EP1801914A1 - Antenna and central locking system using the same - Google Patents

Antenna and central locking system using the same Download PDF

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Publication number
EP1801914A1
EP1801914A1 EP05360056A EP05360056A EP1801914A1 EP 1801914 A1 EP1801914 A1 EP 1801914A1 EP 05360056 A EP05360056 A EP 05360056A EP 05360056 A EP05360056 A EP 05360056A EP 1801914 A1 EP1801914 A1 EP 1801914A1
Authority
EP
European Patent Office
Prior art keywords
antenna
vehicle
receiver
antenna according
metal structure
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.)
Ceased
Application number
EP05360056A
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German (de)
French (fr)
Inventor
Jean-Matthieu Stricker
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.)
Delphi Technologies Inc
Original Assignee
Delphi Technologies Inc
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 Delphi Technologies Inc filed Critical Delphi Technologies Inc
Priority to EP05360056A priority Critical patent/EP1801914A1/en
Priority to US11/635,326 priority patent/US20070146217A1/en
Publication of EP1801914A1 publication Critical patent/EP1801914A1/en
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/32—Adaptation for use in or on road or rail vehicles
    • H01Q1/3208—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used
    • H01Q1/3233—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
    • H01Q1/3241—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems particular used in keyless entry systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/32—Vertical arrangement of element
    • H01Q9/36—Vertical arrangement of element with top loading

