Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
  • H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
  • H01Q11/02—Non-resonant antennas, e.g. travelling-wave antenna
  • H01Q11/08—Helical antennas
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
  • H01Q1/362—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith for broadside radiating helical antennas
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/50—Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• • 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
  • H01Q1/521—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure reducing the coupling between adjacent antennas
  • H01Q1/523—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure reducing the coupling between adjacent antennas between antennas of an array
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/29—Combinations of different interacting antenna units for giving a desired directional characteristic

Definitions

• the invention relates to radio frequency antennas including those that can be used in wireless radio systems.
• Antenna is an essential part of a wireless radio device.
• GB 2 292 638 A discloses an antenna formed of a cylindrical dielectric bar (of high relative dielectric permittivity - greater than 5), said bar being hollowed out to allow the passage of a feed structure.
• the antenna comprises a plurality of radiating elements on the outer surface of the bar, the radiating elements being connected in parallel between the power supply and a ground plane.
• the invention proposes a compact antenna solution that is easily achievable.
• an antenna structure adapted to be disposed on a ground plane comprising:
• a three-dimensional support substrate of partially hollowed dielectric material comprising a peripheral wall extending between a proximal end and a distal end, said support substrate defining an internal volume;
• the first conductive pattern inscribed on the peripheral wall of the support substrate, the first conductive pattern comprising a lower end adapted to be connected to a ground plane and an upper end;
• antennal structure alone or in combination are:
• the support substrate has a cylindrical shape of revolution, truncated cone, cube, hexagonal base straight prism, truncated pyramid, sinuous profile volume;
• the first pattern is a conductive thread or a conductive ribbon;
• the first pattern is inscribed on the peripheral wall so as to be helically wound around the support substrate;
• the first pattern is meandering, sinusoid-shaped, a combination of rectilinear (s) and sinuous (s), shaped fractal (s);
• the second pattern is configured to at least partially seal the distal end of the support substrate
• the second conductive pattern comprises a transverse profile selected from the following group: right, slot, succession of straight lines, successions of straight lines and curves, succession of curved lines;
• the second conductive pattern comprises: a hollow section having a peripheral wall extending between a lower end and an upper end, said section extending into the internal volume defined by the support substrate; a flange extending from the upper end of the section to the distal end of the support substrate;
• the second conductive pattern also comprises a bottom completely closing the lower end of the section.
• the invention provides an antenna comprising a ground plane and an antenna structure according to the first aspect of the invention disposed above said ground plane, the lower end of the first conductive pattern being connected to the plane of the earth. mass.
• the antenna of the invention further comprises an excitation probe adapted to feed the antenna structure, the excitation probe being connected via the central conductor of said excitation probe to the first conductive pattern via a point of contact. connection located along the first conductive pattern on the peripheral wall.
• the invention proposes an antenna assembly comprising a ground plane; a plurality of identical antenna structures according to the first aspect of the invention, an excitation probe connected via the central conductor of said excitation probe to the first conductive pattern of a single antenna structure among the plurality of antenna structures , said antenna structure and excited element defining a primary element for the antennal assembly, the at least one other antennal structure defining at least one passive "passive" non-powered element.
• the antenna assembly comprises two antenna structures arranged on the ground plane side by side and separated by a distance less than a fraction of the operating wavelength ⁇ of the antenna assembly, typically less than ⁇ / 20; it comprises three antennal structures arranged on the ground plane in a triangular manner;
• It comprises at least one conductive wall adapted to reduce the coupling between the antenna structures, the conductive wall forming an electrical screen between the antennal structures.
• the antenna of the invention has extremely small dimensions compared to the wavelength of the signal (that is to say of the order of ⁇ / 50, or even less than this value).
• the invention makes it possible to have an antenna or an extremely compact antenna assembly for a fixed operating frequency.
• the invention offers a very great simplicity of performance adjustment.
• the operating frequency is particularly easy to adjust since it is a function of the value of the developed length of the first conductive pattern, as well as the shape factor and the dimensions chosen for the second conductive pattern.
