiation pattern and at least one sectoral radiation pattern.
• Another object of the invention, in at least one of its embodiments, is to implement such a system that does not require the use of phase shifters and amplifiers to ensure the reconfigurability of its radiation pattern.
• Another objective of the invention in at least one of its embodiments, is to implement such a system that allows a reconfigurability (passage of a directional radiation sectorial, or vice versa), while maintaining the same axis of misalignment.
• Another object of the invention in at least one of its embodiments, is to implement such a system that allows a reconfigurability in several planes each associated with a distinct azimuthal direction distinct.
• the invention in at least one of its embodiments, still aims to implement such a system that is simpler and less costly to achieve than conventional reconfigurable radiation field / sectoral antenna systems.
• the invention relates to an antenna system whose radiation pattern is reconfigurable from a set of radiation patterns comprising, for at least one plane associated with a given azimuthal direction, at least one directional radiation pattern. in said plane, and at least one sectoral radiation pattern in said plane.
• This system comprises a plurality of source antennas and reconfiguration means, for switching from one diagram to another among said set of radiation patterns.
• the reconfiguration means comprise: power management means of said source antennas, generating a plurality of power configurations each associated with a radiation pattern separate from said set of radiation patterns, said plurality of power configuration comprising, for at least one associated plane at a given azimuth direction,
• the general principle of the invention consists in associating a dielectric lens with a plurality of source antennas in an antenna system in order to make it easily reconfigurable, for at least one plane associated with a given azimuthal direction, by feeding or not certain source antennas.
• the invention is based on a completely new and inventive approach, and on a surprising effect. Indeed, because of the presence of the lens, the greater the number of source antennas powered, the more the radiation pattern is sectoral. On the contrary, in the technique of the prior art (without a lens, but by varying the amplitude and phase of each of the source antennas), the greater the number of source antennas powered, the more the radiation pattern is directive. .
• Such an antenna system does not require the implementation of phase shifters and amplifiers to ensure the reconfigurability of its radiation pattern.
• it has several advantages over conventional field / sector reconfigurable radiation pattern antenna systems: it has improved radiation efficiency (because it has low losses); it is wider band (because there are no phase shifters); it is particularly adapted to millimeter frequencies; - It is simpler and less expensive to make.
• said dielectric lens belongs to the group comprising: homogeneous or inhomogeneous index-gradient spherical lenses, and index-gradient inhomogeneous hemispherical lenses.
• said plurality of power supply configurations comprises at least one configuration, associated with a sectoral radiation pattern in said plane, in which all the source antennas contained in said plane are fed.
• all source antennas that are powered are with the same amplitude and the same phase.
• said plurality of power supply configurations comprises at least one configuration, associated with a sectorial radiation pattern in said plane and offset along a given misalignment axis, in which there are more antennas fed on one side than on the other. the other of an axis of symmetry of distribution of the source antennas in said plane.
• said plurality of power supply configurations comprises at least one configuration, associated with a directional radiation pattern in said plane and offset along said given misalignment axis.
• said plurality of source antennas are distributed according to a network belonging to the group comprising: linear networks, making it possible to define the directional or sectoral nature of each radiation pattern, for a single plane associated with a given azimuthal direction; and areal networks, for defining the directional or sectoral nature of each radiation pattern, for at least two planes each associated with a distinct predetermined azimuthal direction.
• the power management means of said source antennas comprise at least one switch belonging to the group comprising: PIN diodes; MMIC amplifiers; MEMS.
• the invention also relates to a device transmitter and / or receiver of radio waves comprising at least one antennal system as described above.
• FIGS. IB present a sectoral radiation pattern
• FIG. 1A obtained at 58.5 GHz when applying the value pairs indicated in FIG. 1B to six source antennas of an antenna system according to the prior art
• FIG. 2A shows a diagram of a first antennal system, according to one particular embodiment of the invention, based on a six-lens shells associated with four source antennas based waveguide
• FIG. 2B shows a diagram of a second antennal system according to a particular embodiment of the invention, based on a three-shell lens associated with five printed source antennas
• FIGS. 3A and 3B show diagrams of top views of the aforementioned second antennal system in the case where the source antennas are in the H plane (FIG. 3A) and in the case where the source antennas are in the E plane (FIG.
