EP3605730B1 - Antenna device with two different and secant planar substrates - Google Patents

Antenna device with two different and secant planar substrates Download PDF

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Publication number
EP3605730B1
EP3605730B1 EP19189713.1A EP19189713A EP3605730B1 EP 3605730 B1 EP3605730 B1 EP 3605730B1 EP 19189713 A EP19189713 A EP 19189713A EP 3605730 B1 EP3605730 B1 EP 3605730B1
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EP
European Patent Office
Prior art keywords
substrate
electrically conductive
antenna
face
antenna device
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EP19189713.1A
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German (de)
French (fr)
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EP3605730A1 (en
Inventor
Jean-François PINTOS
Christophe Delaveaud
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Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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    • 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
    • H01Q15/0006—Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices
    • H01Q15/006—Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces
    • H01Q15/008—Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces said selective devices having Sievenpipers' mushroom elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
    • H01Q1/526—Electromagnetic shields
    • 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
    • H01Q19/10—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 reflecting surfaces
    • 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
    • H01Q5/40—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
    • H01Q5/45—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements using two or more feeds in association with a common reflecting, diffracting or refracting device
    • 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
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/32—Vertical arrangement of element

Definitions

  • the present invention relates to an antenna device with two different intersecting planar substrates.
  • the second substrate is generally used to electromagnetically isolate the first radiating portion of the first substrate from the second non-radiating portion for electrical connection, for example by deploying a metallic ground plane of the side of the radiating portion.
  • electromagnetic interference between the support and the second substrate are capable of exciting at least one electromagnetic resonance mode specific to the second substrate.
  • These interferences then generate, via the own electromagnetic resonance mode(s) possibly excited in the bandwidth of the radio antenna which extends in the first radiating portion of the first substrate, a disturbance of the radiation of the latter. This disturbance affects the performance of the antenna device.
  • a technical solution to reduce or cancel such a disturbance consists of adding short circuits between the metallic ground plane of the second substrate and the metallic support. But this solution is not possible in many numerous concrete applications with compact structures in which integration constraints do not allow such additions.
  • the document WO 2017/056437 A1 discloses an antenna device with two different and intersecting planar substrates as described above, in which a metamaterial structure is also present on the upper face of the second substrate.
  • the documents US 2005/0168394 A1 And EP 0 945 917 A2 each disclose an antenna device with two different and intersecting planar substrates as described above.
  • the document US 7,142,822 B2 discloses a radio frequency circuit substrate having a metamaterial structure.
  • Said at least one radio antenna is at least one printed antenna extending over at least one face of the first substrate.
  • Said at least one radio antenna comprises a first antenna printed at low frequencies operating in a first electromagnetic frequency band and a second antenna printed at high frequencies operating in a second electromagnetic frequency band all higher than the electromagnetic frequencies of the first frequency band.
  • metamaterial structures are known to generate multiple modes of electromagnetic resonances, or even to increase the number of resonances in cavities, as for example taught in the article by Seetharamdoo et al, entitled “Investigation on the use of metamaterials to lower the operating frequency of reverberation chamber”, published at the EMC Europe 2011 conference York (UK), September 26-30, 2011 (pages 680 to 685 of the Proceedings ), it was observed surprisingly that the addition of a metamaterial structure on the face of the second substrate oriented towards the second half-space is able to protect and electromagnetically isolate the first half-space in which the radio antenna in the particular structure of this type of antenna device.
  • the electrically conductive elements of the metamaterial structure are arranged in a matrix on the lower face of the second substrate.
  • electrical connection pins are arranged between the first and second substrates for an electrical junction of at least part of the electrically conductive means of connection to the metallic ground plane.
  • said at least part of the electrically conductive connection means comprises a portion of metallic ground plane formed in the first substrate.
  • the second substrate has an opening, for example a rectilinear hole, through which the first substrate passes.
  • the first and second substrates are arranged orthogonally.
  • the antenna device 10 shown schematically in front view on the figure 1 comprises a first substrate 12 which extends in a first plane, that of the figure. It further comprises a second substrate 14 which extends in a second plane different and intersecting the first plane, in particular a horizontal plane orthogonal to that of the figure.
  • the second substrate 14 has an opening, for example a rectilinear hole, crossed by the first substrate 12, so that the latter has a first portion 16, located in a first upper half-space relative to the second plane of the second substrate 14, and a second portion 18, located in a second half -lower space relative to the second plane of the second substrate 14.
  • the two substrates are for example made of FR-4 type material (from the English "Flame Resistant 4"), that is to say an epoxy resin composite reinforced with fiberglass.
  • two radio antennas 20 and 22 are formed by metal printing using known screen printing technology.
  • the larger of the two radio antennas i.e. the first printed antenna 20, comprises two metal strips 20A, 20B extending orthogonally from the second plane. These two metal strips 20A, 20B form two feet connected together at their ends most distant from the second plane by a portion of additional metal strip, as well as to another metal strip 20C extending horizontally in the upper part of the first portion radiant 16 of the first substrate 12.
  • the precise configuration of this first printed antenna 20, located furthest to the left on the front face of the first substrate 12, as well as its dimensioning remain concretely up to the appreciation of those skilled in the art depending on the application, impedance matching and targeted radiation. It operates at low frequencies, in a first band of predetermined electromagnetic frequencies.
  • the smaller of the two radio antennas, ie the second printed antenna 22, also includes two metal strips 22A, 22B extending orthogonally from the second plane. These two metal strips 22A, 22B are shorter than the metal strips 20A, 20B. They also form two feet connected together at their ends most distant from the second plane by a portion of additional metal strip, as well as to another metal strip 22C extending horizontally under the metal strip 20C in the first radiating portion 16 of the first substrate 12. The metal strip 22C is shorter than the metal strip 20C.
  • the precise configuration of this second printed antenna 22, located furthest to the right on the front face of the first substrate 12, as well as its dimensioning remain concretely up to the appreciation of those skilled in the art depending on the application, the adaptation impedance and radiation targeted. It operates at high frequencies, in a second band of predetermined electromagnetic frequencies, for example all higher than the electromagnetic frequencies of the first frequency band of the first printed antenna 20.
  • electrically conductive means for connecting the two radio antennas 20 and 22 to an electronic transmission circuit and/or reception are formed in particular by metal printing using the aforementioned screen printing technology.
  • these conductive connection means comprise a metallic ground plane portion 24 formed by metallic printing on the front face of the second lower portion 18 of the first substrate 12.
  • each antenna must first be shaped so as to ensure impedance matching with the electronic transmission and/or reception circuit, then must be respectively connected to the electronic transmission and/or reception circuit and to the plane portion of metallic mass 24 by its two feet.
  • the connection of the first printed antenna 20 to the metal ground plane portion 24 is thus carried out by its antenna base 20A according to known means, not detailed in the figure 1 , which are not necessarily arranged only on the front face of the first substrate 12.
  • the connection of the first printed antenna 20 to the electronic transmission and/or reception circuit is represented symbolically by a first connector block 26.
  • the connection of the second printed antenna 22 to the metallic ground plane portion 24 is made by its antenna base 22A: this can for example be done by continuity of metallic printing on the front face of the first substrate 12.
  • connection of the second antenna 22 printed on the metal ground plane portion 24 is for its part represented symbolically by a second connector block 28.
  • the electronic transmission and/or reception circuit is generally located in the second half -lower space relative to the second plane of the second substrate 14, but is not shown on the figure 1 because it is not useful for a good understanding of the invention.
  • the second substrate 14 has a face, called the upper face because it is that which is oriented towards the first upper half-space in which the two radio antennas 20 and 22 are located, on which a ground plane 30 is formed by metal print. Thanks to the presence of the rectilinear hole crossed by the first substrate 12, the ground plane 30 is not in direct electrical contact with the two radio antennas 20 and 22. Contact is established using electrical connection pins whose two pairs 32 and 34 are represented on the figure 1 . A first pair of pins 32 is arranged in the vicinity of the feet of the first printed antenna 20.
  • It comprises two pins, electrically connected to each other using male and female elements in a manner known per se, one of which is arranged and connected electrically to the metallic ground plane portion 24 of the first substrate 12 and the other to the ground plane 30 of the second substrate 14.
  • a second pair of pins 34 is arranged in the same way in the vicinity of the feet of the second printed antenna 22
  • Other electrical connection pins can be added for the connection of other elements, for example elements of the electronic transmission and/or reception circuit, to the ground plane 30 of the second substrate 14.
  • the second substrate 14 has a face opposite its upper face, called the lower face, oriented towards the second lower half-space in which the second lower portion 18 of the first substrate 12 is located, which is used to electromagnetically isolate the upper half-space from any electromagnetic interference due to the at least partial insertion of the second lower portion 18 of the first substrate 12 in a corresponding slot of a metal support 36 such as a cylindrical mast or candelabra.
  • This exploitation of the lower face of the second substrate 14 consists of deploying there, by metallic printing, a metamaterial structure 38 with multiple electrically conductive elements 40 electrically separated from each other on this lower face.
  • each electrically conductive element 40 of the metamaterial structure 38 is connected to the metallic ground plane 30 using a through metallic via 42 extending into the thickness of the second substrate 14.
  • the metamaterial structure 38 is dimensioned so as to eliminate at least one stationary mode of own electromagnetic resonance of the second substrate 14 capable of being excited by the proximity of the metal support 36, that is to say at least one stationary mode of current distribution capable of appearing in the ground plane 30 of the second substrate 14 at at least one frequency, in particular at least one frequency of the bandwidth of any one of the two antennas 20 and 22.
  • the second substrate 14 can simply be manufactured, with its ground plane 30 on the upper face and its metamaterial structure 38 on the lower face, from a substrate sold commercially with complete metallization on its two faces. It is then sufficient to remove part of the metallization according to the desired patterns on the upper and lower faces of the substrate 14.
  • the antenna device 10 in a protective housing 44 (shown transparent for better visibility of the device 10 on the figure 2 ), only at least part of the second lower portion 18 emerging from under the housing 44 for insertion into the metal support 36.
  • This is generally a plastic radome.
  • the figure 2 also illustrates conventional means 46 with lateral screws for fixing the radome 44 on the metal support 36 as well as the rectilinear hole 48 of the second substrate 14 crossed by the first substrate 12.
  • the Figure 3 further shows that the electrically conductive elements 40 of the metamaterial structure 38 can be square or rectangular in shape and arranged in a matrix on all or part of the lower face of the second substrate 14. This means that the electrically conductive elements 40 are arranged in lines and columns along two main axes, in particular according to a periodic or pseudo-periodic repetition (for example with increasing or decreasing dimensions of the patterns) along one of the two axes or both.
  • FIG. 4 illustrates in perspective an installation comprising the antenna device 10, integrated into the radome 44 and therefore not visible in this figure, as fixed by screwing on the metal support 36. It can be seen that the implementation of the present invention allows to maintain a very good compactness of the whole.
  • Tests were carried out for a first printed antenna 20 shaped and sized to operate in the passband [860; 865] MHz and for a second printed antenna 22 shaped and sized to operate in the bandwidth [2.4000; 2.4835] GHz.
  • FIG. 5A illustrates a curve of reflection coefficients S 11 measured at the input of each of the two antennas of the antenna device 10 when the latter does not include the metamaterial structure 38. Between 0.7 and 2 GHz, this is the evolution of the reflection coefficient S 11 of the first printed antenna 20. Between 2 and 3 GHz, this is the evolution of the reflection coefficient S 11 of the second antenna 22. This results in a complete break in the curve normal at 2GHz.
  • FIG. 5B illustrates another curve of reflection coefficients S 11 measured at the input of each of the two antennas of the same antenna device 10, but this time when the latter comprises the metamaterial structure 38 with electrically conductive elements 40 square of 11 mm from sides.
  • this is the evolution of the reflection coefficient S 11 of the first printed antenna 20.
  • this is the evolution of the reflection coefficient S 11 of the second printed antenna 22.
  • Point m1 now measures a coefficient S 11 - -17.3 dB at 860 MHz.
  • the point m2, measuring a coefficient S 11 -32.2 dB at 865 MHz, is no longer even apparent on the curve.
  • the reflection coefficients of the antennas 20 and 22 have significantly reduced values in the two pass bands [860; 865] MHz and [2.4000; 2.4835] GHz compared to the figure 5A , which demonstrates that the two antennas 20 and 22 have better transmission performances (ie reception and transmission) in the case of Figure 5B than in that of the figure 5A .
  • FIG. 6A illustrates a curve of total efficiency values measured for the second printed antenna 22 of the antenna device 10 when the latter does not include the metamaterial structure 38, between 2.35 and 2.5 GHz.
  • FIG. 6B illustrates another curve of total efficiency values measured for the second printed antenna 22 of the same antenna device 10 between 2.35 and 2.5 GHz, but this time when the latter comprises the metamaterial structure 38 with elements electrically conductive 40 squares of 11 mm sides.
  • the performance is more stable and better, in the bandwidth [2.4000; 2.4835] GHz, in the case of Figure 6B than in that of the Figure 6A .
  • an antenna device such as that described above makes it possible to preserve the radio performance of the antenna(s) it comprises while maintaining very good compactness, when this device is intended to be fixed on a metal support. likely to disturb it electromagnetically.
  • the functionalization of the lower face of the second substrate using a metamaterial structure makes it possible to reduce the interactions of the antenna(s) of the device with its immediate environment.
  • the aforementioned antennas 20 and 22 are printed using screen printing technology, but other types of antennas are compatible with the present invention.
  • antennas 20 and 22 are also printed on the same face of substrate, but antennas printed on two different faces of the same substrate are also suitable.

