Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
  • H01Q9/0414—Substantially flat resonant element parallel to ground plane, e.g. patch antenna in a stacked or folded configuration
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
  • H01Q5/30—Arrangements for providing operation on different wavebands
  • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
  • H01Q5/342—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes
  • H01Q5/35—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes using two or more simultaneously fed points
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
  • H01Q9/04—Resonant antennas
  • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
  • H01Q9/045—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with particular feeding means
  • H01Q9/0457—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with particular feeding means electromagnetically coupled to the feed line

Definitions

• a so-called array antenna comprises a plurality of elementary antennas which may preferably be of the microstrip type, also called paved antennas or "patch antenna" in English terminology.
• These paved antennas comprise a stack of layers of dielectric substrates provided with metal tracks, spaced if necessary by non-etched materials or substrates.
• An elementary microstrip antenna conventionally comprises a radiating element placed on a dielectric layer disposed above a conducting plane serving as ground so as to constitute a resonator.
• the elementary antenna also includes a power distribution device enabling the radiating element to be excited from an input signal.
• the radiating device is coupled to its excitation by a metallized hole (called via) or by a slot. Electromagnetic coupling by slot makes it easier to generate a wide frequency band. It also makes it possible to avoid any via connection between the radiating elements and the excitation which simplifies the manufacture of the elementary antenna.
• the elementary antennas are subject to a certain number of constraints.
• microstrip intended to operate on an extended frequency band which may be greater than one octave, several frequencies of
• the array antennas form an array of elementary antennas, the pitch of which is at Fmax / 2, where At Fmax is the smallest wavelength corresponding to the maximum frequency Fmax of the band, which is a strong constraint the dimensions of the elementary antennas.
• the elementary antenna consists in increasing the volume of the antenna, therefore the height (the thickness), the lateral dimensions being limited by the pitch of the array. Simply increasing the height between the radiating device and the ground plane, however, leads to parasitic phenomena when placing within a network (transverse propagation of undesirable modes).
• the conventionally adopted solution consists in using several superimposed radiating elements. This type of stack is called a double superimposed patch (DPS) in the case of two radiating elements.
• DPS double superimposed patch
• a symmetrical excitation of two excitation points is provided for by means of a power distributor for each of the orthogonal linear polarizations.
• one solution consists in forming the two power distributors on different planes of the microstrip antenna.
• the two power distributors include branches whose projections on a plane
• Each of the distributors comprises two branches which meet outside the surface covered by each of the radiating elements. This configuration is incompatible with the networking of the elementary antenna with a tight mesh (mesh of the order of l ⁇ 3C / 2).
• the distributors are arranged on different planes spaced apart according to the direction of 'stacking. Vias are necessary to pass the signals to the second distributor through the layer containing the first distributor, through a ground plane separating the planes of the two couplers. This generates a strong asymmetry on the geometry and therefore on the behavior of the two linear polarizations.
• An object of the present invention is to limit at least one of the drawbacks listed above.
• the invention relates to an elementary antenna of the type
• microstrip comprising a stack of layers, the elementary antenna being able to be in a planar configuration in which the layers are substantially planar and perpendicular to a stacking axis along which the layers are stacked, the stack comprising a first radiating element conductor and an excitation device coupled to the first radiating element so as to allow excitation of the radiating element according to two orthogonal linear polarizations, the power distribution device comprising:
• a first elementary excitation device configured and coupled to the first radiating element so as to be able to excite a first pair of excitation points formed by a first excitation point and a second point excitation arranged on a first straight line of the first radiating element
• the first elementary excitation device comprising a first conducting line, a second conducting line and a first power distributor able to distribute a power of an input signal received in an input / output point of the first power distributor on the first conductive line and the second conductive line
• a second elementary excitation device configured and coupled to the first radiating element so as to be able to excite a second pair of excitation points formed by a third excitation point and a fourth excitation point arranged on a second straight line of the first radiating element, the second elementary excitation device comprising a third conductive line, a fourth conductive line and a second power distributor capable of distributing a power of an input signal received at an input point / output of the second power distributor on the third conductive line and the fourth conductive line,
• the first, second, third and fourth conductive lines being interposed between the first radiating element and the first and second power distributors along the stacking axis, the first power distributor and the second power distributor being coplanar.
• the first conductive line is opposite the first excitation point
• the second conductive line is opposite the second excitation point
• the third conductive line is opposite the third excitation point
• the fourth line conductive is opposite the fourth point of excitation.
