EP0667984A1 - Monopolar wire-plate antenna - Google Patents

Monopolar wire-plate antenna

Info

Publication number
EP0667984A1
EP0667984A1 EP94926276A EP94926276A EP0667984A1 EP 0667984 A1 EP0667984 A1 EP 0667984A1 EP 94926276 A EP94926276 A EP 94926276A EP 94926276 A EP94926276 A EP 94926276A EP 0667984 A1 EP0667984 A1 EP 0667984A1
Authority
EP
European Patent Office
Prior art keywords
antenna
wires
radiating
capacitive
wire
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP94926276A
Other languages
German (de)
French (fr)
Other versions
EP0667984B1 (en
Inventor
Christophe Delaveaud
Bernard Jecko
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Universite de Limoges
Original Assignee
Universite de Limoges
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Universite de Limoges filed Critical Universite de Limoges
Publication of EP0667984A1 publication Critical patent/EP0667984A1/en
Application granted granted Critical
Publication of EP0667984B1 publication Critical patent/EP0667984B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/48—Earthing means; Earth screens; Counterpoises
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/30—Arrangements for providing operation on different wavebands
    • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
    • H01Q5/314—Individual or coupled radiating elements, each element being fed in an unspecified way using frequency dependent circuits or components, e.g. trap circuits or capacitors
    • H01Q5/321—Individual or coupled radiating elements, each element being fed in an unspecified way using frequency dependent circuits or components, e.g. trap circuits or capacitors within a radiating element or between connected radiating elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/30—Arrangements for providing operation on different wavebands
    • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
    • H01Q5/342—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes
    • H01Q5/357—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes using a single feed point
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
    • H01Q9/0414—Substantially flat resonant element parallel to ground plane, e.g. patch antenna in a stacked or folded configuration

Definitions

  • the present invention relates to a monopolar wire-plate antenna of the type comprising a ground plane, a first radiating element in the form of a capacitive roof capable of being connected to a generator or to a receiver by means of a wire. power supply, and a second radiating element in the form of a radiating conducting wire connecting the capacitive roof to the ground plane.
  • Such an antenna is known from document FR-A-2 668 859.
  • This antenna is composed of two metal surfaces arranged on either side of a dielectric substrate. One of these surfaces, generally the largest, constitutes the ground plane and the other surface constitutes the capacitive roof.
  • the antenna is supplied via the supply wire consisting of a coaxial probe which crosses the ground plane and the substrate and is connected to the capacitive roof.
  • This antenna has the distinction of having an additional active conductive wire, radiating, parallel to the coaxial supply probe and which connects the ground plane to the capacitive roof. This wire returns to ground.
  • Such an antenna is the seat of two resonance phenomena, hence the name of double resonance antenna which is sometimes given to it.
  • the physical parameters of the antenna namely the permittivity of the electrical substrate, its thickness, the radius of the supply wire, the radius of the radiating wire, the distance between the two wires as well as the shape and dimensions of the capacitive roof and of the ground plane, can a priori have any values.
  • the proper functioning of the antenna depends on the relationships between these parameters which limit the possibilities and impose constraints which are sometimes difficult to meet from a technological point of view.
  • a substrate with very low dielectric constant ( ⁇ r ⁇ 2) a distance between the coaxial probe and the radiating wire very small compared to the emission wavelength (d ⁇ o / 50) and a radius of the coaxial probe at least 5 times less than that of the radiating wire.
  • the shape of the capacitive roof is practically arbitrary and only its surface plays a role.
  • it is preferable from the point of view of the adaptation of the aerial that its height is relatively large but does not exceed ⁇ 0/18 .
  • the shape and dimensions of the ground plane only slightly modify the adaptation of the antenna when its surface is at least 10 times greater than that of the capacitive roof, but can significantly modify the radiation pattern, as in all monopolar radiation antennas.
  • this antenna mainly results from a coupling phenomenon between the feeding probe and the radiating wire or no cavity resonance mode intervenes.
  • the addition of the radiating wire under the conditions which will be set out below creates a parallel resonance situated at a frequency much lower than those of the conventional modes of resonance of a plated antenna.
  • a suitable choice of the different physical parameters of the antenna makes it possible, on the one hand, to achieve a correct adaptation of the aerial to conventional generators and receivers, that is to say that the antenna has an impedance, the real part of which is close to a determined value, generally 50 ⁇ , when the imaginary part is canceled, and, on the other hand, to obtain radiation of the so-called monopolar type which has the typical characteristics of the radiation of a monopole:
  • the antenna described in the above-mentioned document has the advantages over prior art antennas of being relatively simple in its design and construction, of having small dimensions compared to the length d '' wave of use, to be able to be correctly adapted with a suitable gain, to have a higher bandwidth than a conventional plated antenna and a radiation of monopolar type stable according to the frequency, and to be able to be used in network, however, it has certain drawbacks.
  • the dimensions of the wires and the distance between the wires must be much less than the working wavelength ⁇ , which is a source of technological difficulties and of fragility, particularly in the microwave.
  • the dimensions although already much less than the wavelength, are still too large for applications on mobiles.
  • the substrate used has a dielectric constant that is too different from 1, the antenna is difficult to adapt and its bandwidth is relatively low.
  • the shape of the monopolar radiation is not easily adjustable, for example to obtain a greater maximum gain or to obtain greater spatial coverage.
  • the present invention aims to overcome these drawbacks.
  • the subject of the invention is a monopolar wire-plate antenna comprising a ground plane, a first radiating element in the form of a capacitive roof capable of being connected to a generator or to a receiver via a supply wire and a second radiating element in the form of a conducting wire connecting the capacitive roof to the ground plane, characterized in that it comprises a plurality of at least one of said radiating elements, arranged so that the antenna operates in monopolar radiation.
  • the word “wire” means not only a conductor with a circular section, but also with any section, such as for example a ribbon.
  • the ground “plane”, as well as the capacitive roof (s) may in fact be curved surfaces, possibly not parallel to each other, in particular for generating monopolar radiation of particular shape, for example narrow with a large maximum gain. or wide with a given illumination sector.
  • the characteristics of the antenna, and in particular the shape of the capacitive roofs are chosen so as to have at the same frequency or at several frequencies close to an antenna working both in monopolar mode and on the classic dipolar modes.
  • the antenna according to the invention comprises a plurality of conducting wires.
  • the antenna according to the invention makes it possible to obtain monopolar radiation and good adaptation much more easily and with much less technological constraints than in the prior art.
  • the radiating wires can be arranged symmetrically with respect to the supply wire.
  • the antenna according to the invention comprises a plurality of capacitive roofs, at least one of the capacitive roofs being arranged to be connected to the generator.
  • the antenna according to the invention can be supplied by a coaxial probe passing through the ground plane, whose power wire is connected to a capacitive roof and whose external conductor connects the ground plane to a roof capacitive located between the ground plane and the capacitive roof connected to the supply wire.
  • An antenna according to the invention comprising several capacitive roofs can be arranged to present a large passband or to present a plurality of resonant frequencies, or to present a monopolar radiation pattern close to a given size.
  • the capacitive roof is substantially rectangular and the radiating wire is connected in the vicinity of the short side of the rectangle.
  • the supply wires and the radiating wires can also be loaded by circuit elements located or distributed along the wire.
  • These elements can be passive linear (resistance, inductance, capacitance, any impedance) or active, but also nonlinear. Chosen appropriately, they allow for example to decrease the dimensions of the antenna, to change the working frequency, or to switch several working frequencies.
  • FIGS. 1, 2a and 2b are three perspective views of three embodiments of the invention.
  • FIGS. 3a, 3b and 3c respectively illustrate the real and imaginary parts of the equivalent impedance Z (f) and the reflection coefficient S-
  • FIGS. 5a, 5b and 5c respectively illustrate the real and imaginary parts of the equivalent impedance Z (f) and the reflection coefficient Si 1 (f) of an antenna according to the embodiment of FIG. 2, and
  • the antenna of Figure 1 is formed of a dielectric substrate 1 fully metallized on one of its faces 2 to form the ground plane and partially metallized on its other face 3 to form the capacitive roof.
  • a coaxial supply probe 4 passes through the ground plane 2 and the substrate 1 and is connected to the capacitive roof 3.
  • Radiant conductive wires 5 also pass through the substrate 1 to connect the ground plane 2 to the capacitive roof 3.
  • the radiating wires 5 can be placed, a priori, anywhere under the capacitive roof 3 of the antenna but, depending on their position, their influence on the operation of the antenna will be more or less significant. On the other hand, the introduction of too many radiating wires (from four) can reduce the phenomenon of double resonance and make it unusable from the point of view of the adaptation of the air to microwave generators. .
  • the dielectric substrate 1 on which the ground plane 2 and the roof 3 of the antenna is deposited does not necessarily consist of a single dielectric material but can consist of a superposition of layers with any dielectric constants .
  • the shape and dimensions of the substrate 1 are arbitrary but generally, for practical reasons, its dimensions do not exceed those of the ground plane 2.
  • each additional radiating wire introduces new physical parameters of the antenna, namely, the radius of the wire added radiator, its distance from the coaxial supply probe as well as the distances separating it from the other radiating wires.
  • These additional physical parameters complicate the relationships between the physical parameters of the antenna but, in reality, they simplify the problem and soften the constraints necessary for obtaining the operation of the monopolar wire-plate antenna.
  • the wire of the feed probe 4 no longer necessarily has to be of a diameter much smaller than that of the radiating wires, but can be of identical or greater diameter.
  • the wires 5 should no longer be located too close to the coaxial supply probe 4 but should preferably be located towards the ends of the roof of the antenna.
  • the radius of the wires 5 is preferably less than the radius of the feeding probe and, the more the wires 5 are numerous or close to the feeding probe, the smaller their radius must be.
  • the antenna with several radiating wires has a generally larger roof and a slightly greater height to operate at the same frequency.
  • the introduction of a dielectric medium or of a superposition of different dielectric media makes it possible to reduce these dimensions.
  • the double resonance antenna having a single radiating wire is suitably adaptable to 50 ⁇ only for substrates with very low permittivity ( ⁇ r ⁇ 1, 2), the introduction of additional radiating wires allows '' very easily adapt any monopolar wire-plate antenna produced on any substrate, or combination of substrates.
  • the operating principle of the double resonance antenna having several radiating wires is similar to that of the double resonance antenna having only one wire. Adding radiant wires additional does not create new parallel resonances linked to each of the radiating wires, but modifies that created by a radiating wire.
  • the height of the substrate (s) 1 and the number of radiating wires are chosen, which gives the approximate operating frequency
  • the monopolar wire-plate antenna having several radiating wires has radiation characteristics similar to those of the double resonance antenna which has only one radiating wire, namely radiation of the monopolar type which takes place through power wire and radiant wires.
  • the multiplication of the wires 5 now makes it possible to perfectly symmetrize the radiation by arranging the wires 5 symmetrically with respect to the supply probe 4 located in the center of the antenna.
  • ground plane 2 and, to a lesser degree, those of the substrate 1 introduce, as with any antenna with monopolar radiation, modifications of the radiation diagram.
  • the characteristics of an antenna of the type shown in FIG. 1 will be given below with two wires 5 and a coaxial feed probe 4 with a diameter of 1.27 mm, the two wires 5 being arranged symmetrically with respect to the probe 4 and the axis of each of the wires being 3.3 mm from the axis of the probe.
  • the electrical substrate 1 consists of a 10 mm thick plate of polymethyl methacrylate of 72 mm ⁇ 72 mm, and with a permittivity equal to approximately 2.5.
  • the ground plane 2 covers an entire face of the plate 1 and the capacitive roof is centered on the other face and is of dimension 20 mm ⁇ 20 mm.
  • Figures 3 to 6 show in solid lines the measured quantities and, in dashed lines, the theoretical quantities.
  • Figures 3a and 3b respectively show the real part and the imaginary part of the input impedance of the antenna and Figure 3c shows the resulting reflection coefficient.
  • FIGS. 4a and 4b show the gain achieved, obtained respectively in the plane of the wires and in the plane orthogonal to the plane of the wires, and evaluated over the entire space surrounding the antenna.
  • the antenna has a reflection coefficient S-n (f) of the order of -20 dB (only 1% of the incident power is reflected) at the frequency of 1.77 GHz.
  • the gain realized represented in FIG. 4 at this same frequency of 1.77 GHz takes account of all the losses (mismatch, ohmic and dielectric losses) and reaches a maximum value of approximately 2.5 dB at 45 ° due the deformation of the radiation diagram due to the dimensions of the ground plane.
  • the dielectric is the ambient air.
  • the ground plane 10 is surmounted by a first capacitive roof 11 itself surmounted by a second capacitive roof 12. Only the first capacitive roof 11 is connected to a coaxial supply probe 13 passing through the ground plane 10 for its connection to a generator.
  • the first capacitive roof 1 1 is also connected to the ground plane 10 by two conductive wires 14 and 14 'arranged relative to the probe 13 like the wires 5 of the embodiment of FIG. 1.
  • the second capacitive roof 12 is connected to the first capacitive roof 11 by two radiating wires 15 and 15 'in contact with the roof 11 at two points located between the contact points of the probe 13 and those of the wires 14 and 14' on the other side of the roof 11.
  • the assembly of the probe 13 crosses the ground plane 10. Its external tubular conductor 13 "electrically connects the ground plane 10 to the first capacitive roof 1 1, while the central conductor 13 'is connected to the upper capacitive roof 12.
  • the roof 12 here has an elongated rectangular shape.
  • the radiating wires 15 and 15 ′ are connected to the roof 12 at locations adjacent to the short sides 12 ′ to the roof 12.
  • wires 15 and 15 ' are here loaded by circuits 20 and 20' having an adequate impedance, active or passive.
  • the constraints to be imposed on the physical parameters linked to the bottom stage are known from the description given above with reference to FIG. 1, they must henceforth be modulated so as not to penalize the highest resonance too much. Indeed, it is necessary to make exploitable, from the point of view of the adaptation to 50 ⁇ , the second double resonance by a joint action on, on the one hand, all the physical parameters related to the first stage, then d on the other hand, on the physical parameters linked to the second stage and which influence the two resonances (namely: the dimensions of the upper roof 12, the value of the permittivity of the dielectric substrate of the second stage and its thickness) and finally, an action on the physical parameters which act only on the second resonance, independently of the other (namely: the radius of the upper radiating wires 15 and 15 'and the distance which separate them).
  • the coaxial supply probe 13 has a large diameter, that the radiating wires 14 and 14 ′ of the bottom stage are distant from the coaxial probe 13 and have a radius at least three to four times less than that of the supply probe, and that the radiating wires 15 and 15 ′ of the upper stage have the same diameter or even greater than that of the supply probe and are also distant from each other that the wires 14 and 14 'are from the probe 13.
  • the placement of the wires under the roofs is arbitrary and only the distances between them are significant; however, a centered and symmetrical arrangement allows symmetrization of the radiation pattern.
  • the respective heights of each of the antennas should preferably be of the same order of magnitude with respect to the wavelength emitted and not exceed ⁇ 0/15 .
  • the roof surfaces should not be too different if we want to keep the resonances close and a ratio of 1, 4 on the surfaces appears as a maximum not to be exceeded.
  • the dielectric substrates they can allow the resonances to be brought closer or further apart as well as to modify the quality coefficients of the resonances.
  • the dual resonance antenna with multiple radiating elements can be used in two different ways: either it is used as a device with a large bandwidth and, in this case, the characteristics of each superimposed element must lead to overlapping of the frequency bands of operation of each of the antennas in order to carry out an adaptation to 50 ⁇ broadband.
  • Either this type of aerial is used as a device with several resonant frequencies but with identical radiation diagram and, in this case, each of the operating frequency bands must be distinct from the neighboring bands.
  • the dimensions of the roofs, the heights, the substrates and the number of respective radiating wires are chosen on each floor, which gives the approximate operating frequencies;
  • the placement of the wires, their radius and the distances which separate them are chosen concerning the stage where the coaxial supply probe (s) is located while readjusting physical parameters of the other stages having an action on all the resonances, namely: the dimensions of the roofs, the heights and the value of the dielectric permittivity of the substrates; this results in an adjustment of the resonance frequencies associated with a precise positioning of the real and imaginary part of the impedance relating only to the resonance linked to the stage which contains the supply probe, which makes it possible to optimize the adaptation of the device at this first frequency.
  • the radiation of the device is essentially carried out by means of the wires placed at the level of each of the superimposed double resonance antennas.
  • the radiation generated by the device has characteristics identical to the radiation of a monopoly.
  • the device exhibits remarkable stability of the radiation diagram as a function of the frequency since the "double resonance" phenomena are situated well below the cavity resonance modes of the printed antennas.
  • slight changes in the radiation pattern can be observed when the frequency varies significantly due to diffraction by the edges of the ground plane whose effects vary with the wavelength, which is the case for all antennas monopolar radiation.
  • FIGs 5 and 6 illustrate the results obtained with an antenna of the type of that of Figure 2 in which the ground plane 10 has dimensions of 99 mm x 99 mm, the lower capacitive roof 11 has dimensions of 39 mm x 39 mm and the upper capacitive roof 12 has dimensions of 26 mm x 26 mm.
  • the capacitive roof 11 is spaced 10 mm from the ground plane 10 and the two capacitive roofs 11 and 12 are also separated by 10 mm.
  • the coaxial supply probe 13 as well as the radiating wires 15 and 15 ' have a diameter of 1.27 mm and the radiating wires 14 and 14' have a diameter of 0.4 mm.
  • the wires 3 and 4 are 6.6 mm apart and the wires 14 and 14 'are each 9.9 mm apart from the supply probe 13.
  • the resonance frequencies of the fundamental mode of the resonant cavity type of each of the two superposed antennas are respectively located around 3.8 GHz and 5.7 GHz.
  • the position of the wires could be determined so as to also allow the antenna to operate on the resonant modes.
  • FIGS. 5 and 6 show the theoretical results in solid lines and in broken lines the experimental results.
  • FIG. 5 represents the electrical characteristics of the antenna, namely the real and imaginary parts of the input impedance (FIGS. 5a and 5b) and the reflection coefficient measured with respect to 50 ohms (FIG. 5c).
  • Figures 6a and 6b show the gain of the antenna obtained in the plane of the wires and evaluated in the entire space surrounding the antenna at the two operating frequencies of 1, 2 GHz and 2.1 GHz respectively.
  • the antenna then has two "double resonances" located around 1.1 GHz and 2 GHz.
  • An incomplete optimization of the physical parameters of the antenna nevertheless makes it possible to obtain two reflection coefficients of the order from -12 dB at 1.2 GHz and 2.1 GHz.
  • the difference observed in the determination of the high resonance frequency is due to a practical implementation slightly different from the antenna studied in theory.
  • This multi-stage device allows the creation of multiple "double resonances" located close to each other or not.
  • This multi-stage device immediately has two main advantages:
  • the technique of superimposing double resonance antennas allows the complete device to fully retain the characteristics of the double resonance antenna and in particular the advantages set out above.
  • a monopolar type radiation which is practically stable as a function of frequency will be obtained.