Description

La présente invention concerne un dispositif d'antenne à deux substrats plans différents et sécants.The present invention relates to an antenna device with two different intersecting planar substrates.

Plus précisément, elle s'applique à un dispositif d'antenne comportant :

  • un premier substrat, s'étendant dans un premier plan, comportant au moins une face où sont formés :
    • au moins une antenne radioélectrique s'étendant dans une première portion rayonnante du premier substrat, et
    • des moyens électriquement conducteurs de raccordement de ladite au moins une antenne radioélectrique à un circuit électronique d'émission et/ou réception, ces moyens électriquement conducteurs s'étendant dans une deuxième portion du premier substrat,
  • un deuxième substrat s'étendant dans un deuxième plan différent et sécant du premier plan, séparant la première portion rayonnante du premier substrat, située dans un premier demi-espace par rapport à ce deuxième plan, de la deuxième portion du premier substrat, située dans un deuxième demi-espace par rapport à ce deuxième plan.
More precisely, it applies to an antenna device comprising:
  • a first substrate, extending in a first plane, comprising at least one face where:
    • at least one radio antenna extending in a first radiating portion of the first substrate, and
    • electrically conductive means for connecting said at least one radio antenna to an electronic transmission and/or reception circuit, these electrically conductive means extending in a second portion of the first substrate,
  • a second substrate extending in a second plane different and secant from the first plane, separating the first radiating portion of the first substrate, located in a first half-space relative to this second plane, from the second portion of the first substrate, located in a second half-space relative to this second plane.