• the level of adaptation of the antenna of the invention can also be easily optimized by a suitable choice of the position of the excitation point on the first pattern vis-à-vis the lower end the first pattern, itself connected to the ground.
• the invention makes it possible to have an antenna solution or an antenna assembly which has a very great ease of realization at low cost.
• FIG. 1 illustrates an antenna according to one embodiment of the invention
• FIGS. 2a, 2b, 2c, 2d, 2e, 2f and 2g illustrate several forms of the support substrate of an antenna structure according to the invention
• FIGS. 3a, 3b and 3c illustrate several forms of the first conductive pattern of an antenna structure according to the invention
• FIGS. 4a, 4b, 4c, 4d, 4e, 4f, 4g and 4h illustrate the shape of the transverse profile of the second conductive pattern of an antenna structure according to the invention
• FIGS. 5a, 5b and 5c respectively illustrate a perspective view, a sectional view B-B 'and a side view of an antenna according to one embodiment of the invention
• FIG. 6 illustrates a perspective view of a first conductive pattern inscribed on a support substrate of an antenna structure according to one embodiment of the invention
• FIG. 7 illustrates a perspective view of a second conductive pattern of an antenna structure according to one embodiment of the invention.
• FIG. 8 illustrates an antenna assembly according to a first embodiment of the invention
• FIG. 9 illustrates an antenna assembly according to a second embodiment of the invention.
• FIG. 10 illustrates an antenna assembly according to a third embodiment of the invention.
• an antenna A comprises an antenna structure Ai and a ground plane M, the antenna structure is disposed above the ground plane M.
• the antenna structure Ai comprises: a substrate S support three-dimensional dielectric material partially hollowed out, a first conductive pattern Ml and a second conductive pattern M2.
• the partially recessed substrate S comprises a peripheral side wall S1 which extends between a proximal end S2 and a distal end S3.
• the support substrate S defines an internal volume S4 which can be partially filled with dielectric material. The internal volume S4 is thus surrounded by the peripheral wall SI.
• the support substrate S may be a dielectric material of plastic type or plastic foam, whose electrical characteristics are preferably very close to those of air, or even simply be air.
• the relative dielectric permittivity of the support substrate S is preferably close to 1, that is to say between 1 and 1.5.
• the first pattern M1 is inscribed on the peripheral side wall S1 of the substrate S and comprises a lower end Einf adapted to be connected to the ground plane M and an upper end Esup.
• the second conductive pattern M2 is configured to be contained in the volume S4 of the substrate S and is electrically connected to the upper end Esup of the first pattern M1.
• the second pattern M2 is preferably made on a three-dimensional surface. This is typically a pellet conductive pattern.
• the three-dimensional surface may be a surface of the substrate S or a surface of a separate element inserted in the volume S4.
• the second conductive pattern M2 is further configured to close off the distal end S3 of the support substrate S.
• the antenna comprises a coaxial excitation probe 10 whose central conductor 11 is connected at a point P of the first conductive pattern M1 on the peripheral wall SI of the support S.
• the support substrate S can take several forms: cylinder of revolution (FIG.
• FIG. 2a truncated cone
• FIG. 2b truncated cone
• FIG. 2c spherical cap
• FIG. 2d cube
• FIG. 2d right hexagonal prism
• FIG. 2e truncated pyramid
• FIG. 2f truncated pyramid
• FIG. Figure 2g any arbitrary contoured volume
• the first pattern M1 can take many forms.
• FIGS. 3a, 3b and 3c illustrate developed views of the peripheral side wall S1 of the support substrate S with several forms for the first M1: multi-turn helix pattern (FIG. 3a), m horrndre geometry (FIG. 3b) or FIG. well any form (Figure 3c). It can also be a combination of rectilinear (s) and sinuous (s) or shaped fractal (s) (not shown) or sinusoidal (not shown).
• the first conductive pattern Ml may be either a conductive wire or a conductive ribbon.
• the diameter of the conducting wire is between 0.25 mm and 5 mm, preferably 1 mm.