Landscapes

  • Waveguide Aerials (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Details Of Aerials (AREA)

Abstract

The invention relates to a monopolar wire-plate antenna comprising a ground plane (10), a first radiating element configured like a capacitive roof (11, 12) and connectable to a generator, and a second radiating element configured like a conductive wire (14, 14', 15, 15') connecting the capacitive roof to the ground plane. It is also provided with a plurality of at least one of said radiating elements.

Description

Antenne fil-plaque monopolaire Monopolar wire-plate antenna
La présente invention concerne une antenne fil-plaque monopolaire du type comprenant un plan de masse, un premier élément rayonnant sous la forme d'un toit capacitif susceptible d'être connecté à un générateur ou à un récepteur par l'intermédiaire d'un fil d'alimentation, et un deuxième élément rayonnant sous la forme d'un fil conducteur rayonnant reliant le toit capacitif au plan de masse.The present invention relates to a monopolar wire-plate antenna of the type comprising a ground plane, a first radiating element in the form of a capacitive roof capable of being connected to a generator or to a receiver by means of a wire. power supply, and a second radiating element in the form of a radiating conducting wire connecting the capacitive roof to the ground plane.
Une telle antenne est connue par le document FR-A-2 668 859.Such an antenna is known from document FR-A-2 668 859.
Cette antenne est composée de deux surfaces métalliques disposées de part et d'autre d'un substrat diélectrique. L'une de ces surfaces, généralement la plus grande, constitue le plan de masse et l'autre surface constitue le toit capacitif. L'alimentation de l'antenne s'effectue par l'intermédiaire du fil d'alimentation constitué d'une sonde coaxiale qui traverse le plan de masse et le substrat et est connectée au toit capacitif.This antenna is composed of two metal surfaces arranged on either side of a dielectric substrate. One of these surfaces, generally the largest, constitutes the ground plane and the other surface constitutes the capacitive roof. The antenna is supplied via the supply wire consisting of a coaxial probe which crosses the ground plane and the substrate and is connected to the capacitive roof.
Cette antenne a la particularité de posséder un fil conducteur supplémentaire actif, rayonnant, parallèle à la sonde coaxiale d'alimentation et qui relie le plan de masse au toit capacitif. Ce fil effectue un retour à la masse. Une telle antenne est le siège de deux phénomènes de résonance, d'où le nom d'antenne à double résonance qui lui est parfois donné.This antenna has the distinction of having an additional active conductive wire, radiating, parallel to the coaxial supply probe and which connects the ground plane to the capacitive roof. This wire returns to ground. Such an antenna is the seat of two resonance phenomena, hence the name of double resonance antenna which is sometimes given to it.
Les paramètres physiques de l'antenne, à savoir la permittivité du substrat électrique, son épaisseur, le rayon du fil d'alimentation, le rayon du fil rayonnant, la distance entre les deux fils ainsi que la forme et les dimensions du toit capacitif et du plan de masse, peuvent a priori avoir des valeurs quelconques. Toutefois le fonctionnement convenable de l'antenne dépend des relations entre ces paramètres qui limitent les possibilités et imposent des contraintes parfois difficiles à respecter du point de vue technologique.The physical parameters of the antenna, namely the permittivity of the electrical substrate, its thickness, the radius of the supply wire, the radius of the radiating wire, the distance between the two wires as well as the shape and dimensions of the capacitive roof and of the ground plane, can a priori have any values. However, the proper functioning of the antenna depends on the relationships between these parameters which limit the possibilities and impose constraints which are sometimes difficult to meet from a technological point of view.
Ainsi pour obtenir une bonne adaptation de l'antenne, il faut de préférence un substrat à très faible constante diélectrique (εr < 2), une distance entre la sonde coaxiale et le fil rayonnant très faible par rapport à la longueur d'onde d'émission (d < λo/50) et un rayon de la sonde coaxiale au moins 5 fois inférieur à celui du fil rayonnant. En revanche, la forme du toit capacitif est pratiquement arbitraire et seule sa surface joue un rôle. D'autre part, il est préférable du point de vue de l'adaptation de l'aérien que sa hauteur soit relativement importante mais n'excède pas λ0/18. La forme et les dimensions du plan de masse ne modifient que dans une faible mesure l'adaptation de l'antenne lorsque sa surface est au moins 10 fois supérieure à celle du toit capacitif mais peuvent modifier notablement le diagramme de rayonnement, comme dans toutes les antennes à rayonnement monopolaire.Thus to obtain a good adaptation of the antenna, it is preferably necessary a substrate with very low dielectric constant (ε r <2), a distance between the coaxial probe and the radiating wire very small compared to the emission wavelength (d <λ o / 50) and a radius of the coaxial probe at least 5 times less than that of the radiating wire. On the other hand, the shape of the capacitive roof is practically arbitrary and only its surface plays a role. On the other hand, it is preferable from the point of view of the adaptation of the aerial that its height is relatively large but does not exceed λ 0/18 . The shape and dimensions of the ground plane only slightly modify the adaptation of the antenna when its surface is at least 10 times greater than that of the capacitive roof, but can significantly modify the radiation pattern, as in all monopolar radiation antennas.
Le fonctionnement de cette antenne résulte principalement d'un phénomène de couplage entre la sonde d'alimentation et le fil rayonnant ou aucun mode de résonance de cavité n'intervient.The operation of this antenna mainly results from a coupling phenomenon between the feeding probe and the radiating wire or no cavity resonance mode intervenes.
L'ajout du fil rayonnant sous les conditions qui seront exposées ci-après crée une résonance parallèle située à une fréquence très inférieure à celles des modes classiques de résonance d'une antenne plaquée. Un choix convenable des différents paramètres physiques de l'antenne permet d'une part de réaliser une adaptation correcte de l'aérien aux générateurs et aux récepteurs classiques, c'est-à-dire que l'antenne présente une impédance dont la partie réelle est proche d'une valeur déterminée, généralement 50 Ω, lorsque la partie imaginaire s'annule, et, d'autre part, d'obtenir un rayonnement du type dit monopolaire qui présente les caractéristiques typiques du rayonnement d'un monopôle :The addition of the radiating wire under the conditions which will be set out below creates a parallel resonance situated at a frequency much lower than those of the conventional modes of resonance of a plated antenna. A suitable choice of the different physical parameters of the antenna makes it possible, on the one hand, to achieve a correct adaptation of the aerial to conventional generators and receivers, that is to say that the antenna has an impedance, the real part of which is close to a determined value, generally 50 Ω, when the imaginary part is canceled, and, on the other hand, to obtain radiation of the so-called monopolar type which has the typical characteristics of the radiation of a monopole:
- Lobe à symétrie de révolution.- Lobe with symmetry of revolution.
- Rayonnement maximal parallèlement au plan de masse lorsqu'il est très grand, et nul dans l'axe des fils.- Maximum radiation parallel to the ground plane when it is very large, and zero in the axis of the wires.
- Polarisation linéaire avec champ électrique dans un plan perpendiculaire à l'antenne. Par conséquent, si l'antenne décrite dans le document précité présente vis- à-vis des antennes de l'art antérieur les avantages d'être relativement simple dans sa conception et sa réalisation, de posséder des dimensions faibles par rapport à la longueur d'onde d'utilisation, de pouvoir être correctement adaptée avec un gain convenable, de posséder une bande passante plus importante qu'une antenne plaquée classique et un rayonnement de type monopolaire stable en fonction de la fréquence, et de pouvoir être utilisée en réseau, elle présente toutefois certains inconvénients.- Linear polarization with electric field in a plane perpendicular to the antenna. Consequently, if the antenna described in the above-mentioned document has the advantages over prior art antennas of being relatively simple in its design and construction, of having small dimensions compared to the length d '' wave of use, to be able to be correctly adapted with a suitable gain, to have a higher bandwidth than a conventional plated antenna and a radiation of monopolar type stable according to the frequency, and to be able to be used in network, however, it has certain drawbacks.
En particulier, pour placer l'antenne dans les conditions d'un rayonnement monopolaire, les dimensions des fils et la distance entre les fils doivent être très inférieures à la longueur d'onde λ de travail, ce qui est source de difficultés technologiques et de fragilité, particulièrement en microonde. D'autre part, pour une utilisation en basses fréquences, les dimensions, bien que déjà très inférieures à la longueur d'onde, sont encore trop grandes pour les applications sur les mobiles. De plus, lorsque le substrat utilisé a une constante diélectrique trop différente de 1 , l'antenne est difficile à adapter et sa bande passante est relativement faible. Enfin, la forme du rayonnement monopolaire n'est pas facilement ajustable, par exemple pour obtenir un gain maximum plus important ou pour obtenir une couverture spatiale plus grande.In particular, to place the antenna in the conditions of monopolar radiation, the dimensions of the wires and the distance between the wires must be much less than the working wavelength λ, which is a source of technological difficulties and of fragility, particularly in the microwave. On the other hand, for use at low frequencies, the dimensions, although already much less than the wavelength, are still too large for applications on mobiles. In addition, when the substrate used has a dielectric constant that is too different from 1, the antenna is difficult to adapt and its bandwidth is relatively low. Finally, the shape of the monopolar radiation is not easily adjustable, for example to obtain a greater maximum gain or to obtain greater spatial coverage.
La présente invention vise à pallier ces inconvénients.The present invention aims to overcome these drawbacks.
A cet effet, l'invention a pour objet une antenne fil-plaque monopolaire comprenant un plan de masse, un premier élément rayonnant sous la forme d'un toit capacitif susceptible d'être connecté à un générateur ou à un récepteur par l'intermédiaire d'un fil d'alimentation et un deuxième élément rayonnant sous la forme d'un fil conducteur reliant le toit capacitif au plan de masse, caractérisée par le fait qu'elle comprend une pluralité d'au moins l'un desdits éléments rayonnants, agencés pour que l'antenne fonctionne en rayonnement monopolaire.To this end, the subject of the invention is a monopolar wire-plate antenna comprising a ground plane, a first radiating element in the form of a capacitive roof capable of being connected to a generator or to a receiver via a supply wire and a second radiating element in the form of a conducting wire connecting the capacitive roof to the ground plane, characterized in that it comprises a plurality of at least one of said radiating elements, arranged so that the antenna operates in monopolar radiation.
On verra ci-après qu'un tel agencement permet de résoudre les problèmes exposés ci-dessus. On notera par ailleurs que l'on entend par le mot "fil" non seulement un conducteur à section circulaire, mais également à section quelconque, tel par exemple qu'un ruban. De même, le "plan" de masse, ainsi que le ou les toits capacitifs, peuvent être en fait des surfaces courbes, éventuellement non parallèles entre elles, notamment pour générer un rayonnement monopolaire de forme particulière, par exemple étroit avec un gain maximum important ou large avec un secteur d'illumination donné.It will be seen below that such an arrangement makes it possible to solve the problems set out above. It will also be noted that the word "wire" means not only a conductor with a circular section, but also with any section, such as for example a ribbon. Likewise, the ground "plane", as well as the capacitive roof (s), may in fact be curved surfaces, possibly not parallel to each other, in particular for generating monopolar radiation of particular shape, for example narrow with a large maximum gain. or wide with a given illumination sector.