Definitions

  • the present invention relates to the general technical field of transmitting and / or receiving antennas used in particular in locking / unlocking systems of vehicle doors.
  • These locking / unlocking systems are already known and allow the user to lock and unlock the doors of a vehicle at a distance.
  • These operations are generally implemented by a receiver integrated in the vehicle and by an integrated transmitter for example in a vehicle key.
  • the present invention particularly relates to an antenna intended to be connected to a transmitter and / or receiver, thus constituting a fixed antenna of a locking / unlocking system.
  • Such an antenna captures an electromagnetic field and transforms it into an electrical signal transmitted to the receiver.
  • the latter is advantageously mounted on a printed circuit support.
  • the antenna is for example made of a conducting wire traversed by high frequency currents. It therefore constitutes a transition device between the guided propagation medium, namely a power line connected to a transmitter and / or a receiver, and a free propagation space, in this case air. This transition must be done with maximum efficiency. This assumes an impedance matching between the antenna and the free propagation space, and therefore the control of the impedance of the antenna.
  • the impedance of the antenna should be as high as possible for its real part, for example between a dozen ohms and a hundred or so ohms. The values of these impedances are indicative.
  • the real part of the impedance reflects the radiation resistance, representative of the gain of the antenna transforming the electromagnetic field into electrical power and vice versa.
  • the reactive part of this same impedance should be as low as possible, and preferably neither inductive (+ jX) nor capacitive (-jX).
  • the impedance of the antenna often has a capacitive portion, because of its reduced dimensions and / or because of its location in the vicinity of a ground plane. The latter is defined by the grouping of components and metal tracks reported on the printed circuit support. The performance of the assembly comprising the antenna and a receiver or an emitter may therefore not be optimal and the impedance matching may not be performed correctly.
  • the antenna according to the invention operates in stationary wave regime, meaning that the distribution of the electric current is not uniform over its length.
  • Stationary antennas are used in the frequency domain of the UHF band, centered around 434 MHz. The corresponding wavelength at such a frequency is about 70 cm.
  • a functional antenna is then related to the frequency, and therefore to the wavelength.
  • the antenna In such a standing wave regime, the antenna is in principle comparable to a quarter-wave line: this means that the optimal performances are obtained with an antenna length equal to or close to a quarter of the length of the antenna. wave, which corresponds in this case to approximately 17.5 cm. It is obviously impossible to integrate an antenna of such length in a known locking / unlocking system. The size of such an antenna is indeed too important, especially for implantation in a vehicle.
  • the known antennas preferably extend in the extension plane of the support of the printed circuit, in the vicinity and along the ground plane.
  • Current antennas are of the type comprising at least one conductive track attached to a printed circuit support, with a free end and a base intended to be connected to a receiver and / or transmitter.
  • the conductive antenna forming track is actually part of the printed circuit and can be performed by any known process, for example by screen printing. In known configurations, and so that the support of the printed circuit does not have too large dimensions, the antenna in its entirety is placed near the ground plane, hence the disadvantages mentioned.
  • the conductive track is doubled on the opposite faces of the printed circuit support.
  • the conductive tracks are then for example connected every 5 to 10 mm by metallized holes, and are located substantially at the same distance from the ground plane.
  • the locking / unlocking systems are activated and deactivated by means of a radio wave remote control which, for known systems, has a relatively limited range. Their range is generally not greater than a radius of about 6 meters around the vehicle. However, more and more vehicle manufacturers are demanding a maximum range of at least 20 meters around the vehicle, in order to achieve 100% system reliability within a 6-meter radius, regardless of the vehicle environment. The latter may for example be surrounded by other vehicles, trees, buildings or other obstacles that negatively influence the transmission of radio waves.
  • a possible improvement would be to use in the receiving circuit electronic components with increased performance.
  • the use of such components would have the effect of increasing the standby energy consumption of the locking / unlocking system, which is obviously not sought, as well as increasing the direct costs associated with the use of components. more efficient.
  • the radio signal emitted by the remote control propagates by reflection and diffraction through openings of the vehicle constituted by the windows, to arrive at a receiving antenna located for example behind the steering wheel.
  • a location of the receiving antenna inside the vehicle substantially decreases the maximum range of the remote control compared to a receiving antenna not confined in the vehicle.
  • the propagation through the panes is also attenuated by their structure: they are now often athermic and include for this purpose a metallization attenuating the radio signal passing through them.
  • One solution is to increase the power of the transmitter disposed in the key of the user. It is not advisable because such an increase in power means an increase in the size, which comes up against the reduced space available in such a key to house the transmitter and a suitable power supply battery.
  • the increase in power of such a transmitter also has the consequence of increasing the power consumption, and therefore the frequency of replacement of the batteries.
  • the range of a remote control device for locking and unlocking the doors also depends on the link budget between the transmitter and the receiver.
  • the link budget relates to the complete chain from the transmitter to the receiver. This balance takes into account the power of the transmitter and the sensitivity of the receiver, and also the losses and gains of each element of the chain, including the antenna.
  • the power is limited by the low voltage technology (from 3 to 6 volts), the energy autonomy of the power supply and the current that can be delivered by it.
  • the reduced dimensions of the transmitter most often the size of a key, limit the efficiency of the transmitting antenna.
  • the link budget also depends on the position of the transmitter key, the terrain, the propagation environment and the structure of the vehicle. The size of the windows of the vehicle, the constituent material of said windows (for example in their athermic version) and the position of the receiver in the vehicle finally also influence this balance.
  • the sensitivity of the torque constituted by the antenna and the receiver depends on the efficiency of the antenna as well as the technology of the receiver (of integrated circuit type). This technology has limitations related to energy consumption constraints, which must be as low as possible.
  • the amplification stage may also interfere with certain frequencies.
  • the amplification stage must optimally present a transfer function F between its input signal and its output signal which is linear.
  • the amplification stage in fact degrades the linearity performance at the input of the receiver.
  • the linearity defects result in polynomials of the second and / or third degree expressing said transfer function F. These polynomials generate parasitic frequencies that may interfere with the receiver's nominal channel, ie the usual operating frequency, in transmit / receive, of the antenna. This interference effect is a determining parameter for the receiver because it degrades the overall performance of the receiver.
  • the object of the present invention is to increase the overall reliability and efficiency of a remote locking / unlocking system by radiocommunications, primarily increasing its maximum range.
  • the objective is to obtain for example a maximum range greater than 20 m, as well as a theoretically infallible operation within a radius of 6 m around said vehicle, while not generating the additional disadvantages, for example mentioned above.
  • This extension for example orthogonal to the support, makes it possible to increase the length of the antenna, which thus approaches more than a quarter of the wavelength. It also promotes excitation by other directional components of the electromagnetic field constituting radiocommunications. Finally, this solution distances at least a portion of the antenna from the printed circuit support and from the ground plane. The efficiency of the antenna is thus improved, because the density of the field lines between the ground plane and the metal structure is lower for this portion than that existing between the ground plane and the conductive tracks.
  • the antenna of the invention operates much better in both transmit mode and receive mode. In transmission mode, it becomes possible to transfer data from the vehicle to a remote control carried by the user.
  • the antenna can also easily switch from a transmission mode to a reception mode in a specific frequency.
  • the two conductive tracks have substantially the same length.
  • the metal structure is then arranged approximately in the center of the antenna, positioning that allows to take maximum advantage of its performance.
  • the metal structure is in fact positioned where the distribution of current in the antenna is the highest.
  • a stiffening element may further be attached to the metal structure to improve automation.
  • the conductive strip may for example have a width of between 1 and 10 mm and a thickness of between 0.2 and 1 mm.
  • the metal structure may have a U-shape, with two legs whose free ends are connected to the tracks.
  • the stiffening element can then for example consist of a cross member, for example of synthetic material, connecting the two legs of the U-shape and to which it is fixed by fixing studs.
  • An automated mounting arm or installation can thus easily grasp said cross and position the metal structure accurately on the support of the printed circuit, for fixing purposes.
  • the antenna may comprise a so-called peak capacity at its free end.
  • This peak capacity gives the antenna characteristics in principle obtained with an antenna of greater length. This virtually increases the length of the antenna without substantially increasing its size.
  • the antenna can also include a localized inductance at its base, and which also increases its performance.
  • the base inductor again makes it possible to increase virtually the length of the antenna without substantially increasing its bulk. More specifically, the use of a base inductor allows on the one hand to increase the current flowing at the base of the antenna and on the other hand to provide an inductive component (+ jx) to the impedance of the antenna.
  • This inductive component (+ jx) makes it possible to partially compensate the intrinsic capacitive component (-jx) of the antenna impedance, and thus to improve the impedance matching between the antenna and the impedance of the antenna. receiver and / or transmitter input.
  • the antenna can of course simultaneously comprise a base inductance and a peak capacitance.
  • the invention also relates to a receiver or a transceiver provided with such an antenna. Finally, it covers a remote locking / unlocking system of the doors of a vehicle, comprising a mobile transmitting device carried by the user of the vehicle and a fixed receiver associated with an antenna as described previously, said fixed receiver being arranged to inside the vehicle.
  • the invention also relates to a remote locking / unlocking system of the doors of a vehicle comprising a mobile transceiver device carried by the user of the vehicle and a fixed transceiver associated with such an antenna, said transmitter-receiver fixed receiver being disposed inside the vehicle.
  • the user can, thanks to the invention, benefit from a more efficient search and location function for his vehicle in a crowded environment such as a parking lot.
  • Figure 1 shows an antenna according to the invention.
  • the antenna comprises two conductive tracks 1 and 2 reported for example by screen printing on a printed circuit support.
  • the tracks 1, 2 have a copper thickness of between 15 and 80 microns and the dielectric constant of the printed circuit support is for example between 3 and 10.
  • the conductive tracks 1, 2 may optionally be each disposed on one side of a printed circuit support, and connected by metallized holes every 5 mm.
  • the antenna of the invention further comprises a metal structure 3 connecting the two conductive tracks 1 and 2, actually making a bridge between them.
  • the metal structure 3 is for example in the form of a U, having two lateral legs 4 and 5 and a central branch or bottom 6. These are rigid conductive strips, for example having a width slightly greater than that tracks 1, 2 to facilitate the possible gripping of the U by automatic installation arms.
  • the antenna shown in FIGS. 2 and 4 comprises, at its free end 7, a charging capacitor 8.
  • This latter consists of a substantially rectangular coppered surface approximately 1.5 cm long and 1 cm wide.
  • This load capacity 8 reported on the support 1a partially makes it possible to overcome the small dimensions of the antenna by improving its performance without increasing its length, by increasing the electric current at the base of the antenna on the one hand, and the real part of its impedance on the other hand. The shortage of antenna length relative to a quarter of the wavelength is thus partially caught up.
  • the other end 9 of the conductive track 1 is intended to be connected for example to a receiver 10. This end 9 thus constitutes the base of the antenna.
  • FIG. 2 shows a ground plane 11 separated from the peak capacitor 8, in particular by the material constituting the support 1 a.
  • the latter has dielectric characteristics such as to increase the density of the field lines between the antenna, and in particular the peak capacitance 8, and the ground plane 11, thus reducing the efficiency and the efficiency of the antenna.
  • holes 13 with a diameter of between 3 and 4 mm have been formed in the support 1a around the crown capacity 8, and more generally around the last third of the antenna length. This gives an improvement of about 10 to 15% of the scope of the latter.
  • the overall length L of the antenna can, in each embodiment illustrated, be less than a quarter of the wavelength resulting from the frequency used.
  • Another improvement of the antenna may consist in adding to its base 9 an inductor 14 at or near the point of connection to the receiver 10.
  • This inductor 14 also increases the performance of the antenna according to the invention, without increasing its length and / or its size.
  • the metal structure 3 makes it possible to increase the distance between part of the antenna and the ground plane 11 on the one hand and to increase the length of the antenna on the other hand. It extends in a plane perpendicular to the plane of the support 1a, and practically doubles the range between the mobile transmitter and the fixed receiver placed in the vehicle.
  • FIGS. 2 and 3 make it possible to emphasize and verify the actual contribution of the metal structure 3, which leads to a reduction in the value of the inductance 14 at the base of the antenna (this for example, from 39nH to 27nH). This decrease results from a modification of the distribution of the electric current in the antenna, and more precisely of an increase of the current at the base of the antenna.
  • a measurement of the impedance of the antenna shows that the real part of the impedance has practically doubled thanks to the use of the metal structure 3.
  • FIGS. 4 and 5 show alternative configurations of the invention.
  • FIG. 6 represents a printed circuit support 1 a on which various components have been reported, and in particular an antenna according to the invention.
  • the receiver is in this case surrounded by a metal protective cage 10a.
  • the metal structure 3 comprises in this figure a stiffening arm 15 of synthetic material.
  • the latter comprises at its ends fixing studs 15a for gripping the legs 4 and 5 of the metal structure 3.
  • the metal structure 3 is then rigid enough to be manipulated, moved and positioned on the support 1a via an automated arm.
  • the metal structure 3 can thus be attached to the support 1a in the same way as various other electronic components implanted on the printed circuit. These components can perform functions related or not to the locking / unlocking system.

