Abstract: Method and device for calibrating an antenna includes the following steps: define a number n of positions of angles for the aircraft situated in a calibration zone: measure the value of the orientation of the antenna for each position n, [#a(n), #a(n)]; define the theoretical orientation of the antenna [#a(n)*, #a(n)*] by taking account of the pitch value, of the roll value, of the yaw value (heading) for the aircraft for each position n, and of the orientation values of the satellite [#r(n), #r(n)]: [Aa(n)*, Ea(n)*]=F(H(n), P(n), R(n), ##, ##, #R, ##, Ar(n), Er(n)), where F is a chosen geometric function; define a criterion C: C=#(#a(n)?#a(n)*)2+(#a(n)?#a(n)*)2; minimize the value of the criterion C so as to determine the bias values (##, ##, #R, ##) from the values [Aa*(n), Ea*(n)] and use the said bias values to minimize the disparities between the measured angles and the theoretical angles.

Abstract: Method and device for calibrating an antenna includes the following steps: define a number n of positions of angles for the aircraft situated in a calibration zone: measure the value of the orientation of the antenna for each position n, [#a(n), #a(n)]; define the theoretical orientation of the antenna [#a(n)*, #a(n)*] by taking account of the pitch value, of the roll value, of the yaw value (heading) for the aircraft for each position n, and of the orientation values of the satellite [#r(n), #r(n)]: [Aa(n)*, Ea(n)*]=F(H(n), P(n), R(n), ##, ##, #R, ##, Ar(n), Er(n)), where F is a chosen geometric function; define a criterion C: C=#(#a(n)?#a(n)*)2+(#a(n)?#a(n)*)2; minimize the value of the criterion C so as to determine the bias values (##, ##, #R, ##) from the values [Aa*(n), Ea*(n)] and use the said bias values to minimize the disparities between the measured angles and the theoretical angles.

Abstract: A dual-polarization communication antenna for satellite mobile links comprising a number of radiant elements etched on a substrate, a connector enabling the antenna elements to be connected to a power source, said antenna including one or more subantennas, each of said subantennas including: N dual-polarization antenna elements mounted in series with one another and linked together by means of a portion of a first conduction line C1; K dual-polarization antenna elements linked together by means of a portion of a second conduction line C3, said K antenna elements being arranged relative to one another in parallel; wherein said lines C1, C3 are electrically linked and linked to the connector; and the set formed by the N antenna elements is mounted in series with the set of the K antenna elements.

Abstract: A protective ballistic radome for a satellite antenna which can turn about an axis of rotation, has: a circular support in the form of a ring, having an axis of revolution RR? to coincide with the axis of rotation, with the circular support having a lower base and an upper part in planes respectively parallel and perpendicular to the axis RR?, an annular groove, having an axis of revolution that coincides with the axis RR?, opening onto the upper part of the circular support, a set of n contiguous walls having upper ends and lower ends in planes that are respectively parallel and perpendicular to the axis RR?, the walls having their lower ends inserted into the annular groove of the circular support in order to form a ballistic wall in the form of a tube of circular section, having the same axis of revolution RR?, about said satellite antenna.

Abstract: A dual-polarization communication antenna for satellite mobile links comprising a number of radiant elements etched on a substrate, a connector enabling the antenna elements to be connected to a power source, said antenna including one or more subantennas, each of said subantennas including: N dual-polarization antenna elements mounted in series with one another and linked together by means of a portion of a first conduction line C1; K dual-polarization antenna elements linked together by means of a portion of a second conduction line C3, said K antenna elements being arranged relative to one another in parallel; wherein said lines C1, C3 are electrically linked and linked to the connector; and the set formed by the N antenna elements is mounted in series with the set of the K antenna elements.

Abstract: Microwave source and polarizer which is formed of an electroformed monobloc comprising a thick plate or septum, greater than 1 mm in thickness. Frequencies of application include the 7.25 GHz and 8.4 GHz frequency bands.

Abstract: Microwave source and polarizer which is formed of an electroformed monobloc comprising a thick plate or septum, greater than 1 mm in thickness. Frequencies of application include the 7.25 GHz and 8.4 GHz frequency bands.

Abstract: The invention relates to a digital radiocommunication system having an antenna, one or several modems and frequency translators. The system also has at least one device external to the modems connected firstly to at least one modem, and secondly to at least one frequency translator. This device is designed to execute mathematical processing in base band on communication signals output from the modem and/or the translator, for example such as modulation by spectrum spreading of the signal received from the modem; and demodulation by spectrum dispreading of the signal received from frequency translators. Another purpose of the invention is a signal processing method like that used in the system. The invention is applicable to satellite radiocommunication systems onboard mobile ground stations capable of communicating while in movement.

Abstract: Radiofrequency apparatus and method including at least one transmitter and/or receiver of a useful signal S0, at least one device adapted to the application of a coefficient N to the useful signal S0. The method includes modulating the useful signal S0 with a frequency Fm, transposing the modulated signal S1 to a frequency Fm+Fol, and multiplying the transposed, modulated signal S3 by a coefficient N in order to obtain a signal S4 at a transmission frequency Fe.

