Abstract: A method of manufacturing an array antenna comprising: a design phase wherein an array layout of said array antenna is synthesized and radiating elements are designed to be arranged according to said array layout; and a phase of physically making said array antenna wherein the radiating elements are arranged according to said array layout.

Abstract: A method for manufacturing an array antenna having a design phase, including synthesizing an array layout of the array antenna and choosing or designing radiating elements to be arranged according to the array layout; and a phase of physically making the array antenna, including arranging the radiating elements according to the array layout; the design phase having the steps of: a) synthesizing an array layout complying with a required minimum beamwidth, a required field of view, a required side lobe level and a target angular dependence of the maximum directivity of the array antenna over the required field of view; b) determining shaped radiation patterns of the radiating elements in order to approximate said target angular dependence of the maximum directivity of the array antenna over the required field of view; and c) choosing or designing radiating elements having the shaped radiation patterns determined at step b).

Abstract: A method of transmitting data packets from a terminal (T) to a gateway receiver (GWR) over a channel shared with other terminals using an unslotted spread spectrum random access protocol, characterized in that transmission is performed at a transmit power level given by the sum of a deterministic term, function of a communication link budget, and of a random term, following a predetermined probability distribution. A method of operating a communication system, based on the method of transmitting data packets. A communication system and a terminal for implementing the methods.

Abstract: A digital beam-forming network for an array antenna having N>1 antenna ports, to be associated to respective antenna elements, and M?1 beam ports (BP), corresponding to respective antenna beams. The digital beam-forming network comprises a plurality of complex weighting elements interconnected through summing nodes. At least one of the complex weighting elements is connected to either two antenna ports, to be associated with respective antenna elements which are arranged symmetrically with respect to the symmetry axis, or two beam ports corresponding to respective antenna beams pointing toward directions which are symmetrical with respect to the symmetry axis, or both. The digital beam forming network can be a part of an array antenna comprising N antenna elements, NS of which are arranged according to an array pattern having a symmetry axis, NS being an even integer different from zero.

Abstract: A deployable structure comprises a first and second flexible tension members respectively defining a first and second contours of a ring. A first plurality of rigid compression members extends between the first and second contours. Only one end of each first plurality compression member is mounted on the first contour. A second plurality of rigid compression members extends between the first and second contours. Only one end of each second plurality compression member is mounted on the second contour. The first and second plurality of compression members are arranged with a repetitive crossing pattern around the ring. A first plurality of flexible tension members link each end of a compression member mounted on one of said contours to an end of another non-mounted compression member and a second plurality of flexible tension members link each end of a non-mounted compression member to an end of another non-mounted compression member.

Abstract: The application discloses a one or two dimensional array of electromagnetic scatterers n scatterers (ED), whereby the aforementioned scatterers (ED) are arranged aperiodically on a curved line or surface (S). Further, the application describes a reflectarray antenna comprising at least one such array of electromagnetic scatters (ED) and at least one receiving and/or transmitting feed (F), cooperating with said array to generate an antenna beam A method for designing and manufacturing sais array and said antenna is explained. The method optimizes in a several stages all degrees of freedom in order improve the performance of reflectarrays, increase the flexibility thereof and/or the conformity thereof with design specifications (radio pattern) and/or allowing said specifications to be satisfied with a smaller number of scatters.

Abstract: A data detection method, having the steps of: a. receiving a signal transmitted over a communication channel, the signal being representative of at least a stream of interfering symbols xk, each representing one or more bits of a transmitted message; b. filtering the received signal through at least a filter bank having at least a first filter representative of a linear response of the channel and a second filter representative of a non-linear response of the channel, and sampling the filtered signals at the symbol rate, thus obtaining respective sequences of filtered samples rk(1) rk(3); and c. jointly computing the a posteriori probabilities of N>1 consecutive symbols xk. A data detector for carrying out such a method, and a method of transmitting data over a nonlinear channel, optimizing spectral efficiency when data detection is performed using such a method is also provided.

Abstract: A wideband reflectarray antenna for dual polarizations application is formed by an array of phasing cells, where each cell contains two orthogonal or quasi-orthogonal sets of parallel conductive dipoles printed on two levels of a multilayered grounded substrate. The dipoles for each polarization are coupled in both horizontal and vertical directions, providing a large broadband operation and low cross-polarization with only two levels of metallizations. The antenna is designed by adjusting the lengths of the dipoles to produce the phase-shift required to collimate or shape the radiated beam in dual-polarization when illuminated by a feed, either in broadband or dual-frequency operation. The invention also relates to a design and manufacturing method for producing the reflectarray antenna, based on the optimization of the dipole lengths for each phasing cell.

