EP1698051A1 - Radio frequency (rf) and/or microwave power amplification device and corresponding radio communication terminal - Google Patents

Radio frequency (rf) and/or microwave power amplification device and corresponding radio communication terminal

Info

Publication number
EP1698051A1
EP1698051A1 EP04805495A EP04805495A EP1698051A1 EP 1698051 A1 EP1698051 A1 EP 1698051A1 EP 04805495 A EP04805495 A EP 04805495A EP 04805495 A EP04805495 A EP 04805495A EP 1698051 A1 EP1698051 A1 EP 1698051A1
Authority
EP
European Patent Office
Prior art keywords
power
power amplification
sensor
amplification device
shielding
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.)
Withdrawn
Application number
EP04805495A
Other languages
German (de)
French (fr)
Inventor
Grégory FRON
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.)
Sierra Wireless SA
Original Assignee
Wavecom SA
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 Wavecom SA filed Critical Wavecom SA
Publication of EP1698051A1 publication Critical patent/EP1698051A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3036—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers
    • H03G3/3042—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers
    • H03G3/3047—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers for intermittent signals, e.g. burst signals
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/52—Circuit arrangements for protecting such amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/189—High frequency amplifiers, e.g. radio frequency amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/189—High frequency amplifiers, e.g. radio frequency amplifiers
    • H03F3/19—High frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/004—Control by varying the supply voltage
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/465—Power sensing
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/78—A comparator being used in a controlling circuit of an amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/10—Gain control characterised by the type of controlled element
    • H03G2201/103—Gain control characterised by the type of controlled element being an amplifying element
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/20—Gain control characterized by the position of the detection
    • H03G2201/206—Gain control characterized by the position of the detection being in radio frequency
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/30—Gain control characterized by the type of controlled signal
    • H03G2201/307—Gain control characterized by the type of controlled signal being radio frequency signal
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/40—Combined gain and bias control