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  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Lock And Its Accessories (AREA)

Abstract

The antenna has conductive tracks (1, 2) attached to a printed circuit support, extending between a base connected to a receiver and/or transmitter and a free end. A metal structure (3) is attached to the support, where the structure is a rigid metallic strip. The metal structure forms a bridge between proximal ends of the conductive tracks, and extends partially projecting from the plane of extension of the support.

Description

La présente invention se rapporte au domaine technique général des antennes d'émission et/ou de réception utilisées notamment dans des systèmes de verrouillage / déverrouillage de portes d'un véhicule. Ces systèmes de verrouillage / déverrouillage sont déjà connus et permettent à l'utilisateur de verrouiller et de déverrouiller les portes d'un véhicule à distance. Ces opérations sont en général mises en oeuvre par un récepteur intégré dans le véhicule et par un émetteur intégré par exemple dans une clé du véhicule.The present invention relates to the general technical field of transmitting and / or receiving antennas used in particular in locking / unlocking systems of vehicle doors. These locking / unlocking systems are already known and allow the user to lock and unlock the doors of a vehicle at a distance. These operations are generally implemented by a receiver integrated in the vehicle and by an integrated transmitter for example in a vehicle key.

La présente invention concerne notamment une antenne destinée à être reliée à un émetteur et/ou récepteur, constituant ainsi une antenne fixe d'un système de verrouillage / déverrouillage. Une telle antenne capte un champ électromagnétique et le transforme en un signal électrique transmis au récepteur. Ce dernier est avantageusement monté sur un support de circuit imprimé. L'antenne est par exemple constituée d'un fil conducteur parcouru par des courants à hautes fréquences. Elle constitue dès lors un dispositif de transition entre le milieu de propagation guidé, à savoir une ligne d'alimentation reliée à un émetteur et/ou un récepteur, et un espace de propagation libre, en l'occurrence l'air. Cette transition doit être effectuée avec un maximum de rendement. Ceci suppose une adaptation d'impédance entre l'antenne et l'espace de propagation libre, et par conséquent la maîtrise de l'impédance de l'antenne.The present invention particularly relates to an antenna intended to be connected to a transmitter and / or receiver, thus constituting a fixed antenna of a locking / unlocking system. Such an antenna captures an electromagnetic field and transforms it into an electrical signal transmitted to the receiver. The latter is advantageously mounted on a printed circuit support. The antenna is for example made of a conducting wire traversed by high frequency currents. It therefore constitutes a transition device between the guided propagation medium, namely a power line connected to a transmitter and / or a receiver, and a free propagation space, in this case air. This transition must be done with maximum efficiency. This assumes an impedance matching between the antenna and the free propagation space, and therefore the control of the impedance of the antenna.

L'impédance de l'antenne devra être aussi élevée que possible pour sa partie réelle, par exemple comprise entre une dizaine d'Ohms et une centaine d'Ohms environ. Les valeurs de ces impédances sont indicatives. La partie réelle de l'impédance traduit la résistance de rayonnement, représentative du gain de l'antenne transformant le champ électromagnétique en puissance électrique et inversement. La partie réactive de cette même impédance devra être aussi faible que possible, et de préférence ni inductive (+jX), ni capacitive (-jX). Or, dans la pratique, l'impédance de l'antenne présente souvent une partie capacitive, du fait de ses dimensions réduites et/ou du fait de sa localisation au voisinage d'un plan de masse. Ce dernier est défini par le groupement des composants et pistes métalliques rapportés sur le support de circuit imprimé. Les performances de l'ensemble comprenant l'antenne et un récepteur ou un émetteur peuvent donc ne pas être optimales et l'adaptation d'impédance n'être pas réalisée de manière correcte.The impedance of the antenna should be as high as possible for its real part, for example between a dozen ohms and a hundred or so ohms. The values of these impedances are indicative. The real part of the impedance reflects the radiation resistance, representative of the gain of the antenna transforming the electromagnetic field into electrical power and vice versa. The reactive part of this same impedance should be as low as possible, and preferably neither inductive (+ jX) nor capacitive (-jX). However, in practice, the impedance of the antenna often has a capacitive portion, because of its reduced dimensions and / or because of its location in the vicinity of a ground plane. The latter is defined by the grouping of components and metal tracks reported on the printed circuit support. The performance of the assembly comprising the antenna and a receiver or an emitter may therefore not be optimal and the impedance matching may not be performed correctly.

L'antenne conforme à l'invention fonctionne en régime d'ondes stationnaires, signifiant que la répartition du courant électrique n'est pas uniforme sur sa longueur. Les antennes stationnaires sont utilisées dans le domaine de fréquence de la bande UHF, centrée autour de 434 MHz. La longueur d'onde correspondante à une telle fréquence est d'environ 70 cm.The antenna according to the invention operates in stationary wave regime, meaning that the distribution of the electric current is not uniform over its length. Stationary antennas are used in the frequency domain of the UHF band, centered around 434 MHz. The corresponding wavelength at such a frequency is about 70 cm.

Les dimensions d'une antenne fonctionnelle sont ensuite liées à la fréquence, et par conséquent à la longueur d'onde. Dans un tel régime d'ondes stationnaires, l'antenne est en principe assimilable à une ligne quart d'onde : cela signifie que les performances optimales sont obtenues avec une longueur d'antenne égale ou s'approchant du quart de la longueur d'onde, ce qui correspond dans le présent cas d'espèce à environ 17,5 cm. Il est évidemment impossible d'intégrer une antenne d'une telle longueur dans un système de verrouillage / déverrouillage connu. L'encombrement d'une telle antenne est en effet trop important, en particulier pour une implantation dans un véhicule.The dimensions of a functional antenna are then related to the frequency, and therefore to the wavelength. In such a standing wave regime, the antenna is in principle comparable to a quarter-wave line: this means that the optimal performances are obtained with an antenna length equal to or close to a quarter of the length of the antenna. wave, which corresponds in this case to approximately 17.5 cm. It is obviously impossible to integrate an antenna of such length in a known locking / unlocking system. The size of such an antenna is indeed too important, especially for implantation in a vehicle.

Afin de réduire l'encombrement de l'antenne sans diminuer de façon trop importante sa longueur, les antennes connues s'étendent de préférence dans le plan d'extension du support du circuit imprimé, au voisinage et le long du plan de masse.In order to reduce the size of the antenna without significantly reducing its length, the known antennas preferably extend in the extension plane of the support of the printed circuit, in the vicinity and along the ground plane.