• the first power distributor is connected to the first conductive line and to the second conductive line at access points of the power distributor, of which orthogonal projections on the first radiating element are distant from the first excitation point. and from the second excitation point along the second straight line, and in which the second power distributor is connected to the third conductive line and to the fourth conductive line at access points of the power distributor, including orthogonal projections on the first radiating element are distant from the third excitation point and from the fourth excitation point along the first straight line.
• the power distributors are Wilkinson distributors, each power distributor comprising two S-shaped branches, deviating from one another from the junction point to two parts then approach each other to the respective ends of a resistor by which the branches are connected, then deviating again from each other to reach respective access points of the distribution frame power, the extreme parts being distant from each other by a distance greater than the distance separating the junction point of the resistance.
• the first distributor and the second distributor are identical to each other.
• a line being an orthogonal projection of a bisector of the first line and the second line on the plane of the distributors.
• the first distributor and the second distributor are identical to each other.
• first and second distributors are asymmetrical with respect to the line.
• each of the first and second power distributors comprises a common branch
• each of the two branches being coupled to one of the conductive lines via an access point of the branch, a straight line connecting the access points of each distributor power extending parallel and close to a first side of the rectangle and an entry / exit point of the power distributor being closer to another side of the rectangle parallel to the first side than said straight line.
• the first radiating element comprises a center, the first excitation point and the second excitation point being positioned symmetrically with respect to the center, and the third excitation point and the fourth excitation point being positioned symmetrically with respect to the center.
• the elementary antenna comprises a second radiating element superimposed on the first radiating element.
• the antenna comprises a first elementary assembly of at least one slot extending linearly opposite the first straight line and facing the first excitation point and the second excitation point and a second elementary assembly at least one slit extending linearly opposite the second straight line and facing the third excitation point and the fourth excitation point, the first elementary set of at least one slit and the second elementary set at least one slot for coupling the excitation device and the first conductive radiating element.
• the invention also relates to a network antenna comprising a plurality of elementary antennas according to the invention.
• the elementary antennas form an array of elementary antennas.
• Figure 1 schematically shows an exploded view of an example
• FIG. 2 diagrammatically represents these conductive planes in section along a plane parallel to the stacking direction
• Figure 3 schematically shows a projection, on the plane of the first radiating element, of the slots and conductive lines of the elementary antenna of Figures 1 and 2 as well as the projections of access points and excitation points ,
• FIG. 4 represents an example of a plan of the antenna distributors
• FIG. 5 shows schematically T distributors.
• the invention also relates to an elementary antenna as well as to a network antenna comprising an array of elementary antennas according to the invention.
• Figure 1 shows schematically an exploded view of an example
• microstrip antenna elementary antenna of the planar type also called microstrip antenna.
• the elementary antenna is able to be in a plane configuration in
• stack comprises a stack of substantially planar layers perpendicular to a stacking direction represented by the z axis.
• the elementary antenna can be flexible and be able to present a
• the stack comprises parallel conducting planes, spaced apart according to
• FIG. 1 A sectional view of the elementary antenna is shown in Figure 2. In order not to overload Figures 1 and 2, only the conducting planes are shown.
• Intervals are made between the successive conducting planes. These intervals each include at least one layer of a dielectric substrate which may, for example, be a layer of air or foam.
• the elementary antenna A comprises a radiating device B of the superimposed double patch type, comprising:
• ground plane means a conductive plane acting as a ground plane
• first radiating element 1 surmounting the upper intermediate ground plane 3
• the first radiating element 1 is called excited block and the second
• the double superimposed patch is adjusted to make a double resonator.
• Each radiating element 1, 2 is in the form of a conductive plate. It has, for example, a substantially rectangular shape as shown in Figure 1. Alternatively, each radiating element may have a different shape (square, disc, etc.). Whatever the geometry of each radiating element, it is possible to define a center there.
• the radiating elements 1, 2 are arranged so that the center C1 of the first radiating element is located opposite the center C2 of the second radiating element, that is to say on the same axis parallel to the direction of stack represented by the z axis.
• the radiating device B comprises a single radiating element.
• the excitation device C overcomes a lower ground plane D.
• a first elementary excitation device 11, v1, v2, L1, L2 configured and coupled to the first radiating element 1 so as to be able to excite a first pair of excitation points of the first radiating element 1, the first pair comprising a first excitation point p1 and a second excitation point p2 arranged on a first straight line D1 of the first radiating element 1,
• a second elementary excitation device 21, v3, v4, L3, L4 configured and coupled to the first radiating element 1 so as to be able to excite a second pair of excitation points of the first radiating element, the second pair comprising a third excitation point p3 and a fourth excitation point p4 arranged on a second straight line D2 of the first radiating element 1.
