Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
  • H01Q13/02—Waveguide horns
  • H01Q13/04—Biconical horns
• • 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
  • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
  • H01Q9/28—Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49016—Antenna or wave energy "plumbing" making

Definitions

• the present invention relates to telecommunication antennas, in particular antennas of the ultra wideband (ULB) type.
• ULB ultra wideband
• ULB technology compared to a conventional radio technology (for example narrow-band type with carrier), is to offer very high bit rates.
• Another known advantage of ULB technology is that it has a very high robustness against the problems of interference and fading of a signal in cases of multipath propagation.
• Another known advantage of this ULB technology is that it has an extremely wide frequency spectrum.
• ULB antenna embodiments For example, a first large family of ULB antennas corresponding to antennas of the dipole type (for example of the biconical, planar type of square or triangular geometry type) and of the monopole type is known.
• the antennas of this first family can provide good performance, a problem is that their size is dependent on the working frequency of the antenna.
• the dimension in particular of the radiating elements is imposed by the lowest working frequency used in the intended application.
• each of the cones is equal to ⁇ / 4, where ⁇ is the largest working wavelength in the intended application.
• a second large family of ULB antennas is also known.
• Antennas with radiating elements such as coaxial horns or TEM hornets (acronym for the expression "Transverse
• Other variants in this second family of antennas are still based classically on the use of radiating elements with shaped profiles, usually according to exponential laws, and excitation systems based on baluns or cavities [9-]. 10].
• the designer can play on a larger number of parameters of freedom than previously.
• the stress on the dimension of the radiating elements as a function of the working frequencies is relaxed, which offers the possibility for example of using radiating elements of smaller dimensions than that of the first family of antennas.
• An antenna having radiating elements in planar configuration with double slots [H] is known in particular.
• Another antenna of this third large family comprises radiating elements in configuration with two double planar slots positioned perpendicularly [12].
• a disadvantage of these antennas is that they do not make it possible to obtain a homogeneous radiation pattern in an azimuthal plane.
• the document FR 2 843237 discloses a monopole type antenna of the first aforementioned large family.
• this antenna has in particular the disadvantages of controlling the electromagnetic field by means only of a surface shaped according to a calyx 1.
• this antenna does not generate a localized signal in its central region, and has no means of adaptation to promote a localized coupling between the excitation means 4 and said region.
• US 2532551 and FR 2573576 relate to an ultra wideband antenna belonging to the second large family mentioned above. They are indeed antennas with biconical cornet. They have the abovementioned disadvantages for this type of antenna in particular because of a lack of localized coupling of the signal in the central region.
• WO 02/056418 relates to a broadband electromagnetic probe.
• this antenna is not ultra-wideband type and does not lend itself to it either. It has in particular a single surface 100 for controlling the electromagnetic field, the surface 250 being connected to a mass. In addition, it does not have an efficient and compact adaptation means to promote a localized coupling between the coaxial attack 302 and the zone 400.
• An object of the invention is therefore to provide an improved antenna.
• the object of the invention is to propose an ULB antenna with omnidirectional radiation in an azimuthal plane and with a gain value that is as constant as possible with the frequency in this plane.
• the antenna of the invention advantageously has a simple geometry and allows a great flexibility of design to meet very different specifications.
• the invention thus proposes an ultra broadband antenna characterized in that it comprises:
• first and second shaped surfaces thus defining a radiating element, these surfaces furthermore having a symmetry of revolution about a longitudinal axis of the antenna, being arranged facing each other relative to each other; to a plane orthogonal to the longitudinal axis and containing the horizontal axis, and having a profile and dimensions adapted to control characteristics of an electromagnetic field in the area, so that the antenna has a substantially constant gain in the frequency band, in azimuthal plane,
• an excitation means extending parallel to the longitudinal axis and capable of supplying the signal in a localized manner in the central region
• an adaptation means associated with the first shaped surface, projecting into the central region of the zone and toward the second shaped surface, the adaptation means being able to promote localized coupling between the excitation means; and said area.