• FIG. 5A shows top view diagrams of the aforementioned second antennal system in the case where the five source antennas are powered (FIG. 5A) and in the case where only the central source antenna among the five source antennas is powered ( Figure 5B);
• FIG. 6 is a diagram showing the evolution of the angular distribution of the 77 GHz radiation pattern of a fourth antenna system according to a particular embodiment of the invention, comprising 9 source antennas based on a waveguide and a 9-shell lens, when the number of fed source antenna (s) goes from 1 to 9;
• FIGS. 7A and 7B show a diagram (FIG.
• FIG. 7A representing the evolution of the angular distribution of the 77 GHz radiation pattern of a fifth antenna system according to a particular embodiment of the invention, comprising 8 aligned source antennas (FIG. 7B) and a 9-shell lens, when varying the supplied source antenna triplet;
• FIG. 8 illustrates an exemplary hexagonal surface array of source antennas;
• FIG. 9 illustrates an Oxyz mark, in which the angles PHI ( ⁇ ) and THETA ( ⁇ ) are represented;
• FIGS. 10A, 10B and 10C show diagrams of top views of an antenna system comprising source antennas arranged according to a surface network, in different cases of supplying the source antennas;
• HA and HB show diagrams of top views of the same antennal system, the supply of the source antennas being such that in one case (FIG. 1A) the radiation pattern is directional and depointed and in the other case (figure HB) the radiation pattern is sectorial and misaligned along the same misalignment axis. 6. Description of an embodiment of the invention
• a particular embodiment of the invention relates to an antenna system comprising: a source antenna array disposed on a substrate, the source antennas each emitting radiation; reconfiguration means making it possible to switch from one diagram to another among a set of radiation diagrams comprising, for at least one plane associated with a given azimuthal direction, at least one directional radiation pattern in said plane and at least one a sectoral radiation pattern in the aforementioned plan.
• the reconfiguration means comprise: a dielectric lens disposed above the source antennas and for focusing the rays of the supplied source antennas; source antenna power management means, generating a plurality of power supply configurations each associated with a radiation pattern distinct from the set of radiation patterns, the plurality of power supply configurations comprising, for at least a plane associated with a given azimuthal direction: * at least one first configuration, associated with a directional radiation in the aforementioned plane, in which N source antenna (s) contained in the aforementioned plane is (are) fed, with N ⁇ 2; and
• At least one second configuration associated with a sectoral radiation pattern in the aforementioned plane, in which N 'source antennas contained in the aforementioned plane are fed, with N'> N.
• the dielectric lens is for example: a homogeneous spherical lens (lens called "constant K” for example) or an inhomogeneous spherical lens index gradient (L ⁇ neburg lens for example); an inhomogeneous index-gradient hemispherical lens (for example Maxwell's Poisson à demi-oeil lens).
• a non-homogeneous gradient-indexed lens of the Maxwell Poisson's Eye type is used in the form of a hemisphere as described in the patent application. French No 2888407 published on January 12, 2007.
• the index-gradient non-homogeneous lens of Maxwell's Poisson's eye type produced in the form of a hemisphere according to the particular embodiment of the invention, comprises N concentric shells in the form of a half-sphere, discrete dielectric constants different and nested with each other without empty space between two successive shells, with 3 ⁇ N ⁇ 20, the discrete dielectric constants of the N shells being such that they define a discrete distribution approaching at best the aforementioned theoretical distribution of the dielectric constant inside the lens.
• source antennas are chosen which are compatible with a good insertion of their radiation into the lens (that is to say which make it possible to minimize the "spill-over" or overflow of the radiation of the lens).
• source antennas based on waveguides are used.