Dans ce type de dispositif à structure souvent très compacte, le deuxième substrat est généralement exploité pour isoler électromagnétiquement la première portion rayonnante du premier substrat de la deuxième portion à vocation non rayonnante de raccordement électrique, par exemple en y déployant un plan de masse métallique du côté de la portion rayonnante. Mais lorsque le dispositif d'antenne est ensuite fixé sur un support qui lui aussi est métallique, par exemple un mât ou candélabre cylindrique, cette fixation s'opérant logiquement du côté du deuxième demi-espace précité, des interférences électromagnétiques entre le support et le deuxième substrat sont susceptibles d'exciter au moins un mode de résonance électromagnétique propre du deuxième substrat. Ces interférences engendrent alors, via le ou les modes de résonances électromagnétiques propres excités éventuellement dans la bande passante de l'antenne radioélectrique qui s'étend dans la première portion rayonnante du premier substrat, une perturbation du rayonnement de cette dernière. Cette perturbation nuit aux performances du dispositif d'antenne.In this type of device with an often very compact structure, the second substrate is generally used to electromagnetically isolate the first radiating portion of the first substrate from the second non-radiating portion for electrical connection, for example by deploying a metallic ground plane of the side of the radiating portion. But when the antenna device is then fixed on a support which is also metallic, for example a mast or cylindrical candelabra, this fixing logically taking place on the side of the aforementioned second half-space, electromagnetic interference between the support and the second substrate are capable of exciting at least one electromagnetic resonance mode specific to the second substrate. These interferences then generate, via the own electromagnetic resonance mode(s) possibly excited in the bandwidth of the radio antenna which extends in the first radiating portion of the first substrate, a disturbance of the radiation of the latter. This disturbance affects the performance of the antenna device.

Une solution technique pour réduire ou annuler une telle perturbation consiste à ajouter des courts-circuits entre le plan de masse métallique du deuxième substrat et le support métallique. Mais cette solution n'est pas envisageable dans de nombreuses applications concrètes à structures compactes dans lesquelles des contraintes d'intégration ne permettent pas de tels ajouts.A technical solution to reduce or cancel such a disturbance consists of adding short circuits between the metallic ground plane of the second substrate and the metallic support. But this solution is not possible in many numerous concrete applications with compact structures in which integration constraints do not allow such additions.

Le document WO 2017/056437 A1 divulgue un dispositif d'antenne à deux substrats plans différents et sécants tel que décrit précédemment, dans lequel une structure de métamatériau est en outre présente en face supérieure du deuxième substrat. Les documents US 2005/0168394 A1 et EP 0 945 917 A2 divulguent chacun un dispositif d'antenne à deux substrats plans différents et sécants tel que décrit précédemment. Le document US 7,142,822 B2 divulgue un substrat de circuit radiofréquence présentant une structure de métamatériau.The document WO 2017/056437 A1 discloses an antenna device with two different and intersecting planar substrates as described above, in which a metamaterial structure is also present on the upper face of the second substrate. The documents US 2005/0168394 A1 And EP 0 945 917 A2 each disclose an antenna device with two different and intersecting planar substrates as described above. The document US 7,142,822 B2 discloses a radio frequency circuit substrate having a metamaterial structure.

Il peut ainsi être souhaité de prévoir un dispositif d'antenne compact qui permette de s'affranchir d'au moins une partie des problèmes et contraintes précités, notamment d'une perturbation telle que celle mentionnée ci-dessus.It may thus be desired to provide a compact antenna device which makes it possible to overcome at least part of the aforementioned problems and constraints, in particular a disturbance such as that mentioned above.

Il est donc proposé un dispositif d'antenne comportant :

  • un premier substrat, s'étendant dans un premier plan, présentant au moins une face où sont formés :
    • au moins une antenne radioélectrique s'étendant dans une première portion rayonnante du premier substrat, et
    • des moyens électriquement conducteurs de raccordement de ladite au moins une antenne radioélectrique à un circuit électronique d'émission et/ou réception, ces moyens électriquement conducteurs s'étendant dans une deuxième portion du premier substrat,
  • un deuxième substrat s'étendant dans un deuxième plan différent et sécant du premier plan, séparant la première portion rayonnante du premier substrat, située dans un premier demi-espace par rapport à ce deuxième plan, de la deuxième portion du premier substrat, située dans un deuxième demi-espace par rapport à ce deuxième plan,
dans lequel le deuxième substrat présente une face, dite face inférieure et orientée du côté dudit deuxième demi-espace dans lequel sont situés les moyens électriquement conducteurs de raccordement, comportant une structure de métamatériau à multiples éléments électriquement conducteurs séparés électriquement les uns des autres sur cette face inférieure.An antenna device is therefore proposed comprising:
  • a first substrate, extending in a first plane, having at least one face where:
    • at least one radio antenna extending in a first radiating portion of the first substrate, and
    • electrically conductive means for connecting said at least one radio antenna to an electronic transmission and/or reception circuit, these electrically conductive means extending in a second portion of the first substrate,
  • a second substrate extending in a second plane different and secant from the first plane, separating the first radiating portion of the first substrate, located in a first half-space relative to this second plane, from the second portion of the first substrate, located in a second half-space relative to this second plane,
in which the second substrate has a face, called the lower face and oriented towards the side of said second half-space in which the electrically conductive connection means are located, comprising a metamaterial structure with multiple electrically conductive elements electrically separated from each other on this lower side.

Ladite au moins une antenne radioélectrique est au moins une antenne imprimée s'étendant sur au moins une face du premier substrat.Said at least one radio antenna is at least one printed antenna extending over at least one face of the first substrate.

Ladite au moins une antenne radioélectrique comporte une première antenne imprimée à basses fréquences opérant dans une première bande de fréquences électromagnétiques et une deuxième antenne imprimée à hautes fréquences opérant dans une deuxième bande de fréquences électromagnétiques toutes plus élevées que les fréquences électromagnétiques de la première bande de fréquences.Said at least one radio antenna comprises a first antenna printed at low frequencies operating in a first electromagnetic frequency band and a second antenna printed at high frequencies operating in a second electromagnetic frequency band all higher than the electromagnetic frequencies of the first frequency band.

Le deuxième substrat présente :

  • un plan de masse métallique s'étendant sur une autre face, dite face supérieure et opposée à la face inférieure comportant la structure de métamatériau, et
  • des vias traversants raccordant chaque élément électriquement conducteur de la structure de métamatériau au plan de masse métallique.
The second substrate presents:
  • a metallic ground plane extending on another face, called the upper face and opposite the lower face comprising the metamaterial structure, and
  • through-vias connecting each electrically conductive element of the metamaterial structure to the metallic ground plane.