Dans un mode de fonctionnement particulier, les caractéristiques de l'antenne, et notamment la forme des toits capacitifs, sont choisies de façon à disposer à une même fréquence ou à plusieurs fréquences voisines d'une antenne travaillant à la fois sur le mode monopolaire et sur les modes classiques dipolaires.In a particular operating mode, the characteristics of the antenna, and in particular the shape of the capacitive roofs, are chosen so as to have at the same frequency or at several frequencies close to an antenna working both in monopolar mode and on the classic dipolar modes.
Egalement dans un mode de réalisation particulier, l'antenne selon l'invention comporte une pluralité de fils conducteurs.Also in a particular embodiment, the antenna according to the invention comprises a plurality of conducting wires.
En particulier, l'antenne selon l'invention permet d'obtenir un rayonnement monopolaire et une bonne adaptation beaucoup plus facilement et avec des contraintes technologiques beaucoup moins fortes que dans l'état de la technique.In particular, the antenna according to the invention makes it possible to obtain monopolar radiation and good adaptation much more easily and with much less technological constraints than in the prior art.
Plus particulièrement les fils rayonnants peuvent être disposés symétriquement par rapport au fil d'alimentation.More particularly, the radiating wires can be arranged symmetrically with respect to the supply wire.
Dans un autre mode de réalisation particulier, l'antenne selon l'invention comporte une pluralité de toits capacitifs, au moins un des toits capacitifs étant agencé pour être connecté au générateur.In another particular embodiment, the antenna according to the invention comprises a plurality of capacitive roofs, at least one of the capacitive roofs being arranged to be connected to the generator.
Dans ce dernier cas, l'antenne selon l'invention peut être alimentée par une sonde coaxiale traversant le plan de masse, dont le fil d'alimentation est connecté à un toit capacitif et dont le conducteur extérieur relie le plan de masse à un toit capacitif situé entre le plan de masse et le toit capacitif connecté au fil d'alimentation. Une antenne selon l'invention comportant plusieurs toits capacitifs peut être agencée pour présenter une large bande passante ou pour présenter une pluralité de fréquences de résonance, ou pour présenter un diagramme de rayonnement monopolaire voisin d'un gabarit donné.In the latter case, the antenna according to the invention can be supplied by a coaxial probe passing through the ground plane, whose power wire is connected to a capacitive roof and whose external conductor connects the ground plane to a roof capacitive located between the ground plane and the capacitive roof connected to the supply wire. An antenna according to the invention comprising several capacitive roofs can be arranged to present a large passband or to present a plurality of resonant frequencies, or to present a monopolar radiation pattern close to a given size.
Dans un mode de réalisation particulier, le toit capacitif est sensiblement rectangulaire et le fil rayonnant est connecté au voisinage du petit côté du rectangle.In a particular embodiment, the capacitive roof is substantially rectangular and the radiating wire is connected in the vicinity of the short side of the rectangle.
On a pu constater que cet agencement permet de diminuer la surface et la hauteur par rapport au plan de masse. Cette condition de fonctionnement est très importante dans le cas des antennes basses fréquences (typiquement antennes radio), pour lesquelles les dimensions des antennes sont conséquentes.It has been observed that this arrangement makes it possible to reduce the surface and the height relative to the ground plane. This operating condition is very important in the case of low frequency antennas (typically radio antennas), for which the dimensions of the antennas are substantial.
Les fils d'alimentation et les fils rayonnants peuvent également être chargés par des éléments de circuits localisés ou répartis le long du fil.The supply wires and the radiating wires can also be loaded by circuit elements located or distributed along the wire.
Ces éléments peuvent être linéaires passifs (résistance , self, capacité, impédance quelconque) ou actifs, mais aussi non linéaires. Choisis convenablement, ils permettent par exemple de diminuer les dimensions de l'antenne, de changer la fréquence de travail, ou de commuter plusieurs fréquences de travail.These elements can be passive linear (resistance, inductance, capacitance, any impedance) or active, but also nonlinear. Chosen appropriately, they allow for example to decrease the dimensions of the antenna, to change the working frequency, or to switch several working frequencies.
On décrira maintenant à titre d'exemple non limitatif des modes de réalisation particuliers de l'invention en référence aux dessins schématiques annexés dans lesquels :We will now describe, by way of nonlimiting example, particular embodiments of the invention with reference to the appended schematic drawings in which:
- les figures 1 , 2a et 2b sont trois vues en perspectives de trois modes de réalisation de l'invention,FIGS. 1, 2a and 2b are three perspective views of three embodiments of the invention,
- les figures 3a, 3b et 3c illustrent respectivement les parties réelles et imaginaires de l'impédance équivalente Z (f) et le coefficient de réflexion S-| -| (f) d'une antenne selon le mode de réalisation de la figure 1 , - les figures 4a et 4b illustrent respectivement pour cette même antenne les gains réalisés dans le plan des fils et dans le plan orthogonal,- Figures 3a, 3b and 3c respectively illustrate the real and imaginary parts of the equivalent impedance Z (f) and the reflection coefficient S- | - | (f) an antenna according to the embodiment of FIG. 1, FIGS. 4a and 4b respectively illustrate for this same antenna the gains made in the plane of the wires and in the orthogonal plane,
- les figures 5a, 5b et 5c illustrent respectivement les parties réelles et imaginaires de l'impédance équivalente Z (f) et le coefficient de réflexion Si 1 (f) d'une antenne selon le mode de réalisation de la figure 2, etFIGS. 5a, 5b and 5c respectively illustrate the real and imaginary parts of the equivalent impedance Z (f) and the reflection coefficient Si 1 (f) of an antenna according to the embodiment of FIG. 2, and
- les figures 6a et 6b illustrent pour cette même antenne les gains réalisés dans le plan des fils à de fréquences différentes.- Figures 6a and 6b illustrate for this same antenna the gains made in the plane of the wires at different frequencies.
L'antenne de la figure 1 est formée d'un substrat diélectrique 1 totalement métallisé sur une de ses faces 2 pour former le plan de masse et partiellement métallisé sur son autre face 3 pour former le toit capacitif. Une sonde coaxiale d'alimentation 4 traverse le plan de masse 2 et le substrat 1 et est connectée au toit capacitif 3. Des fils conducteurs rayonnants 5 traversent également le substrat 1 pour relier le plan de masse 2 au toit capacitif 3.The antenna of Figure 1 is formed of a dielectric substrate 1 fully metallized on one of its faces 2 to form the ground plane and partially metallized on its other face 3 to form the capacitive roof. A coaxial supply probe 4 passes through the ground plane 2 and the substrate 1 and is connected to the capacitive roof 3. Radiant conductive wires 5 also pass through the substrate 1 to connect the ground plane 2 to the capacitive roof 3.
Les fils rayonnants 5 peuvent être disposés, a priori, n'importe où sous le toit capacitif 3 de l'antenne mais, suivant leur position, leur influence sur le fonctionnement de l'antenne sera plus ou moins importante. D'autre part, l'introduction d'un trop grand nombre de fils rayonnants (à partir de quatre) peut atténuer le phénomène de double résonance et le rendre non utilisable du point de vue de l'adaptation de l'aérien aux générateurs microondes.The radiating wires 5 can be placed, a priori, anywhere under the capacitive roof 3 of the antenna but, depending on their position, their influence on the operation of the antenna will be more or less significant. On the other hand, the introduction of too many radiating wires (from four) can reduce the phenomenon of double resonance and make it unusable from the point of view of the adaptation of the air to microwave generators. .
Par ailleurs, le substrat diélectrique 1 sur lequel est déposé le plan de masse 2 et le toit 3 de l'antenne n'est pas obligatoirement constitué d'un seul matériau diélectrique mais peut être constituée d'une superposition de couches à constantes diélectriques quelconques. La forme et les dimensions du substrat 1 sont arbitraires mais généralement, pour des raisons pratiques, ses dimensions ne dépassent pas celles du plan de masse 2.Furthermore, the dielectric substrate 1 on which the ground plane 2 and the roof 3 of the antenna is deposited does not necessarily consist of a single dielectric material but can consist of a superposition of layers with any dielectric constants . The shape and dimensions of the substrate 1 are arbitrary but generally, for practical reasons, its dimensions do not exceed those of the ground plane 2.
L'introduction de chaque fil rayonnant supplémentaire introduit de nouveaux paramètres physiques de l'antenne, à savoir, le rayon du fil rayonnant ajouté, sa distance à la sonde coaxiale d'alimentation ainsi que les distances le séparant des autres fils rayonnants. Ces paramètres physiques supplémentaires compliquent les relations entre les paramètres physiques de l'antenne mais, en réalité, ils simplifient le problème et assouplissent les contraintes nécessaires à l'obtention du fonctionnement de l'antenne fil-plaque monopolaire.The introduction of each additional radiating wire introduces new physical parameters of the antenna, namely, the radius of the wire added radiator, its distance from the coaxial supply probe as well as the distances separating it from the other radiating wires. These additional physical parameters complicate the relationships between the physical parameters of the antenna but, in reality, they simplify the problem and soften the constraints necessary for obtaining the operation of the monopolar wire-plate antenna.
C'est ainsi que le fil de la sonde d'alimentation 4 ne doit plus nécessairement être de diamètre très inférieur à celui des fils rayonnants, mais peut être de diamètre identique ou supérieur. Egalement, les fils 5 ne doivent plus être situés trop proches de la sonde coaxiale d'alimentation 4 mais doivent se trouver de préférence vers les extrémités du toit de l'antenne. Le rayon des fils 5 est de préférence inférieur au rayon de la sonde d'alimentation et, plus les fils 5 sont nombreux ou proches de la sonde d'alimentation, plus leur rayon doit être petit.Thus the wire of the feed probe 4 no longer necessarily has to be of a diameter much smaller than that of the radiating wires, but can be of identical or greater diameter. Also, the wires 5 should no longer be located too close to the coaxial supply probe 4 but should preferably be located towards the ends of the roof of the antenna. The radius of the wires 5 is preferably less than the radius of the feeding probe and, the more the wires 5 are numerous or close to the feeding probe, the smaller their radius must be.
Comparée à l'antenne à double résonance à un seul fil rayonnant, l'antenne à plusieurs fils rayonnants présente un toit généralement plus grand et une hauteur légèrement plus importante pour fonctionner à la même fréquence. Toutefois, l'introduction d'un milieu diélectrique ou d'une superposition de milieux diélectriques différents permet de réduire ces dimensions. D'ailleurs, si l'antenne à double résonance possédant un seul fil rayonnant n'est convenablement adaptable à 50 Ω que pour des substrats à très faible permittivité (εr < 1 ,2), l'introduction de fils rayonnants supplémentaires permet d'adapter très aisément n'importe quelle antenne fil-plaque monopolaire réalisée sur n'importe quel substrat, ou combinaison de substrats.Compared to the double resonance antenna with a single radiating wire, the antenna with several radiating wires has a generally larger roof and a slightly greater height to operate at the same frequency. However, the introduction of a dielectric medium or of a superposition of different dielectric media makes it possible to reduce these dimensions. Moreover, if the double resonance antenna having a single radiating wire is suitably adaptable to 50 Ω only for substrates with very low permittivity (ε r <1, 2), the introduction of additional radiating wires allows '' very easily adapt any monopolar wire-plate antenna produced on any substrate, or combination of substrates.