Dans ce cas, pour augmenter le rayonnement de l'antenne, c'est-à-dire son efficacité, il est souhaitable de réduire la densité des lignes de champ entre l'antenne et le plan de masse. Or, cette densité est augmentée du fait du caractère diélectrique du support de circuit imprimé séparant le plan de masse de l'antenne, et d'autre part par la localisation de celle-ci dans le plan du support.In this case, to increase the radiation of the antenna, that is to say its efficiency, it is desirable to reduce the density of the field lines between the antenna and the ground plane. However, this density is increased because of the dielectric character of the printed circuit support separating the ground plane of the antenna, and secondly by the location thereof in the plane of the support.

Les antennes actuelles sont du type comportant au moins une piste conductrice rapportée sur un support de circuit imprimé, avec une extrémité libre et une base destinée à être connectée à un récepteur et/ou émetteur.Current antennas are of the type comprising at least one conductive track attached to a printed circuit support, with a free end and a base intended to be connected to a receiver and / or transmitter.

La piste conductrice formant antenne fait en réalité partie du circuit imprimé et peut être réalisée par tout processus connu, par exemple par sérigraphie. Dans les configurations connues, et afin que le support du circuit imprimé n'ait pas des dimensions trop importantes, l'antenne dans sa totalité est placée à proximité du plan de masse, d'où les inconvénients mentionnés.The conductive antenna forming track is actually part of the printed circuit and can be performed by any known process, for example by screen printing. In known configurations, and so that the support of the printed circuit does not have too large dimensions, the antenna in its entirety is placed near the ground plane, hence the disadvantages mentioned.

C'est le cas également des configurations dans lesquelles, afin de pallier au problème des pertes par conduction, la piste conductrice est doublée sur les faces opposées du support du circuit imprimé. Les pistes conductrices sont alors par exemple reliées tous les 5 à 10mm par des trous métallisés, et sont localisées sensiblement à la même distance du plan de masse.This is also the case for configurations in which, in order to overcome the problem of conductive losses, the conductive track is doubled on the opposite faces of the printed circuit support. The conductive tracks are then for example connected every 5 to 10 mm by metallized holes, and are located substantially at the same distance from the ground plane.

Les systèmes de verrouillage / déverrouillage connus présentent donc des inconvénients se traduisant par une efficacité et une fiabilité réduites, en particulier lorsque l'utilisateur souhaitant activer ou désactiver le système de verrouillage / déverrouillage ne se trouve pas à proximité immédiate dudit véhicule.Known locking / unlocking systems therefore have drawbacks resulting in reduced efficiency and reliability, especially when the user wishing to activate or deactivate the locking / unlocking system is not in the immediate vicinity of said vehicle.

Les systèmes de verrouillage / déverrouillage sont activés et désactivés par l'intermédiaire d'une télécommande à ondes radio qui présente, pour les systèmes connus, une portée relativement limitée. Leur portée n'est en général pas supérieure à un rayon d'environ 6 mètres autour du véhicule. Or, les constructeurs de véhicules sont de plus en plus nombreux à exiger une portée maximale d'au moins 20 mètres autour du véhicule, de manière à obtenir une fiabilité de fonctionnement à 100 % du système dans un rayon de 6 mètres, quel que soit l'environnement du véhicule. Ce dernier peut par exemple être entouré d'autres véhicules, d'arbres, de bâtiments ou d'autres obstacles influençant de façon négative la transmission d'ondes radio.The locking / unlocking systems are activated and deactivated by means of a radio wave remote control which, for known systems, has a relatively limited range. Their range is generally not greater than a radius of about 6 meters around the vehicle. However, more and more vehicle manufacturers are demanding a maximum range of at least 20 meters around the vehicle, in order to achieve 100% system reliability within a 6-meter radius, regardless of the vehicle environment. The latter may for example be surrounded by other vehicles, trees, buildings or other obstacles that negatively influence the transmission of radio waves.

Une amélioration envisageable serait d'utiliser dans le circuit de réception des composants électroniques présentant des performances accrues. L'utilisation de tels composants aurait cependant pour conséquence d'augmenter la consommation d'énergie en veille du système verrouillage / déverrouillage, ce qui n'est évidemment pas recherché, ainsi que d'augmenter les coûts directs liés à l'utilisation de composants plus performants.A possible improvement would be to use in the receiving circuit electronic components with increased performance. The use of such components, however, would have the effect of increasing the standby energy consumption of the locking / unlocking system, which is obviously not sought, as well as increasing the direct costs associated with the use of components. more efficient.

Le signal radio émis par la télécommande se propage par réflexion et par diffraction jusqu'au travers d'ouvertures du véhicule constituées par les vitres, pour arriver à une antenne réceptrice localisée par exemple derrière le volant. Une telle localisation de l'antenne réceptrice à l'intérieur du véhicule diminue substantiellement la portée maximale de la télécommande par comparaison avec une antenne réceptrice non confinée dans le véhicule.The radio signal emitted by the remote control propagates by reflection and diffraction through openings of the vehicle constituted by the windows, to arrive at a receiving antenna located for example behind the steering wheel. Such a location of the receiving antenna inside the vehicle substantially decreases the maximum range of the remote control compared to a receiving antenna not confined in the vehicle.

La propagation au travers des vitres est également atténuée par leur structure : elles sont à présent souvent athermiques et comportent à cet effet une métallisation atténuant le signal radio les traversant.The propagation through the panes is also attenuated by their structure: they are now often athermic and include for this purpose a metallization attenuating the radio signal passing through them.

Une solution consiste à augmenter la puissance de l'émetteur disposé dans la clé de l'utilisateur. Elle n'est pas judicieuse car une telle augmentation de puissance signifie une augmentation de l'encombrement, laquelle se heurte à l'espace réduit disponible dans une telle clé pour y loger l'émetteur et une pile d'alimentation électrique adéquate. L'augmentation de puissance d'un tel émetteur a de plus pour conséquence d'augmenter la consommation d'énergie électrique, et par conséquent la fréquence de remplacement des piles.One solution is to increase the power of the transmitter disposed in the key of the user. It is not advisable because such an increase in power means an increase in the size, which comes up against the reduced space available in such a key to house the transmitter and a suitable power supply battery. The increase in power of such a transmitter also has the consequence of increasing the power consumption, and therefore the frequency of replacement of the batteries.

La portée d'un dispositif de commande à distance pour le verrouillage et le déverrouillage des portes dépend également du bilan de liaison entre l'émetteur et le récepteur. Le bilan de liaison concerne la chaîne complète allant de l'émetteur au récepteur. Ce bilan prend en compte la puissance de l'émetteur et la sensibilité du récepteur, et également les pertes et gains de chaque élément de la chaîne, y compris l'antenne.The range of a remote control device for locking and unlocking the doors also depends on the link budget between the transmitter and the receiver. The link budget relates to the complete chain from the transmitter to the receiver. This balance takes into account the power of the transmitter and the sensitivity of the receiver, and also the losses and gains of each element of the chain, including the antenna.