En effet, alors que les structures de métamatériaux sont réputées pour engendrer de multiples modes de résonances électromagnétiques, voire même d'augmenter le nombre de résonances dans des cavités, comme par exemple enseigné dans l'article de Seetharamdoo et al, intitulé « Investigation on the use of metamaterials to lower the operating frequency of réverbération chamber », publié à l'occasion de la conférence EMC Europe 2011 York (UK), 26-30 septembre 2011 (pages 680 à 685 des Proceedings ), il a été observé de façon étonnante que l'ajout d'une structure de métamatériau sur la face du deuxième substrat orientée vers le deuxième demi-espace est apte à protéger et isoler électromagnétiquement le premier demi-espace dans lequel se situe l'antenne radioélectrique dans la structure particulière de ce type de dispositif d'antenne.Indeed, while metamaterial structures are known to generate multiple modes of electromagnetic resonances, or even to increase the number of resonances in cavities, as for example taught in the article by Seetharamdoo et al, entitled “Investigation on the use of metamaterials to lower the operating frequency of reverberation chamber”, published at the EMC Europe 2011 conference York (UK), September 26-30, 2011 (pages 680 to 685 of the Proceedings ), it was observed surprisingly that the addition of a metamaterial structure on the face of the second substrate oriented towards the second half-space is able to protect and electromagnetically isolate the first half-space in which the radio antenna in the particular structure of this type of antenna device.

De façon optionnelle, les éléments électriquement conducteurs de la structure de métamatériau sont disposés matriciellement sur la face inférieure du deuxième substrat.Optionally, the electrically conductive elements of the metamaterial structure are arranged in a matrix on the lower face of the second substrate.

De façon optionnelle également, au moins l'un des paramètres de l'ensemble constitué :

  • du nombre d'éléments électriquement conducteurs de la structure de métamatériau,
  • d'une distribution des éléments électriquement conducteurs de la structure de métamatériau sur la face inférieure du deuxième substrat,
  • d'au moins une dimension de chaque élément électriquement conducteur de la structure de métamatériau, et
  • des espaces entre éléments électriquement conducteurs de la structure de métamatériau,
est réglé de manière à supprimer au moins un mode stationnaire de résonance électromagnétique propre du deuxième substrat.Also optionally, at least one of the parameters of the set consisting of:
  • the number of electrically conductive elements of the metamaterial structure,
  • a distribution of the electrically conductive elements of the metamaterial structure on the lower face of the second substrate,
  • at least one dimension of each electrically conductive element of the metamaterial structure, and
  • spaces between electrically conductive elements of the metamaterial structure,
is adjusted so as to suppress at least one stationary mode of own electromagnetic resonance of the second substrate.

De façon optionnelle également, des broches de raccordement électrique sont disposées entre les premier et deuxième substrats pour une jonction électrique d'au moins une partie des moyens électriquement conducteurs de raccordement au plan de masse métallique.Also optionally, electrical connection pins are arranged between the first and second substrates for an electrical junction of at least part of the electrically conductive means of connection to the metallic ground plane.

De façon optionnelle également, ladite au moins une partie des moyens électriquement conducteurs de raccordement comporte une portion de plan de masse métallique formée dans le premier substrat.Also optionally, said at least part of the electrically conductive connection means comprises a portion of metallic ground plane formed in the first substrate.

De façon optionnelle également, le deuxième substrat présente une ouverture, par exemple un trou rectiligne, traversée par le premier substrat.Also optionally, the second substrate has an opening, for example a rectilinear hole, through which the first substrate passes.

De façon optionnelle également, les premier et deuxième substrats sont disposés orthogonalement.Also optionally, the first and second substrates are arranged orthogonally.

L'invention sera mieux comprise à l'aide de la description qui va suivre, donnée uniquement à titre d'exemple et faite en se référant aux dessins annexés dans lesquels :

  • la figure 1 représente schématiquement et en vue de face la structure générale des éléments principaux d'un dispositif d'antenne selon un mode de réalisation de l'invention, tel qu'inséré dans un support de type mât ou candélabre cylindrique,
  • les figures 2 et 3 illustrent en perspectives vues de dessus et de dessous une réalisation concrète du dispositif d'antenne de la figure 1,
  • la figure 4 illustre en perspective une installation comportant le dispositif d'antenne des figures 2 et 3 fixé à un support,
  • les figures 5A et 5B sont des courbes comparatives de coefficients de réflexion de dispositifs d'antennes respectivement selon l'état de l'art et selon l'invention, et
  • les figures 6A et 6B sont des courbes comparatives de rendements de dispositifs d'antennes respectivement selon l'état de l'art et selon l'invention.
The invention will be better understood with the help of the description which follows, given solely by way of example and made with reference to the appended drawings in which:
  • there figure 1 represents schematically and in front view the general structure of the main elements of an antenna device according to one embodiment of the invention, as inserted in a mast or cylindrical candelabra type support,
  • THE figures 2 and 3 illustrate in perspective views from above and below a concrete realization of the antenna device of the figure 1 ,
  • there Figure 4 illustrates in perspective an installation comprising the antenna device of the figures 2 and 3 attached to a support,
  • THE Figures 5A and 5B are comparative curves of reflection coefficients of antenna devices respectively according to the state of the art and according to the invention, and
  • THE Figures 6A and 6B are comparative efficiency curves of antenna devices respectively according to the state of the art and according to the invention.

Le dispositif d'antenne 10 représenté schématiquement en vue de face sur la figure 1 comporte un premier substrat 12 qui s'étend dans un premier plan, celui de la figure. Il comporte en outre un deuxième substrat 14 qui s'étend dans un deuxième plan différent et sécant du premier plan, notamment un plan horizontal orthogonal à celui de la figure. Le deuxième substrat 14 présente une ouverture, par exemple un trou rectiligne, traversée par le premier substrat 12, de sorte que ce dernier présente une première portion 16, située dans un premier demi-espace supérieur par rapport au deuxième plan du deuxième substrat 14, et une deuxième portion 18, située dans un deuxième demi-espace inférieur par rapport au deuxième plan du deuxième substrat 14. Les deux substrats sont par exemple en matériau de type FR-4 (de l'anglais « Flame Résistant 4 »), c'est-à-dire en composite de résine époxy renforcé de fibre de verre.The antenna device 10 shown schematically in front view on the figure 1 comprises a first substrate 12 which extends in a first plane, that of the figure. It further comprises a second substrate 14 which extends in a second plane different and intersecting the first plane, in particular a horizontal plane orthogonal to that of the figure. The second substrate 14 has an opening, for example a rectilinear hole, crossed by the first substrate 12, so that the latter has a first portion 16, located in a first upper half-space relative to the second plane of the second substrate 14, and a second portion 18, located in a second half -lower space relative to the second plane of the second substrate 14. The two substrates are for example made of FR-4 type material (from the English "Flame Resistant 4"), that is to say an epoxy resin composite reinforced with fiberglass.

Sur la face avant visible et dans la première portion supérieure 16 du premier substrat 12, formant une première portion rayonnante de ce premier substrat 12, deux antennes radioélectriques 20 et 22 sont formées par impression métallique selon une technologie sérigraphique connue.On the visible front face and in the first upper portion 16 of the first substrate 12, forming a first radiating portion of this first substrate 12, two radio antennas 20 and 22 are formed by metal printing using known screen printing technology.

La plus grande des deux antennes radioélectriques, i.e. la première antenne imprimée 20, comporte deux bandes métalliques 20A, 20B s'étendant orthogonalement depuis le deuxième plan. Ces deux bandes métalliques 20A, 20B forment deux pieds reliés entre eux à leurs extrémités les plus distantes du deuxième plan par une portion de bande métallique supplémentaire, ainsi qu'à une autre bande métallique 20C s'étendant horizontalement en partie supérieure de la première portion rayonnante 16 du premier substrat 12. La configuration précise de cette première antenne imprimée 20, située la plus à gauche en face avant du premier substrat 12, ainsi que son dimensionnement restent concrètement à l'appréciation de l'homme du métier en fonction de l'application, de l'adaptation d'impédance et du rayonnement visés. Elle opère à basses fréquences, dans une première bande de fréquences électromagnétiques prédéterminées.The larger of the two radio antennas, i.e. the first printed antenna 20, comprises two metal strips 20A, 20B extending orthogonally from the second plane. These two metal strips 20A, 20B form two feet connected together at their ends most distant from the second plane by a portion of additional metal strip, as well as to another metal strip 20C extending horizontally in the upper part of the first portion radiant 16 of the first substrate 12. The precise configuration of this first printed antenna 20, located furthest to the left on the front face of the first substrate 12, as well as its dimensioning remain concretely up to the appreciation of those skilled in the art depending on the application, impedance matching and targeted radiation. It operates at low frequencies, in a first band of predetermined electromagnetic frequencies.