D'autre part, d'un point de vue pratique, il est préférable de placer dans certains cas les fils 5 symétriquement par rapport à la sonde coaxiale d'alimentation 4, en plaçant, par exemple, cette sonde d'alimentation au centre du toit capacitif 3 de l'antenne.On the other hand, from a practical point of view, it is preferable in certain cases to place the wires 5 symmetrically with respect to the coaxial supply probe 4, by placing, for example, this supply probe in the center of the capacitive roof 3 of the antenna.
Le principe de fonctionnement de l'antenne à double résonance possédant plusieurs fils rayonnants est similaire à celui de l'antenne à double résonance ne présentant qu'un seul fil. L'ajout de fils rayonnants supplémentaires ne crée pas de nouvelles résonances parallèles liées à chacun des fils rayonnants, mais modifie celle créée par un fil rayonnant.The operating principle of the double resonance antenna having several radiating wires is similar to that of the double resonance antenna having only one wire. Adding radiant wires additional does not create new parallel resonances linked to each of the radiating wires, but modifies that created by a radiating wire.
En effet, en première approximation, il est possible de considérer que le phénomène de double résonance est désormais créé par la "self équivalente" à l'ensemble des fils 5 qui court-circuite la capacité de l'antenne. Cette self est désormais plus faible, eu égard à la mise en parallèle des selfs liées à chacun des fils 5, ce qui explique que la fréquence de résonance se trouve décalée vers les hautes fréquences et que cette résonance présente un coefficient de qualité moins élevé. L'introduction de substrats diélectriques à forte permittivité fait redescendre la fréquence de résonance et augmenter le coefficient de qualité en modifiant, principalement, les mutuelles inductances entre les fils.Indeed, as a first approximation, it is possible to consider that the phenomenon of double resonance is now created by the "equivalent self" to the set of wires 5 which short-circuits the capacity of the antenna. This inductance is now lower, having regard to the paralleling of the inductors linked to each of the wires 5, which explains that the resonance frequency is shifted towards the high frequencies and that this resonance has a lower quality coefficient. The introduction of high permittivity dielectric substrates lowers the resonance frequency and increases the quality coefficient by modifying, mainly, the mutual inductances between the wires.
La diminution du coefficient de qualité de la double résonance apparaît très bénéfique du point de vue de l'adaptation de l'aérien aux générateurs microondes car il permet de maintenir la partie réelle de l'impédance proche de 50 Ω et la partie imaginaire nulle sur une bande de fréquence plus grande, ce qui permet d'obtenir une augmentation de la bande passante.The reduction in the quality coefficient of the double resonance appears very beneficial from the point of view of the adaptation of the aerial to the microwave generators because it makes it possible to maintain the real part of the impedance close to 50 Ω and the imaginary part zero on a larger frequency band, which allows an increase in bandwidth.
Ces propriétés sont générales et se retrouvent avec des paramètres d'antenne très différents à des fréquences de fonctionnement quelconques. Aussi, le choix de la fréquence d'utilisation est à la discrétion de l'utilisateur.These properties are general and are found with very different antenna parameters at any operating frequency. Also, the choice of frequency of use is at the discretion of the user.
En conséquence, l'obtention d'une adaptation correcte à une certaine fréquence peut être réalisée de la façon suivante :Consequently, obtaining a correct adaptation at a certain frequency can be carried out as follows:
- on choisit la surface du toit 3, la hauteur du ou des substrats 1 et le nombre de fils rayonnants ce qui donne la fréquence approximative de fonctionnement,- the surface of the roof 3, the height of the substrate (s) 1 and the number of radiating wires are chosen, which gives the approximate operating frequency,
- on choisit le placement des fils 5, leur rayon et les distances qui les séparent, ce qui permet un ajustement de la fréquence, et de la partie réelle et de la partie imaginaire de l'impédance, et par conséquent une optimisation de l'adaptation de l'antenne,- we choose the placement of the wires 5, their radius and the distances between them, which allows an adjustment of the frequency, and of the part real and of the imaginary part of the impedance, and consequently an optimization of the adaptation of the antenna,
- on choisit les dimensions du plan de masse 2, ce qui détermine le diagramme de rayonnement,- the dimensions of the ground plane 2 are chosen, which determines the radiation diagram,
L'antenne fil-plaque monopolaire possédant plusieurs fils rayonnants présente des caractéristiques de rayonnement similaires à celles de l'antenne à double résonance qui ne possède qu'un fil rayonnant, à savoir un rayonnement de type monopolaire qui s'effectue par l'intermédiaire du fil d'alimentation et des fils rayonnants.The monopolar wire-plate antenna having several radiating wires has radiation characteristics similar to those of the double resonance antenna which has only one radiating wire, namely radiation of the monopolar type which takes place through power wire and radiant wires.
La multiplication des fils 5 permet dorénavant de symétriser parfaitement le rayonnement en disposant les fils 5 de manière symétrique vis-à-vis de la sonde d'alimentation 4 située au centre de l'antenne.The multiplication of the wires 5 now makes it possible to perfectly symmetrize the radiation by arranging the wires 5 symmetrically with respect to the supply probe 4 located in the center of the antenna.
Les dimensions du plan de masse 2 et, à un degré moindre, celles du substrat 1 introduisent, comme pour toute antenne à rayonnement monopolaire, des modifications du diagramme de rayonnement.The dimensions of the ground plane 2 and, to a lesser degree, those of the substrate 1 introduce, as with any antenna with monopolar radiation, modifications of the radiation diagram.
On donnera ci-après les caractéristiques d'une antenne du type de celle représentée à la figure 1 avec deux fils 5 et une sonde coaxiale d'alimentation 4 de diamètre 1 ,27 mm, les deux fils 5 étant disposés symétriquement par rapport à la sonde 4 et l'axe de chacun des fils étant distant de 3,3 mm de l'axe de la sonde. Le substrat électrique 1 est constitué d'une plaque de 10 mm d'épaisseur de polyméthacrylate de méthyle de 72 mm x 72 mm, et de permittivité égale à environ à 2,5. Le plan de masse 2 couvre toute une face de la plaque 1 et le toit capacitif est centré sur l'autre face et est de dimension de 20 mm x 20 mm.The characteristics of an antenna of the type shown in FIG. 1 will be given below with two wires 5 and a coaxial feed probe 4 with a diameter of 1.27 mm, the two wires 5 being arranged symmetrically with respect to the probe 4 and the axis of each of the wires being 3.3 mm from the axis of the probe. The electrical substrate 1 consists of a 10 mm thick plate of polymethyl methacrylate of 72 mm × 72 mm, and with a permittivity equal to approximately 2.5. The ground plane 2 covers an entire face of the plate 1 and the capacitive roof is centered on the other face and is of dimension 20 mm × 20 mm.
Les figures 3 à 6 représentent en traits pleins les grandeurs mesurées et, en traits interrompus, les grandeurs théoriques. Les figures 3a et 3b montrent respectivement la partie réelle et la partie imaginaire de l'impédance d'entrée de l'antenne et la figure 3c montre le coefficient de réflexion qui en résulte. De même, les figures 4a et 4b montrent le gain réalisé, obtenu respectivement dans le plan des fils et dans le plan orthogonal au plan des fils, et évalué sur tout l'espace entourant l'antenne.Figures 3 to 6 show in solid lines the measured quantities and, in dashed lines, the theoretical quantities. Figures 3a and 3b respectively show the real part and the imaginary part of the input impedance of the antenna and Figure 3c shows the resulting reflection coefficient. Likewise, FIGS. 4a and 4b show the gain achieved, obtained respectively in the plane of the wires and in the plane orthogonal to the plane of the wires, and evaluated over the entire space surrounding the antenna.
Ces résultats permettent de vérifier l'excellente adaptation de l'antenne (figure 3) ainsi que l'allure typique du rayonnement monopolaire déformée par l'effet de diffraction des arêtes du plan de masse (figure 4). L'antenne présente un coefficient de réflexion S-n (f) de l'ordre de -20 dB (seulement 1 % de la puissance incidente est réfléchie) à la fréquence de 1 ,77 GHz.These results make it possible to verify the excellent adaptation of the antenna (FIG. 3) as well as the typical shape of the monopolar radiation deformed by the diffraction effect of the edges of the ground plane (FIG. 4). The antenna has a reflection coefficient S-n (f) of the order of -20 dB (only 1% of the incident power is reflected) at the frequency of 1.77 GHz.
Le gain réalisé représenté à la figure 4 à cette même fréquence de 1 ,77 GHz tient compte de l'ensemble des pertes (désadaptation, pertes ohmiques et diélectriques) et atteint une valeur maximale d'environ 2,5 dB à 45° en raison de la déformation du diagramme de rayonnement due aux dimensions du plan de masse.The gain realized represented in FIG. 4 at this same frequency of 1.77 GHz takes account of all the losses (mismatch, ohmic and dielectric losses) and reaches a maximum value of approximately 2.5 dB at 45 ° due the deformation of the radiation diagram due to the dimensions of the ground plane.
Outre les avantages présentés par l'antenne à double résonance à un seul fil rayonnant vis-à-vis des antennes antérieures et que reprend l'antenne à double résonance à plusieurs fils rayonnants, la multiplication des fils rayonnants sur ce type d'antenne présente d'autres avantages.In addition to the advantages presented by the double resonance antenna with a single radiating wire with respect to the previous antennas and which takes up the double resonance antenna with several radiating wires, the multiplication of radiating wires on this type of antenna presents other advantages.
En effet, l'introduction de fils rayonnants supplémentaires autorise plus de liberté sur les paramètres physiques de l'antenne, ce qui permet :Indeed, the introduction of additional radiating wires allows more freedom on the physical parameters of the antenna, which allows:
- une adaptation de l'aérien plus aisée ;- easier adaptation of the aerial;
- la possibilité d'utiliser des substrats à forte permittivité ;- the possibility of using substrates with high permittivity;
- un élargissement de la bande passante : 8 % de bande pour un TOS de 2 ou 20 % de bande pour un TOS de 5,8 (|S-j -\ | de - 3 dB) ;- a broadening of the bandwidth: 8% of band for a TOS of 2 or 20% of band for a TOS of 5.8 (| S-j - \ | of - 3 dB);
- une configuration physique de l'antenne pas obligatoirement unique et facilement modulable ;- a physical configuration of the antenna that is not necessarily unique and easily modular;
- une symétrisation parfaite du diagramme de rayonnement dans tout l'espace. La réalisation technologique de l'aérien apparaît désormais plus aisée car les contraintes imposées sur les paramètres physiques pour obtenir un fonctionnement correct sont moins strictes ou pénalisantes.- perfect symmetrization of the radiation pattern throughout the space. The technological realization of the aerial now appears easier because the constraints imposed on the physical parameters to obtain correct operation are less strict or penalizing.
Du point de vue de la réalisation, on obtient les avantages suivants :From the point of view of implementation, the following advantages are obtained:
- une solidité de l'antenne accrue par l'introduction de fils rayonnants supplémentaires et d'une sonde coaxiale de gros diamètre ;- increased antenna strength by the introduction of additional radiating wires and a large diameter coaxial probe;
- la possibilité de réaliser une antenne sans substrat diélectrique, le toit étant maintenu par l'ensemble des fils ;- The possibility of making an antenna without a dielectric substrate, the roof being held by all of the wires;
- la possibilité d'utiliser des substrats diélectriques facilitant la réalisation et renforçant la rigidité de l'antenne.- the possibility of using dielectric substrates facilitating the production and strengthening the rigidity of the antenna.