Du côté de l'émetteur, la puissance est limitée par la technologie basse tension (de 3 à 6 volts), l'autonomie d'énergie de la pile d'alimentation et le courant délivrable par celle-ci. Ainsi, les dimensions réduites de l'émetteur, le plus souvent de la taille d'une clé, limitent l'efficacité de l'antenne d'émission. Le bilan de liaison dépend également de la position de la clé émettrice, du terrain, de l'environnement de propagation et de la structure du véhicule. La taille des vitres du véhicule, le matériau constitutif desdites vitres (par exemple dans leur version athermique) et la position du récepteur dans le véhicule influencent enfin également ce bilan.On the transmitter side, the power is limited by the low voltage technology (from 3 to 6 volts), the energy autonomy of the power supply and the current that can be delivered by it. Thus, the reduced dimensions of the transmitter, most often the size of a key, limit the efficiency of the transmitting antenna. The link budget also depends on the position of the transmitter key, the terrain, the propagation environment and the structure of the vehicle. The size of the windows of the vehicle, the constituent material of said windows (for example in their athermic version) and the position of the receiver in the vehicle finally also influence this balance.

La sensibilité du couple constitué par l'antenne et le récepteur dépend du rendement de l'antenne ainsi que de la technologie du récepteur (de type circuit intégré). Cette technologie présente des limitations liées à des contraintes de consommation d'énergie, qui doivent être les plus faibles possible.The sensitivity of the torque constituted by the antenna and the receiver depends on the efficiency of the antenna as well as the technology of the receiver (of integrated circuit type). This technology has limitations related to energy consumption constraints, which must be as low as possible.

Il est possible d'intercaler un étage d'amplification à faible bruit entre l'antenne et le circuit de réception, mais au détriment de la consommation d'énergie.It is possible to insert a low noise amplification stage between the antenna and the reception circuit, but at the expense of the energy consumption.

L'étage d'amplification risque également de brouiller certaines fréquences. L'étage d'amplification doit optimalement présenter une fonction de transfert F entre son signal d'entrée et son signal de sortie qui est linéaire. Or, l'étage d'amplification dégrade en réalité les performances de linéarité à l'entrée du récepteur. Les défauts de linéarité se traduisent par des polynômes du deuxième et/ou du troisième degré exprimant ladite fonction de transfert F. Ces polynômes génèrent des fréquences parasites qui peuvent interférer avec le canal nominal du récepteur, c'est-à-dire la fréquence de fonctionnement habituelle, en émission/réception, de l'antenne. Cet effet d'interférence est un paramètre déterminant pour le récepteur, car il dégrade les performances globales du récepteur.The amplification stage may also interfere with certain frequencies. The amplification stage must optimally present a transfer function F between its input signal and its output signal which is linear. However, the amplification stage in fact degrades the linearity performance at the input of the receiver. The linearity defects result in polynomials of the second and / or third degree expressing said transfer function F. These polynomials generate parasitic frequencies that may interfere with the receiver's nominal channel, ie the usual operating frequency, in transmit / receive, of the antenna. This interference effect is a determining parameter for the receiver because it degrades the overall performance of the receiver.

Il est donc difficile d'augmenter substantiellement la portée d'un système de verrouillage / déverrouillage à distance d'un véhicule sans influer négativement sur un certain nombre de paramètres et générer une altération de l'efficacité ou une augmentation des coûts d'un tel système.It is therefore difficult to substantially increase the range of a remote locking / unlocking system of a vehicle without adversely affecting a number of parameters and to generate an alteration of the efficiency or an increase in the costs of such a system. system.

Le but de la présente invention est d'augmenter la fiabilité et l'efficacité globales d'un système de verrouillage / déverrouillage à distance par radiocommunications, en augmentant à titre principal sa portée maximale.The object of the present invention is to increase the overall reliability and efficiency of a remote locking / unlocking system by radiocommunications, primarily increasing its maximum range.

L'objectif est d'obtenir par exemple une portée maximale supérieure à 20 m, ainsi qu'un fonctionnement théoriquement infaillible dans un rayon de 6 m autour dudit véhicule, tout en ne générant pas les inconvénients supplémentaires par exemple mentionnés ci-dessus.The objective is to obtain for example a maximum range greater than 20 m, as well as a theoretically infallible operation within a radius of 6 m around said vehicle, while not generating the additional disadvantages, for example mentioned above.

Selon l'invention, pour remplir ces objectifs, l'antenne comporte classiquement au moins une piste conductrice rapportée sur un support de circuit imprimé, s'étendant entre une base destinée à être connectée à un récepteur et/ou émetteur et une extrémité libre, et elle se caractérise à titre principal en ce qu'elle comprend :

  • deux pistes conductrices disjointes et s'étendant dans le prolongement l'une de l'autre ,
  • ainsi qu'une structure métallique rapportée sur le support de circuit imprimé et réalisant un pontage entre les extrémités proximales des deux pistes conductrices, la structure métallique s'étendant au moins en partie en saillie du plan d'extension du support.
According to the invention, to fulfill these objectives, the antenna conventionally comprises at least one conductive track attached to a printed circuit support, extending between a base intended to be connected to a receiver and / or transmitter and a free end, and it is mainly characterized in that it includes:
  • two conductive tracks disjoined and extending in the extension of one another,
  • and a metal structure attached to the printed circuit support and bridging between the proximal ends of the two conductive tracks, the metal structure extending at least in part projecting from the extension plane of the support.

Cette extension, par exemple orthogonale par rapport au support, permet d'augmenter la longueur de l'antenne, laquelle s'approche ainsi davantage d'un quart de la longueur d'onde. Elle favorise en outre l'excitation par d'autres composantes directionnelles du champ électromagnétique constitutif des radiocommunications. Enfin, cette solution éloigne au moins une portion de l'antenne du support de circuit imprimé et du plan de masse. L'efficacité de l'antenne se trouve donc améliorée, car la densité des lignes de champ entre le plan de masse et la structure métallique est plus faible pour cette portion que celle existant entre le plan de masse et les pistes conductrices.This extension, for example orthogonal to the support, makes it possible to increase the length of the antenna, which thus approaches more than a quarter of the wavelength. It also promotes excitation by other directional components of the electromagnetic field constituting radiocommunications. Finally, this solution distances at least a portion of the antenna from the printed circuit support and from the ground plane. The efficiency of the antenna is thus improved, because the density of the field lines between the ground plane and the metal structure is lower for this portion than that existing between the ground plane and the conductive tracks.

L'antenne de l'invention fonctionne alors bien mieux autant dans le mode émission que dans le mode réception. En mode émission, il devient envisageable de transférer des données à partir du véhicule vers une télécommande portée par l'utilisateur. L'antenne peut d'ailleurs facilement passer d'un mode émission à un mode réception dans une fréquence déterminée.The antenna of the invention operates much better in both transmit mode and receive mode. In transmission mode, it becomes possible to transfer data from the vehicle to a remote control carried by the user. The antenna can also easily switch from a transmission mode to a reception mode in a specific frequency.