Abstract: Method and radiofrequency apparatus comprising at least one transmitter and/or one receiver of one or more useful signals comprising at least one device adapted to applying a coefficient to the useful signal or signals. Application to BPSK to QPSK type modulation.

Abstract: An antenna system enabling a link between an airborne object sending out a signal E with any polarization and a moving body equipped with a dual-polarization antenna comprises at least one device to determine the position of the moving body and of the airborne object, and an assembly for positioning the antenna. The system comprises at least one polarization combiner receiving two signals H and V coming from the dual-polarization antenna, the signals H and V resulting from the signal coming from the airborne object; the combiner being adapted to recombining the signals H and V in order to obtain a signal E optimizing the link balance between the moving body and the airborne object.

Abstract: Method and radiofrequency apparatus comprising at least one transmitter and/or one receiver of one or more useful signals comprising at least one device adapted to applying a coefficient (N, K1, K2) to the useful signal or signals. Application to BPSK or QPSK type modulation.

Abstract: Radiofrequency apparatus and method comprising at least one transmitter and/or receiver of a useful signal S0, at least one device (4) adapted to the application of a coefficient N to the useful signal S0.

Abstract: A logic analyzer is provided with probes (20) deriving the signals to be tested which are introduced into a digitizer (22) provided with comparators which carry out a digitization according to a logic system having two states. It comprises a change-over circuit (21) arranged between the probe and the digitizer, which permits associating several or all comparators with a given signal to be tested to extend its digitization to a multi-level logic system. The change-over circuit (21) is constituted by a matrix of MOS transfer gates or field effect transistors (FET's). When the multi-level logic system has at least one medium state limited by two references, the medium state is displayed on a display device (24) according to a straight line or a monotonic curve joining the two references between the beginning and the end of the medium state. When the duration of the medium state exceeds a predetermined duration, the display device (24) is switched on to display the medium state.

Abstract: A logic analyzer for plural input channels generates trigger signals for first and second triggering modes selected by a multiplexer. In the first mode, a channel selector produces a detection signal in the form of a pulse when the plural input channels simultaneously have logic states matching a reference combination input to the channel selector. In the second mode, the channel selector produces a detection signal in the form of a pulse corresponding to the logic state of a channel selected by a channel selection signal input to the channel selector. The first mode triggering signal exhibits a digital transition when the pulse endures at least as long as a target time period determined by a target count times the interval between clock pulses while the second mode trigger signal exhibits a digital transition when the pulse terminates before enduring for the target time period.

Abstract: The invention relates to a charge transfer device (CTD) having two or four phases, for which the speed of transferring the stored charges is increased by means of self-induction members connected to each of the clock areas of each memory element so that the capacitive impedance presented initially to the clock signal generator by the CTD becomes a substantially resistive impedance. Such a charge transfer device having an increased transfer speed is used in digital oscilloscopy or in systems for handling pictures.

Abstract: Attenuator having a high input impedance and several switching levels for high frequencies and oscilloscope and active probe comprising such an attenuator. A high frequency attenuator (15) having a high input impedance and several switching stages intended to attenuate a high-frequency electric signal introduced at an input terminal (10) of the attenuator. The attenuator supplies at a low-impedance output terminal (11) an output signal corresponding to the attenuated input signal. The attenuator comprises k broadband amplifiers A.sub.n (1.ltoreq.n.ltoreq.k) having a very small input capacitance, capacitances D.sub.n arranged between each input and each output of each amplifier, and capacitances C.sub.n arranged between each input of each amplifier and the input terminal of the attenuator. The accurate attenuation switching levels are obtained by using different ratios C.sub.n /D.sub.

Abstract: A high frequency probe for a logic analyzer adapted to operate with different types of logic circuits, and signals which may or may not be superimposed on a dc component. After an input capacitance, a high frequency amplifier feeds both an output terminal and a compensator circuit which compares the deviation between low frequency or dc components appearing at the input and output terminals, and compensates for the deviation by reinjecting a signal at the input of the high frequency amplifier. Variable attenuation may also be also be included between the high frequency amplifier and the output terminal.

Abstract: A method and an arrangement for recovering an analog signal E(t) and for displaying and/or processing it, for example, on an oscilloscope as a useful recovered signal X(t), in the envelope display mode and/or in the signal display mode. In the method, the average values of the k results are determined which are obtained after multiplication of the analog signal E(t) by the function f.sub.k (t) chosen as a function of the passband of the analog signal E(t). These average values can also be obtained by means of a filter having a pulse response h.sub.k (t), where h.sub.k (t)=f.sub.k (.tau.-t). The filter has at its k outputs transmittances h.sub.k (t). These average values permit of calculating k coefficients S.sub.k, which serve to determine the calculated recovered signal S(t).