La plus petite des deux antennes radioélectriques, i.e. la deuxième antenne imprimée 22, comporte elle aussi deux bandes métalliques 22A, 22B s'étendant orthogonalement depuis le deuxième plan. Ces deux bandes métalliques 22A, 22B sont plus courtes que les bandes métalliques 20A, 20B. Elles forment également deux pieds reliés entre eux à leurs extrémités les plus distantes du deuxième plan par une portion de bande métallique supplémentaire, ainsi qu'à une autre bande métallique 22C s'étendant horizontalement sous la bande métallique 20C dans la première portion rayonnante 16 du premier substrat 12. La bande métallique 22C est plus courte que la bande métallique 20C. La configuration précise de cette deuxième antenne imprimée 22, située la plus à droite en face avant du premier substrat 12, ainsi que son dimensionnement restent concrètement à l'appréciation de l'homme du métier en fonction de l'application, de l'adaptation d'impédance et du rayonnement visés. Elle opère à hautes fréquences, dans une deuxième bande de fréquences électromagnétiques prédéterminées, par exemple toutes plus élevées que les fréquences électromagnétiques de la première bande de fréquences de la première antenne imprimée 20.The smaller of the two radio antennas, ie the second printed antenna 22, also includes two metal strips 22A, 22B extending orthogonally from the second plane. These two metal strips 22A, 22B are shorter than the metal strips 20A, 20B. They also form two feet connected together at their ends most distant from the second plane by a portion of additional metal strip, as well as to another metal strip 22C extending horizontally under the metal strip 20C in the first radiating portion 16 of the first substrate 12. The metal strip 22C is shorter than the metal strip 20C. The precise configuration of this second printed antenna 22, located furthest to the right on the front face of the first substrate 12, as well as its dimensioning remain concretely up to the appreciation of those skilled in the art depending on the application, the adaptation impedance and radiation targeted. It operates at high frequencies, in a second band of predetermined electromagnetic frequencies, for example all higher than the electromagnetic frequencies of the first frequency band of the first printed antenna 20.

Sur la face avant visible et dans la deuxième portion inférieure 18 du premier substrat 12, séparée de la première portion rayonnante 16 par le deuxième substrat 14, des moyens électriquement conducteurs de raccordement des deux antennes radioélectriques 20 et 22 à un circuit électronique d'émission et/ou réception sont formés notamment par impression métallique selon la technologie sérigraphique précitée. En particulier, ces moyens conducteurs de raccordement comportent une portion de plan de masse métallique 24 formée par impression métallique sur la face avant de la deuxième portion inférieure 18 du premier substrat 12. La façon dont les pieds d'antennes 20A, 20B et 22A, 22B sont raccordés électriquement au circuit électronique d'émission et/ou réception et à la portion de plan de masse métallique 24 n'est pas précisément illustrée sur la figure 1 parce qu'elle est à la portée de l'homme du métier. Généralement, chaque antenne doit préalablement être conformée de manière à assurer une adaptation d'impédance avec le circuit électronique d'émission et/ou réception, puis doit être respectivement raccordée au circuit électronique d'émission et/ou réception et à la portion de plan de masse métallique 24 par ses deux pieds. Le raccordement de la première antenne imprimée 20 à la portion de plan de masse métallique 24 est ainsi réalisé par son pied d'antenne 20A selon des moyens connus, non détaillés sur la figure 1, qui ne sont pas nécessairement disposés uniquement en face avant du premier substrat 12. Le raccordement de la première antenne imprimée 20 au circuit électronique d'émission et/ou réception est quant à lui représenté symboliquement par un premier bloc connecteur 26. De même, le raccordement de la deuxième antenne imprimée 22 à la portion de plan de masse métallique 24 est réalisé par son pied d'antenne 22A : cela peut par exemple se faire par continuité d'impression métallique en face avant du premier substrat 12. Le raccordement de la deuxième antenne imprimée 22 à la portion de plan de masse métallique 24 est quant à lui représenté symboliquement par un deuxième bloc connecteur 28. Enfin, le circuit électronique d'émission et/ou réception est situé d'une façon générale dans le deuxième demi-espace inférieur par rapport au deuxième plan du deuxième substrat 14, mais n'est pas représenté sur la figure 1 parce qu'il n'est pas utile à la bonne compréhension de l'invention.On the visible front face and in the second lower portion 18 of the first substrate 12, separated from the first radiating portion 16 by the second substrate 14, electrically conductive means for connecting the two radio antennas 20 and 22 to an electronic transmission circuit and/or reception are formed in particular by metal printing using the aforementioned screen printing technology. In particular, these conductive connection means comprise a metallic ground plane portion 24 formed by metallic printing on the front face of the second lower portion 18 of the first substrate 12. The way in which the antenna bases 20A, 20B and 22A, 22B are electrically connected to the electronic transmission and/or reception circuit and to the metal ground plane portion 24 is not precisely illustrated on the figure 1 because it is within the reach of those skilled in the art. Generally, each antenna must first be shaped so as to ensure impedance matching with the electronic transmission and/or reception circuit, then must be respectively connected to the electronic transmission and/or reception circuit and to the plane portion of metallic mass 24 by its two feet. The connection of the first printed antenna 20 to the metal ground plane portion 24 is thus carried out by its antenna base 20A according to known means, not detailed in the figure 1 , which are not necessarily arranged only on the front face of the first substrate 12. The connection of the first printed antenna 20 to the electronic transmission and/or reception circuit is represented symbolically by a first connector block 26. Likewise, the connection of the second printed antenna 22 to the metallic ground plane portion 24 is made by its antenna base 22A: this can for example be done by continuity of metallic printing on the front face of the first substrate 12. The connection of the second antenna 22 printed on the metal ground plane portion 24 is for its part represented symbolically by a second connector block 28. Finally, the electronic transmission and/or reception circuit is generally located in the second half -lower space relative to the second plane of the second substrate 14, but is not shown on the figure 1 because it is not useful for a good understanding of the invention.