Definitions

  • Radiofrequency (RF) and / or microwave power amplification device and corresponding radiocommunication terminal.
  • the field of the invention is that of power amplification. More specifically, the invention relates to a radiofrequency or hyperfrequency power amplification device, intended in particular for radiocommunication terminals of radiotelephone type, PDAs (in English "Personal Digital
  • FIG. 1 illustrates the general functioning of such a power amplifier 11 within the overall diagram of a radiotelephone As shown in FIG. 1, the power amplifier 11 generates the power necessary for the antenna 10, via an antenna "switch" (or switch) 110 which allows the frequency band and the operating mode to be selected (transmission or reception).
  • switch or switch
  • the power amplifier 11 interacts with c a block referenced 12 performing filtering and adaptation operations ("matching") and a block referenced 14 performing the transmission / reception functions.
  • the baseband part referenced 13 has not been detailed in FIG. 13.
  • the set of blocks 12 to 14 of FIG. 1 do not form an integral part of the present invention, and are therefore not described here in more detail. .
  • control module 111 The role of such a control module 111 is to control the power delivered at the output of the power amplification device 11, as a function in particular of the operating temperature, the supply voltage of the radio telephone battery, the impedance load, etc.
  • FIGS. 2A to 2C several techniques are known for producing such a control module 111, illustrated by FIGS. 2A to 2C.
  • the first of these techniques, illustrated in FIG. 2A, consists in producing a closed loop servo-control of the power delivered.
  • the power amplification device of FIG. 2A comprises an amplifier 21, which, in a particular embodiment of the invention, can be preceded and followed by optional link capacitors 20, 22.
  • the control loop of the power delivered at output 30, intended for the antenna of the radiocommunication terminal comprises: a coupler 23; an RF power detection module 24 also including a comparator, also called a "detector / comparator”; a polarization controller 25.
  • the ramp 26 supplies the detector / comparator 24 with a reference voltage, coming from the baseband 13.
  • the coupler 23 takes part of the power (RF or microwave) supplied by the amplifier 21, and transmits it to the detector / comparator 24, which generates a voltage from this measured power. The latter then compares the voltage it has generated with the reference voltage supplied by the base band 26.
  • the polarization controller 25 modifies the voltage supplied to the amplifier 21, so as to adjust the power delivered at output 30.
  • Two techniques are also known for controlling the power delivered at the output of such a power amplifier, called “ open loop ", which are illustrated by Figures 2B and 2C.
  • the assembly of FIG. 2B proposes to control the power amplifier 21 with current. Again, in the particular variant of FIG. 2B, such an amplifier 21 is preceded and followed by two optional connection capacitors 20, 22.
  • the assembly of FIG. 2B comprises, as before, a ramp 26 providing a reference from the baseband 13, a comparator 27 and a polarization controller 25.
  • the voltages Vbat and Vcc correspond respectively to the voltage delivered by the battery of the radiocommunication terminal and to the supply voltage of the power amplifier 21. Knowing the value of the resistor 28, the intensity of the current I flowing through it is deduced therefrom. After comparing 24 of this intensity with the reference intensity 26, the polarization controller 25 corrects the setpoint of the power amplifier 21, to adjust the power delivered at output 30.
  • the assembly of FIG. 2C illustrates the last known technique , consisting in slaving the supply voltage of the amplifier 21 in open loop. Again, in the particular embodiment of Figure 2C, an optional first link capacitor 20 precedes the amplifier 21, and an optional second link capacitor 22 follows it. A MOSFET-type transistor 29 is used to control the supply voltage Vcc of the amplifier 21.
  • FIG. 2A is therefore the most efficient technique of the three techniques of the prior art above, but it is also the most expensive technique.
  • the technologies used for the design of couplers are different from those used for the design of amplifier chips 21 or controller chips 25 (conventionally of the AsGa or CMOS type), which induces a great difficulty of integration.
  • the open-loop voltage control of FIG. 2C exhibits poor performance, both in terms of power control and of current consumption, when the power delivered is low.
  • this technique also has the drawback of a voltage drop across the MOSFET transistor, due to the existence of a parasitic resistance, this which induces a drop in yield.
  • an objective of the invention is to provide a technique for controlling the power delivered at the output of a power amplifier, in particular for radiocommunication terminals, which has performances at least similar to those of the closed-loop technique. of the prior art, in particular in the event of poor adaptation of the load.
  • Another objective of the invention is to propose such a technique which is simpler and less costly to implement than the techniques of the prior art.
  • the invention also aims to provide such a technique which allows easy integration, in particular thanks to compatibility of the design technologies of the various components used.
  • the invention also aims to propose such a technique which allows the design of a more compact power amplification device than according to the prior art.
  • Another object of the invention is to provide such a technique which exhibits reduced RF losses on the transmission path.
  • the invention also has the secondary objective of proposing such a technique which is insensitive to possible disturbances induced by the antenna to which the generated power is supplied.
  • Another secondary objective of the invention is to provide such a technique which makes it possible to dispense with the presence of attenuators in the device for controlling the power delivered at the output. 5.
  • radiocommunication comprising means for shielding said device and means for controlling a power delivered at the output of said device, comprising a power control loop having reference means, detection means, comparison means and means power amplification.
  • said control means also comprise at least one sensor of radiated energy within said device.
  • the invention proposes to produce such a closed-loop control (as for the solution of the prior art described above in relation to FIG. 2A), so as to obtain satisfactory operating performance, while avoiding use expensive couplers that are difficult to integrate.
  • the invention proposes using one or more sensor (s), acting as an antenna, making it possible to capture the energy radiated within the device.
  • the invention therefore differs greatly from the techniques of the prior art, which were all based on the measurement or evaluation of an energy or power conducted, possibly after attenuation, and not on the evaluation of a radiated power.
  • the device of the invention While offering good operating performance, in particular in terms of controlling the power delivered at the output of the device, the device of the invention therefore also has advantages in terms of cost and integration, compared to the prior techniques.
  • said shielding means couple between said power amplification means and said sensor.
  • said sensor belongs to the group comprising: inductors; - the routing lines of a printed circuit of said device; MEMS (in English "Micro-Electro-Mechanical Systems", in French “Micro-electro-mechanical systems”); the radiating elements printed on a printed circuit of said device; LC or RLC type tuned circuits.
  • said means power amplifier and said sensor are placed close to each other, so as to optimize said coupling.
  • the invention proposes, on the contrary, to bring the amplifier and the sensor as close as possible , to increase this phenomenon, and therefore optimize the operation of the device. It is thus possible to design devices that are much more compact and much less bulky than according to the prior art.
  • said shielding means induce an attenuation of at least 10 dB of an energy external to said device picked up by said sensor with respect to said energy radiated within said device picked up by said sensor. If this attenuation is higher, typically at least 20 dB, the operation of the device is further optimized. This prevents the radiotelephone antenna from causing disturbances in the operation of the power amplification device.
  • said control means make it possible to control said power delivered as an output as a function of at least one parameter belonging to the group comprising: an operating temperature of said device; a supply voltage of said device; a load impedance of said device.
  • said sensor is integrated into said detection means. This increases the integration and compactness of the device.
  • the sensor can for example be written on top of the detector / comparator chip.
  • said shielding means comprise a metal shielding cover having a surface substantially parallel to a printed circuit forming the base of said device and four sides substantially perpendicular to said surface coming to bear on each of the edges of said printed circuit.
  • the shielding means can also take the form of any metallic element covering the printed circuit, connected to its ground, and performing a shielding function.
  • the invention also relates to a radiocommunication terminal, comprising a power amplification device as described above. 6.
  • FIG. 1 shows a block diagram of the radiofrequency part of a radiocommunication terminal, comprising a power amplification device intended to supply the antenna of the terminal;
  • FIGS. 2A to 2C describe three techniques of the prior art for controlling the power delivered at the output of a power amplification device;
  • FIG. 3 describes a power amplification device according to the invention, in which the control of the power delivered at the output comprises a closed loop implementing a sensor of the radiated energy within the device;
  • - Figures 4A and 4B show two embodiments of the sensor of the Figure 3;
  • FIG. 5 illustrates a detailed embodiment of the power amplification device of the invention
  • FIG. 6 shows a Smith chart representing the performance, as a function of the load impedance, of the device of the invention
  • FIGS. 7A to 7D show comparative curves of the influence of the adaptation of the load ("load mismatch") for the solution of the invention and for two solutions of the prior art.
  • the general principle of the invention is based on the use of a radiating element making it possible to capture the radiated energy (and not conducted) within a device for power amplification, so as to achieve a closed loop control of the RF or microwave power delivered at the output of this device. Referring to FIG. 3, a block diagram of such a power amplification device according to the invention is presented.
  • the identical elements are designated by the same reference numeral.
  • the power amplifier 21 is preceded upstream, and followed downstream, by a link capacitor 20, 22.
  • Such link capacitors are optional.
  • the downstream capacitor 22 separates the output of the power amplifier 21 from the output 30 of the amplification device of FIG. 3.
  • Such an output 30 is for example connected to the external antenna of a radiocommunication terminal.
  • the control of the power delivered on the output 30 of the device is carried out by means of a closed control loop comprising : a sensor 31 of the energy radiated within the device, symbolized by the arrows 33; reference means, in the form of a ramp 26, generated by the baseband part of the radiocommunication terminal, and delivering a reference voltage serving as a reference for the power delivered at output 30 of the device; - Detection and comparison means 24, also called “detector / comparator" (Detector / CAP), which recover the value of the radiated power picked up by the radiating element 31 and compare it to the reference voltage supplied by the ramp 26; means 25 for controlling the polarization of the power amplifier 21, making it possible, as a function of the result of the comparison 24, to regulate this polarization, so that the power detected by the detector / comparator 24 and converted into voltage is also as close as possible to the reference voltage indicated by the ramp 26.
  • a closed control loop comprising : a sensor 31 of the energy radiated within the device, symbolized by
  • a sensor 31 which captures the electromagnetic field which radiates in the physical structure of the module of FIG. 3.
  • couplers FIG. 2A
  • the absence of discrete couplers in the power amplification device of FIG. 3 makes it possible to greatly reduce its cost price.
  • the device of FIG. 3 also includes a shield 32, which can take the form of a metal bowl covering the printed circuit on which the various components are installed, or even a metal grid.
  • such shielding 32 can take the form of any metallized element connected to the ground of the circuit, performing a shielding function and covering the printed circuit.
  • a shield 32 was essentially intended to prevent the energy radiated by the power amplification device from leaving the device (in the form of harmonics conveyed by the ambient air), and coming disrupt the other functional blocks of the radiocommunication terminal, or other neighboring equipment.
  • such shielding 32 also participates in coupling, by reflecting towards the sensor 31 the radiated energy 33 conveyed by the ambient medium (air).
  • the sensor 31 thus recovers the energy reflected by the shielding 32, but also the energy which comes directly from the chip of the power amplifier 21, or from leaks by the lines of the printed circuit (or PCB for "Printed Circuit Board”") of the overall arrangement.
  • the proportion of the power captured by the sensor 31 which corresponds to the power actually delivered by the amplifier 21 depends on the nature of the sensor, its size and its technical characteristics. It can be evaluated that the shield 32 plays approximately half (or 3 dB) in the total power recovered by the sensor 31.
  • Such a shield 32 must be effective enough to "block” the power radiated by the antenna of the radiotelephone connected to the output 30 of the device, and prevent this power from being picked up by the radiating element 31.
  • the coupling between the external antenna (connected to the output 30) and the sensor 31 should be approximately 20 dB less than the coupling between the power amplifier 21 and the sensor 31.
  • the device of the present invention exploits this coupling effect as much as possible, to increase the value of the radiated power evaluated by the sensor 31.
  • the invention proposes in particular to bring the sensor 31 and the detector 24 as close as possible to the chip of the power amplifier 21, whereas attempts have hitherto been made in the prior art to keep these elements of each other. The invention therefore allows better integrability and a smaller footprint than conventional devices known to date.
  • the tolerance on the dimensions (size and thickness) of the shield is very small (typically of the order of 100 ⁇ m) in front of the wavelength radiated in the device (for systems whose operating frequencies are less than 5 GHz), which is therefore not problematic. Reproducibility is ensured for long wavelengths compared to the physical dimensions of the detector 24 and of the sensor 31.
  • the sensor 31 can take various forms, some of which are illustrated in FIGS. 4A and 4B. Thus, in FIG.
  • the senor 31 is produced in the form of a MEMS 41 (for "Micro-Electro-Mechanical System", “micro-electromechanical system” - inductance with a high coefficient of quality and high precision) implanted on an integrated circuit 40 produced using CMOS, BiCMOS or SiGe technology.
  • CMOS complementary metal-oxide-semiconductor
  • SiGe complementary metal-oxide-se
  • FIG. 4B illustrates another embodiment of the sensor 31 in the form of an inductor 42. More generally, the sensor 31 can be any type of radiating element acting as an antenna and capable of capturing the energy radiated within the power amplification device.
  • such a sensor 31 can take the form of a line of a PCB routing or of a radiating element integrated on top of a chip, for example the chip of the detector / comparator 24.
  • the sensor 31 When the sensor 31 is produced in the form of an inductor, it may for example be a wound coil of 12 nH, in the context of a "GSM / DCS dual band" power amplifier.
  • the sensor 31 is an LC or RLC type tuned circuit, the values of the components of which are chosen (according to techniques well known to those skilled in the art) so as to obtain gain bumps at frequencies of operation of the radiocommunication terminal antenna (typically at 900 MHz and 1800 MHz in the case of a GSM radiotelephone).
  • the power amplification device of the invention remains much smaller than the device of the prior art based on couplers (FIG. 2A), which is conventionally produced on a substrate. ceramic.
  • the invention makes it possible to dispense with the resistive attenuator generally located upstream of the coupler according to the prior art. All the components of the power amplification device of the invention can be produced using the same technology, hence great ease of integration.
  • the closed control loop of FIG. 3, comprising in particular the detector / CAP 24 and the controller 25, can be produced in software form. The comparison of the powers is then carried out in the baseband part of the radiocommunication terminal.
  • FIG. 5 presents in more detail a practical embodiment of the power amplification device of FIG.
  • the Smith chart of FIG. 6 characterizes the tolerance of the power amplification device of the invention to an antenna of the radiocommunication terminal which would be defective, and therefore would not be centered on 50 ⁇ . It was carried out for a power amplifier produced on gallium arsenide (GaAs technology), and illustrates the variation of the Stationary Wave Rate, or TOS any phase. On the abacus of figure 6, the more the impedance of the load moves away from the value 50 ⁇ , corresponding to the center of the abacus, the more the TOS increases.
  • GaAs technology gallium arsenide
  • FIGS. 7A to 7D present the comparative performances of the power amplification device of the invention and of corresponding devices of the prior art. More specifically, FIGS. 7A and 7B correspond to a device for amplifying the power of a radiocommunication terminal conforming to the GSM standard, while FIGS. 7C and 7D correspond to the same device for a radiotelephone of the DCS ("Digital Cellular") type. System “, for" digital cellular system ").
  • the curves of FIGS. 7A and 7C represent the maximum power delivered at the output of the power amplification device, expressed in dBm, as a function of the standing wave rate, or TOS, and therefore represent the influence maximum (respectively minimum) of a poor adaptation of the load.
  • the solid lines curves relate more particularly to a closed loop control power amplification device of the type illustrated in FIG. 2A.
  • the dashed lines relate to a power amplification device, the control of which is carried out in an open loop, and therefore characterize the intrinsic behavior of the power amplifier chip.
  • the curves in dotted lines are representative of the performance of the device of the invention ( Figure 3).
  • the performance of the device of the invention implementing an evaluation of the radiated power within the device, are very close to those of the closed-loop slave device of FIG. 2A, which implements an evaluation, by couplers, of the power driven within the device.
  • the device of the invention has performances similar to that of the prior art based on couplers (FIG.
  • the power control technique of the device of the invention has the following advantages compared to previous techniques: - reduced cost, thanks in particular to the elimination of couplers; reduction of RF losses on the transmission path; performances at least equal to those of the prior art based on couplers, in the event of poor load adaptation; - a possibility of integrating the device in the form of a very small component, thanks to the possibility of making all the elements of the device according to the same technology, and of minimizing the distance between the detector and the sensor; the leaks, which were critical in the prior closed loop system of Figure 2A, are no longer so.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Transmitters (AREA)
  • Amplifiers (AREA)

Abstract

The invention relates to a radio frequency (RF) and/or microwave power amplification device which is intended, for example, for a radio communication terminal, comprising means for shielding the device and means for controlling the power delivered as output from said device, said power-control means comprising a power servo loop having power-amplification means, reference means, detection means and comparison means. According to the invention, the aforementioned control means also comprise at least one sensor to detect the energy radiated inside the device.