Dans le mode de réalisation de la figure 2a, le diélectrique est l'air ambiant. Le plan de masse 10 est surmonté par un premier toit capacitif 11 lui-même surmonté par un deuxième toit capacitif 12. Seul le premier toit capacitif 11 est connecté à une sonde coaxiale d'alimentation 13 traversant le plan de masse 10 pour sa connexion à un générateur.In the embodiment of FIG. 2a, the dielectric is the ambient air. The ground plane 10 is surmounted by a first capacitive roof 11 itself surmounted by a second capacitive roof 12. Only the first capacitive roof 11 is connected to a coaxial supply probe 13 passing through the ground plane 10 for its connection to a generator.
Le premier toit capacitif 1 1 est par ailleurs relié au plan de masse 10 par deux fils conducteurs 14 et 14' disposés par rapport à la sonde 13 comme les fils 5 du mode de réalisation de la figure 1. Le deuxième toit capacitif 12 est relié au premier toit capacitif 11 par deux fils rayonnants 15 et 15' en contact avec le toit 11 en deux points situés entre les points de contact de la sonde 13 et ceux des fils 14 et 14' de l'autre côté du toit 11.The first capacitive roof 1 1 is also connected to the ground plane 10 by two conductive wires 14 and 14 'arranged relative to the probe 13 like the wires 5 of the embodiment of FIG. 1. The second capacitive roof 12 is connected to the first capacitive roof 11 by two radiating wires 15 and 15 'in contact with the roof 11 at two points located between the contact points of the probe 13 and those of the wires 14 and 14' on the other side of the roof 11.
On verra ci-après qu'un tel dispositif engendre deux fréquences de résonance.We will see below that such a device generates two resonant frequencies.
Dans le mode de réalisation de la figure 2b, l'ensemble de la sonde 13 traverse le plan de masse 10. Son conducteur tubulaire extérieur 13" relie électriquement le plan de masse 10 au premier toit capacitif 1 1 , tandis que le conducteur central 13' est relié au toit capacitif supérieur 12. Le toit 12 possède ici une forme rectangulaire allongée. Les fils rayonnants 15 et 15' sont connectés au toit 12 en des emplacements voisins des petits côtés 12' u toit 12.In the embodiment of FIG. 2b, the assembly of the probe 13 crosses the ground plane 10. Its external tubular conductor 13 "electrically connects the ground plane 10 to the first capacitive roof 1 1, while the central conductor 13 'is connected to the upper capacitive roof 12. The roof 12 here has an elongated rectangular shape. The radiating wires 15 and 15 ′ are connected to the roof 12 at locations adjacent to the short sides 12 ′ to the roof 12.
Les fils 15 et 15' sont ici chargés par des circuits 20 et 20' présentant un impédance adéquate, actifs ou passifs.The wires 15 and 15 'are here loaded by circuits 20 and 20' having an adequate impedance, active or passive.
Bien entendu, un plus grand nombre de toits ainsi qu'un agencement différent des fils rayonnants est envisageable dans les modes de réalisation des figures 2a et 2b.Of course, a larger number of roofs and a different arrangement of the radiating wires can be envisaged in the embodiments of FIGS. 2a and 2b.
On a pu constater que la forme des toits est pratiquement arbitraire et que seule leur surface compte. Pour des raisons pratiques et simplificatrices, on peut placer le toit 12 ayant la surface la plus petite le plus haut au- dessus du plan de masse 10, le toit 11 le plus grand étant placé immédiatement au-dessus du plan de masse. Ainsi, la sonde d'alimentation est uniquement connectée au toit 11 le plus grand à travers le plan de masse. Ce dont donc les paramètres physiques liés à l'étage inférieur qui agissent principalement sur la résonance la plus basse ; la résonance la plus haute est, quant à elle, fixée d'une part par les paramètres physiques liés à l'étage du haut, mais également par ceux de l'étage du bas contenant la sonde coaxiale d'alimentation 13.We have seen that the shape of roofs is practically arbitrary and that only their surface counts. For practical and simplifying reasons, it is possible to place the roof 12 having the smallest surface the highest above the ground plane 10, the largest roof 11 being placed immediately above the ground plane. Thus, the supply probe is only connected to the largest roof 11 through the ground plane. Which therefore the physical parameters related to the lower stage which act mainly on the lowest resonance; the highest resonance is, for its part, fixed on the one hand by the physical parameters linked to the upper stage, but also by those of the lower stage containing the coaxial supply probe 13.
Ainsi, si les contraintes à imposer sur les paramètres physiques liés à l'étage du bas sont connus par la description donnée ci-dessus en référence à la figure 1 , ils doivent dorénavant être modulés pour ne pas trop pénaliser la résonance la plus haute. En effet, il est nécessaire de rendre exploitable, du point de vue de l'adaptation à 50 Ω, la seconde double résonance par une action conjointe sur, d'une part, l'ensemble des paramètres physiques liés au premier étage, puis d'autre part, sur les paramètres physiques liés au deuxième étage et qui influencent les deux résonances (à savoir : les dimensions du toit supérieur 12, la valeur de la permittivité du substrat diélectrique du deuxième étage et son épaisseur) et enfin, une action sur les paramètres physiques qui agissent uniquement sur la seconde résonance, indépendamment de l'autre (à savoir : le rayon des fils rayonnants supérieurs 15 et 15' et la distance qui les séparent). Globalement, il est apparu préférable que la sonde coaxiale d'alimentation 13 ait un diamètre important, que les fils rayonnants 14 et 14' de l'étage du bas soient éloignés de la sonde coaxiale 13 et possèdent un rayon au moins trois à quatre fois inférieur à celui de la sonde d'alimentation, et que les fils rayonnants 15 et 15' de l'étage du haut aient un diamètre identique voire supérieur à celui de la sonde d'alimentation et soient également éloignés l'un de l'autre que les fils 14 et 14' le sont de la sonde 13. D'ailleurs, le placement des fils sous les toits est arbitraire et seules les distances les séparant sont importantes ; toutefois, une disposition centrée et symétrique permet de symétriser le diagramme de rayonnement. Les hauteurs respectives de chacune des antennes doivent de préférence être du même ordre de grandeur par rapport à la longueur d'onde émise et ne pas excéder λ0/15.Thus, if the constraints to be imposed on the physical parameters linked to the bottom stage are known from the description given above with reference to FIG. 1, they must henceforth be modulated so as not to penalize the highest resonance too much. Indeed, it is necessary to make exploitable, from the point of view of the adaptation to 50 Ω, the second double resonance by a joint action on, on the one hand, all the physical parameters related to the first stage, then d on the other hand, on the physical parameters linked to the second stage and which influence the two resonances (namely: the dimensions of the upper roof 12, the value of the permittivity of the dielectric substrate of the second stage and its thickness) and finally, an action on the physical parameters which act only on the second resonance, independently of the other (namely: the radius of the upper radiating wires 15 and 15 'and the distance which separate them). Overall, it appeared preferable that the coaxial supply probe 13 has a large diameter, that the radiating wires 14 and 14 ′ of the bottom stage are distant from the coaxial probe 13 and have a radius at least three to four times less than that of the supply probe, and that the radiating wires 15 and 15 ′ of the upper stage have the same diameter or even greater than that of the supply probe and are also distant from each other that the wires 14 and 14 'are from the probe 13. Moreover, the placement of the wires under the roofs is arbitrary and only the distances between them are significant; however, a centered and symmetrical arrangement allows symmetrization of the radiation pattern. The respective heights of each of the antennas should preferably be of the same order of magnitude with respect to the wavelength emitted and not exceed λ 0/15 .
Les surfaces des toits ne doivent pas être trop différentes si l'on veut garder les résonances proches et un rapport de 1 ,4 sur les surfaces apparaît comme un maximum à ne pas dépasser. Quant aux substrats diélectriques, ils peuvent permettre de rapprocher ou d'éloigner les résonances ainsi que de modifier les coefficients de qualité des résonances.The roof surfaces should not be too different if we want to keep the resonances close and a ratio of 1, 4 on the surfaces appears as a maximum not to be exceeded. As for the dielectric substrates, they can allow the resonances to be brought closer or further apart as well as to modify the quality coefficients of the resonances.
Si le principe de fonctionnement de ce dispositif reprend celui de l'antenne à double résonance pour chaque toit de l'antenne, le phénomène se complique toutefois, du fait de la présence de toits inférieurs qui peuvent agir comme plan de masse vis-à-vis des toits supérieurs. D'autre part, les phénomènes de couplage n'ont plus uniquement lieu entre les fils d'un même étage mais également avec ceux des autres étages. Ainsi, le phénomène de double résonance lié au premier étage où se trouve la sonde d'alimentation est pratiquement indépendant des résonances dues aux étages supérieurs, mais chacune des résonances dues aux étages supérieurs dépend fortement de celles liées aux étages inférieurs.If the principle of operation of this device takes again that of the antenna with double resonance for each roof of the antenna, the phenomenon is complicated however, because of the presence of lower roofs which can act as ground plane with screws of the upper roofs. On the other hand, the coupling phenomena no longer take place only between the wires of the same stage but also with those of the other stages. Thus, the phenomenon of double resonance linked to the first stage where the supply probe is located is practically independent of the resonances due to the upper stages, but each of the resonances due to the upper stages strongly depends on those linked to the lower stages.
Bien que, dans ce cas, l'établissement d'un circuit équivalent apparaisse difficile, l'apparition des résonances parallèles, situées bien en dessous des modes classiques de résonance de cavité des antennes imprimées, résulte toujours d'un court-circuit réalisé par l'intermédiaire des fils rayonnants (et éventuellement des toits et fils rayonnants inférieurs) au niveau des capacités présentées par chaque toit du dispositif.Although in this case the establishment of an equivalent circuit appears difficult, the appearance of parallel resonances, situated well below the conventional modes of cavity resonance of printed antennas, always results from a short circuit produced by radiating wires (and possibly lower radiant roofs and wires) at the level of the capacities presented by each roof of the device.
Ces propriétés sont générales et se retrouvent avec des paramètres physiques d'antennes très différents à des fréquences de travail quelconques.These properties are general and are found with very different antenna physical parameters at any working frequency.
L'antenne à double résonance à éléments rayonnants multiples peut être employée de deux manières différentes : soit elle est utilisée comme un dispositif présentant une large bande passante et, dans ce cas, les caractéristiques de chaque élément superposé doivent conduire au chevauchement des bandes de fréquence de fonctionnement de chacune des antennes afin de réaliser une adaptation à 50 Ω large bande. Soit ce type d'aérien est utilisé comme un dispositif à plusieurs fréquences de résonance mais à diagramme de rayonnement identique et, dans ce cas, chacune des bandes de fréquence de fonctionnement doit être distincte des bandes voisines.The dual resonance antenna with multiple radiating elements can be used in two different ways: either it is used as a device with a large bandwidth and, in this case, the characteristics of each superimposed element must lead to overlapping of the frequency bands of operation of each of the antennas in order to carry out an adaptation to 50 Ω broadband. Either this type of aerial is used as a device with several resonant frequencies but with identical radiation diagram and, in this case, each of the operating frequency bands must be distinct from the neighboring bands.