Le deuxième substrat 14 présente une face, dite face supérieure parce que c'est celle qui est orientée du côté du premier demi-espace supérieur dans lequel sont situées les deux antennes radioélectriques 20 et 22, sur laquelle est formé un plan de masse 30 par impression métallique. Grâce à la présence du trou rectiligne traversé par le premier substrat 12, le plan de masse 30 n'est pas en contact électrique direct avec les deux antennes radioélectriques 20 et 22. Le contact est établi à l'aide de broches de raccordement électrique dont deux paires 32 et 34 sont représentées sur la figure 1. Une première paire de broches 32 est disposée au voisinage des pieds de la première antenne imprimée 20. Elle comporte deux broches, raccordées électriquement entre elles à l'aide éléments mâles et femelles de façon connue en soi, dont l'une est disposée et connectée électriquement à la portion de plan de masse métallique 24 du premier substrat 12 et l'autre au plan de masse 30 du deuxième substrat 14. Une deuxième paire de broches 34 est disposée de la même façon au voisinage des pieds de la deuxième antenne imprimée 22. D'autres broches de raccordement électrique peuvent être ajoutées pour le raccordement d'autres éléments, par exemple des éléments du circuit électronique d'émission et/ou réception, au plan de masse 30 du deuxième substrat 14.The second substrate 14 has a face, called the upper face because it is that which is oriented towards the first upper half-space in which the two radio antennas 20 and 22 are located, on which a ground plane 30 is formed by metal print. Thanks to the presence of the rectilinear hole crossed by the first substrate 12, the ground plane 30 is not in direct electrical contact with the two radio antennas 20 and 22. Contact is established using electrical connection pins whose two pairs 32 and 34 are represented on the figure 1 . A first pair of pins 32 is arranged in the vicinity of the feet of the first printed antenna 20. It comprises two pins, electrically connected to each other using male and female elements in a manner known per se, one of which is arranged and connected electrically to the metallic ground plane portion 24 of the first substrate 12 and the other to the ground plane 30 of the second substrate 14. A second pair of pins 34 is arranged in the same way in the vicinity of the feet of the second printed antenna 22 Other electrical connection pins can be added for the connection of other elements, for example elements of the electronic transmission and/or reception circuit, to the ground plane 30 of the second substrate 14.

Conformément à la présente invention, le deuxième substrat 14 présente une face opposée à sa face supérieure, dite face inférieure, orientée du côté du deuxième demi-espace inférieur dans lequel est située la deuxième portion inférieure 18 du premier substrat 12, qui est exploitée pour isoler électromagnétiquement le demi-espace supérieur de toute interférence électromagnétique due à l'insertion au moins partielle de la deuxième portion inférieure 18 du premier substrat 12 dans une fente correspondante d'un support métallique 36 tel qu'un mât ou candélabre cylindrique. Cette exploitation de la face inférieure du deuxième substrat 14 consiste à y déployer, par impression métallique, une structure de métamatériau 38 à multiples éléments électriquement conducteurs 40 séparés électriquement les uns des autres sur cette face inférieure. Avantageusement, chaque élément électriquement conducteur 40 de la structure de métamatériau 38 est raccordé au plan de masse métallique 30 à l'aide d'un via métallique traversant 42 s'étendant dans l'épaisseur du deuxième substrat 14.In accordance with the present invention, the second substrate 14 has a face opposite its upper face, called the lower face, oriented towards the second lower half-space in which the second lower portion 18 of the first substrate 12 is located, which is used to electromagnetically isolate the upper half-space from any electromagnetic interference due to the at least partial insertion of the second lower portion 18 of the first substrate 12 in a corresponding slot of a metal support 36 such as a cylindrical mast or candelabra. This exploitation of the lower face of the second substrate 14 consists of deploying there, by metallic printing, a metamaterial structure 38 with multiple electrically conductive elements 40 electrically separated from each other on this lower face. Advantageously, each electrically conductive element 40 of the metamaterial structure 38 is connected to the metallic ground plane 30 using a through metallic via 42 extending into the thickness of the second substrate 14.

Plus précisément, la structure de métamatériau 38 est dimensionnée de manière à supprimer au moins un mode stationnaire de résonance électromagnétique propre du deuxième substrat 14 susceptible d'être excité par la proximité du support métallique 36, c'est-à-dire au moins un mode stationnaire de distribution de courant pouvant apparaître dans le plan de masse 30 du deuxième substrat 14 à au moins une fréquence, notamment au moins une fréquence de la bande passante de l'une quelconque des deux antennes 20 et 22.More precisely, the metamaterial structure 38 is dimensioned so as to eliminate at least one stationary mode of own electromagnetic resonance of the second substrate 14 capable of being excited by the proximity of the metal support 36, that is to say at least one stationary mode of current distribution capable of appearing in the ground plane 30 of the second substrate 14 at at least one frequency, in particular at least one frequency of the bandwidth of any one of the two antennas 20 and 22.

L'homme du métier est apte à régler, par essais et mesures, certains paramètres de la structure de métamatériau 38, tels que :

  • le nombre d'éléments électriquement conducteurs 40 et leur distribution,
  • la forme, la largeur, la longueur ou toute autre dimension caractéristique de chaque élément conducteur 40,
  • les espaces entre les éléments électriquement conducteurs 40.
Those skilled in the art are able to adjust, by tests and measurements, certain parameters of the metamaterial structure 38, such as:
  • the number of electrically conductive elements 40 and their distribution,
  • the shape, width, length or any other characteristic dimension of each conductive element 40,
  • the spaces between the electrically conductive elements 40.

En particulier, il est avantageux de dimensionner les éléments conducteurs 40 à l'échelle des demi-longueurs d'ondes visées pour conférer pleinement à la structure 38 ses propriétés de métamatériau.In particular, it is advantageous to dimension the conductive elements 40 on the scale of the targeted half-wavelengths to fully give the structure 38 its metamaterial properties.

On notera qu'en pratique, le deuxième substrat 14 peut être simplement fabriqué, avec son plan de masse 30 en face supérieure et sa structure de métamatériau 38 en face inférieure, à partir d'un substrat vendu dans le commerce avec une métallisation complète sur ses deux faces. Il suffit alors de retirer une partie de la métallisation en fonction des motifs souhaités en faces supérieure et inférieure du substrat 14.It will be noted that in practice, the second substrate 14 can simply be manufactured, with its ground plane 30 on the upper face and its metamaterial structure 38 on the lower face, from a substrate sold commercially with complete metallization on its two faces. It is then sufficient to remove part of the metallization according to the desired patterns on the upper and lower faces of the substrate 14.

Comme illustré sur les figures 2 et 3, il est concrètement avantageux d'intégrer le dispositif d'antenne 10 dans un boîtier protecteur 44 (représenté transparent pour une meilleure visibilité du dispositif 10 sur la figure 2), seule au moins une partie de la deuxième portion inférieure 18 sortant sous le boîtier 44 pour son insertion dans le support métallique 36. Il s'agit généralement d'un radôme en matière plastique. En perspective vue de dessus, la figure 2 illustre également des moyens classiques 46 à vis latérales de fixation du radôme 44 sur le support métallique 36 ainsi que le trou rectiligne 48 du deuxième substrat 14 traversé par le premier substrat 12. En perspective vue de dessous, la figure 3 montre en outre que les éléments électriquement conducteurs 40 de la structure de métamatériau 38 peuvent être de forme carrée ou rectangulaire et disposés matriciellement sur tout ou partie de la face inférieure du deuxième substrat 14. Cela signifie que les éléments électriquement conducteurs 40 sont disposés en lignes et colonnes selon deux axes principaux, notamment selon une répétition périodique ou pseudo-périodique (par exemple à dimensions croissantes ou décroissantes des motifs) le long de l'un des deux axes ou des deux.As illustrated on the figures 2 and 3 , it is concretely advantageous to integrate the antenna device 10 in a protective housing 44 (shown transparent for better visibility of the device 10 on the figure 2 ), only at least part of the second lower portion 18 emerging from under the housing 44 for insertion into the metal support 36. This is generally a plastic radome. In perspective seen from above, the figure 2 also illustrates conventional means 46 with lateral screws for fixing the radome 44 on the metal support 36 as well as the rectilinear hole 48 of the second substrate 14 crossed by the first substrate 12. In perspective view from below, the Figure 3 further shows that the electrically conductive elements 40 of the metamaterial structure 38 can be square or rectangular in shape and arranged in a matrix on all or part of the lower face of the second substrate 14. This means that the electrically conductive elements 40 are arranged in lines and columns along two main axes, in particular according to a periodic or pseudo-periodic repetition (for example with increasing or decreasing dimensions of the patterns) along one of the two axes or both.