Selon une possibilité, les deux pistes conductrices présentent sensiblement la même longueur. La structure métallique est alors disposée approximativement au centre de l'antenne, positionnement qui permet de profiter au maximum de son rendement. La structure métallique est en effet alors positionnée là où la distribution de courant dans l'antenne est la plus élevée.According to one possibility, the two conductive tracks have substantially the same length. The metal structure is then arranged approximately in the center of the antenna, positioning that allows to take maximum advantage of its performance. The metal structure is in fact positioned where the distribution of current in the antenna is the highest.

Elle peut être constituée d'une bande conductrice rigide, susceptible dans ce cas d'être rapportée de façon automatisée sur le support de circuit imprimé pour réaliser la liaison entre les deux pistes conductrices adjacentes. Un élément de rigidification peut en outre être fixé sur la structure métallique en vue d'améliorer l'automatisation .It may consist of a rigid conductive strip, capable in this case to be reported automatically on the printed circuit support to achieve the connection between the two adjacent conductive tracks. A stiffening element may further be attached to the metal structure to improve automation.

La bande conductrice peut par exemple présenter une largeur comprise entre 1 et 10 mm et une épaisseur comprise entre 0.2 et 1 mm.The conductive strip may for example have a width of between 1 and 10 mm and a thickness of between 0.2 and 1 mm.

Selon un exemple de configuration, la structure métallique peut présenter une forme en U, comportant deux jambages dont les extrémités libres sont connectées aux pistes.According to an exemplary configuration, the metal structure may have a U-shape, with two legs whose free ends are connected to the tracks.

L'élément de rigidification peut alors par exemple consister en une traverse, par exemple en matière synthétique, reliant les deux jambages de la forme en U et auxquels elle est fixée par des plots de fixation. Un bras de montage ou de pose automatisé peut ainsi saisir facilement ladite traverse et positionner la structure métallique de façon précise sur le support du circuit imprimé, à des fins de fixation.The stiffening element can then for example consist of a cross member, for example of synthetic material, connecting the two legs of the U-shape and to which it is fixed by fixing studs. An automated mounting arm or installation can thus easily grasp said cross and position the metal structure accurately on the support of the printed circuit, for fixing purposes.

Selon un exemple de réalisation, l'antenne peut comporter une capacité dite de sommet à son extrémité libre. Cette capacité de sommet confère à l'antenne des caractéristiques en principe obtenues avec une antenne de plus grande longueur. On augmente donc virtuellement la longueur de l'antenne sans augmenter substantiellement son encombrement.According to an exemplary embodiment, the antenna may comprise a so-called peak capacity at its free end. This peak capacity gives the antenna characteristics in principle obtained with an antenna of greater length. This virtually increases the length of the antenna without substantially increasing its size.

L'antenne peut par ailleurs également comporter une inductance localisée à sa base, et qui augmente aussi ses performances. L'inductance de base permet à nouveau d'augmenter virtuellement la longueur de l'antenne sans augmenter substantiellement son encombrement. Plus précisément, l'utilisation d'une inductance de base permet d'une part d'augmenter le courant circulant à la base de l'antenne et d'autre part d'apporter une composante inductive (+jx) à l'impédance de l'antenne.The antenna can also include a localized inductance at its base, and which also increases its performance. The base inductor again makes it possible to increase virtually the length of the antenna without substantially increasing its bulk. More specifically, the use of a base inductor allows on the one hand to increase the current flowing at the base of the antenna and on the other hand to provide an inductive component (+ jx) to the impedance of the antenna.

Cette composante inductive (+jx) permet de compenser en partie la composante capacitive (-jx) intrinsèque de l'impédance de l'antenne, et donc d'améliorer l'adaptation d'impédance entre l'antenne et l'impédance d'entrée du récepteur et/ou de l'émetteur.This inductive component (+ jx) makes it possible to partially compensate the intrinsic capacitive component (-jx) of the antenna impedance, and thus to improve the impedance matching between the antenna and the impedance of the antenna. receiver and / or transmitter input.

L'antenne peut bien entendu comporter simultanément une inductance de base et une capacité de sommet.The antenna can of course simultaneously comprise a base inductance and a peak capacitance.

L'invention concerne également un récepteur ou un émetteur-récepteur muni d'une telle antenne. Enfin, elle couvre un système de verrouillage / déverrouillage à distance des portes d'un véhicule, comprenant un dispositif émetteur mobile porté par l'utilisateur du véhicule et un récepteur fixe associé à une antenne telle que décrite auparavant, ledit récepteur fixe étant disposé à l'intérieur du véhicule.The invention also relates to a receiver or a transceiver provided with such an antenna. Finally, it covers a remote locking / unlocking system of the doors of a vehicle, comprising a mobile transmitting device carried by the user of the vehicle and a fixed receiver associated with an antenna as described previously, said fixed receiver being arranged to inside the vehicle.

Alternativement, l'invention concerne encore un système de verrouillage / déverrouillage à distance des portes d'un véhicule comprenant un dispositif émetteur-récepteur mobile porté par l'utilisateur du véhicule et un émetteur-récepteur fixe associé à une telle antenne, ledit émetteur-récepteur fixe étant disposé à l'intérieur du véhicule.Alternatively, the invention also relates to a remote locking / unlocking system of the doors of a vehicle comprising a mobile transceiver device carried by the user of the vehicle and a fixed transceiver associated with such an antenna, said transmitter-receiver fixed receiver being disposed inside the vehicle.

Outre le verrouillage / déverrouillage, l'utilisateur peut grâce à l'invention bénéficier d'une fonction plus efficace de recherche et de localisation de son véhicule dans un environnement encombré tel qu'un parking.In addition to locking / unlocking, the user can, thanks to the invention, benefit from a more efficient search and location function for his vehicle in a crowded environment such as a parking lot.

D'autres caractéristiques et avantages de l'invention ressortiront également de la description détaillée figurant ci-après, en référence aux dessins annexés, dans lesquels :

  • la figure 1 est une vue schématique en perspective d'un exemple de réalisation d'une antenne conforme à l'invention ;
  • les figures 2, 3, 4 et 5 représentent schématiquement des exemples de réalisation d'un récepteur associé à une antenne conforme à l'invention ;
  • la figure 6 est un exemple de réalisation d'intégration d'une antenne conforme à l'invention sur un support de circuit imprimé.
Other characteristics and advantages of the invention will also emerge from the detailed description given below, with reference to the appended drawings, in which:
  • Figure 1 is a schematic perspective view of an exemplary embodiment of an antenna according to the invention;
  • Figures 2, 3, 4 and 5 show schematically embodiments of a receiver associated with an antenna according to the invention;
  • Figure 6 is an exemplary embodiment of integration of an antenna according to the invention on a printed circuit support.

La figure 1 représente une antenne conforme à l'invention. L'antenne comporte deux pistes conductrices 1 et 2 rapportées par exemple par sérigraphie sur un support de circuit imprimé. Les pistes 1, 2 présentent une épaisseur de cuivre comprise entre 15 et 80 µm et la constante diélectrique du support du circuit imprimé est par exemple comprise entre 3 et 10.Figure 1 shows an antenna according to the invention. The antenna comprises two conductive tracks 1 and 2 reported for example by screen printing on a printed circuit support. The tracks 1, 2 have a copper thickness of between 15 and 80 microns and the dielectric constant of the printed circuit support is for example between 3 and 10.