Toutefois, quel que soit le type d'utilisation du dispositif souhaité, un fonctionnement correct du dispositif peut être obtenu de la façon exposée ci-après. Du fait du nombre important de paramètres physiques à fixer et compte tenu du fait que certains paramètres modifient l'ensemble des résonances, il est important de procéder par étapes et de commencer par fixer les paramètres physiques ayant une large influence. C'est ainsi qu'il faut d'abord s'attacher à choisir les paramètres liés à l'étage inférieur contenant la sonde d'alimentation et ensuite choisir, étage par étage, les paramètres physiques liés principalement à chacune des résonances afin d'optimiser l'adaptation du dispositif à 50 Ω.However, whatever the type of use of the desired device, correct operation of the device can be obtained as explained below. Because of the large number of physical parameters to be fixed and given the fact that certain parameters modify the set of resonances, it is important to proceed in stages and to start by fixing the physical parameters having a large influence. This is how we must first focus on choosing the parameters linked to the lower stage containing the supply probe and then choose, stage by stage, the physical parameters linked mainly to each of the resonances in order to optimize the adaptation of the device to 50 Ω.
On procède donc de la façon suivanteWe therefore proceed as follows
- on choisit les dimensions des toits, les hauteurs, les substrats et le nombre de fils rayonnants respectifs à chaque étage, ce qui donne les fréquences approximatives de fonctionnement ; - on choisit le placement des fils, leur rayon et les distances qui les séparent concernant l'étage où se trouve la ou les sondes coaxiales d'alimentation tout en réajustant des paramètres physiques des autres étages ayant une action sur l'ensemble des résonances, à savoir : les dimensions des toits, les hauteurs et la valeur de la permittivité diélectrique des substrats ; il en résulte un ajustement des fréquences de résonance associé à un positionnement précis de la partie réelle et imaginaire de l'impédance concernant uniquement la résonance liée à l'étage qui contient la sonde d'alimentation, ce qui permet d'optimiser l'adaptation du dispositif à cette première fréquence.- the dimensions of the roofs, the heights, the substrates and the number of respective radiating wires are chosen on each floor, which gives the approximate operating frequencies; - the placement of the wires, their radius and the distances which separate them are chosen concerning the stage where the coaxial supply probe (s) is located while readjusting physical parameters of the other stages having an action on all the resonances, namely: the dimensions of the roofs, the heights and the value of the dielectric permittivity of the substrates; this results in an adjustment of the resonance frequencies associated with a precise positioning of the real and imaginary part of the impedance relating only to the resonance linked to the stage which contains the supply probe, which makes it possible to optimize the adaptation of the device at this first frequency.
Ensuite, pour chacun des toits constitutifs du dispositif et en commençant par l'étage situé immédiatement au-dessus du précédent :Then, for each of the roofs making up the device and starting with the floor located immediately above the previous one:
- on choisit le placement des fils, leur rayon et les distances qui les séparent de manière à modifier uniquement la résonance liée à cet étage et celles liées aux étages supérieurs, d'où un ajustement de la fréquence de résonance concernée, et de la partie réelle et imaginaire de l'impédance afin d'optimiser l'adaptation du dispositif à cette fréquence. Les résonances supérieures pourront être éventuellement modifiées mais elles le seront de nouveau lors de l'optimisation des paramètres les concernant ;- we choose the placement of the wires, their radius and the distances between them so as to modify only the resonance linked to this stage and those linked to the upper stages, hence an adjustment of the resonance frequency concerned, and of the part real and imaginary of the impedance in order to optimize the adaptation of the device to this frequency. The higher resonances may be modified if necessary, but they will be modified again when the parameters relating to them are optimized;
- enfin, on choisit des dimensions du plan de masse pour déterminer le diagramme de rayonnement.- finally, we choose dimensions of the ground plane to determine the radiation diagram.
Le rayonnement du dispositif s'effectue pour l'essentiel par l'intermédiaire des fils placés au niveau de chacune des antennes à double résonance superposées. Ainsi, le rayonnement engendré par le dispositif présente des caractéristiques identiques au rayonnement d'un monopole.The radiation of the device is essentially carried out by means of the wires placed at the level of each of the superimposed double resonance antennas. Thus, the radiation generated by the device has characteristics identical to the radiation of a monopoly.
Toutefois, il est à noter que le dispositif présente une remarquable stabilité du diagramme de rayonnement en fonction de la fréquence puisque les phénomènes de "double résonance" se situent bien en dessous des modes de résonance de cavité des antennes imprimées. Cependant, de légères modifications du diagramme de rayonnement sont observables lorsque la fréquence varie de façon importante à cause de la diffraction par les arêtes du plan de masse dont les effets varient avec la longueur d'onde, ce qui est le cas pour toutes les antennes à rayonnement monopolaire.However, it should be noted that the device exhibits remarkable stability of the radiation diagram as a function of the frequency since the "double resonance" phenomena are situated well below the cavity resonance modes of the printed antennas. However, slight changes in the radiation pattern can be observed when the frequency varies significantly due to diffraction by the edges of the ground plane whose effects vary with the wavelength, which is the case for all antennas monopolar radiation.
Les figures 5 et 6 illustrent les résultats obtenus avec une antenne du type de celle de la figure 2 dans laquelle le plan de masse 10 a des dimensions de 99 mm x 99 mm, le toit capacitif inférieur 11 a des dimensions de 39 mm x 39 mm et le toit capacitif supérieur 12 a des dimensions de 26 mm x 26 mm. Le toit capacitif 11 est distant de 10 mm du plan de masse 10 et les deux toits capacitifs 11 et 12 sont séparés également de 10 mm. La sonde coaxiale d'alimentation 13 ainsi que les fils rayonnants 15 et 15' ont un diamètre de 1 ,27 mm et les fils rayonnants 14 et 14' ont un diamètre de 0,4 mm. Les fils 3 et 4 sont distants de 6,6 mm et les fils 14 et 14' sont chacun distants de 9,9 mm de la sonde d'alimentation 13.Figures 5 and 6 illustrate the results obtained with an antenna of the type of that of Figure 2 in which the ground plane 10 has dimensions of 99 mm x 99 mm, the lower capacitive roof 11 has dimensions of 39 mm x 39 mm and the upper capacitive roof 12 has dimensions of 26 mm x 26 mm. The capacitive roof 11 is spaced 10 mm from the ground plane 10 and the two capacitive roofs 11 and 12 are also separated by 10 mm. The coaxial supply probe 13 as well as the radiating wires 15 and 15 'have a diameter of 1.27 mm and the radiating wires 14 and 14' have a diameter of 0.4 mm. The wires 3 and 4 are 6.6 mm apart and the wires 14 and 14 'are each 9.9 mm apart from the supply probe 13.
Les fréquences de résonance du mode fondamental de type cavité résonnante de chacune des deux antennes superposées sont respectivement situées vers 3,8 GHz et 5,7 GHz. La position des fils pourrait être déterminée de façon à permettre également un fonctionnement de l'antenne sur les modes résonnants.The resonance frequencies of the fundamental mode of the resonant cavity type of each of the two superposed antennas are respectively located around 3.8 GHz and 5.7 GHz. The position of the wires could be determined so as to also allow the antenna to operate on the resonant modes.
On a représenté aux figures 5 et 6 en trait plein les résultats théoriques et en trait interrompus les résultats expérimentaux.FIGS. 5 and 6 show the theoretical results in solid lines and in broken lines the experimental results.
La figure 5 représente les caractéristiques électriques de l'antenne à savoir les parties réelles et imaginaires de l'impédance d'entrée (figures 5a et 5b) et le coefficient de réflexion mesuré par rapport à 50 ohms (figure 5c). Les figures 6a et 6b montrent le gain réalisé de l'antenne obtenu dans le plan des fils et évalué dans tout l'espace entourant l'antenne aux deux fréquences de fonctionnement de 1 ,2 GHz et 2,1 GHz respectivement.FIG. 5 represents the electrical characteristics of the antenna, namely the real and imaginary parts of the input impedance (FIGS. 5a and 5b) and the reflection coefficient measured with respect to 50 ohms (FIG. 5c). Figures 6a and 6b show the gain of the antenna obtained in the plane of the wires and evaluated in the entire space surrounding the antenna at the two operating frequencies of 1, 2 GHz and 2.1 GHz respectively.
L'antenne présente alors deux "doubles résonances" situées vers 1 ,1 GHz et 2 GHz. Une optimisation incomplète des paramètres physiques de l'antenne permet pourtant d'obtenir deux coefficients de réflexion de l'ordre de -12 dB à 1 ,2 GHz et 2,1 GHz. L'écart observé au niveau de la détermination de la fréquence de résonance haute est dû à une réalisation pratique légèrement différente de l'antenne étudiée en théorie.The antenna then has two "double resonances" located around 1.1 GHz and 2 GHz. An incomplete optimization of the physical parameters of the antenna nevertheless makes it possible to obtain two reflection coefficients of the order from -12 dB at 1.2 GHz and 2.1 GHz. The difference observed in the determination of the high resonance frequency is due to a practical implementation slightly different from the antenna studied in theory.
On observe alors, aux deux fréquences de fonctionnement, un rayonnement de type monopolaire légèrement déformé par la diffraction due au plan de masse. On notera que le diagramme le plus déformé est celui évalué à la fréquence la plus haute mais que le rayonnement avant de l'antenne (-90°<θ<90°) est presque identique aux deux fréquences de fonctionnement séparées de 0,9 GHz (courbes expérimentales).One then observes, at the two operating frequencies, a radiation of the monopolar type slightly deformed by the diffraction due to the ground plane. It will be noted that the most distorted diagram is that evaluated at the highest frequency but that the radiation before the antenna (-90 ° <θ <90 °) is almost identical at the two operating frequencies separated by 0.9 GHz (experimental curves).
Les valeurs de gain réalisé, obtenues aux deux fréquences de fonctionnement, à savoir, 1 ,4 dB à f = 1 ,2 GHz et 1 ,9 dB à f = 2,1 GHz (courbes expérimentales) sont conformes aux valeurs escomptées compte tenu de l'adaptation à -12 dB obtenue à ces fréquences et pourraient être augmentées moyennant une adaptation à 50 Ω optimisée.The gain values obtained, obtained at the two operating frequencies, namely, 1.4 dB at f = 1.2 GHz and 1.9 dB at f = 2.1 GHz (experimental curves) are in line with the expected values taking into account of the adaptation to -12 dB obtained at these frequencies and could be increased by means of an adaptation to optimized 50 Ω.
Le rayonnement obtenu dans le plan orthogonal au plan des fils fournit des résultats identiques qui ne sont pas présentés ici.The radiation obtained in the plane orthogonal to the plane of the wires provides identical results which are not presented here.
Ce dispositif à étages multiples permet la création de multiples "doubles résonances" situées proches les unes des autres ou pas. Ainsi, un tel dispositif présente immédiatement deux principaux intérêts :This multi-stage device allows the creation of multiple "double resonances" located close to each other or not. Thus, such a device immediately has two main advantages:
- une adaptation à 50 Ω très large bande obtenue par chevauchement des bandes passantes liées à chacune des antennes superposées. 75 % de bande passante pour un |S-| -| | de - 3dB a été obtenu avec seulement deux antennes superposées.- an adaptation to 50 Ω very wide band obtained by overlapping the pass bands linked to each of the superimposed antennas. 75% bandwidth for a | S- | - | | de - 3dB was obtained with only two superimposed antennas.
- une adaptation aux générateurs microondes sur des bandes de fréquences distinctes, proches ou éloignées.- adaptation to microwave generators on separate frequency bands, near or far.
D'autre part, la technique de superposition d'antennes à double résonance permet au dispositif complet de garder intégralement les caractéristiques de l'antenne à double résonance et notamment les avantages exposés ci- dessus . On obtiendra en outre un rayonnement de type monopolaire pratiquement stable en fonction de la fréquence. On the other hand, the technique of superimposing double resonance antennas allows the complete device to fully retain the characteristics of the double resonance antenna and in particular the advantages set out above. In addition, a monopolar type radiation which is practically stable as a function of frequency will be obtained.