La figure 4 illustre en perspective une installation comportant le dispositif d'antenne 10, intégré dans le radôme 44 et donc non visible sur cette figure, tel que fixé par vissage sur le support métallique 36. On y voit que la mise en oeuvre de la présente invention permet de conserver une très bonne compacité de l'ensemble.There Figure 4 illustrates in perspective an installation comprising the antenna device 10, integrated into the radome 44 and therefore not visible in this figure, as fixed by screwing on the metal support 36. It can be seen that the implementation of the present invention allows to maintain a very good compactness of the whole.

Des tests ont été effectués pour une première antenne imprimée 20 conformée et dimensionnée pour opérer dans la bande passante [860 ; 865] MHz et pour une deuxième antenne imprimée 22 conformée et dimensionnée pour opérer dans la bande passante [2,4000 ; 2,4835] GHz.Tests were carried out for a first printed antenna 20 shaped and sized to operate in the passband [860; 865] MHz and for a second printed antenna 22 shaped and sized to operate in the bandwidth [2.4000; 2.4835] GHz.

La figure 5A illustre une courbe de coefficients de réflexion S11 mesurés en entrée de chacune des deux antennes du dispositif d'antenne 10 lorsque ce dernier ne comporte pas la structure de métamatériau 38. Entre 0,7 et 2 GHz, il s'agit de l'évolution du coefficient de réflexion S11 de la première antenne imprimée 20. Entre 2 et 3 GHz, il s'agit de l'évolution du coefficient de réflexion S11 de la deuxième antenne 22. Il en résulte une rupture de courbe tout à fait normale à 2GHz. On y a par ailleurs noté le point m1 qui mesure un coefficient S11 = -16,7 dB à 860 MHz et le point m2 qui mesure un coefficient S11 = -28,8 dB à 865 MHz pour la première antenne 20, ainsi que le point m3 qui mesure un coefficient S11 = -10,6 dB à 2,4000 GHz et le point m4 qui mesure un coefficient S11 = -10,1 dB à 2,4835 GHz pour la deuxième antenne imprimée 22.There figure 5A illustrates a curve of reflection coefficients S 11 measured at the input of each of the two antennas of the antenna device 10 when the latter does not include the metamaterial structure 38. Between 0.7 and 2 GHz, this is the evolution of the reflection coefficient S 11 of the first printed antenna 20. Between 2 and 3 GHz, this is the evolution of the reflection coefficient S 11 of the second antenna 22. This results in a complete break in the curve normal at 2GHz. We have also noted the point m1 which measures a coefficient S 11 = -16.7 dB at 860 MHz and the point m2 which measures a coefficient S 11 = -28.8 dB at 865 MHz for the first antenna 20, as well that the point m3 which measures a coefficient S 11 = -10.6 dB at 2.4000 GHz and the point m4 which measures a coefficient S 11 = -10.1 dB at 2.4835 GHz for the second printed antenna 22.

La figure 5B illustre une autre courbe de coefficients de réflexion S11 mesurés en entrée de chacune des deux antennes du même dispositif d'antenne 10, mais cette fois-ci lorsque ce dernier comporte la structure de métamatériau 38 avec des éléments électriquement conducteurs 40 carrés de 11 mm de côtés. Entre 0,7 et 2 GHz, il s'agit de l'évolution du coefficient de réflexion S11 de la première antenne imprimée 20. Entre 2 et 3 GHz, il s'agit de l'évolution du coefficient de réflexion S11 de la deuxième antenne imprimée 22. Le point m1 mesure désormais un coefficient S11 - -17,3 dB à 860 MHz. Le point m2, mesurant un coefficient S11 = -32,2 dB à 865 MHz, n'est même plus apparent sur la courbe. Le point m3 mesure un coefficient S11 - -17,5 dB à 2,4000 GHz et le point m4 mesure un coefficient S11 = -14,7 dB à 2,4835 GHz. D'une façon générale, les coefficients de réflexion des antennes 20 et 22 présentent des valeurs nettement réduites dans les deux bandes passantes [860 ; 865] MHz et [2,4000 ; 2,4835] GHz par rapport à la figure 5A, ce qui démontre que les deux antennes 20 et 22 présentent de meilleures performances en transmission (i.e. en réception et émission) dans le cas de la figure 5B que dans celui de la figure 5A.There Figure 5B illustrates another curve of reflection coefficients S 11 measured at the input of each of the two antennas of the same antenna device 10, but this time when the latter comprises the metamaterial structure 38 with electrically conductive elements 40 square of 11 mm from sides. Between 0.7 and 2 GHz, this is the evolution of the reflection coefficient S 11 of the first printed antenna 20. Between 2 and 3 GHz, this is the evolution of the reflection coefficient S 11 of the second printed antenna 22. Point m1 now measures a coefficient S 11 - -17.3 dB at 860 MHz. The point m2, measuring a coefficient S 11 = -32.2 dB at 865 MHz, is no longer even apparent on the curve. Point m3 measures a coefficient S 11 - -17.5 dB at 2.4000 GHz and point m4 measures a coefficient S 11 = -14.7 dB at 2.4835 GHz. Generally speaking, the reflection coefficients of the antennas 20 and 22 have significantly reduced values in the two pass bands [860; 865] MHz and [2.4000; 2.4835] GHz compared to the figure 5A , which demonstrates that the two antennas 20 and 22 have better transmission performances (ie reception and transmission) in the case of Figure 5B than in that of the figure 5A .

La figure 6A illustre une courbe de valeurs de rendement total mesurées pour la deuxième antenne imprimée 22 du dispositif d'antenne 10 lorsque ce dernier ne comporte pas la structure de métamatériau 38, entre 2,35 et 2,5 GHz. On y a par ailleurs noté le point m1 qui mesure un rendement ρ = 51,6 % à 2,4000 GHz et le point m2 qui mesure un rendement ρ = 80,2 % à 2,4835 GHz.There Figure 6A illustrates a curve of total efficiency values measured for the second printed antenna 22 of the antenna device 10 when the latter does not include the metamaterial structure 38, between 2.35 and 2.5 GHz. We also noted the point m1 which measures an efficiency ρ = 51.6% at 2.4000 GHz and the point m2 which measures an efficiency ρ = 80.2% at 2.4835 GHz.

La figure 6B illustre une autre courbe de valeurs de rendement total mesurées pour la deuxième antenne imprimée 22 du même dispositif d'antenne 10 entre 2,35 et 2,5 GHz, mais cette fois-ci lorsque ce dernier comporte la structure de métamatériau 38 avec des éléments électriquement conducteurs 40 carrés de 11 mm de côtés. Le point m1 mesure désormais un rendement ρ = 75,2 % à 2,4000 GHz et le point m2 mesure un rendement ρ = 74,4 % à 2,4835 GHz. D'une façon générale, le rendement est plus stable et meilleur, dans la bande passante [2,4000 ; 2,4835] GHz, dans le cas de la figure 6B que dans celui de la figure 6A.There Figure 6B illustrates another curve of total efficiency values measured for the second printed antenna 22 of the same antenna device 10 between 2.35 and 2.5 GHz, but this time when the latter comprises the metamaterial structure 38 with elements electrically conductive 40 squares of 11 mm sides. Point m1 now measures an efficiency ρ = 75.2% at 2.4000 GHz and point m2 measures an efficiency ρ = 74.4% at 2.4835 GHz. Generally speaking, the performance is more stable and better, in the bandwidth [2.4000; 2.4835] GHz, in the case of Figure 6B than in that of the Figure 6A .