Description

Dispositif d'amplification de puissance radiofréquence (RF) et/ou hyperfréquence, et terminal de radiocommunication correspondant. 1. Domaine de l'invention Le domaine de l'invention est celui de l'amplification de puissance. Plus précisément, l'invention concerne un dispositif d'amplification de puissance radiofréquence ou hyperfréquence, destiné notamment aux terminaux de radiocommunications de type radiotéléphones, PDAs (en anglais "Personal Digital Radiofrequency (RF) and / or microwave power amplification device, and corresponding radiocommunication terminal. 1. Field of the invention The field of the invention is that of power amplification. More specifically, the invention relates to a radiofrequency or hyperfrequency power amplification device, intended in particular for radiocommunication terminals of radiotelephone type, PDAs (in English "Personal Digital
Assistant", pour "assistant numérique personnel"), ordinateurs portables, etc. Dans les radiotéléphones, de tels amplificateurs de puissance sont destinés à générer et fournir à l'antenne une puissance de fonctionnement suffisante pour que le terminal puisse communiquer avec la station de base la plus proche. Selon la norme GSM (pour "Groupe Spécial Mobiles") par exemple, l'amplificateur de puissance génère la puissance nécessaire à l'antenne par pas de 2 dB. La figure 1 illustre le fonctionnement général d'un tel amplificateur de puissance 11 au sein du schéma global d'un radiotéléphone. Comme représenté sur la figure 1, l'amplificateur de puissance 11 génère la puissance nécessaire à l'antenne 10, via un "switch" (ou commutateur) d'antenne 110 qui permet de sélectionner la bande de fréquence et le mode de fonctionnement (émission ou réception). Sans décrire plus en détail cette figure, on notera cependant que l'amplificateur de puissance 11 interagit avec un bloc référencé 12 réalisant des opérations de filtrage et d'adaptation ("matching") et un bloc référencé 14 réalisant les fonctions d'émission/réception. La partie bande de base référencée 13 n'a pas été détaillée sur la figure 13. L'ensemble des blocs 12 à 14 de la figure 1 ne font pas partie intégrante de la présente invention, et ne sont donc pas décrits ici plus en détail. On pourra se référer, pour plus d'informations, aux schémas classiques de terminaux de radiocommunications, tels que préconisés par exemple par les normes GSM ou UMTS ("Universal Mobile Télécommunication System" pour "Système de télécommunications mobile universel"). 2. Solutions de l'art antérieur Comme illustré sur la figure 1, un tel dispositif d'amplification de puissance 11 comprend un module 111 de contrôle de l'amplificateur 112 de puissance. Un tel module de contrôle 111 a pour rôle de contrôler la puissance délivrée en sortie du dispositif d'amplification de puissance 11, en fonction notamment de la température de fonctionnement, de la tension d'alimentation de la batterie du radiotéléphone, de l'impédance de la charge, etc. On connaît à ce jour plusieurs techniques de réalisation d'un tel module de contrôle 111, illustrées par les figures 2A à 2C. La première de ces techniques, illustrée par la figure 2A, consiste à réaliser un asservissement en boucle fermée ("closed loop") de la puissance délivrée. Le dispositif d'amplification de puissance de la figure 2A comprend un amplificateur 21, qui, dans un mode de réalisation particulier de l'invention, peut être précédé et suivi de condensateurs de liaison optionnels 20, 22. La boucle d'asservissement de la puissance délivrée en sortie 30, à destination de l'antenne du terminal de radiocommunications, comprend : un coupleur 23 ; un module 24 de détection de la puissance RF incluant également un comparateur, encore appelé "détecteur/comparateur" ; un contrôleur de polarisation 25. La rampe 26 fournit au détecteur/comparateur 24 une tension de référence, en provenance de la bande de base 13. Le coupleur 23 prélève une partie de la puissance (RF ou hyperfréquence) fournie par l'amplificateur 21, et la transmet au détecteur/comparateur 24, qui génère une tension à partir de cette puissance mesurée. Ce dernier compare ensuite la tension qu'il a générée à la tension de référence fournie par la bande de base 26. Si la puissance délivrée diffère de la puissance de référence (associée à la tension de référence fournie par la bande de base 26), le contrôleur de polarisation 25 modifie alors la tension fournie à l'amplificateur 21, de façon à ajuster la puissance délivrée en sortie 30. On connaît également deux techniques de contrôle de la puissance délivrée en sortie d'un tel amplificateur de puissance, dites "en boucle ouverte", qui sont illustrées par les figures 2B et 2C. Le montage de la figure 2B propose de contrôler l'amplificateur de puissance 21 en courant. A nouveau, dans la variante particulière de la figure 2B, un tel amplificateur 21 est précédé et suivi de deux condensateurs de liaison optionnels 20, 22. Le montage de la figure 2B comprend, comme précédemment, une rampe 26 fournissant une référence en provenance de la bande de base 13, un comparateur 27 et un contrôleur de polarisation 25. Les tensions Vbat et Vcc correspondent respectivement à la tension délivrée par la batterie du terminal de radiocommunication et à la tension d'alimentation de l'amplificateur de puissance 21. Connaissant la valeur de la résistance 28, on en déduit l'intensité du courant I qui la traverse. Après comparaison 24 de cette intensité avec l'intensité de référence 26, le contrôleur de polarisation 25 corrige la consigne de l'amplificateur de puissance 21, pour ajuster la puissance délivrée en sortie 30. Le montage de la figure 2C illustre la dernière technique connue, consistant à asservir la tension d'alimentation de l'amplificateur 21 en boucle ouverte. A nouveau, dans le mode de réalisation particulier de la figure 2C, un premier condensateur de liaison optionnel 20 précède l'amplificateur 21, et un second condensateur de liaison optionnel 22 le suit. On utilise un transistor 29 de type MOSFET pour asservir la tension Vcc d'alimentation de l'amplificateur 21. Cet asservissement est réalisé au moyen d'un comparateur 27, dont la consigne est donnée par une rampe 26 reliée à la bande de base 13. La tension Vcc est pilotée de façon que la puissance RF ou hyperfréquence délivrée en sortie 30 de l'amplificateur soit égale à la puissance de référence associée à la tension de référence donnée par la rampe 26. 3. Inconvénients de l'art antérieur Ces différentes techniques de l'art antérieur présentent de nombreux inconvénients. La technique de contrôle en boucle fermée de la figure 2A, bien que permettant un excellent contrôle de la puissance de sortie, tout en présentant une consommation en courant satisfaisante, a pour inconvénient d'induire des pertes RF, de l'ordre de 0,2 à 0,3 dB. Un tel système présente cependant un très bon comportement lorsque la charge varie, i.e. lorsque l'antenne est de qualité médiocre. Le contrôle en boucle fermée de la figure 2A est donc la technique la plus performante des trois techniques de l'art antérieur ci-dessus, mais elle est également la technique la plus coûteuse. En outre, les technologies utilisées pour la conception de coupleurs sont différentes de celles utilisées pour la conception des puces d'amplificateur 21 ou de contrôleur 25 (classiquement de type AsGa ou CMOS), ce qui induit une forte difficulté d'intégration. Le contrôle en tension en boucle ouverte de la figure 2C présente des performances médiocres, tant en termes de contrôle de puissance que de consommation de courant, lorsque la puissance délivrée est faible. Bien que l'intégration d'un tel dispositif soit plus facile que dans le cas de la figure 2A, cette technique présente également pour inconvénient une chute de tension à travers le transistor MOSFET, due à l'existence d'une résistance parasite, ce qui induit une baisse de rendement. Enfin, la technique de contrôle en courant en boucle ouverte de la figure 2B présente des performances améliorées par rapport à la technique de la figure 2C en termes d'intégrabilité, de consommation de courant et de perte de puissance. Elle ne permet cependant pas un contrôle de puissance aussi performant que celui de la technique en boucle fermée de la figure 2A. 4. Objectifs de l'invention L'invention a notamment pour objectif de pallier ces inconvénients de l'art antérieur. Plus précisément, un objectif de l'invention est de fournir une technique de contrôle de la puissance délivrée en sortie d'un amplificateur de puissance, notamment pour terminaux de radiocommunication, qui présente des performances au moins similaires à celles de la technique en boucle fermée de l'art antérieur, notamment en cas de mauvaise adaptation de la charge. Un autre objectif de l'invention est de proposer une telle technique qui soit plus simple et moins coûteuse à mettre en œuvre que les techniques de l'art antérieur. L'invention a encore pour objectif de fournir une telle technique qui permette une intégration facile, grâce notamment à une compatibilité des technologies de conception des différents composants employés. L'invention a aussi pour objectif de proposer une telle technique qui permette la conception d'un dispositif d'amplification de puissance plus compact que selon l'art antérieur. Un autre objectif de l'invention est de fournir une telle technique qui présente des pertes RF réduites sur le chemin de transmission. L'invention a encore comme objectif secondaire de proposer une telle technique qui soit insensible à d'éventuelles perturbations induites par l'antenne à laquelle est fournie la puissance générée. Un autre objectif secondaire de l'invention est de fournir une telle technique qui permette de s'affranchir de la présence d'atténuateurs dans le dispositif de contrôle de la puissance délivrée en sortie. 