• the width of the ribbon is between 0.5 mm and 10 mm, preferably 2 mm.
• the developed length of the conductive wire or conductor ribbon is one of the operating frequency control elements. The longer this length is, the lower the frequency of the corresponding antenna.
• the second pattern M2 can also take several forms.
• FIGS. 4a, 4b, 4c, 4d, 4e, 4f, 4g and 4h illustrate the shape of the transverse profile for the second pattern M2: right (FIG. 4a), slot (FIG. 4b), succession of straight lines (FIGS. 4c and 4e). ), successions of straight lines and curves ( Figures 4d and 4f), succession of curved lines ( Figures 4g and 4h).
• the second pattern M2 may have a part that extends inside the internal volume S4 of the support substrate S towards the proximal end S2 of the substrate support S.
• the second pattern M2 may comprise a solid form factor as is the case in FIGS. 4a, 4b, 4c, 4d, 4e, 4f, 4g and 4h or hollowed out at its center (for example a ring). .
• the volume of the support substrate S is used both to support and to contain an overall conductive pattern that is electrically as long as possible so that the antenna can operate at the lowest possible frequency.
• FIGS. 5a, 5b, 5c and FIGS. 6 and 7 show an antenna according to a preferred embodiment of the invention.
• the support substrate S is of cylindrical shape and the first conductive pattern M1 is in a helix.
• the support substrate S is a cylinder of revolution whose cross section is equal to a disk of diameter d ⁇ ⁇ and whose height is equal to h " ⁇ (with ⁇ the wavelength associated with the frequency of operation of the corresponding antenna).
• the first pattern M1 comprises several turns wound on the peripheral side wall S1 of the support substrate S.
• the second pattern M2 is here of the pellet type inscribed in its entirety within the volume S4 defined by the support substrate S.
• the second conductive M2 pattern consists of three parts: a hollow section C having a peripheral side wall C1 which extends between a lower end C2 and an upper end C3;
• a flange C which extends from the upper end C3 of the section to the distal end S3 of the substrate S support;
• This bottom C is characterized by a surface whose outer perimeter corresponds to the lower end C2 of the section C.
• the flange C takes the form here of an annular conductive pattern of outside diameter d and inner diameter of (with 0 ⁇ d ⁇ d), completed by a section C of conductive tube of diameter and height h ' (With 0 ⁇ h ' ⁇ h), closed at its base by the bottom C "in the form of a conductive disk of diameter D.
• the second conductive pattern M2 closes the entire upper part of the support substrate S.
• section C extends in the internal volume S4 defined by the substrate S support and the bottom C "is contained within this same volume.
• the second pattern M2 comes as an inverted cap above the support substrate S with a portion (that is to say the section C and the bottom C ") inserted inside the internal volume of the substrate S support
• the inverted hat thus forms the three-dimensional support.
• the antenna is plug type.
• the first and second conductive patterns M1, M2 are electrically connected: the second pattern M2 is in particular electrically connected to the upper end Esup of the first conductive pattern M1.
• a radiating element formed by the association of the first conductive pattern M1 and the second conductive pattern M2 is contained in a cylindrical volume, with a diameter of 30 mm and a height of 20 mm. .
• the largest dimension of the antenna (that is to say the diameter of the support substrate S of 30mm) is then of the order of ⁇ / 52, which implies an extremely compact antenna.
• the antenna is perfectly adapted (that is to say a level of adaptation ⁇ -25 dB) and its bandwidth (for an adaptation level lower than -10 dB) is 1.3MHz.
• such an antenna can be used for applications developed at VHF and UHF frequencies.
• the invention also relates to an antenna assembly comprising a ground plane M; a plurality of identical antenna structures Ai (i> 2) as described above and an excitation probe 10 connected at a point P of the first conductive pattern Ml of a single antenna structure among the plurality of antenna structures A1, A2 , so as to feed an antenna structure.
• the antenna structure thus excited defines a primary element for the antennal assembly, the at least one other antennal structure defining at least one non-powered "passive" secondary element.