• Preferred non-limiting aspects of this antenna are the following:
• the zone comprises a monoblock of material which has a symmetry of revolution with respect to the longitudinal axis;
• the zone is completely filled by the monoblock of material; the two shaped surfaces are formed respectively by two distinct elements;
• the monoblock of material is arranged to support the two distinct elements
• the antenna further comprises in said zone spacers and / or rods whose ends are integral with the two distinct elements;
• the two shaped surfaces respectively correspond to first and second opposite surfaces of the monoblock of material so that these two shaped surfaces and this monoblock of material form only one piece;
• the monoblock of material further has an outer wafer in contact with the air and constituting an outer side of the antenna; the monoblock of material also has an internal wafer enclosing at least part of the central region of the zone;
• the central region enclosed at least in part by the inner slice comprises air;
• the one or more slices of the monoblock of material have a profile that makes it possible to control the characteristics of the electromagnetic field in the zone;
• At least a portion of the profile of the slice (s) of the monoblock of material has, in longitudinal section, a form selected from the following: a. rectilinear, b. concave with respect to the longitudinal axis, c. convex with respect to the longitudinal axis;
• At least a portion of a profile of each of the two shaped surfaces has, in longitudinal section, a shape selected from the following: a. rectilinear, b. concave to the plane orthogonal to the longitudinal axis and containing the horizontal axis, c. convex with respect to the plane orthogonal to the longitudinal axis and containing the horizontal axis; the profile of at least one of the two shaped surfaces comprises at least one point of inflection;
• the second shaped surface comprises substantially at its center an orifice, said orifice comprising at least part of the excitation means;
• the excitation means is a coaxial line having a central core, one end of which is in contact with the adaptation means;
• the monoblock of material is a dielectric material of the type taken from the following list: foam, plastic, ceramic; - the slice (s) includes (s) conductive patterns;
• the antenna has a symmetry of revolution about the longitudinal axis
• the antenna is arranged to receive an electronic circuit not far from it and to protect it from the electromagnetic field that it radiates;
• the electronic circuit is arranged as close as possible to the antenna; the second shaped surface forms a recess on the outside of the antenna and in that the electronic circuit is integrated in this recess;
• the adaptation means is a lug
• the two shaped surfaces are metallized.
• the invention also provides a telecommunication system characterized in that it comprises an ultra wideband antenna with the above characteristics taken alone or in combination.
• FIG. 1 is a sectional view along a plane containing the longitudinal axis (Z) of an antenna according to the invention having two shaped surfaces arranged symmetrically with respect to a plane perpendicular to the longitudinal axis (Z) and containing the horizontal axis (X);
• - Figure 2 is an enlarged view in longitudinal section of the central region of the zone, in which the excitation and adaptation elements are located;
• FIG. 3 is a longitudinal sectional view of two antennas according to the invention each having two shaped surfaces whose profile is substantially different from that of the antenna shown in FIG. 1,
• FIG. 4 is an antenna of the invention in which the zone is entirely filled with air
• FIG. 5 is an antenna of the invention comprising in the zone a monoblock of material which has two slices (T and T ');
• FIG. 6 is a longitudinal sectional view of an antenna according to the invention having two shaped surfaces whose profile is different and whose slice (T) has a profile parallel to the longitudinal axis (Z),
• FIG. 7 is a view in longitudinal section of an antenna according to the invention having two shaped surfaces whose profile is different and whose edge (T) has a rectilinear profile inclined with respect to the longitudinal axis,
• FIG. 8 is a variant of the antenna of FIG. 7 in which the profile of the facing surfaces and the slice (T) are still played.
• FIG. 9 shows, in longitudinal section, an antenna of the invention, the edge (T) of the monoblock of material having a curved profile towards the outside of the antenna
• FIG. 10 shows in longitudinal section an antenna of the invention, the slice (T) of the monoblock of material having a curved profile towards the inside of the antenna
• FIG. 11 is an antenna of the invention, the edge (T) of which comprises conductive patterns on the surface;
• FIG. 12 illustrates the integration of an electronic circuit in an external recess of an antenna of the invention
• FIG. 13 is a detailed exemplary embodiment of an antenna of the invention
• FIG. 14 shows a simulation of the adaptation as a function of a chosen frequency band of the antenna taken as an example in FIG. 13.