Claims

REVENDICATIONS
1. Antenne fil-plaque monopolaire comprenant un plan de masse (2 ; 10), un premier élément rayonnant sous la forme d'un toit capacitif (3 ; 11 , 12) susceptible d'être connecté à un générateur ou à un récepteur par l'intermédiaire d'un fil d'alimentation, et un deuxième élément rayonnant sous la forme d'un fil conducteur (5 ; 14, 14', 15, 15') reliant le toit capacitif au plan de masse, caractérisée par le fait qu'elle comprend une pluralité d'au moins l'un desdits éléments rayonnants, agencés pour que l'antenne fonctionne en rayonnement monopolaire.1. Monopolar wire-plate antenna comprising a ground plane (2; 10), a first radiating element in the form of a capacitive roof (3; 11, 12) capable of being connected to a generator or to a receiver by via a supply wire, and a second radiating element in the form of a conductive wire (5; 14, 14 ', 15, 15') connecting the capacitive roof to the ground plane, characterized by the fact that it comprises a plurality of at least one of said radiating elements, arranged so that the antenna operates in monopolar radiation.
2. Antenne selon la revendication 1 , comportant une pluralité de fils rayonnants.2. An antenna according to claim 1, comprising a plurality of radiating wires.
3. Antenne selon la revendication 2, dans laquelle les fils rayonnants sont disposés symétriquement par rapport au fil d'alimentation.3. An antenna according to claim 2, in which the radiating wires are arranged symmetrically with respect to the supply wire.
4. Antenne selon l'une quelconque des revendications 1 à 3, comportant une pluralité de toits capacitifs, au moins un des toits capacitifs étant agencé pour être connecté au générateur.4. An antenna according to any one of claims 1 to 3, comprising a plurality of capacitive roofs, at least one of the capacitive roofs being arranged to be connected to the generator.
5. Antenne selon la revendication 4, alimentée par une sonde coaxiale traversant le plan de masse, dont le fil d'alimentation est connecté à un toit capacitif et dont le conducteur extérieur relie le plan de masse à un toit capacitif situé entre le plan de masse et le toit capacitif connecté au fil d'alimentation.5. Antenna according to claim 4, supplied by a coaxial probe passing through the ground plane, the supply wire of which is connected to a capacitive roof and the external conductor of which connects the ground plane to a capacitive roof situated between the plane of ground and the capacitive roof connected to the power wire.
6. Antenne selon l'une quelconque des revendications 1 à 5, comportant au moins deux toits capacitifs et agencée pour présenter une large bande passante.6. An antenna according to any one of claims 1 to 5, comprising at least two capacitive roofs and arranged to have a large bandwidth.
7. Antenne selon l'une quelconque des revendications 1 à 5, comportant une pluralité de toits capacitifs et agencée pour présenter une pluralité de fréquences de résonance. 7. An antenna according to any one of claims 1 to 5, comprising a plurality of capacitive roofs and arranged to present a plurality of resonant frequencies.
8. Antenne selon l'une quelconque des revendications 1 à 7, dans laquelle le toit capacitif est sensiblement rectangulaire et le fil rayonnant est connecté au voisinage du petit côté du rectangle.8. An antenna according to any one of claims 1 to 7, in which the capacitive roof is substantially rectangular and the radiating wire is connected in the vicinity of the short side of the rectangle.
9. Antenne selon l'une quelconque des revendications 1 à 8, dans laquelle au moins l'un des fils est chargé par un élément de circuit. 9. An antenna according to any one of claims 1 to 8, in which at least one of the wires is loaded by a circuit element.
EP94926276A 1993-09-07 1994-09-06 Monopolar wire-plate antenna Expired - Lifetime EP0667984B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9310597A FR2709878B1 (en) 1993-09-07 1993-09-07 Monopolar wire-plate antenna.
FR9310597 1993-09-07
PCT/FR1994/001044 WO1995007557A1 (en) 1993-09-07 1994-09-06 Monopolar wire-plate antenna

