Abstract: The invention relates to processes and devices which make it possible to directly modulate an RF carrier with a quadrature signal. It consists in filtering (504) this quadrature signal around zero so as to introduce alternately (507, 508) on each of the channels a low-frequency subcarrier that will serve as reference. Each of these channels is alternately demodulated in a synchronous manner (519) cosine-wise and sine-wise. The demodulation signal is filtered (523) so as to recover the subcarrier marred by modulation errors. The measurement of these errors (524) allows feedback correction (503) of the quadrature signal. It makes it possible to perform the major part of the operations in the digital processor (501) and enables direct vector modulation to be made possible at millimeter frequencies.

Abstract: This invention relates to an antenna comprising at least one radiating device, furnished with a rejector filter associated with a frequency band of an interfering signal. In accordance with the invention, such an antenna is characterized in that this rejector filter is adaptive, so as to be active when the interfering signal is detected and its power is above a threshold, this adaptive filter being deactivated when the detected power of this interfering signal is below the threshold.

Abstract: The invention provides a simple solution for a broadband transmitter/receiver for which the working bandwidth is split into at least two non-contiguous sub-bands. The invention uses a filtering means 50 which comprises at least two band-pass filters 51 and 52 provided with switching means 53 and 54. The use of two switched filters 51 and 52 makes it possible to use a single synthesizer 6 to scan two sub-bands of the working bandwidth. The frequency synthesizer 6 operates for one sub-band in supradyne mode and for the other sub-band in infradyne mode. In a variant, the invention uses a third filter and divides the bandwidth into three sub-bands.

Abstract: The invention is a device and a method for cancelling interferences between signals with frequency proximity, inherent to the co-location of multi-standard terminals, in a communication system.

Abstract: The invention proposes an upgradeable product enabling a single circuit to be produced and very easily configured in the factory for a lower production cost. The minimisation of the industrialisation costs is achieved by an increase of production volumes. An outdoor unit of a reception terminal including a return channel, comprises a band-pass filtering means that allows the transposed signals found in a transmission bandwidth to pass, and a rejector filtering means that rejects at least one frequency found in the transmission bandwidth, the rejector filtering means being neutralised when neither the frequency defined in the oscillator nor a multiple frequency of the defined frequency is found in the transmission bandwidth.

Abstract: The method of improving the carrier-to-noise ratio for a receiver with diversity, and the associated device, consists, after extracting, by phase shifting, the noise component of the signals to be demodulated, in optimizing the cancellation of the useful component via a feedback loop acting on the phase shifter and in summing the noise component in phase and in phase opposition with these signals to improve the carrier-to-noise ratio.

Abstract: The gain control method for the RF and IF amplification stages of a bursty data frame reception system enables, following a step for evaluating the received signal strength, the gain adjustment step of the RF amplification stage to be temporarily deferred until a frame structure symbol is received, during which the gain adjustment step of the IF amplification stage takes place simultaneously with that of the RF gain, while retaining an overall gain linearly dependent on the input signal strength.

Abstract: An RF signals amplification block receives a first RF signal, and comprises means of amplification of this first RF signal so as to deliver a second, amplified, RF signal. This signal must be amplified by a predetermined nominal power so as to be delivered at the output of the block. The block comprises means of measurement of the power of the second, amplified, RF signal, means of coupling the amplified RF signal to a first output of the block, a control signal generated by a central processing unit for controlling the coupling means. The invention also relates to an RF signals transmission device intended to be arranged at the focus of RF signals focusing means comprising a block according to the invention and an RF signals transmission antenna/terminal. Particular application to the tracking of nonsynchronous satellites.

Abstract: The invention proposes an upgradable product capable of covering two sub-bands. An outdoor unit comprises, on the uplink, a switchable oscillator coupled to a waveguide featuring a removable cover enabling the said waveguide to be converted into a band rejector filter.

Abstract: The module comprises an input/output access point at a first end of a waveguide with a square cross section, called a square waveguide, two access points made of waveguides with a rectangular cross section, called rectangular waveguides, placed side by side at a second end of the square waveguide and a septum positioned in the square waveguide at the end of a separation region common to the two rectangular waveguides in order to allow the production of two circular polarizations of opposite handedness each associated with a rectangular waveguide. The module is arranged so as to form a diplexer in which the septum is included and where the access points by rectangular waveguide are extended by filters, each access point being endowed with a filter provided in order to transmit a frequency band which is different. The steps of the septum are dimensioned so as to compensate for reflections.