• FIG. 15 shows simulations of radiation patterns in azimuth and elevation of the antenna of FIG. 13, and for different frequencies of said frequency band;
• FIG. 16 shows adaptation and gain measurements of the antenna of FIG. 13 in the azimuthal plane,
• FIG. 17 is a second example of a detailed embodiment of an antenna of the invention.
• FIG. 18 shows a simulation of the adaptation as a function of the selected frequency band of the antenna taken as an example in FIG. 17,
• FIG. 19 shows simulations of azimuth and elevation radiation diagrams of the antenna of FIG. 17, and for different frequencies of said frequency band
• FIG. 20 shows the adaptation and gain measurements of the antenna of FIG. 17 in the azimuthal plane.
• FIG. 21 is a third example of a detailed embodiment of an antenna of the invention.
• FIG. 22 shows adaptation and gain measurements of the antenna of FIG. 21 in the azimuthal plane. It will be noted as a preliminary that in the following text the term distal refers to the center of the antenna.
• This antenna 1 comprises two identical shaped surfaces 3 and 4 facing one another with respect to a plane perpendicular to the longitudinal axis (Z) and containing the horizontal axis (X).
• An area 2 is defined between these two conformal surfaces.
• Zone 2 therefore generally has an outline perfectly defined by the two conforming surfaces 3 and 4 facing each other.
• the latter have a parabola profile (C) open respectively upwardly and downwardly.
• the horizontal axis (X) corresponds to an axis of symmetry for these two surfaces 3 and 4 and therefore for zone 2. More generally still, the antenna, or at least the two surfaces, shaped, have a symmetry of revolution around the vertical axis
• This further comprises an excitation means 6, typically a coaxial line, extending parallel to the vertical axis (Z) and able to provide a signal 5 in a central region of the zone 2.
• this excitation means is integrated in a vertical through orifice made substantially in the center of the shaped surface 4.
• the excitation means 6 can reach the central region of zone 2 from the outside downwards. of the antenna. And as shown in particular in Figure 1, the excitation means is thus able to provide the signal 5 in a localized way in the central region. More precisely still, the excitation means 6 also crosses the central region of the zone 2 to come into intimate contact with a local adaptation means 7 disposed in the center, beneath the shaped surface 3.
• the matching means 7 is substantially opposite the through hole.
• the matching means 7 is in the form of a cylindrical lug protruding from the surface 3 towards the through hole.
• Such adaptation means makes it possible to locally promote a transition of the signal between the excitation means 6 and the zone 2 while remaining of reduced size.
• Figure 2 shows a detailed longitudinal sectional view of the central region of zone 2.
• the lug 7 has a diameter and a height respectively denoted d and h.
• the excitation means represented here by way of nonlimiting example is a coaxial line 6 comprising a central core
• the shaped surfaces 3 and 4 are covered with a thin layer of conductive material and both define a radiating element.
• FIG. 3 illustrates a preferred variant of the invention.
• This monoblock 10 therefore extends around the vertical axis (Z) and from the central region to the end of the antenna defined by the distal edge of the shaped surfaces 3 and 4.
• the surface of the monoblock 10 which is in contact with the air on one side of the antenna constitutes a wafer (T) whose profile may serve as a parameter of freedom to the design of the antenna.
• T wafer
• the two shaped surfaces 3 and 4 are respectively the upper and lower surfaces of the monoblock of material 10 so that there is only one physical part.
• the bulk of the volume of zone 2 is in a way defined by the volume of the monoblock of material itself. It will also be noted that the matching means 7 and the monoblock of material 10 are also in one piece.
• the two shaped surfaces 3 and 4 are respectively formed by two distinct elements 3 'and 4', that is to say two independent physical parts. Zone 2 can then be completely filled with air, as shown in FIG.
• means 10 ' are provided in said zone (2) for fixing the two elements 3' and 4 'with respect to one another.
• Zone 2 may also consist of air and the monoblock of material 10.
• FIG. 1 A non-limiting example is given in FIG. 1
• the monoblock of material 10 has here two slices (T) and (T ') in contact with the air.
• the monoblock 10 corresponds to a ring disposed around the vertical axis (Z).
• the inner wafer (T ') encloses air, but the invention also provides that it can enclose another gas, preferably having dielectric properties.
• the monoblock 10 constitutes a support for the two distinct elements 3 'and 4'.