Publications (2)

Publication Number Publication Date
EP0667984A1 true EP0667984A1 (en) 1995-08-23
EP0667984B1 EP0667984B1 (en) 1998-07-22

Family

ID=9450601

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94926276A Expired - Lifetime EP0667984B1 (en) 1993-09-07 1994-09-06 Monopolar wire-plate antenna

Country Status (9)

Country Link
US (1) US6750825B1 (en)
EP (1) EP0667984B1 (en)
JP (1) JP3457672B2 (en)
CN (1) CN1059760C (en)
AU (1) AU7617994A (en)
CA (1) CA2148796C (en)
DE (1) DE69411885T2 (en)
FR (1) FR2709878B1 (en)
WO (1) WO1995007557A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1407512B1 (en) * 2001-06-18 2014-10-22 Centre National De La Recherche Scientifique (Cnrs) Antenna

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE9802883L (en) * 1998-08-28 2000-02-29 Ericsson Telefon Ab L M Antenna device
GB2352091B (en) * 1999-07-10 2003-09-17 Alan Dick & Company Ltd Patch antenna
US6369761B1 (en) 2000-04-17 2002-04-09 Receptec L.L.C. Dual-band antenna
GB2369497B (en) * 2000-11-28 2004-03-24 Harada Ind Multiband vehicular telephone antenna
JP2005039754A (en) * 2003-06-26 2005-02-10 Alps Electric Co Ltd Antenna system
ITVI20030270A1 (en) 2003-12-31 2005-07-01 Calearo Antenne Srl MULTI-BAY AFT OF SLOTS
FR2870642B1 (en) * 2004-05-19 2008-11-14 Centre Nat Rech Scient Cnrse BIP MATERIAL ANTENNA (PHOTONIC PROHIBITED BAND) WITH A SIDE WALL SURROUNDING A AXIS
WO2008023800A1 (en) * 2006-08-24 2008-02-28 Hitachi Kokusai Electric Inc. Antenna device
WO2008072411A1 (en) * 2006-12-15 2008-06-19 Murata Manufacturing Co., Ltd. Antenna and communication device with that antenna
FR2914113B1 (en) * 2007-03-20 2009-05-01 Trixell Soc Par Actions Simpli MIXED ANTENNA
FR2918803B1 (en) * 2007-07-11 2009-10-02 Advanten Soc Par Actions Simpl ANTENNAIRE SYSTEM COMPRISING A REPLIE MONOPOLE WITH MULTIBRINS PARASITES.
JP5950236B2 (en) * 2011-10-31 2016-07-13 パナソニックＩｐマネジメント株式会社 Wireless terminal
JP2014110555A (en) * 2012-12-03 2014-06-12 Samsung Electronics Co Ltd Antenna device
US10181642B2 (en) * 2013-03-15 2019-01-15 City University Of Hong Kong Patch antenna
CN103531902B (en) * 2013-10-24 2015-09-30 哈尔滨工程大学 Mutual coupling probe and patch tangent feeding classification antenna can fall
FR3030909B1 (en) 2014-12-19 2018-02-02 Commissariat A L'energie Atomique Et Aux Energies Alternatives WIRE-PLATE ANTENNA HAVING A CAPACITIVE ROOF INCORPORATING A SLIT BETWEEN THE POWER SENSOR AND THE SHORT-CIRCUIT WIRE
FR3085550B1 (en) 2018-08-31 2021-05-14 Commissariat Energie Atomique COMPACT ANTENNA DEVICE
FR3091045B1 (en) 2018-12-21 2020-12-11 Commissariat Energie Atomique MONOPOLAR WIRE-PLATE ANTENNA FOR DIFFERENTIAL CONNECTION
RU2705937C1 (en) * 2019-03-19 2019-11-12 Федеральное государственное унитарное предприятие "Ростовский-на-Дону научно-исследовательский институт радиосвязи" (ФГУП "РНИИРС") Microstrip antenna
FR3101486B1 (en) 2019-09-27 2021-09-24 Office National Detudes Rech Aerospatiales MULTI-BAND ANTENNA
FR3108209B1 (en) * 2020-03-10 2022-02-25 Commissariat Energie Atomique Frequency reconfigurable monopolar wire-plate antenna
US12021319B2 (en) * 2022-04-19 2024-06-25 Meta Platforms Technologies, Llc Distributed monopole antenna for enhanced cross-body link

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3852760A (en) * 1973-08-07 1974-12-03 Us Army Electrically small dipolar antenna utilizing tuned lc members
US3967276A (en) * 1975-01-09 1976-06-29 Beam Guidance Inc. Antenna structures having reactance at free end
US4123758A (en) * 1976-02-27 1978-10-31 Sumitomo Electric Industries, Ltd. Disc antenna
US4575725A (en) * 1983-08-29 1986-03-11 Allied Corporation Double tuned, coupled microstrip antenna
FR2552938B1 (en) * 1983-10-04 1986-02-28 Dassault Electronique RADIANT DEVICE WITH IMPROVED MICRO-TAPE STRUCTURE AND APPLICATION TO AN ADAPTIVE ANTENNA
JPH0669122B2 (en) * 1984-08-01 1994-08-31 日本電信電話株式会社 Wideband transmission line antenna
JPS6171702A (en) * 1984-09-17 1986-04-12 Matsushita Electric Ind Co Ltd Small-sized antenna
CA1263745A (en) * 1985-12-03 1989-12-05 Nippon Telegraph & Telephone Corporation Shorted microstrip antenna
US4896162A (en) * 1987-03-16 1990-01-23 Hughes Aircraft Company Capacitance loaded monopole antenna
JPH02162804A (en) * 1988-12-16 1990-06-22 Nissan Motor Co Ltd Flat plate antenna
JPH0821812B2 (en) * 1988-12-27 1996-03-04 原田工業株式会社 Flat antenna for mobile communication
DE69015026T2 (en) * 1989-07-06 1995-05-18 Harada Ind Co Ltd Broadband antenna for mobile radiotelephone connections.
JP2870940B2 (en) * 1990-03-01 1999-03-17 株式会社豊田中央研究所 In-vehicle antenna
FR2668859B1 (en) * 1990-11-07 1993-02-19 Critt Eo DEVICE FOR GENERATING ELECTROMAGNETIC RADIATION USING A DOUBLE RESONANCE ANTENNA.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9507557A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1407512B1 (en) * 2001-06-18 2014-10-22 Centre National De La Recherche Scientifique (Cnrs) Antenna

Also Published As

Publication number Publication date
CN1059760C (en) 2000-12-20
FR2709878B1 (en) 1995-11-24
DE69411885T2 (en) 1999-04-29
JP3457672B2 (en) 2003-10-20
EP0667984B1 (en) 1998-07-22
CN1114518A (en) 1996-01-03
DE69411885D1 (en) 1998-08-27
JPH08503595A (en) 1996-04-16
AU7617994A (en) 1995-03-27
WO1995007557A1 (en) 1995-03-16
CA2148796C (en) 2004-07-13
FR2709878A1 (en) 1995-03-17
US6750825B1 (en) 2004-06-15
CA2148796A1 (en) 1995-03-16

Similar Documents

Publication Publication Date Title
EP0667984B1 (en) Monopolar wire-plate antenna
EP3547450B1 (en) Radiating element with circular polarisation implementing a resonance in a fabry-perot cavity
EP0013222B1 (en) Diode phase shifter for microwaves and electronic scanning antenna comprising same
EP1407512B1 (en) Antenna
EP0805512B1 (en) Compact printed antenna with little radiation in elevation
EP0205212B1 (en) Modular microwave antenna units and antenna composed of such units
EP0886889B1 (en) Wide band printed network antenna
EP1145379B1 (en) Antenna provided with an assembly of filtering materials
EP0145597B1 (en) Plane periodic antenna
WO2019034760A1 (en) Patch antenna having two different radiation modes with two separate working frequencies, device using such an antenna
EP3540853B1 (en) Antenna with broadband transmitter network
EP0661773A1 (en) Conically shaped microstrip patch antenna prepared on a planar substrate and method of its manufacturing
EP1540768B1 (en) Broadband helical antenna
EP2432072B1 (en) Wideband balun on a multilayer circuit for a network antenna
EP0477102B1 (en) Directional network with adjacent radiator elements for radio communication system and unit with such a directional network
EP0654845B1 (en) Adaptable dipole radiating element in printed circuit technology, method for adjustment of the adaptation and corresponding array
EP3942649B1 (en) Compact directional antenna, device comprising such an antenna
EP0088681B1 (en) Dual-reflector antenna with incorporated polarizer
EP0156684A1 (en) Microwave radiating element and its use in an electronically scanned array
FR2677493A1 (en) NETWORK OF RADIANT ELEMENTS WITH AUTOCOMPLEMENTARY TOPOLOGY, AND ANTENNA USING SUCH A NETWORK.
FR2668859A1 (en) Device for generating electromagnetic radiation employing a double-resonance antenna
FR2729011A1 (en) Dual polarisation antenna network
FR2544554A1 (en) Radiating element or receiver of left and right circularly polarised microwave signals and plane antenna comprising an array of such elements juxtaposed

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19950422

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE DK ES FR GB IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 19961007

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE DK ES FR GB IT LI LU MC NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19980722

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19980722

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REF Corresponds to:

Ref document number: 69411885

Country of ref document: DE

Date of ref document: 19980827

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980906

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19981022

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19981022

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19981021

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
BERE Be: lapsed

Owner name: UNIVERSITE DE LIMOGES

Effective date: 19980930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990331

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990531

26N No opposition filed
REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: MICHELI & CIE INGENIEURS-CONSEILS

REG Reference to a national code

Ref country code: CH

Ref legal event code: PUEA

Owner name: UNIVERSITE DE LIMOGES

Free format text: UNIVERSITE DE LIMOGES#123, RUE A. THOMAS#F-87060 LIMOGES CEDEX (FR) -TRANSFER TO- UNIVERSITE DE LIMOGES#123, RUE A. THOMAS#F-87060 LIMOGES CEDEX (FR) $ CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE#3, RUE MICHEL-ANGE#75794 PARIS CEDEX 16 (FR)

Ref country code: CH

Ref legal event code: PFA

Owner name: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE

Free format text: UNIVERSITE DE LIMOGES#123, RUE A. THOMAS#F-87060 LIMOGES CEDEX (FR) $ CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE#3, RUE MICHEL-ANGE#75794 PARIS CEDEX 16 (FR) -TRANSFER TO- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE#3, RUE MICHEL-ANGE#75794 PARIS CEDEX 16 (FR) $ UNIVERSITE DE LIMOGES#33, RUE FRANCOIS MITTERAND#87032 LIMOGES CEDEX 01 (FR)

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20130823

Year of fee payment: 20

Ref country code: DE

Payment date: 20130820

Year of fee payment: 20

Ref country code: CH

Payment date: 20130823

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20130823

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20130826

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69411885

Country of ref document: DE

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69411885

Country of ref document: DE

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20140905

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20140909

REG Reference to a national code

Ref country code: SE

Ref legal event code: EUG

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20140905