Selon un exemple de réalisation non représenté, les pistes conductrices 1, 2 peuvent le cas échéant être disposées chacune sur une des faces d'un support de circuit imprimé, et reliées par des trous métallisés tous les 5 mm.According to an embodiment not shown, the conductive tracks 1, 2 may optionally be each disposed on one side of a printed circuit support, and connected by metallized holes every 5 mm.

L'antenne de l'invention comporte par ailleurs une structure métallique 3 reliant les deux pistes conductrices 1 et 2, réalisant en fait un pontage entre ces dernières. La structure métallique 3 se présente par exemple sous forme d'un U, comportant deux jambages latéraux 4 et 5 ainsi qu'une branche centrale ou fond 6. Il s'agit de bandes conductrices rigides, présentant par exemple une largeur légèrement supérieure à celle des pistes 1, 2 pour faciliter la préhension éventuelle du U par des bras de pose automatique.The antenna of the invention further comprises a metal structure 3 connecting the two conductive tracks 1 and 2, actually making a bridge between them. The metal structure 3 is for example in the form of a U, having two lateral legs 4 and 5 and a central branch or bottom 6. These are rigid conductive strips, for example having a width slightly greater than that tracks 1, 2 to facilitate the possible gripping of the U by automatic installation arms.

L'antenne représentée aux figures 2 et 4 comporte, à son extrémité libre 7, une capacité de charge 8. Cette dernière est constituée d'une surface cuivrée sensiblement rectangulaire d'environ 1,5 cm de long et 1 cm de large. Cette capacité de charge 8, rapportée sur le support 1a, permet en partie de pallier les faibles dimensions de l'antenne en améliorant ses performances sans augmenter sa longueur, par accroissement du courant électrique à la base de l'antenne d'une part, et de la partie réelle de son impédance d'autre part. Le déficit de longueur de l'antenne par rapport au quart de la longueur d'onde est ainsi partiellement rattrapé.The antenna shown in FIGS. 2 and 4 comprises, at its free end 7, a charging capacitor 8. This latter consists of a substantially rectangular coppered surface approximately 1.5 cm long and 1 cm wide. This load capacity 8, reported on the support 1a, partially makes it possible to overcome the small dimensions of the antenna by improving its performance without increasing its length, by increasing the electric current at the base of the antenna on the one hand, and the real part of its impedance on the other hand. The shortage of antenna length relative to a quarter of the wavelength is thus partially caught up.

L'autre extrémité 9 de la piste conductrice 1 est destinée à être connectée par exemple à un récepteur 10. Cette extrémité 9 constitue ainsi la base de l'antenne.The other end 9 of the conductive track 1 is intended to be connected for example to a receiver 10. This end 9 thus constitutes the base of the antenna.

La figure 2, par exemple, montre un plan de masse 11 séparé de la capacité de sommet 8 notamment par la matière constitutive du support 1 a. Ce dernier présente des caractéristiques diélectriques de nature à augmenter la densité des lignes de champ entre l'antenne, et notamment la capacité de sommet 8, et le plan de masse 11, réduisant ainsi l'efficacité et le rendement de l'antenne.FIG. 2, for example, shows a ground plane 11 separated from the peak capacitor 8, in particular by the material constituting the support 1 a. The latter has dielectric characteristics such as to increase the density of the field lines between the antenna, and in particular the peak capacitance 8, and the ground plane 11, thus reducing the efficiency and the efficiency of the antenna.

Afin de pallier ce problème, des trous 13 de diamètre compris entre 3 et 4 mm ont été ménagés dans le support 1 a autour de la capacité de sommet 8, et plus généralement autour du dernier tiers de longueur de l'antenne. On obtient ainsi une amélioration d'environ 10 à 15 % de la portée de celle-ci.To overcome this problem, holes 13 with a diameter of between 3 and 4 mm have been formed in the support 1a around the crown capacity 8, and more generally around the last third of the antenna length. This gives an improvement of about 10 to 15% of the scope of the latter.

Du fait des améliorations apportées, la longueur L globale de l'antenne peut, dans chaque exemple de réalisation illustré, être inférieure au quart de la longueur d'onde résultant de la fréquence utilisée.Because of the improvements made, the overall length L of the antenna can, in each embodiment illustrated, be less than a quarter of the wavelength resulting from the frequency used.

Une autre amélioration de l'antenne peut consister à ajouter à sa base 9 une inductance 14 au point ou au voisinage du point de connexion au récepteur 10. Cette inductance 14 augmente aussi les performances de l'antenne conforme à l'invention, sans augmenter sa longueur et/ou son encombrement.Another improvement of the antenna may consist in adding to its base 9 an inductor 14 at or near the point of connection to the receiver 10. This inductor 14 also increases the performance of the antenna according to the invention, without increasing its length and / or its size.

La structure métallique 3 permet en fait d'augmenter la distance entre une partie de l'antenne et le plan de masse 11 d'une part et d'augmenter la longueur de l'antenne d'autre part. Elle s'étend dans un plan perpendiculaire au plan du support 1 a, et permet pratiquement de doubler la portée entre l'émetteur mobile et le récepteur fixe placé dans le véhicule.The metal structure 3 makes it possible to increase the distance between part of the antenna and the ground plane 11 on the one hand and to increase the length of the antenna on the other hand. It extends in a plane perpendicular to the plane of the support 1a, and practically doubles the range between the mobile transmitter and the fixed receiver placed in the vehicle.

L'exemple de réalisation représenté aux figures 2 et 3 permet de souligner et de vérifier l'apport réel de la structure métallique 3, qui conduit à une diminution de la valeur de l'inductance 14 à la base de l'antenne (celle-ci passe par exemple de 39 nH à 27nH). Cette diminution résulte d'une modification de la distribution du courant électrique dans l'antenne, et plus précisément d'une augmentation du courant à la base de l'antenne. Une mesure de l'impédance de l'antenne montre que la partie réelle de l'impédance a pratiquement doublé grâce à l'utilisation de la structure métallique 3. Les figures 4 et 5 montrent des configurations alternatives de l'invention.The exemplary embodiment shown in FIGS. 2 and 3 makes it possible to emphasize and verify the actual contribution of the metal structure 3, which leads to a reduction in the value of the inductance 14 at the base of the antenna (this for example, from 39nH to 27nH). This decrease results from a modification of the distribution of the electric current in the antenna, and more precisely of an increase of the current at the base of the antenna. A measurement of the impedance of the antenna shows that the real part of the impedance has practically doubled thanks to the use of the metal structure 3. FIGS. 4 and 5 show alternative configurations of the invention.

La figure 6 représente un support 1 a de circuit imprimé sur lequel ont été rapportés divers composants et notamment une antenne conforme à l'invention. Le récepteur est en l'occurrence entouré d'une cage de protection métallique 10a.FIG. 6 represents a printed circuit support 1 a on which various components have been reported, and in particular an antenna according to the invention. The receiver is in this case surrounded by a metal protective cage 10a.