5. Caractéristiques essentielles de l'invention Ces objectifs, ainsi que d'autres qui apparaîtront par la suite, sont atteints à l'aide d'un dispositif d'amplification de puissance radiofréquence (RF) et/ou hyperfréquence, notamment pour terminal de radiocommunication, comprenant des moyens de blindage dudit dispositif et des moyens de contrôle d'une puissance délivrée en sortie dudit dispositif, comprenant une boucle d'asservissement en puissance présentant des moyens de référence, des moyens de détection, des moyens de comparaison et des moyens d'amplification de puissance. Selon l'invention, lesdits moyens de contrôle comprennent également au moins un capteur d'une énergie rayonnée au sein dudit dispositif. Ainsi, l'invention repose sur une approche tout à fait nouvelle et inventive de l'asservissement en puissance d'un dispositif d'amplification radio- ou hyperfréquence, destiné notamment à alimenter une antenne de terminal de radiocommunication de type radiotéléphone, PDA, etc. En effet, l'invention propose de réaliser un tel asservissement en boucle fermée (comme pour la solution de l'art antérieur décrite précédemment en relation avec la figure 2A), de façon à obtenir des performances de fonctionnement satisfaisantes, tout en évitant d'utiliser des coupleurs coûteux et difficiles d'intégration. En lieu et place de ce ou ces coupleur(s), l'invention propose d'utiliser un ou plusieurs capteur(s), agissant comme une antenne, permettant de capter l'énergie rayonnée au sein du dispositif. L'invention diffère donc fortement des techniques de l'art antérieur, qui reposaient toutes sur la mesure ou l'évaluation d'une énergie ou puissance conduite, éventuellement après atténuation, et non sur l'évaluation d'une puissance rayonnée. Tout en proposant de bonnes performances de fonctionnement, notamment en termes de contrôle de la puissance délivrée en sortie du dispositif, le dispositif de l'invention présente donc également des avantages en termes de coût et d'intégration, par rapport aux techniques antérieures. Avantageusement, lesdits moyens de blindage réalisent un couplage entre lesdits moyens d'amplification de puissance et ledit capteur. Un tel phénomène de blindage est astucieusement exploité selon l'invention, alors qu'il était jusqu'à présent, selon toutes les techniques de l'art antérieur, considéré comme un effet néfaste, qu'il fallait à tout prix éviter.Assistant ", for" personal digital assistant "), portable computers, etc. In radiotelephones, such power amplifiers are intended to generate and supply the antenna with sufficient operating power so that the terminal can communicate with the radio station. nearest base. According to the GSM standard (for "Groupe Spécial Mobiles") for example, the power amplifier generates the power necessary for the antenna in 2 dB steps. Figure 1 illustrates the general functioning of such a power amplifier 11 within the overall diagram of a radiotelephone As shown in FIG. 1, the power amplifier 11 generates the power necessary for the antenna 10, via an antenna "switch" (or switch) 110 which allows the frequency band and the operating mode to be selected (transmission or reception). Without describing this figure in more detail, it will however be noted that the power amplifier 11 interacts with c a block referenced 12 performing filtering and adaptation operations ("matching") and a block referenced 14 performing the transmission / reception functions. The baseband part referenced 13 has not been detailed in FIG. 13. The set of blocks 12 to 14 of FIG. 1 do not form an integral part of the present invention, and are therefore not described here in more detail. . Reference may be made, for more information, to conventional diagrams of radiocommunication terminals, as recommended for example by GSM or UMTS standards ("Universal Mobile Telecommunication System" for "Universal mobile telecommunications system"). 2. Solutions of the prior art As illustrated in FIG. 1, such a device for amplifying power 11 includes a module 111 for controlling the power amplifier 112. The role of such a control module 111 is to control the power delivered at the output of the power amplification device 11, as a function in particular of the operating temperature, the supply voltage of the radio telephone battery, the impedance load, etc. To date, several techniques are known for producing such a control module 111, illustrated by FIGS. 2A to 2C. The first of these techniques, illustrated in FIG. 2A, consists in producing a closed loop servo-control of the power delivered. The power amplification device of FIG. 2A comprises an amplifier 21, which, in a particular embodiment of the invention, can be preceded and followed by optional link capacitors 20, 22. The control loop of the power delivered at output 30, intended for the antenna of the radiocommunication terminal, comprises: a coupler 23; an RF power detection module 24 also including a comparator, also called a "detector / comparator"; a polarization controller 25. The ramp 26 supplies the detector / comparator 24 with a reference voltage, coming from the baseband 13. The coupler 23 takes part of the power (RF or microwave) supplied by the amplifier 21, and transmits it to the detector / comparator 24, which generates a voltage from this measured power. The latter then compares the voltage it has generated with the reference voltage supplied by the base band 26. If the power delivered differs from the reference power (associated with the reference voltage supplied by the base band 26), the polarization controller 25 then modifies the voltage supplied to the amplifier 21, so as to adjust the power delivered at output 30. Two techniques are also known for controlling the power delivered at the output of such a power amplifier, called " open loop ", which are illustrated by Figures 2B and 2C. The assembly of FIG. 2B proposes to control the power amplifier 21 with current. Again, in the particular variant of FIG. 2B, such an amplifier 21 is preceded and followed by two optional connection capacitors 20, 22. The assembly of FIG. 2B comprises, as before, a ramp 26 providing a reference from the baseband 13, a comparator 27 and a polarization controller 25. The voltages Vbat and Vcc correspond respectively to the voltage delivered by the battery of the radiocommunication terminal and to the supply voltage of the power amplifier 21. Knowing the value of the resistor 28, the intensity of the current I flowing through it is deduced therefrom. After comparing 24 of this intensity with the reference intensity 26, the polarization controller 25 corrects the setpoint of the power amplifier 21, to adjust the power delivered at output 30. The assembly of FIG. 2C illustrates the last known technique , consisting in slaving the supply voltage of the amplifier 21 in open loop. Again, in the particular embodiment of Figure 2C, an optional first link capacitor 20 precedes the amplifier 21, and an optional second link capacitor 22 follows it. A MOSFET-type transistor 29 is used to control the supply voltage Vcc of the amplifier 21. This control is achieved by means of a comparator 27, the set point of which is given by a ramp 26 connected to the baseband 13 The voltage Vcc is controlled so that the RF or microwave power delivered at output 30 of the amplifier is equal to the reference power associated with the reference voltage given by the ramp 26. 3. Disadvantages of the prior art These different techniques of the prior art have many drawbacks. The closed loop control technique of Figure 2A, although allowing excellent control of the output power, while presenting a satisfactory current consumption has the drawback of inducing RF losses, of the order of 0.2 to 0.3 dB. However, such a system exhibits very good behavior when the load varies, ie when the antenna is of poor quality. The closed loop control of FIG. 2A is therefore the most efficient technique of the three techniques of the prior art above, but it is also the most expensive technique. In addition, the technologies used for the design of couplers are different from those used for the design of amplifier chips 21 or controller chips 25 (conventionally of the AsGa or CMOS type), which induces a great difficulty of integration. The open-loop voltage control of FIG. 2C exhibits poor performance, both in terms of power control and of current consumption, when the power delivered is low. Although the integration of such a device is easier than in the case of FIG. 2A, this technique also has the drawback of a voltage drop across the MOSFET transistor, due to the existence of a parasitic resistance, this which induces a drop in yield. Finally, the open-loop current control technique of FIG. 2B has improved performance compared to the technique of FIG. 2C in terms of integrability, current consumption and power loss. However, it does not allow as powerful a power control as that of the closed loop technique of FIG. 2A. 4. Objectives of the invention The object of the invention is in particular to overcome these drawbacks of the prior art. More specifically, an objective of the invention is to provide a technique for controlling the power delivered at the output of a power amplifier, in particular for radiocommunication terminals, which has performances at least similar to those of the closed-loop technique. of the prior art, in particular in the event of poor adaptation of the load. Another objective of the invention is to propose such a technique which is simpler and less costly to implement than the techniques of the prior art. The invention also aims to provide such a technique which allows easy integration, in particular thanks to compatibility of the design technologies of the various components used. The invention also aims to propose such a technique which allows the design of a more compact power amplification device than according to the prior art. Another object of the invention is to provide such a technique which exhibits reduced RF losses on the transmission path. The invention also has the secondary objective of proposing such a technique which is insensitive to possible disturbances induced by the antenna to which the generated power is supplied. Another secondary objective of the invention is to provide such a technique which makes it possible to dispense with the presence of attenuators in the device for controlling the power delivered at the output. 5. Essential Characteristics of the Invention These objectives, as well as others which will appear subsequently, are achieved using a radiofrequency (RF) and / or microwave power amplification device, in particular for a terminal. radiocommunication, comprising means for shielding said device and means for controlling a power delivered at the output of said device, comprising a power control loop having reference means, detection means, comparison means and means power amplification. According to the invention, said control means also comprise at least one sensor of radiated energy within said device. Thus, the invention is based on a completely new and inventive approach to the servo-power of a radio or microwave amplification device, intended in particular to supply a terminal antenna. radiocommunication such as radiotelephone, PDA, etc. Indeed, the invention proposes to produce such a closed-loop control (as for the solution of the prior art described above in relation to FIG. 2A), so as to obtain satisfactory operating performance, while avoiding use expensive couplers that are difficult to integrate. In place of this or these coupler (s), the invention proposes using one or more sensor (s), acting as an antenna, making it possible to capture the energy radiated within the device. The invention therefore differs greatly from the techniques of the prior art, which were all based on the measurement or evaluation of an energy or power conducted, possibly after attenuation, and not on the evaluation of a radiated power. While offering good operating performance, in particular in terms of controlling the power delivered at the output of the device, the device of the invention therefore also has advantages in terms of cost and integration, compared to the prior techniques. Advantageously, said shielding means couple between said power amplification means and said sensor. Such a shielding phenomenon is cleverly exploited according to the invention, whereas it was until now, according to all the techniques of the prior art, considered to be a harmful effect, which had to be avoided at all costs.