• the antenna of the invention still offers a greater number of freedom parameters.
• a fundamental freedom parameter consists in playing on the profile (C, C) of the shaped surfaces 3 and 4.
• these profiles has, in longitudinal section, a shape chosen from the following: a. rectilinear, b. concave to the plane orthogonal to the longitudinal axis (Z) and containing the horizontal axis (X), c. convex relative to the plane orthogonal to the longitudinal axis (Z) and containing the horizontal axis (X).
• each of the two surfaces 3 and 4 may consist of a juxtaposition of several surface portions, these portions having a shape profile possibly different from each other.
• Figures 1 and 3 showed two shaped surfaces 3 and 4 symmetrical with respect to the horizontal axis with a profile (C) which as a whole had a dish shape convex with respect to this axis.
• FIG. 3B differs in particular from FIG. 3A in that the profiles (C) have a point of inflection.
• the surfaces 3 and 4 have a dish-shaped profile (C, C) open upwardly and downwardly as in FIG. 1, but with generally different curvatures.
• the profile (C) of the surface 3 comprises in particular a point of inflection.
• Figure 7 shows an example of an antenna whose profile (C) of the shaped surface 3 is flared so that it becomes horizontal at the distal ends. As illustrated in these last two figures and Figure 8, we can notice that the designer can also play on the fact that the symmetry of the profiles
• H and H ' denotes the height of the profile (C) and (C) of the respective surfaces 4 and 3.
• the height in question corresponds to the projected distance on the vertical axis between a distal end of the profile and its center located on said vertical axis.
• R and R ' denote the radii of the respective surfaces 4 and 3.
• S denotes the smallest distance separating the two conformal surfaces 3 and 4, or the distance separating these two surfaces in the center of the zone 2.
• the antenna of FIG. 8 is defined by the following system: (C) ⁇ (C), H '> H, R' ⁇ R
• Another parameter of fundamental freedom offered to the designer is to play on the profile of the slice (s) (T, T ') of the monoblock of material 10.
• the profile (QC) of the shaped surfaces 4 and 3 at least a portion of the profiles of the slice or slices (T, T ') has, in longitudinal section, a shape chosen from the following: a. rectilinear, b. concave with respect to the plane orthogonal to the longitudinal axis
• a wafer may consist of a juxtaposition of several wafer portions, these wafer portions having a shape profile possibly different from each other.
• the profile of an external and / or internal wafer may therefore, as a whole, be rectilinear inclined or not with respect to the longitudinal axis (FIGS. 3, 5, 6, 7 and 8 for example), curved outwards (Figure 9), or curved inwards (Figure 10).
• Another parameter of freedom offered to the designer is to be able to have at least one conductive pattern 11 on a slice of the monoblock 10 so as to contribute once more to the control of the characteristics of the electromagnetic field in the zone 2, namely to the control of the characteristics of radiation of the antenna as in particular the appearance of the radiation patterns, the value of the directivity or the polarization.
• a conductive pattern 11 is printed on the outer edge (T) of the antenna.
• Another parameter of freedom still consists in playing on the geometry of the lug 7 by modifying either its shape or its dimensions d and / or h.
• the lug may have a trapezoidal shape in longitudinal section, the smallest side being that of the bottom.
• Figure 12 there is illustrated an additional advantage of the antenna according to the invention.
• the antenna can be arranged to receive not far from it an electronic circuit 12 and to protect it from the electromagnetic field that it radiates.
• the electronic circuit 12 is arranged as close as possible to the antenna (1), which furthermore makes it possible to optimize the signal-to-noise ratio.
• this recess 13 corresponds in this nonlimiting example to the recess formed by the concave shape of the profile (C) of the second shaped surface 4.
• This method is based first of all on the shaping of the monoblock of material 10.
• ⁇ r is relatively close to 1 and tg ( ⁇ ) of the smallest possible value ( ⁇ r is the relative permittivity, and tg ( ⁇ ) the tangent of dielectric losses preferably less than 10 3 in the invention).
• the conformation of the monoblock 10 can be achieved either by machining or by molding the desired part, from a choice of suitable material.
• the shaping being carried out, the selective metallization is then carried out of any profiled surface of the shaped surface 3, on which the adaptation lug 7 has been made, as well as of the shaped surface 4.