• the proposed coupling makes it possible to choose the polarization of the total wave emitted by the antenna, the most suitable for a given environment (by combining these two polarizations with an appropriate phase amplitude relationship). It is possible to obtain a total wave polarized circularly in both directions, or linearly in any direction depending on the phase shifts between these two linearly polarized waves.
• the lines D1 and D2 are orthogonal to each other and to the z axis and pass through the center C1.
• the points p1 and p2 are symmetrical to each other with respect to the center C1 and the points p3 and p4 are symmetrical to each other with respect to the center C1.
• the points p1, p2, p3 and p4 are located at the same
• the invention consists in dividing each
• a power distributor 11 capable of distributing the power of an input signal over the two conductive lines.
• each conductive line L1, L2, L3, or L4 passes opposite the excitation point p1, p2, p3 or p4, to which it is coupled.
• an orthogonal projection of each conductive line on the plane of the first conductive element 1 passes through the excitation point to which the conductive line is coupled.
• the two power distributors 11 and 21 are coplanar, that is to say, placed or etched on the same layer of dielectric substrate.
• the conducting lines L1, L2, L3 and L4 are interposed between the radiating device B and the power distributors 11 and 21, in the direction
• the conducting lines L1, L2, L3 and L4 are arranged in planes distant from the power distributors 21, 22 along the stacking axis.
• each power distributor it is not necessary for each power distributor to have access points opposite the excitation points associated with the power distributor. According to the invention, these are the conductive lines which must be located opposite these excitation points in order to be able to be coupled with these points.
• the power distributors are separated from the lines
• the elementary excitation devices are configured and arranged so that the second elementary excitation device is substantially obtained by rotation of the first elementary excitation device. 90 ° around an axis parallel to z and passing through C1.
• This characteristic makes it possible to obtain a high symmetry between the excitations of the two polarizations due to the symmetry of the electrical paths within the distributors.
• the two power distributors are separated by the straight line DB.
• the conductive lines are linear.
• the conducting lines L1 and L2 are perpendicular to D1 and the lines L3 and L4 are perpendicular to D2.
• the orthogonality between the two pairs of conductive lines also ensures minimal coupling between these pairs of lines.
• the conducting lines L1 and L2 are distant from the lines L3 and L4 along the stacking axis z.
• the lines L1 and L2 are coplanar and included in a first plane P1, perpendicular to the stacking direction z, and the lines L3 and L4 are coplanar and included in a second plane P2, perpendicular to the stacking direction z, distant of the first plane P1 in the stacking direction z.
• the second elementary excitation device is substantially obtained by rotation of the first elementary excitation device by 90 ° around an axis parallel to z and passing through C1.
• the residual asymmetry of the excitation between the two pairs of excitation points is limited to the distance between the two planes carrying the two pairs of lines, which makes it possible to obtain a very stable radiation diagram.
• the two pairs of conductive lines are for example placed or etched on the two respective faces of a dielectric or insulating substrate.
• the thickness of the substrate along the z axis is substantially the thickness necessary and sufficient to provide electrical insulation between the two pairs of lines.
• the minimum thickness of dielectric or insulating material makes it possible to limit the asymmetry between the excitations of the two pairs of excitation points.
• the supply lines are curved.
• each first distributor is a Wilkinson distributor.
• the first elementary power distributor 11 comprises three branches including a common branch b and a first branch b1 comprising an access point a1 electrically connected to the conductive line L1 by a via v1 and a second branch b2 comprising a point d access a2 electrically connected to the second conductive line L2 by a via v2.
• the second elementary power distributor 21 includes three components
• branches including a common branch b ’and a first branch b1’
• the vias v1, v2, v1 ', v2' extend longitudinally in the stacking direction z as shown in Figures 1 and 2.
• Each via passes through the lower intermediate ground plane E interposed between the conductive lines and the power distributors 1 1, 21.
• each elementary distributor extends from an I / O input / output point, I / O' on which is intended to be injected the excitation signal to a point junction J, J 'which are connected the two branches b1 and b2 or b1' and b2 '.
• the distributors being Wilkinson resistive distributors, the two
• branches b1 and b2 (b1 'and b2') of each distributor have an S shape, they first move away from each other from the junction point J (J ') to two extreme parts e and f (e 'and f), then approach each other to the respective ends of a resistor R (R') by which they are connected and then move away again from one of the 'other to reach the respective access points a1 and a2 (a1' and a2 ').