L'invention propose donc une approche tout à fait innovante qui va à encontre des préjugés de l'Homme du Métier. Préférentiellement, ledit capteur appartient au groupe comprenant : les inductances ; - les lignes de routage d'un circuit imprimé dudit dispositif ; les MEMS (en anglais "Micro-Electro-Mechanical Systems", en français "Systèmes micro-électro-mécaniques") ; les éléments rayonnants imprimés sur un circuit imprimé dudit dispositif ; les circuits accordés de type LC ou RLC. Selon une caractéristique avantageuse de l'invention, lesdits moyens d'amplification de puissance et ledit capteur sont placés à proximité les uns des autres, de façon à optimiser ledit couplage. Ainsi, alors qu'on essayait jusqu'à présent d'éloigner au maximum le coupleur et l'amplificateur de puissance, pour éviter tout phénomène néfaste de couplage, l'invention propose au contraire de rapprocher autant que possible l'amplificateur et le capteur, pour accroître ce phénomène, et donc optimiser le fonctionnement du dispositif. On peut ainsi concevoir des dispositifs beaucoup plus compacts et beaucoup moins encombrants que selon l'art antérieur. De manière préférentielle, lesdits moyens de blindage induisent une atténuation d'au moins 10 dB d'une énergie extérieure audit dispositif captée par ledit capteur par rapport à ladite énergie rayonnée au sein dudit dispositif captée par ledit capteur. Si cette atténuation est plus élevée, typiquement au moins égale à 20 dB, le fonctionnement du dispositif est encore optimisé. On évite ainsi que l'antenne du radiotéléphone n'induise des perturbations sur le fonctionnement du dispositif d'amplification de puissance. De manière avantageuse, lorsque ledit capteur est un circuit accordé de type LC ou RLC, les valeurs des composants dudit circuit accordé sont choisies de façon à maximiser ladite puissance délivrée en sortie à au moins une fréquence de fonctionnement prédéterminée dudit dispositif. Par exemple, dans le cas d'un amplificateur de puissance GSM, on choisit la valeur des composants de façon à obtenir en sortie deux bosses de gain à 900 MHz et 1800 MHz. Avantageusement, lesdits moyens de contrôle permettent de contrôler ladite puissance délivrée en sortie en fonction d'au moins un paramètre appartenant au groupe comprenant : une température de fonctionnement dudit dispositif ; une tension d'alimentation dudit dispositif ; une impédance de charge dudit dispositif. Selon une variante de réalisation avantageuse de l'invention, ledit capteur est intégré dans lesdits moyens de détection. On accroît ainsi l'intégration et la compacité du dispositif. Le capteur peut par exemple être inscrit sur le dessus de la puce du détecteur/comparateur. De manière avantageuse, lesdits moyens de blindage comprennent un capot de blindage métallique présentant une surface sensiblement parallèle à un circuit imprimé formant la base dudit dispositif et quatre pans sensiblement perpendiculaires à ladite surface venant en appui sur chacun des bords dudit circuit imprimé. Les moyens de blindage peuvent également prendre la forme de tout élément métallique recouvrant le circuit imprimé, relié à sa masse, et réalisant une fonction de blindage. L'invention concerne aussi un terminal de radiocommunication, comprenant un dispositif d'amplification de puissance tel que décrit précédemment. 6. Liste des figures D'autres caractéristiques et avantages de l'invention apparaîtront plus clairement à la lecture de la description suivante d'un mode de réalisation préférentiel, donné à titre de simple exemple illustratif et non limitatif, et des dessins annexés, parmi lesquels : - la figure 1 présente un synoptique de la partie radiofréquence d'un terminal de radiocommunication, comprenant un dispositif d'amplification de puissance destiné à alimenter l'antenne du terminal ; les figures 2A à 2C décrivent trois techniques de l'art antérieur pour le contrôle de la puissance délivrée en sortie d'un dispositif d'amplification de puissance ; la figure 3 décrit un dispositif d'amplification de puissance selon l'invention, dans lequel le contrôle de la puissance délivrée en sortie comprend une boucle fermée mettant en œuvre un capteur de l'énergie rayonnée au sein du dispositif ; - les figures 4A et 4B présentent deux modes de réalisation du capteur de la figure 3 ; la figure 5 illustre un mode de réalisation détaillé du dispositif d'amplification de puissance de l'invention ; la figure 6 présente une abaque de Smith représentative des performances, en fonction de l'impédance de charge, du dispositif de l'invention ; les figures 7A à 7D présentent des courbes comparatives de l'influence de l'adaptation de la charge ("load mismatch") pour la solution de l'invention et pour deux solutions de l'art antérieur. 7. Description d'un mode de réalisation de l'invention Le principe général de l'invention repose sur l'utilisation d'un élément rayonnant permettant de capter l'énergie rayonnée (et non conduite) au sein d'un dispositif d'amplification de puissance, de façon à réaliser un asservissement en boucle fermée de la puissance RF ou hyperfréquence délivrée en sortie de ce dispositif. On présente, en relation avec la figure 3, un schéma synoptique d'un tel dispositif d'amplification de puissance selon l'invention. Comme on le notera, sur toutes les figures du présent document, les éléments identiques sont désignés par une même référence numérique. Dans l'exemple particulier de la figure 3, l'amplificateur de puissance 21 est précédé en amont, et suivi en aval, d'un condensateur de liaison 20, 22. De tels condensateurs de liaison sont facultatifs. Dans l'exemple de la figure 3, le condensateur aval 22 sépare la sortie de l'amplificateur de puissance 21 de la sortie 30 du dispositif d'amplification de la figure 3. Une telle sortie 30 est par exemple reliée à l'antenne externe d'un terminal de radiocommunication. Le contrôle de la puissance délivrée sur la sortie 30 du dispositif, en fonction notamment de la température, de la tension délivrée par la batterie du terminal, de l'impédance de charge, est réalisé au moyen d'une boucle d'asservissement fermée comprenant : un capteur 31 de l'énergie rayonnée au sein du dispositif, symbolisée par les flèches 33 ; des moyens de référence, sous la forme d'une rampe 26, générée par la partie en bande de base du terminal de radiocommunication, et délivrant une tension de référence servant de consigne à la puissance délivrée en sortie 30 du dispositif ; - des moyens de détection et de comparaison 24, encore appelés "détecteur/comparateur" (Détecteur/CAP), qui récupèrent la valeur de la puissance rayonnée captée par l'élément rayonnant 31 et la comparent à la tension de référence fournie par la rampe 26 ; des moyens de contrôle 25 de la polarisation de l'amplificateur de puissance 21, permettant, en fonction du résultat de la comparaison 24, de réguler cette polarisation, de façon que la puissance détectée par le détecteur/comparateur 24 et convertie en tension soit aussi proche que possible de la tension de référence indiquée par la rampe 26. En d'autres termes, on place donc, à l'entrée du détecteur RF ou hyperfréquence 24, un capteur 31 qui capte le champ électromagnétique qui rayonne dans la structure physique du module de la figure 3. On obtient donc, comme dans le cas de coupleurs (figure 2A), une image de la puissance émise à l'antenne du radiotéléphone, ce qui permet de réaliser le contrôle 25 de la polarisation de l'amplificateur de puissance 21. L'absence de coupleurs discrets dans le dispositif d'amplification de puissance de la figure 3 permet de réduire fortement son coût de revient. Le dispositif de la figure 3 comprend également un blindage 32, qui peut prendre la forme d'une gamelle métallique recouvrant le circuit imprimé sur lequel sont implantés les différents composants, ou encore d'une grille métallique. Plus généralement, un tel blindage 32 peut prendre la forme de tout élément métallisé et relié à la masse du circuit, réalisant une fonction de blindage et recouvrant le circuit imprimé. Selon l'art antérieur, un tel blindage 32 était essentiellement destiné à éviter que l'énergie rayonnée par le dispositif d'amplification de puissance ne sorte du dispositif (sous forme d'harmoniques véhiculés par l'air ambiant), et ne vienne perturber les autres blocs fonctionnels du terminal de radiocommunication, ou d'autres équipements avoisinants. Selon l'invention, un tel blindage 32 participe également au couplage, en réfléchissant vers le capteur 31 l'énergie rayonnée 33 véhiculée par le milieu ambiant (l'air). Le capteur 31 récupère ainsi l'énergie réfléchie par le blindage 32, mais également l'énergie qui provient directement de la puce de l'amplificateur de puissance 21, ou de fuites par les lignes du circuit imprimé (ou PCB pour "Printed Circuit Board") du dispositif global. La proportion de la puissance captée par le capteur 31 qui correspond à la puissance effectivement délivrée par l'amplificateur 21 dépend de la nature du capteur, de sa taille et de ses caractéristiques techniques. On peut évaluer que le blindage 32 joue environ pour moitié (soit 3 dB) dans la puissance totale récupérée par le capteur 31. Un tel blindage 32 doit être suffisamment efficace pour "bloquer" la puissance rayonnée par l'antenne du radiotéléphone connectée à la sortie 30 du dispositif, et éviter que cette puissance ne soit captée par l'élément rayonnant 31. En effet, un tel phénomène néfaste entraînerait un problème de calibration, car le capteur 31 mesurerait, non seulement la puissance rayonnée à l'intérieur du boîtier du dispositif de la figure 3, mais également la puissance extérieure au boîtier, en provenance de l'antenne. La puissance détectée totale serait alors supérieure à la puissance effectivement rayonnée au sein du dispositif, et le contrôleur de polarisation 25 réduirait alors, à tort, la tension d'alimentation de l'amplificateur 21, pour diminuer la puissance RF ou hyperfréquence délivrée sur la sortie 30. Pour éviter ce problème, les inventeurs de la présente demande de brevet ont estimé qu'il était nécessaire que le blindage 32 induise une atténuation d'au moins 10 dB, et idéalement d'au moins 20 dB, de la puissance extérieure. En d'autres termes, il conviendrait que le couplage entre l'antenne extérieure (connectée à la sortie 30) et le capteur 31 soit d'environ 20 dB inférieure au couplage entre l'amplificateur de puissance 21 et le capteur 31. On notera que, contrairement aux solutions classiques de l'art antérieur qui tentaient d'éviter au maximum le phénomène néfaste de couplage induit par le blindage 32, le dispositif de la présente invention exploite autant que possible cet effet de couplage, pour accroître la valeur de la puissance rayonnée évaluée par le capteur 31. Pour ce faire, l'invention propose notamment de rapprocher autant que possible le capteur 31 et le détecteur 24 de la puce de l'amplificateur de puissance 21, alors qu'on tentait jusqu'à présent, dans l'art antérieur, d'éloigner au maximum ces éléments les uns des autres. L'invention permet donc une meilleure intégrabilité et un plus faible encombrement que les dispositifs classiques connus jusqu'à ce jour. Si l'influence du blindage 32 est très importante dans le dispositif d'amplification de puissance de l'invention, on notera cependant que la tolérance sur les dimensions (taille et épaisseur) du blindage est très petite (typiquement de l'ordre de 100 μm) devant la longueur d'onde rayonnée dans le dispositif (pour les systèmes dont les fréquences de fonctionnement sont inférieures à 5 GHz), ce qui n'est donc pas problématique. La reproductibilité est assurée pour des longueurs d'onde grandes devant les dimensions physiques du détecteur 24 et du capteur 31. Le