Il apparaît clairement qu'un dispositif d'antenne tel que celui décrit précédemment permet de préserver les performances radioélectriques de la ou des antennes qu'il comporte tout en conservant une très bonne compacité, lorsque ce dispositif est destiné à être fixé sur un support métallique susceptible de le perturber électromagnétiquement. La fonctionnalisation de la face inférieure du deuxième substrat à l'aide d'une structure de métamatériau permet en effet de réduire les interactions de la ou des antennes du dispositif avec son environnement proche.It clearly appears that an antenna device such as that described above makes it possible to preserve the radio performance of the antenna(s) it comprises while maintaining very good compactness, when this device is intended to be fixed on a metal support. likely to disturb it electromagnetically. The functionalization of the lower face of the second substrate using a metamaterial structure makes it possible to reduce the interactions of the antenna(s) of the device with its immediate environment.

On notera par ailleurs que l'invention n'est pas limitée au mode de réalisation décrit précédemment.It should also be noted that the invention is not limited to the embodiment described above.

Notamment, deux antennes radioélectriques ont été décrites dans le dispositif d'antenne 10, mais les principes de la présente invention sont aisément généralisables à un dispositif d'antenne à plus de deux antennes radioélectriques. Ils sont également applicables à un dispositif d'antenne ne comportant qu'une antenne radioélectrique.In particular, two radio antennas have been described in the antenna device 10, but the principles of the present invention are easily generalizable to an antenna device with more than two radio antennas. They are also applicable to an antenna device comprising only a radio antenna.

Les antennes précitées 20 et 22 sont imprimées en technologie sérigraphique, mais d'autres types d'antennes sont compatibles avec la présente invention.The aforementioned antennas 20 and 22 are printed using screen printing technology, but other types of antennas are compatible with the present invention.

Les antennes précitées 20 et 22 sont en outre imprimées sur une même face de substrat, mais des antennes imprimées sur deux faces différentes d'un même substrat conviennent également.The aforementioned antennas 20 and 22 are also printed on the same face of substrate, but antennas printed on two different faces of the same substrate are also suitable.

Il apparaîtra plus généralement à l'homme de l'art que diverses modifications peuvent être apportées au mode de réalisation décrit ci-dessus, à la lumière de l'enseignement qui vient de lui être divulgué. Dans la présentation détaillée de l'invention qui est faite précédemment, les termes utilisés ne doivent pas être interprétés comme limitant l'invention au modes de réalisation exposé dans la présente description, mais doivent être interprétés pour y inclure tous les équivalents dont la prévision est à la portée de l'homme de l'art en appliquant ses connaissances générales à la mise en oeuvre de l'enseignement qui vient de lui être divulgué.It will appear more generally to those skilled in the art that various modifications can be made to the embodiment described above, in light of the teaching which has just been disclosed to him. In the detailed presentation of the invention which is made previously, the terms used must not be interpreted as limiting the invention to the embodiments set out in the present description, but must be interpreted to include all the equivalents whose prediction is within the reach of the man of the art by applying his general knowledge to the implementation of the teaching which has just been disclosed to him.

Claims (7)

  1. An antenna device (10) comprising:
    - a first substrate (12), extending in a first plane, having at least one face on which are formed:
    • at least one radio antenna (20, 22) extending into a first radiating portion (16) of the first substrate (12), and
    • electrically conductive means (24, 26, 28) for connecting said at least one radio antenna (20, 22) to an electronic transmitter and/or receiver circuit, said electrically conductive means (24, 26, 28) extending in a second portion (18) of the first substrate (12),
    - a second substrate (14) extending in a second plane different from and intersecting the first plane, separating the first radiating portion (16) of the first substrate (12), located in a first half-space with respect to this second plane, from the second portion (18) of the first substrate (12), located in a second half-space with respect to this second plane,
    the second substrate (14) having a face, referred to as the lower face and oriented on the side of said second half-space in which the electrically conductive connection means (24, 26, 28) are located, comprising a metamaterial structure (38) with multiple electrically conductive elements (40) electrically separated from one another on this lower face,
    said at least one radio antenna (20, 22) being at least one printed antenna extending over at least one face of the first substrate (12),
    said at least one radio antenna comprising a first low-frequency printed antenna (20) operating in a first band of electromagnetic frequencies and a second high-frequency printed antenna (22) operating in a second band of electromagnetic frequencies all higher than the electromagnetic frequencies of the first band of frequencies
    the second substrate (14) comprising:
    - a metallic ground plane (30) extending on another face, called the upper face and opposite the lower face comprising the metamaterial structure (38), and
    - through vias (42) connecting each electrically conductive element (40) of the metamaterial structure (38) to the metal ground plane (30).
  2. The antenna device (10) according to claim 1, wherein the electrically conductive elements (40) of the metamaterial structure (38) are arranged in a matrix on the lower face of the second substrate (14).
  3. The antenna device (10) according to claim 1 or 2, wherein at least one of the parameters of the set consisting of:
    - the number of electrically conductive elements (40) of the metamaterial structure (38),
    - a distribution of the electrically conductive elements (40) of the metamaterial structure (38) on the lower face of the second substrate (14),
    - at least one dimension of each electrically conductive element (40) of the metamaterial structure (38), and
    - the spaces between electrically conductive elements (40) of the metamaterial structure (38),
    is set to suppress at least one stationary electromagnetic resonance mode of the second substrate (14).
  4. The antenna device (10) according to any one of claims 1 to 3, wherein electrical connection pins (32, 34) are arranged between the first and second substrates (12, 14) for electrical connection of at least part (24) of the electrically conductive connection means (24, 26, 28) to the metallic ground plane (30).
  5. The antenna device (10) according to claim 4, wherein said at least one part (24) of the electrically conductive connection means (24, 26, 28) comprises a metal ground plane portion formed in the first substrate (12).
  6. The antenna device (10) according to any one of claims 1 to 5, wherein the second substrate (14) has an opening, for example a rectilinear hole (48), through which the first substrate (12) passes.
  7. The antenna device (10) according to any one of claims 1 to 6, wherein the first and second substrates (12, 14) are arranged orthogonally.
EP19189713.1A 2018-08-02 2019-08-02 Antenna device with two different and secant planar substrates Active EP3605730B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1857244A FR3084778B1 (en) 2018-08-02 2018-08-02 ANTENNA DEVICE WITH TWO DIFFERENT AND SECANT FLAT SUBSTRATES

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EP3605730A1 EP3605730A1 (en) 2020-02-05
EP3605730B1 true EP3605730B1 (en) 2023-11-01

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Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100263181B1 (en) * 1998-02-27 2000-08-01 윤종용 Antenna of portable radio equipment
JP2004022587A (en) * 2002-06-12 2004-01-22 Denso Corp Cabinet
JP4234617B2 (en) * 2004-01-30 2009-03-04 富士通コンポーネント株式会社 Antenna device
JP6763372B2 (en) * 2015-04-02 2020-09-30 日本電気株式会社 Multi-band antenna and wireless communication device
JPWO2017056437A1 (en) * 2015-09-29 2018-07-19 日本電気株式会社 Multiband antenna and wireless communication device

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FR3084778A1 (en) 2020-02-07
FR3084778B1 (en) 2020-07-24

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