• waveguide source antennas makes it possible to reduce the insertion losses of the radiation emitted by the source antennas in the focusing means.
• source antennas printed on a substrate for example metal tracks printed on a printed circuit
• the antenna system is simpler to manufacture and less expensive.
• FIGS. 2A and 2B show a diagram of a first antennal system 2100 based on a six-shell lens 2110, 2111 to 2116, associated with four waveguide-based source antennas, 2121 to 2124, according to the first exemplary embodiment according to the particular embodiment of the invention (FIG. 2A) and a diagram of a second antennal system 2200 based on a 2210 lens with three shells, 2211 to 2213, associated with five source antennas printed, 2221 to 2225, according to the second exemplary embodiment according to the particular embodiment of the invention ( Figure 2B).
• the five printed source antennas (also called “patches”) 2221 to 2225 are printed on a substrate 2226.
• the increase in the number of shells in the lens of an antenna system according to the invention makes it possible to improve the directivity in the "directional radiation pattern" configuration of this system (that is to say when a number N ⁇ 2 of source antennas are fed, N being for example equal to one if the total number of antenna antennas of the antenna array is odd and equal to two if the total number of source antenna is even) .
• the source antennas may be aligned in the plane H of the antenna system (as illustrated by FIG. diagram of a top view of the second aforementioned antennal system in the case where its patches are aligned in the plane H) but they can also be aligned in the plane E of the antennal system (as illustrated by FIG. 3B showing a diagram a top view of the second aforementioned antennal system in the case where its patches are aligned in the plane E); the number of source antennas included in the antenna system may be even or odd.
• the reconfiguration means illustrated in FIG. 4 comprise a lens 701 and power management means 702.
• the power management means 702 are, for example, a circuit antenna power supply 71 to which is added a switching module 72, for example, based on PIN diode switches or amplifiers MMIC or MEMS.
• This switching module controlled by a switching signal applied to it by a control module 73 which, according to the invention, makes it possible to manage the supply of a variable number of source antennas 74, in order to dynamically reconfigure the radiation pattern, and pass including a directional radiation pattern to a sectoral radiation pattern, or vice versa.
• a control module 73 which, according to the invention, makes it possible to manage the supply of a variable number of source antennas 74, in order to dynamically reconfigure the radiation pattern, and pass including a directional radiation pattern to a sectoral radiation pattern, or vice versa.
• all source antennas 74 which are powered are with the same amplitude and the same phase.
• FIGS. 5A and 5B diagrams of top views of the aforementioned second antenna system 2200 are presented in the case where the five source antennas 2221 to 2225 are fed simultaneously (FIG. 5A) and in the case where only the 2223 central source antenna among the five source antennas 2221 to 2225 is fed (Figure 5B).
• the second antenna system transmits a radiation pattern shaped by the lens 2210 which is a sectoral radiation pattern.
• the second antenna system In the case where only the central source antenna 2223 among the source antennas 2221 to 2225 is fed by the supply circuit, then the second antenna system emits a radiation pattern shaped by the lens 2210 which is a radiation pattern. directive. Thus we find the property of the lenses, namely the focusing by the lens of the radiation coming from the central source antenna 2223. Thus, in this case, the shaped radiation pattern is a focused radiation pattern.
• a third antenna system (not shown) identical to the second antennal system except that it comprises an even number (for example six) of source antennas, then, if we feed both central source antennas among the source antennas, then the third antennal system emits a radiation pattern shaped by the lens which is a directional radiation pattern.
• FIGS. HA and HB diagrams of top views of an antennal system with eight source antennas 111 to 118 and a 2200 lens with three shells are presented: in the case where only one, the second source antenna in from the right
• the antennal system emits a radiation pattern (shaped by the lens) which is a directional radiation pattern misaligned along a given misalignment axis (defined by a non-zero angle THETA, in the reference point described below in relation to Figure 9, assuming that the source antennas are aligned along the axis Ox).