capteur 31 peut prendre diverses formes, dont certaines sont illustrées par les figures 4A et 4B. Ainsi, sur la figure 4A, le capteur 31 est réalisé sous la forme d'un MEMS 41 (pour "Micro-Electro-Mechanical System", "système micro-électromécanique" - inductance de fort coefficient de qualité et de forte précision) implanté sur un circuit intégré 40 réalisé selon une technologie CMOS, BiCMOS ou encore SiGe. Un tel circuit intégré comprend les différents éléments constitutifs du dispositif d'amplification de puissance de l'invention (détecteur, comparateur, amplificateur de puissance, condensateurs, contrôleur...), de sorte que le dispositif global est très compact. La figure 4B illustre un autre mode de réalisation du capteur 31 sous la forme d'une inductance 42. Plus généralement, le capteur 31 peut être tout type d'élément rayonnant agissant comme une antenne et capable de capter l'énergie rayonnée au sein du dispositif d'amplification de puissance. Notamment, un tel capteur 31 peut prendre la forme d'une ligne d'un routage de PCB ou d'un élément rayonnant intégré sur le dessus d'une puce, par exemple la puce du détecteur/comparateur 24. Lorsque le capteur 31 est réalisé sous la forme d'une inductance, il peut s'agir par exemple d'une self bobinée de 12 nH, dans le cadre d'un amplificateur de puissance "GSM/DCS dual band". Dans une variante de réalisation, le capteur 31 est un circuit accordé de type LC ou RLC, dont les valeurs des composants sont choisies (selon des techniques bien connues de l'Homme du Métier) de façon à obtenir des bosses de gain aux fréquences de fonctionnement de l'antenne du terminal de radiocommunication (typiquement à 900 MHz et 1800 MHz dans le cas d'un radiotéléphone GSM). Quelle que soit la forme choisie pour le capteur 31, le dispositif d'amplification de puissance de l'invention reste beaucoup plus petit que le dispositif de l'art antérieur à base de coupleurs (figure 2A), qui est classiquement réalisé sur un substrat céramique. En outre, l'invention permet de se dispenser de l'atténuateur résistif généralement situé en amont du coupleur selon l'art antérieur. Tous les composants du dispositif d'amplification de puissance de l'invention peuvent être réalisés selon la même technologie, d'où une grande facilité d'intégration. Dans une variante de réalisation de l'invention, la boucle fermée d'asservissement de la figure 3, comprenant notamment le détecteur/CAP 24 et le contrôleur 25, peut être réalisée sous forme logicielle. La comparaison des puissances est alors réalisée dans la partie en bande de base du terminal de radiocommunication. La figure 5 présente plus en détail un exemple de réalisation pratique du dispositif d'amplification de puissance de la figure 3, faisant apparaître plus clairement les différents composants de chacun des blocs fonctionnels 23 à 26. Un tel exemple d'agencement est communiqué à titre illustratif, et ne sera donc pas décrit ici plus en détail. L'abaque de Smith de la figure 6 caractérise la tolérance du dispositif d'amplification de puissance de l'invention à une antenne du terminal de radiocommunication qui serait défectueuse, et ne serait donc pas centrée sur 50 Ω. Elle a été réalisée pour un amplificateur de puissance réalisé sur arsénure de gallium (technologie GaAs), et illustre la variation du Taux d'Ondes Stationnaires, ou TOS toute phase. Sur l'abaque de la figure 6, plus l'impédance de la charge s'éloigne de la valeur 50 Ω, correspondant au centre de l'abaque, et plus le TOS augmente. Les figures 7A à 7D présentent quant à elles les performances comparatives du dispositif d'amplification de puissance de l'invention et de dispositifs correspondants de l'art antérieur. Plus précisément, les figures 7A et 7B correspondent à un dispositif d'amplification de puissance d'un terminal de radiocommunication conforme à la norme GSM, alors que les figures 7C et 7D correspondent au même dispositif pour un radiotéléphone de type DCS ("Digital Cellular System", pour "système cellulaire numérique"). Les courbes des figures 7A et 7C (respectivement 7B et 7D) représentent la puissance maximale délivrée en sortie du dispositif d'amplification de puissance, exprimée en dBm, en fonction du taux d'ondes stationnaires, ou TOS, et représentent donc l'influence maximale (respectivement minimale) d'une mauvaise adaptation de la charge. Les courbes en trait plein concernent plus particulièrement un dispositif d'amplification de puissance à asservissement en boucle fermée du type illustré en figure 2A. Les courbes en traits mixtes concernent quant à elle un dispositif d'amplification de puissance dont le contrôle est réalisé en boucle ouverte, et caractérisent donc le comportement intrinsèque de la puce de l'amplificateur de puissance. Enfin, les courbes en traits pointillés sont représentatives des performances du dispositif de l'invention (figure 3). Comme on peut le constater, les performances du dispositif de l'invention, mettant en œuvre une évaluation de la puissance rayonnée au sein du dispositif, sont très proches de celles du dispositif asservi en boucle fermée de la figure 2A, qui met en œuvre une évaluation, par coupleurs, de la puissance conduite au sein du dispositif. Plus généralement, le dispositif de l'invention présente des performances similaires à celui de l'art antérieur à base de coupleurs (figure 2A), tant en termes de puissance de sortie que de comportement vis-à-vis d'une mauvaise adaptation de la charge et de performances sur le chemin de transmission. En résumé, la technique de contrôle de puissance du dispositif de l'invention présente les avantages suivants par rapport aux techniques antérieures : - un coût réduit, grâce notamment à la suppression des coupleurs ; une réduction des pertes RF sur le chemin de transmission ; des performances au moins égales à celles de la technique antérieure à base de coupleurs, en cas de mauvaise adaptation de la charge ; - une possibilité d'intégrer le dispositif sous la forme d'un composant de très petite taille, grâce à la possibilité de réaliser tous les éléments du dispositif selon la même technologie, et de minimiser la distance entre le détecteur et le capteur ; les fuites, qui étaient critiques dans le système antérieur en boucle fermée de la figure 2A, ne le sont plus. The invention therefore proposes a completely innovative approach which goes against the prejudices of those skilled in the art. Preferably, said sensor belongs to the group comprising: inductors; - the routing lines of a printed circuit of said device; MEMS (in English "Micro-Electro-Mechanical Systems", in French "Micro-electro-mechanical systems"); the radiating elements printed on a printed circuit of said device; LC or RLC type tuned circuits. According to an advantageous characteristic of the invention, said means power amplifier and said sensor are placed close to each other, so as to optimize said coupling. Thus, while until now we have tried to keep the coupler and the power amplifier as far apart as possible, to avoid any harmful phenomenon of coupling, the invention proposes, on the contrary, to bring the amplifier and the sensor as close as possible , to increase this phenomenon, and therefore optimize the operation of the device. It is thus possible to design devices that are much more compact and much less bulky than according to the prior art. Preferably, said shielding means induce an attenuation of at least 10 dB of an energy external to said device picked up by said sensor with respect to said energy radiated within said device picked up by said sensor. If this attenuation is higher, typically at least 20 dB, the operation of the device is further optimized. This prevents the radiotelephone antenna from causing disturbances in the operation of the power amplification device. Advantageously, when said sensor is a tuned circuit of LC or RLC type, the values of the components of said tuned circuit are chosen so as to maximize said power delivered at output at at least one predetermined operating frequency of said device. For example, in the case of a GSM power amplifier, the value of the components is chosen so as to obtain at the output two gain bumps at 900 MHz and 1800 MHz. Advantageously, said control means make it possible to control said power delivered as an output as a function of at least one parameter belonging to the group comprising: an operating temperature of said device; a supply voltage of said device; a load impedance of said device. According to an advantageous alternative embodiment of the invention, said sensor is integrated into said detection means. This increases the integration and compactness of the device. The sensor can for example be written on top of the detector / comparator chip. Advantageously, said shielding means comprise a metal shielding cover having a surface substantially parallel to a printed circuit forming the base of said device and four sides substantially perpendicular to said surface coming to bear on each of the edges of said printed circuit. The shielding means can also take the form of any metallic element covering the printed circuit, connected to its ground, and performing a shielding function. The invention also relates to a radiocommunication terminal, comprising a power amplification device as described above. 6. List of Figures Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment, given by way of simple illustrative and nonlimiting example, and of the appended drawings, among which: - Figure 1 shows a block diagram of the radiofrequency part of a radiocommunication terminal, comprising a power amplification device intended to supply the antenna of the terminal; FIGS. 2A to 2C describe three techniques of the prior art for controlling the power delivered at the output of a power amplification device; FIG. 3 describes a power amplification device according to the invention, in which the control of the power delivered at the output comprises a closed loop implementing a sensor of the radiated energy within the device; - Figures 4A and 4B show two embodiments of the sensor of the Figure 3; FIG. 5 illustrates a detailed embodiment of the power amplification device of the invention; FIG. 6 shows a Smith chart representing the performance, as a function of the load impedance, of the device of the invention; FIGS. 7A to 7D show comparative curves of the influence of the adaptation of the load ("load mismatch") for the solution of the invention and for two solutions of the prior art. 7. Description of an embodiment of the invention The general principle of the invention is based on the use of a radiating element making it possible to capture the radiated energy (and not conducted) within a device for power amplification, so as to achieve a closed loop control of the RF or microwave power delivered at the output of this device. Referring to FIG. 3, a block diagram of such a power amplification device according to the invention is presented. As will be noted, in all the figures in this document, the identical elements are designated by the same reference numeral. In the particular example of FIG. 3, the power amplifier 21 is preceded upstream, and followed downstream, by a link capacitor 20, 22. Such link capacitors are optional. In the example of FIG. 3, the downstream capacitor 22 separates the output of the power amplifier 21 from the output 30 of the