Abstract: The invention relates to a wideband phase shift device. A phase shift ? is introduced on the fixed frequency local oscillator. The principle of the invention is to realise a double translation of the input signals. The phase variation introduced at the level of the local oscillator has a positive value on one of the translated signals and a negative value on the other. The signals are recombined at the reception frequency with a phase difference of 2 ? so as to maximise the amplitude of the signal at the output of the summator.

Abstract: The reception device according to the invention enables, through a predictive detection of fading on the channels adjacent to the selected channel n, the phase of the incoming signals received from secondary antennas to be corrected so as to eliminate the fading.

Abstract: The invention aims to minimize the analogue/digital converter over-dimensioning within the framework of reception of signals originating from a satellite and exhibiting power levels which can vary over time. The invention proposes a technique of automatic gain control which handles the setting of the noise level associated with the amplified signal. The automatic gain control is achieved by neutralizing the signal received by the antenna, and by adjusting the gain during the neutralization of the signal received until a predetermined noise level is obtained at the end of the reception facility. The invention also pertains to a device comprising the means for implementing the method.

Abstract: The invention relates to a transmitting device limiting the out-of-band interferences. The modulation is done with or without inversion of the spectrum. Next, frequency transposition is done in supradyne or infradyne fashion such that the parasitic effects originating from the modulation are always situated in the frequency band allocated for transmission. The invention relates to the transmission method, on the one hand, and to the transmission device, on the other hand.

Abstract: The invention proposes a filtering device having a frequency response which is symmetrical, using asymmetrical filters coupled by transposition means. The advantageous characteristics of the asymmetrical filters are retained and the faults associated with the asymmetry are eliminated. The asymmetrical filters are, for example, quartz filters. The invention also proposes an external transmission and reception unit, using the filtering device with the application of the filtering method.

Abstract: The invention proposes a radio wave emission block intended to modify a satellite-based reception installation into a cheaper emission/reception installation. The emission block comprises a first input/output terminal and a second input/output terminal electrically linked to the first input/output terminal by way of a band rejection filter which rejects the intermediate emission frequency band. The invention also pertains to a tranmission device comprising a reception block coupled with the emission block.

Abstract: The invention relates to a device for converting frequencies comprising a local oscillator of fixed frequency and a first mixer with two inputs and an output, a first input receiving the signal to be converted and a second input receiving the signal arising from the local oscillator. It further comprises a second mixer with two inputs and an output, a first input receiving the signal arising from the phase-shifted local oscillator and the second input receiving a dc signal whose value is dependent on the power of the residual spectral component at the output of an adder receiving as input the signals arising from the first and from the second mixer(s) and giving as output a transposed signal. The invention applies in particular in terminals operating in the Ka band.

Abstract: The invention relates to VHF adapters for cable networks of the ODU type. It consists in using two conversion chains, up and down, in which a very stable signal reference oscillator drives means of generating the VHF and IF local frequencies common to these two conversion chains. A very selective surface wave filter makes it possible to rject the frequency of the local oscillator at the level of the first intermediate frequency. It makes it possible to obtain a DOCSIS compatible millimeter MWS ODU whose frequency stability and spectral purity satisfy the constraints of the cable standard without undertaking spectral inversion of the signals transmitted and received.

Abstract: The system for receiving broadcast digital data (in particular pay television services) comprises a master digital terminal, and at least one slave digital terminal connected to the master terminal by a link and able to receive protected digital data. The slave digital terminal can access the protected data only if information necessary for accessing the data and received by the master digital terminal is sent by way of link to the slave digital terminal within a predetermined deadline. This information is in particular access entitlements to television services or keys for descrambling the services.

Abstract: The module comprises an input/output access point at a first end of a waveguide with a square cross section, called a square waveguide, two access points made of waveguides with a rectangular cross section, called rectangular waveguides, placed side by side at a second end of the square waveguide and a septum positioned in the square waveguide at the end of a separation region common to the two rectangular waveguides in order to allow the production of two circular polarizations of opposite handedness each associated with a rectangular waveguide. The module is arranged so as to form a diplexer in which the septum is included and where the access points by rectangular waveguide are extended by filters, each access point being endowed with a filter provided in order to transmit a frequency band which is different. The steps of the septum are dimensioned so as to compensate for reflections.