• the antenna system emits a radiation pattern (shaped by the lens) which is a sectorial radiation diagram that is off-set according to the same misalignment axis as in FIG.
• the source antenna referenced 117 is the central antenna of the group of antennas referenced 116 to 118.
• FIG. 6 shows a diagram representing the evolution of the angular distribution (in directivity (or also directivity) expressed in dB as a function of the angle (referenced ⁇ ) expressed in degrees of the radiation pattern at 77GHz of a fourth antennal system according to the particular embodiment of the invention, comprising 9 waveguide-based source antennas and a 9-shell lens, when the number of antenna (s) fed source (s) is respectively 1 (curve 501), 3 (curve 502), 5 (curve 503), 7 (curve 504) and 9 (curve 505).
• curve 501 illustrates a directional radiation pattern
• curve 505 illustrates a sectoral radiation pattern
• FIGS. 7A and 7B a diagram (FIG. 7A) representing the evolution of the power distribution (that is to say the directivity radiation pattern, or "directivity” in English) is presented.
• dB as a function of the angle (referenced ⁇ ) expressed in degrees) at 77 GHz, of a fifth antenna system according to the particular embodiment of the invention, comprising 8 source antennas 61 to 68 aligned (FIG.
• these six feed configurations of the 8 source antennas 61 to 66 correspond to six branched sectoral radiation diagrams.
• the reconfigurability of the above antennal systems according to the particular embodiment of the invention is obtained simply by feeding or not some of the source antennas of the source antenna array.
• the reconfigurability of the radiation pattern of these antenna systems is achieved by the implementation of a switching module in a conventional power supply circuit.
• a first application of such an antenna system according to the invention is the implementation in a collision-avoidance radar at 77 GHz, for example, embedded in an automobile.
• a solution to this problem may be an antenna system according to the particular embodiment of the invention, the radiation pattern of which is reconfigurable.
• a second application of such an antennal system according to the invention is that of broadband indoor communications (for example in a home) general public.
• broadband indoor communications for example in a home
• the use, in this context, of the reconfigurable antennal system according to the invention is advantageous because in such a case of presence of an obstacle, the antenna system can switch from a directional radiation pattern to a control diagram. sectoral radiation, which then allows, by multipath, to restore communication.
• the source antennas are distributed in a linear array, which may be flat (ID) or not (2D).
• the source antenna array is a surface network, which may be plane (2D) or shaped (3D).
• FIG. 8 illustrates an example of a hexagonal network of source antennas 81, making it possible to have the same distance between the source antennas and thus of mirror the radiation pattern. On the other hand, it shows that the arrangement of sources does not necessarily follow a Cartesian mesh.
• FIG. 9 illustrates an Oxyz mark, in which the angles PHI ( ⁇ ) and THETA ( ⁇ ) are represented. At each value of the angle PHI corresponds a distinct azimuthal direction. The angle THETA makes it possible to measure the misalignment of the beam, if it is supposed that the pattern of the grating is centered on the center 0 of the mark.
• FIGS. 10A, 10B and 10C show diagrams of top views of an antenna system comprising: nine source antennas arranged in a three-line and three-column areal network, centered on the center of the marker, and a lens (not shown) ).
• the fed antennas are represented by a rectangle whose surface is black.
• the unpowered antennas are represented by a rectangle whose surface is white.
• the source antennas of the middle column and the middle line are fed simultaneously.
• all the source antennas (those of the three columns and of the three lines) are fed simultaneously.
• the antenna system emits a radiation pattern that is sectoral for any PHI angle (i.e., in all planes each associated with an azimuth direction itself defined by a distinct PHI angle).
• the source antennas of the middle column are fed simultaneously.

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• 2007
  • 2007-07-20 FR FR0756664A patent/FR2919121B1/fr not_active Expired - Fee Related
• 2008
  • 2008-07-18 WO PCT/EP2008/059478 patent/WO2009013248A1/fr active Application Filing
  • 2008-07-18 EP EP08786258A patent/EP2171799A1/de not_active Ceased

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