• the Wilkinson distributors are flattened.
• the end parts e and f are distant from each other, according to D1, by a distance greater than the distance separating the junction point of the resistance J along the line D2.
• the extreme parts e ’and f are distant from each other, according to D2, by a distance greater than the distance separating the junction point of the resistance J’ along the line D1.
• each distributor 11 (21) each comprise two rectilinear elongated portions p, q and r, s (p ', q' and r ', s') substantially parallel to each other located between the junction point J (J ') and one of the ends of the resistor.
• the distributors are of the reactive type, for example in a T shape, are less bulky and simpler to produce than the resistive distributors.
• Reactive T distributors 31, 41 are shown in Figure 5. They
• the two branches 32 and 33 (42 and 43) are collinear.
• parasitic resonance phenomena between the power distributors and the DPS, very narrow in frequency appear, disturbing the operation of the DPS at these frequencies.
• the use of a resistive distributor, for example, of the Wilkinson type makes it possible to limit these disturbances. It allows to obtain a stable diagram and to suppress any parasitic resonance in a wide frequency band.
• ring type couplers called “rat-race hybrid ring coupler” in English terminology
• ladder type called “line coupler” in English terminology
• each access point a1, a2, a3 or a4 is opposite a point on its conductive line L1, L2, L3, or L4 respectively which is closer to 'one end of the line
• each power distributor 11, and respectively 21 is configured so that a signal injected on its common branch is divided into two signals of the same power and of the same phase available at its two access points a1, a2 and respectively a1 ', a2'.
• the two branches b1 and b2 of the first power distributor 11 are therefore symmetrical to each other with respect to a projection, on the plane of the power distributors, of a straight line of the first radiating element 1 passing through C1 and parallel to D2.
• the two branches b1 'and b2' of the second power distributor 21 are symmetrical to each other with respect to a projection, on the plane of the power distributors, of a straight line of the first radiating element 1 passing through C1 and parallel to D2.
• the junction points J, J ’ are each on one of these projections. This characteristic promotes symmetry of excitement.
• the radiating elements are delimited by a substantially rectangular surface, for example square, comprising four sides c1, c2, c3, c4; c1 being parallel to c4 and c2 being parallel to c3.
• junction point J and the I / O entry / exit point are located between the line d and the side c4.
• the I / O entry / exit point is closer to the side c3 than the points a1 and a2 and the I / O exit entry point is closer to the side c4 than the points a1 'and a2 '.
• the elementary antenna comprises, as visible in FIG. 4, shielding studs extending continuously from the lower ground plane D to the lower intermediate ground plane E. These studs are not shown in the other figures for clarity. These pads include several sets of shielding pads spaced two by two at a distance much less than the minimum wavelength of the microwave signals carried by the elementary antenna.
• These shielding pads include first shielding pads 120
• Second shielding studs 121, 121 ’ are arranged between each
• Third shielding pads 122, 122 ’ are arranged between the common branch b, b’ and one of the branches b1, b1 ’, of each power distributor in order to ensure decoupling between these two branches.
• the elementary antenna A comprises a set of slots F1, F2, which are for example oblong rectangles, open in the upper intermediate ground plane 3.
• the set of slots comprises:
• Each slot F1 of the first elementary set extends linearly along a line parallel to the line D1.
• Each slot F2 of the second elementary set extends linearly along a line parallel to the line D2.
• each elementary assembly of at least one slot is symmetrical with respect to a point situated opposite the center C1 on the z axis.
• the set of open slots in the upper intermediate ground plane 3 comprises a cruciform slot F.
• the cruciform slot F is formed by two orthogonal linear slots F1 and F2 intersecting next to the center C1.
• the coupling is, by
• the excitation devices are capable of being used in reception to ensure the reception of the signals polarized according to D1 and D2 and to transmit them on the I / O and I / O output inputs.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)
• Waveguide Aerials (AREA)
• Details Of Aerials (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2018
  • 2018-12-20 FR FR1873475A patent/FR3091046B1/fr active Active
• 2019
  • 2019-12-19 EP EP19829574.3A patent/EP3900113B1/de active Active
  • 2019-12-19 WO PCT/EP2019/086495 patent/WO2020127854A1/fr unknown
  • 2019-12-19 ES ES19829574T patent/ES2940567T3/es active Active

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