• Said metallization may, for example, be performed by depositing a conductive paint or by electrochemical deposition of a metal.
• slice (T) of the support monoblock 10 is, for its part, not metallized.
• the coaxial line 6 can then be connected to the antenna.
• an electrical continuity, solder or conductive adhesive must be provided, on the one hand, between the peripheral conductor 6 'positioned at the level of savings and the metallization on the surface 4, and secondly between the central conductor of the coaxial 6 "and the lower part of the adapter pin 7.
• the central core 6" then passes through the monoblock of dielectric material 10 via a small hole of height e.
• This manufacturing method has the advantage of having a very great simplicity of realization and a low cost.
• Concerning the excitation means 6, the solution adopted corresponds to the use of a standard Teflon coaxial cable, with characteristic impedance
• this material 10 (monobloc foam for example) has been machined by micro-milling to collectively produce the assembly consisting of surfaces 3 and 4, and the adapter element 7 in one piece .
• Figure 15 gives the azimuth and elevation radiation patterns for several frequencies distributed over the entire bandwidth (ie, 3.1 GHz, 5.0 GHz, 6.85 GHz, 8.5 GHz and 10.6 GHz).
• the radiation of the antenna is of omnidirectional type in the azimuthal plane, with a small dispersion of the gain value in this plane as a function of the frequency (respectively: 0.6dBi, -2.4dBi , 1.IdBi, 2.4dBi and 1.7dBi for the previous frequency values).
• several prototypes were realized and characterized in adaptation and in transmission, this last measurement being carried out in the azimuthal plane and on the basis of a simple link budget between two antennas. of the invention, separated by a distance D.
• ⁇ is the wavelength
• Pr the received power
• G the gain of the antennas
• the measured curve 41 reveals ripples related to the presence of multiple paths. These exist to the extent that the characterization was not performed in anechoic chamber.
• the result obtained for the gain is therefore more qualitative than quantitative.
• FIG. 17 A second example of a detailed embodiment of an antenna according to the invention is illustrated in FIG. 17.
• FIG. 19 represents the azimuth and elevation radiation patterns at the same frequencies as those used for the first exemplary embodiment (i.e. 3.1GHz, 5.0GHz, 6.85GHz, 8.5GHz and
• the radiation of the antenna is always omnidirectional type in azimuth, associated with a small variation of the value of the gain in this plane, as a function of the frequency (respectively: 1.5dBi,
• the value of the gain 44 in the azimuthal plane is again in conformity with the simulation, with a limited variation in the range [-2dBi, 2dBi].
• the shaped surface 4 of this antenna is in the form of a spherical cap, while the upper shaped surface 3 has a bell-shaped profile inverted shape and flared at the edges.
• Experimental measurements in adaptation and gain in the azimuthal plane are given in Figure 22.
• the reflection coefficient 50 always remains below -12 dB over the entire 3.1 GHz-10.6 GHz working band. This antenna therefore has a very satisfactory adaptation, as in the case of the previous antennas.
• this third embodiment provides satisfactory performance and in particular a very small volume. Indeed, the volume of this antenna is 37.7 cm 3 , while the volume occupied by the first embodiment described above is 61.6 cm 3 .
• the present invention proposes an ultra broadband antenna offering a very great flexibility of design and thus satisfying a variety of specifications.
• one or more antennas of the invention in different equipment such as in a computer, a fixed or mobile telephone, a printer, a television, a CD-ROM reader, or more generally in any equipment where wireless communication is used.

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• 2005
  • 2005-03-24 FR FR0502922A patent/FR2883671A1/fr active Pending
• 2006
  • 2006-03-24 WO PCT/EP2006/061035 patent/WO2006100306A1/fr active Application Filing
  • 2006-03-24 JP JP2008502425A patent/JP5203925B2/ja active Active
  • 2006-03-24 EP EP06725305A patent/EP1861895A1/fr not_active Ceased
  • 2006-03-24 US US11/887,020 patent/US8013801B2/en active Active
  • 2006-03-24 CN CNA2006800138053A patent/CN101164198A/zh active Pending
  • 2006-03-24 KR KR1020077024405A patent/KR101281329B1/ko active IP Right Grant

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