La structure métallique 3 comporte dans cette figure un bras de rigidification 15 en matière synthétique. Ce dernier comprend à ses extrémités des plots de fixation 15a permettant d'enserrer les jambages 4 et 5 de la structure métallique 3. La structure métallique 3 est alors suffisamment rigide pour être manipulée, déplacée et positionnée sur le support 1a par l'intermédiaire d'un bras automatisé. La structure métallique 3 peut ainsi être rapportée sur le support 1 a de la même façon que divers autres composants électroniques implantés sur le circuit imprimé. Ces composants peuvent remplir des fonctions liées ou non au système de verrouillage / déverrouillage.The metal structure 3 comprises in this figure a stiffening arm 15 of synthetic material. The latter comprises at its ends fixing studs 15a for gripping the legs 4 and 5 of the metal structure 3. The metal structure 3 is then rigid enough to be manipulated, moved and positioned on the support 1a via an automated arm. The metal structure 3 can thus be attached to the support 1a in the same way as various other electronic components implanted on the printed circuit. These components can perform functions related or not to the locking / unlocking system.

Claims (12)

Antenne du type pièce conductrice allongée, destinée aux radiocommunications, comportant au moins une piste conductrice (2 ou 1) rapportée sur un support (1 a) de circuit imprimé, s'étendant entre une base (9) destinée à être connectée à un récepteur (10) et/ou émetteur et une extrémité libre (7), caractérisée en ce qu'elle comporte : - deux pistes conductrices (1, 2) disjointes s'étendant dans le prolongement l'une de l'autre , - ainsi qu'une structure métallique (3) rapportée sur le support (1 a) de circuit imprimé et réalisant un pontage entre les extrémités proximales des deux pistes conductrices (1, 2), la structure métallique (3) s'étendant au moins en partie en saillie du plan d'extension du support (1a). Elongated conductive part antenna for radiocommunications comprising at least one conductive track (2 or 1) attached to a printed circuit carrier (1 a) extending between a base (9) to be connected to a receiver (10) and / or transmitter and a free end (7), characterized in that it comprises: two disjoint conductive tracks (1, 2) extending in the extension of one another, - and a metal structure (3) attached to the support (1 a) of printed circuit and bridging between the proximal ends of the two conductive tracks (1, 2), the metal structure (3) extending at least partly projecting from the extension plane of the support (1a). Antenne selon la revendication précédente, caractérisée en ce que les deux pistes conductrices (1, 2) présentent sensiblement la même longueur.Antenna according to the preceding claim, characterized in that the two conductive tracks (1, 2) have substantially the same length. Antenne selon l'une quelconque des revendications précédentes, caractérisée en ce que la structure métallique (3) est une bande conductrice rigide.Antenna according to any one of the preceding claims, characterized in that the metal structure (3) is a rigid conductive strip. Antenne selon l'une quelconque des revendications précédentes, caractérisée en ce qu'un élément de rigidification (15) est fixé sur la structure métallique (3).Antenna according to one of the preceding claims, characterized in that a stiffening element (15) is fixed to the metal structure (3). Antenne selon l'une quelconque des revendications 3 et 4, caractérisée en ce que la structure métallique (3) présente une forme en U dont les extrémités libres des jambages (4, 5) sont connectées aux pistes (1, 2).Antenna according to any one of claims 3 and 4, characterized in that the metal structure (3) has a U-shaped whose free ends of the legs (4, 5) are connected to the tracks (1, 2). Antenne selon la revendication précédente, caractérisée en ce qu'une traverse (15) de rigidification est fixée via des plots de fixation (15a, 15b) aux jambages (4, 5).Antenna according to the preceding claim, characterized in that a crossbar (15) for stiffening is fixed via fixing studs (15a, 15b) to the legs (4, 5). Antenne selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle comporte une capacité de sommet (8) localisée au niveau de son extrémité libre (7).Antenna according to any one of the preceding claims, characterized in that it comprises a vertex capacity (8) located at its free end (7). Antenne selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle comporte une inductance (14) localisée au niveau de sa base (9).Antenna according to any one of the preceding claims, characterized in that it comprises an inductor (14) located at its base (9). Récepteur (10) relié à une antenne conforme à l'une quelconque des revendications 1 à 8.Receiver (10) connected to an antenna according to any one of claims 1 to 8. Emetteur-récepteur (10) relié à une antenne conforme à l'une quelconque des revendications 1 à 8.Transceiver (10) connected to an antenna according to any one of claims 1 to 8. Système de verrouillage / déverrouillage à distance des portes d'un véhicule comprenant un dispositif émetteur mobile porté par l'utilisateur du véhicule et un récepteur (10) conforme à la revendication 9, ledit récepteur (10) étant disposé à l'intérieur du véhicule.A door remote locking / unlocking system of a vehicle comprising a mobile transmitter device carried by the user of the vehicle and a receiver (10) according to claim 9, said receiver (10) being disposed inside the vehicle . Système de verrouillage / déverrouillage à distance des portes d'un véhicule comprenant un dispositif émetteur-récepteur mobile porté par l'utilisateur du véhicule et un émetteur-récepteur (10) fixe conforme à la revendication 10, ledit émetteur-récepteur (10) fixe étant disposé à l'intérieur du véhicule.Vehicle door remote locking / unlocking system comprising a vehicle user-carried mobile transceiver device and a fixed transceiver (10) according to claim 10, said transceiver (10) fixed being arranged inside the vehicle.
EP05360056A 2005-12-23 2005-12-23 Antenna and central locking system using the same Ceased EP1801914A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP05360056A EP1801914A1 (en) 2005-12-23 2005-12-23 Antenna and central locking system using the same
US11/635,326 US20070146217A1 (en) 2005-12-23 2006-12-07 Antenna and remote locking/unlocking system including such an antenna

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EP05360056A EP1801914A1 (en) 2005-12-23 2005-12-23 Antenna and central locking system using the same

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EP1801914A1 true EP1801914A1 (en) 2007-06-27

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JP2009060403A (en) * 2007-08-31 2009-03-19 Fujitsu Microelectronics Ltd Radio equipment and antenna provided on radio equipment

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KR101700744B1 (en) * 2010-01-29 2017-02-01 삼성전자주식회사 Built-in antenna for portable terminal

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EP1505689A1 (en) * 2003-08-08 2005-02-09 Hitachi Metals, Ltd. Chip antenna device and communications apparatus using same

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JP2002151930A (en) * 2000-11-14 2002-05-24 Murata Mfg Co Ltd Antenna structure and radio equipment provided with it
US20020101382A1 (en) * 2001-02-01 2002-08-01 Takayoshi Konishi Chip antenna and antenna unit including the same
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Publication number Priority date Publication date Assignee Title
JP2009060403A (en) * 2007-08-31 2009-03-19 Fujitsu Microelectronics Ltd Radio equipment and antenna provided on radio equipment
US8026855B2 (en) 2007-08-31 2011-09-27 Fujitsu Semiconductor Limited Radio apparatus and antenna thereof

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