• the antennal assembly comprises an antenna and at least one antenna structure that acts as a parasitic element located near the antenna.
• the antenna assembly has an enlarged bandwidth.
• FIG. 8 illustrates an antenna assembly comprising two antenna structures A1, A2 arranged one beside the other.
• the configuration consists in associating a first and a second antenna structures A1, A2, positioned relative to one another at a very small distance D with respect to the wavelength of the signal ⁇ , and this in order to maintain overall dimensions for the antennal assembly particularly reduced.
• the distance D between the two structures (that is to say the distance between the central axes of symmetry of the structures A1 , A2) is 70mm, or about ⁇ / 22 (hence D ⁇ ⁇ ). Note that this very great proximity between the structures is made possible by the miniature nature of the antennal structures used (the size of the antennal structures is of the order of ⁇ / 52).
• the first antenna structure A1 fed by the coaxial excitation probe 10 acts as a primary radiating element, supplied at a connection point P by the central conductor 11 of the excitation probe 10.
• the first fed Al antenna structure is electromagnetically coupled to the second antennal structure, of identical configuration, but which is, in turn, unpowered.
• This second antennal structure therefore plays the role of a "passive" secondary element, initially operating at the same resonant frequency as the first antenna structure A1 and positioned in its close environment, in order to be physically coupled thereto.
• the electrical response obtained on the first antennal structure A1 is then of the two-frequency type, with frequency values relatively close to each other.
• the frequency difference is a function of the value of the coupling level existing between the first antenna structure A1 and the second antenna structure A2. The lower this level, the closer the frequencies are.
• the level of the first antenna structure A1 coupled to the second antenna structure A2 we thus obtain, finally, a response equivalent to that of a two-pole band pass filter, which results in a significant widening of the bandwidth compared to that which would be obtained if only the first antennal structure was used.
• the two resonance frequencies involved in the electrical response must be very close to one another, which leads, a priori, to fix a level of coupling between the antenna structures Al, A2 very weak.
• the reduction of the coupling can simply be obtained thanks to the presence of an electric screen between the two antenna structures A1, A2, this screen can be achieved, for example, by the use of a conductive wall 100 electrically connected to its base on the ground plane, as shown in Figure 9.
• the position of the conductive wall 100, as well as its geometry and its dimensions allow to adjust the value of the coupling and thus to finely control the appearance of the electrical response in the bandwidth.
• the basic principle consists in constructing at the primary element level an electrical response of the multi-pole bandpass filter type by exploiting the coupling of this primary element Al with all the elements.
• other "passive" secondary elements Ai i> l.
• the number n of antennal structures, their geometrical disposition on the ground plane, as well as the number, the positions and the characteristics of the conducting walls constitute parameters of freedom as for the design and the optimization of such antennal set.
• FIG. 10 illustrates an antenna assembly comprising three antenna structures A1, A2, A3 disposed on the ground plane M in a triangular manner and comprising two conducting walls.
• This prototype corresponds to the association of two antenna structures such as the antenna of the embodiment illustrated in FIG. 5a.
• each antenna structure of this prototype is ⁇ / 52.
• the antennal set operates at a frequency of 193MHz.
• the two antennal structures are separated by a distance D of 70mm, ie ⁇ / 22 and the electric screen allowing to control the level of coupling between the two elements is a simple rectangular conducting wall of dimensions 30x70mm 2 , positioned between the two structures antennal.

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• 2013
  • 2013-07-15 FR FR1356954A patent/FR3008550B1/fr active Active
• 2014
  • 2014-07-15 WO PCT/EP2014/065176 patent/WO2015007746A1/fr not_active Ceased
  • 2014-07-15 EP EP14739168.4A patent/EP3022802B1/de active Active
  • 2014-07-15 CN CN201480046398.0A patent/CN105556748B/zh active Active
  • 2014-07-15 US US14/905,605 patent/US10944163B2/en active Active
  • 2014-07-15 HK HK16111528.0A patent/HK1223455A1/zh unknown

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