amplification device of FIG. 3. Such an output 30 is for example connected to the external antenna of a radiocommunication terminal. The control of the power delivered on the output 30 of the device, depending in particular on the temperature, the voltage delivered by the battery of the terminal, the load impedance, is carried out by means of a closed control loop comprising : a sensor 31 of the energy radiated within the device, symbolized by the arrows 33; reference means, in the form of a ramp 26, generated by the baseband part of the radiocommunication terminal, and delivering a reference voltage serving as a reference for the power delivered at output 30 of the device; - Detection and comparison means 24, also called "detector / comparator" (Detector / CAP), which recover the value of the radiated power picked up by the radiating element 31 and compare it to the reference voltage supplied by the ramp 26; means 25 for controlling the polarization of the power amplifier 21, making it possible, as a function of the result of the comparison 24, to regulate this polarization, so that the power detected by the detector / comparator 24 and converted into voltage is also as close as possible to the reference voltage indicated by the ramp 26. In other words, there is therefore placed, at the input of the RF or microwave detector 24, a sensor 31 which captures the electromagnetic field which radiates in the physical structure of the module of FIG. 3. One thus obtains, as in the case of couplers (FIG. 2A), an image of the power emitted on the antenna of the radiotelephone, which makes it possible to carry out the control 25 of the polarization of the amplifier. power 21. The absence of discrete couplers in the power amplification device of FIG. 3 makes it possible to greatly reduce its cost price. The device of FIG. 3 also includes a shield 32, which can take the form of a metal bowl covering the printed circuit on which the various components are installed, or even a metal grid. More generally, such shielding 32 can take the form of any metallized element connected to the ground of the circuit, performing a shielding function and covering the printed circuit. According to the prior art, such a shield 32 was essentially intended to prevent the energy radiated by the power amplification device from leaving the device (in the form of harmonics conveyed by the ambient air), and coming disrupt the other functional blocks of the radiocommunication terminal, or other neighboring equipment. According to the invention, such shielding 32 also participates in coupling, by reflecting towards the sensor 31 the radiated energy 33 conveyed by the ambient medium (air). The sensor 31 thus recovers the energy reflected by the shielding 32, but also the energy which comes directly from the chip of the power amplifier 21, or from leaks by the lines of the printed circuit (or PCB for "Printed Circuit Board"") of the overall arrangement. The proportion of the power captured by the sensor 31 which corresponds to the power actually delivered by the amplifier 21 depends on the nature of the sensor, its size and its technical characteristics. It can be evaluated that the shield 32 plays approximately half (or 3 dB) in the total power recovered by the sensor 31. Such a shield 32 must be effective enough to "block" the power radiated by the antenna of the radiotelephone connected to the output 30 of the device, and prevent this power from being picked up by the radiating element 31. Indeed, such a harmful phenomenon would cause a calibration problem, because the sensor 31 would measure, not only the power radiated inside the housing of the device of FIG. 3, but also the power external to the box, coming from the antenna. The total detected power would then be greater than the power effectively radiated within the device, and the polarization controller 25 would then erroneously reduce the supply voltage of the amplifier 21, to reduce the RF or microwave power delivered on the output 30. To avoid this problem, the inventors of the present patent application estimated that it was necessary for the shield 32 to induce an attenuation of at least 10 dB, and ideally at least 20 dB, of the external power. . In other words, the coupling between the external antenna (connected to the output 30) and the sensor 31 should be approximately 20 dB less than the coupling between the power amplifier 21 and the sensor 31. Note that, unlike the conventional solutions of the prior art which were trying to avoid as much as possible the harmful phenomenon of coupling induced by the shielding 32, the device of the present invention exploits this coupling effect as much as possible, to increase the value of the radiated power evaluated by the sensor 31. To do this, the invention proposes in particular to bring the sensor 31 and the detector 24 as close as possible to the chip of the power amplifier 21, whereas attempts have hitherto been made in the prior art to keep these elements of each other. The invention therefore allows better integrability and a smaller footprint than conventional devices known to date. If the influence of the shield 32 is very important in the power amplification device of the invention, it will however be noted that the tolerance on the dimensions (size and thickness) of the shield is very small (typically of the order of 100 μm) in front of the wavelength radiated in the device (for systems whose operating frequencies are less than 5 GHz), which is therefore not problematic. Reproducibility is ensured for long wavelengths compared to the physical dimensions of the detector 24 and of the sensor 31. The sensor 31 can take various forms, some of which are illustrated in FIGS. 4A and 4B. Thus, in FIG. 4A, the sensor 31 is produced in the form of a MEMS 41 (for "Micro-Electro-Mechanical System", "micro-electromechanical system" - inductance with a high coefficient of quality and high precision) implanted on an integrated circuit 40 produced using CMOS, BiCMOS or SiGe technology. Such an integrated circuit includes the various constituent elements of the power amplification device of the invention (detector, comparator, power amplifier, capacitors, controller, etc.), so that the overall device is very compact. FIG. 4B illustrates another embodiment of the sensor 31 in the form of an inductor 42. More generally, the sensor 31 can be any type of radiating element acting as an antenna and capable of capturing the energy radiated within the power amplification device. In particular, such a sensor 31 can take the form of a line of a PCB routing or of a radiating element integrated on top of a chip, for example the chip of the detector / comparator 24. When the sensor 31 is produced in the form of an inductor, it may for example be a wound coil of 12 nH, in the context of a "GSM / DCS dual band" power amplifier. In an alternative embodiment, the sensor 31 is an LC or RLC type tuned circuit, the values of the components of which are chosen (according to techniques well known to those skilled in the art) so as to obtain gain bumps at frequencies of operation of the radiocommunication terminal antenna (typically at 900 MHz and 1800 MHz in the case of a GSM radiotelephone). Whatever the shape chosen for the sensor 31, the power amplification device of the invention remains much smaller than the device of the prior art based on couplers (FIG. 2A), which is conventionally produced on a substrate. ceramic. In addition, the invention makes it possible to dispense with the resistive attenuator generally located upstream of the coupler according to the prior art. All the components of the power amplification device of the invention can be produced using the same technology, hence great ease of integration. In an alternative embodiment of the invention, the closed control loop of FIG. 3, comprising in particular the detector / CAP 24 and the controller 25, can be produced in software form. The comparison of the powers is then carried out in the baseband part of the radiocommunication terminal. FIG. 5 presents in more detail a practical embodiment of the power amplification device of FIG. 3, showing more clearly the various components of each of the functional blocks 23 to 26. Such an example of arrangement is communicated by way of illustrative, and will therefore not be described here in more detail. The Smith chart of FIG. 6 characterizes the tolerance of the power amplification device of the invention to an antenna of the radiocommunication terminal which would be defective, and therefore would not be centered on 50 Ω. It was carried out for a power amplifier produced on gallium arsenide (GaAs technology), and illustrates the variation of the Stationary Wave Rate, or TOS any phase. On the abacus of figure 6, the more the impedance of the load moves away from the value 50 Ω, corresponding to the center of the abacus, the more the TOS increases. FIGS. 7A to 7D present the comparative performances of the power amplification device of the invention and of corresponding devices of the prior art. More specifically, FIGS. 7A and 7B correspond to a device for amplifying the power of a radiocommunication terminal conforming to the GSM standard, while FIGS. 7C and 7D correspond to the same device for a radiotelephone of the DCS ("Digital Cellular") type. System ", for" digital cellular system "). The curves of FIGS. 7A and 7C (respectively 7B and 7D) represent the maximum power delivered at the output of the power amplification device, expressed in dBm, as a function of the standing wave rate, or TOS, and therefore represent the influence maximum (respectively minimum) of a poor adaptation of the load. The solid lines curves relate more particularly to a closed loop control power amplification device of the type illustrated in FIG. 2A. The dashed lines relate to a power amplification device, the control of which is carried out in an open loop, and therefore characterize the intrinsic behavior of the power amplifier chip. Finally, the curves in dotted lines are representative of the performance of the device of the invention (Figure 3). As can be seen, the performance of the device of the invention, implementing an evaluation of the radiated power within the device, are very close to those of the closed-loop slave device of FIG. 2A, which implements an evaluation, by couplers, of the power driven within the device. More generally, the device of the invention has performances similar to that of the prior art based on couplers (FIG. 2A), both in terms of output power and behavior with regard to poor adaptation of load and performance on the transmission path. In summary, the power control technique of the device of the invention has the following advantages compared to previous techniques: - reduced cost, thanks in particular to the elimination of couplers; reduction of RF losses on the transmission path; performances at least equal to those of the prior art based on couplers, in the event of poor load adaptation; - a possibility of integrating the device in the form of a very small component, thanks to the possibility of making all the elements of the device according to the same technology, and of minimizing the distance between the detector and the sensor; the leaks, which were critical in the prior closed loop system of Figure 2A, are no longer so.

Claims

REVENDICATIONS
1. Dispositif d'amplification de puissance radiofréquence (RF) et/ou hyperfréquence, notamment pour terminal de radiocommunication, comprenant des moyens de blindage dudit dispositif et des moyens de contrôle d'une puissance délivrée en sortie dudit dispositif, comprenant une boucle d'asservissement en puissance présentant des moyens de référence, des moyens de détection, des moyens de comparaison et des moyens d'amplification de puissance, caractérisé en ce que lesdits moyens de contrôle comprennent également au moins un capteur d'une énergie rayonnée au sein dudit dispositif.1. Radio frequency (RF) and / or microwave power amplification device, in particular for radiocommunication terminal, comprising means for shielding said device and means for controlling a power delivered at the output of said device, comprising a loop of power control having reference means, detection means, comparison means and power amplification means, characterized in that said control means also comprise at least one sensor of radiated energy within said device .
2. Dispositif d'amplification de puissance selon la revendication 1, caractérisé en ce que lesdits moyens de blindage réalisent un couplage entre lesdits moyens d'amplification de puissance et ledit capteur.2. Power amplification device according to claim 1, characterized in that said shielding means couple between said power amplification means and said sensor.
3. Dispositif d'amplification de puissance selon l'une quelconque des revendications 1 et 2, caractérisé en ce que ledit capteur appartient au groupe comprenant : les inductances ; les lignes de routage d'un circuit imprimé dudit dispositif ; les MEMS (en anglais "Micro-Electro-Mechanical Systems", en français "Systèmes micro-électro-mécaniques") ; les éléments rayonnants imprimés sur un circuit imprimé dudit dispositif ; les circuits accordés de type LC ou RLC.3. Power amplification device according to any one of claims 1 and 2, characterized in that said sensor belongs to the group comprising: the inductors; the routing lines of a printed circuit of said device; MEMS (in English "Micro-Electro-Mechanical Systems", in French "Micro-electro-mechanical systems"); the radiating elements printed on a printed circuit of said device; LC or RLC type tuned circuits.
4. Dispositif d'amplification de puissance selon l'une quelconque des revendications 1 à 3, caractérisé en ce que lesdits moyens d'amplification de puissance et ledit capteur sont placés à proximité les uns des autres, de façon à optimiser ledit couplage.4. Power amplification device according to any one of claims 1 to 3, characterized in that said power amplification means and said sensor are placed close to each other, so as to optimize said coupling.
5. Dispositif d'amplification de puissance selon l'une quelconque des revendications 1 à 4, caractérisé en ce que lesdits moyens de blindage induisent une atténuation d'au moins 10 dB d'une énergie extérieure audit dispositif captée par ledit capteur par rapport à ladite énergie rayonnée au sein dudit dispositif captée par ledit capteur.5. Power amplification device according to any one of claims 1 to 4, characterized in that said shielding means induce an attenuation of at least 10 dB of an energy external to said device picked up by said sensor with respect to said energy radiated within said device received by said sensor.
6. Dispositif d'amplification de puissance selon l'une quelconque des revendications 3 à 5, caractérisé en ce que, lorsque ledit capteur est un circuit accordé de type LC ou RLC, les valeurs des composants dudit circuit accordé sont choisies de façon à maximiser ladite puissance délivrée en sortie à au moins une fréquence de fonctionnement prédéterminée dudit dispositif.6. Power amplification device according to any one of claims 3 to 5, characterized in that, when said sensor is a tuned circuit of LC or RLC type, the values of the components of said tuned circuit are chosen so as to maximize said power output at at least a predetermined operating frequency of said device.
7. Dispositif d'amplification de puissance selon l'une quelconque des revendications 1 à 6, caractérisé en ce que lesdits moyens de contrôle permettent de contrôler ladite puissance délivrée en sortie en fonction d'au moins un paramètre appartenant au groupe comprenant : une température de fonctionnement dudit dispositif ; une tension d'alimentation dudit dispositif ; une impédance de charge dudit dispositif.7. Power amplification device according to any one of claims 1 to 6, characterized in that said control means make it possible to control said power delivered as an output as a function of at least one parameter belonging to the group comprising: a temperature operating said device; a supply voltage of said device; a load impedance of said device.
8. Dispositif d'amplification de puissance selon l'une quelconque des revendications 1 à 7, caractérisé en ce que ledit capteur est intégré dans lesdits moyens de détection.8. Power amplification device according to any one of claims 1 to 7, characterized in that said sensor is integrated in said detection means.
9. Dispositif d'amplification de puissance selon l'une quelconque des revendications 1 à 8, caractérisé en ce que lesdits moyens de blindage comprennent un capot de blindage métallique présentant une surface sensiblement parallèle à un circuit imprimé formant la base dudit dispositif et quatre pans sensiblement perpendiculaires à ladite surface venant en appui sur chacun des bords dudit circuit imprimé.9. Power amplification device according to any one of claims 1 to 8, characterized in that said shielding means comprise a metal shielding cover having a surface substantially parallel to a printed circuit forming the base of said device and four sides substantially perpendicular to said surface bearing on each of the edges of said printed circuit.
10. Terminal de radiocommunication, caractérisé en ce qu'il comprend un dispositif d'amplification de puissance selon l'une quelconque des revendications 1 à 9. 10. Radiocommunication terminal, characterized in that it comprises a power amplification device according to any one of claims 1 to 9.
EP04805495A 2003-12-23 2004-11-19 Radio frequency (rf) and/or microwave power amplification device and corresponding radio communication terminal Withdrawn EP1698051A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0315340A FR2864376B1 (en) 2003-12-23 2003-12-23 RADIO FREQUENCY (RF) AND / OR HYPERFREQUENCY POWER AMPLIFICATION DEVICE AND CORRESPONDING RADIOCOMMUNICATION TERMINAL
PCT/FR2004/002962 WO2005071829A1 (en) 2003-12-23 2004-11-19 Radio frequency (rf) and/or microwave power amplification device and corresponding radio communication terminal

Publications (1)

Publication Number Publication Date
EP1698051A1 true EP1698051A1 (en) 2006-09-06

Family

ID=34630546

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04805495A Withdrawn EP1698051A1 (en) 2003-12-23 2004-11-19 Radio frequency (rf) and/or microwave power amplification device and corresponding radio communication terminal

Country Status (5)

Country Link
US (1) US7720447B2 (en)
EP (1) EP1698051A1 (en)
CN (1) CN1898861B (en)
FR (1) FR2864376B1 (en)
WO (1) WO2005071829A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5149715B2 (en) * 2008-06-30 2013-02-20 キヤノン株式会社 COMMUNICATION SYSTEM, COMMUNICATION DEVICE, ITS CONTROL METHOD, PROGRAM

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6208135B1 (en) * 1994-07-22 2001-03-27 Steve J. Shattil Inductive noise cancellation circuit for electromagnetic pickups
JPH08195632A (en) * 1995-01-17 1996-07-30 Toyota Motor Corp Preamplifier for gps antenna
US6009311A (en) * 1996-02-21 1999-12-28 Etymotic Research Method and apparatus for reducing audio interference from cellular telephone transmissions
DE19905635C2 (en) * 1999-02-11 2001-05-17 Daimler Chrysler Ag Portable radio transmitter, especially radio key
US6681125B1 (en) * 1999-04-08 2004-01-20 Jong-Myung Woo Wireless telecommunication terminal
US6564038B1 (en) * 2000-02-23 2003-05-13 Lucent Technologies Inc. Method and apparatus for suppressing interference using active shielding techniques
US6957051B1 (en) * 2000-09-29 2005-10-18 Avaya Technology Corp. Apparatus for local reduction of electromagnetic field using an active shield and method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2005071829A1 *

Also Published As

Publication number Publication date
US20070159258A1 (en) 2007-07-12
CN1898861A (en) 2007-01-17
CN1898861B (en) 2010-09-29
FR2864376A1 (en) 2005-06-24
FR2864376B1 (en) 2006-03-10
WO2005071829A1 (en) 2005-08-04
US7720447B2 (en) 2010-05-18

Similar Documents

Publication Publication Date Title
EP1172929B1 (en) Low noise amplifier arrangement especially for cellular mobile telephone
EP0963039B1 (en) Radio-frequency device comprising a power amplifier circuit with a stabilising circuit, and a transmit-receive mobile terminal incorporating such a device
FR2794307A1 (en) Over voltage protection circuit for mobile telephone power amplifier, has transistor amplifiers with final stage including grid circuit between collector to base region connected to produce compensation feedback voltage
EP3082072A1 (en) Receiving unit of an rfid tag
EP0455570A1 (en) Very wide bandwidth amplifier device for DC to microwave frequencies, particularly in the form of an integrated circuit
EP1698051A1 (en) Radio frequency (rf) and/or microwave power amplification device and corresponding radio communication terminal
EP2652835A1 (en) Active band stop filter
EP2705605B1 (en) Amplification circuit and reception chain
CA2246002A1 (en) Transmitter for radiotelephone terminal and corresponding terminal
FR2750816A1 (en) DIELECTRIC RESONATOR SOURCE IN GALLERY MODE
EP2182631A2 (en) Broadband microwave frequency amplifier cell with variable gain and amplifier comprising such a cell
EP1251634A1 (en) Transconductance stage and RF communications device including such a stage
WO2021165210A1 (en) Integrated circuit comprising an adaptation and filtering network, and corresponding adaptation and filtering method
FR2967537A1 (en) Antenna i.e. planar Inverted-F slot antenna, for e.g. mobile telephone to receive TV channels during live telecasting of sports events, has adaptation element realizing inductive impedance adaptation if antenna is capacitive type antenna
EP0120756A1 (en) Oscillator comprising high-frequency bandpass amplifier having an adaptable impedance
EP3619815B1 (en) Method for controlling the matching of an antenna to a transmission path, and corresponding device
FR2823031A1 (en) GAIN SWITCHING AMPLIFIER DEVICE, PARTICULARLY FOR A CELLULAR MOBILE TELEPHONE
EP1337038B1 (en) Power control loop, radiofrequency amplifying circuit, and transmitter for radiofrequency signals having such a circuit
EP2464005B1 (en) Differential amplifier for asymmetric / symmetric conversion
EP2278704A1 (en) Radiofrequency signal power amplifying method and apparatus.
FR2882204A1 (en) Broadband microwave monolithic integrated circuit amplifier circuit for optical telecommunication application, has short-circuit series resistor of gate of each polarization transistor of polarization cell with its source integrated to cell
FR3048831A1 (en) IMPROVED RECEPTION CHAIN; EMISSION-RECEPTION MODULE HAVING SUCH A RECEIVING CHAIN
EP2168242B1 (en) Active switching device and hyper-frequency integrated circuit including such device
FR2678435A1 (en) VARIABLE ATTENUATOR WITH PHASE CORRECTION.
FR2767013A1 (en) METHOD AND DEVICE FOR MONITORING THE ENVELOPE OF A RADIO SIGNAL

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: 20060512

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LU MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20071004

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20140503