Abstract: A radio-frequency power amplifier with envelope tracking, having a power RF amplifying device for amplifying a RF signal and a switching DC/DC converter for providing the power RF amplifying device with a DC power supply at a voltage level (VSUPP) proportional to an envelope of the RF signal, wherein the switching DC/DC converter has a reversed buck topology. Advantageously the switching device is a N-type GaN Field Effect Transistor having its drain connected to the ground.

Abstract: A method of providing multi-beam coverage of a Region of Interest (ROI) in a multi-beam satellite communication system in which a non-uniform traffic demand density is defined over said Region of Interest, the method including partitioning the Region of Interest into N>1 non-overlapping cells (V1-V10, Vi); and generating N satellite beams, each of the satellite beams providing coverage of a respective cell. The step of partitioning the Region of Interest into N>1 non-overlapping cells is performed in such a way that the traffic demand associated to the cells is substantially uniform. Advantageously, the cells form a Voronoi diagram defined over the Region of Interest, the satellite beams being pointed towards the cells of the Voronoi diagram. A satellite communication system implementing the method is also provided.

Abstract: An offset imaging antenna system with compensated optical aberrations comprises a main a paraboloid reflector, a first paraboloid sub reflector, and a first feeding array as an arrangement of first feed array elements to illuminate or to be illuminated by the first sub reflector. The main reflector and the first sub reflector are confocal by sharing a common focal point. The first feeding array has a curved shape that corresponds to a first equivalent array of magnified image feed elements lying on a plane crossing the main optical centre and perpendicular to the main bore-sight axis, all the first feed array elements being positioned as to provide a planar distribution of the positions of the image feed elements onto the first equivalent array after a second reflection by the main reflector with a central image point coinciding with the main reflector optical centre under a maximum illumination condition.

Abstract: A digital beam-forming network (DBF) for an array antenna having N>1 antenna ports (EP), to be associated to respective antenna elements (RE), and M?1 beam ports (BP), corresponding to respective antenna beams (AB), said digital beam-forming network comprising a plurality of complex weighting elements (CWE-SE, CWE-SB, CWE-SESB) interconnected through summing nodes (SN); wherein at least one of said complex weighting element is connected to either two antenna ports, to be associated to respective antenna elements which are arranged symmetrically with respect to said symmetry axis, or two beam ports corresponding to respective antenna beams pointing toward directions which are symmetrical with respect to said symmetry axis, or both. An array antenna comprising N antenna elements, NS of which are arranged according to an array pattern having a symmetry axis, NS being an even integer different from zero, and such a digital beam-forming network.

Abstract: A beam-forming network for an emitting array antenna having at least NB input ports connected to respective beam ports of the beam-forming network and at least NOSA>1 output ports, for associating to each output port a linear combination of input signals from respective input ports; a set of at least NOSA lossless single-mode networks, each having an input port connected to a respective output port of multi-beam network and at least NNOSAOSA>1 output ports, for associating to each output port a signal obtained by weighting an input signal from the input port; and a set of at least NNOSA?NNOSAOSA lossless multi-mode networks, each having at least NNOSAOSA NOSANOSA input ports, each one connected to an output port of a respective single-mode network, and at least NENOSA>1 output ports connected to respective antenna ports of the beam-forming network, for associating to each output port a linear combination of input signals from respective input ports.

Abstract: A satellite communication system including a multibeam satellite for generating a plurality of feeder beams and a plurality of user beams over a region of interest, a plurality of spatially-separated gateway stations for providing feeder links to said multibeam satellite via respective feeder beams; and a control for operating said gateway stations and multibeam satellite such that: in nominal conditions, NGW gateway stations exchange data with K user beams, each of the gateway stations allocating a fraction of its bandwidth to each of the user beams; and in case of fading, data are switched from faded to unfaded gateway stations, whereby none of said user terminals experiences service outage. A method of performing satellite communication using the satellite communication system, and a multibeam communication satellite payload for carrying out the method are provided.

Abstract: An Uplink Power Control method of adjusting an operating point of a High-Power Amplifier (HPA) of a ground-to-satellite emitter (GWj, GWk, GWl) as a function of propagation attenuation, characterized in that the method includes the steps of: a) determining an optimal Output Back Off value of the High-Power Amplifier which, for an operational propagation attenuation level, maximizes a Signal over Noise plus total interference ratio at the satellite taking into account contributions from cochannel and cross-polar interferences, intermodulation interferences and thermal noise; and b) setting the operating point of the High-Power Amplifier at the optimal Output Back Off value. A ground-to-satellite emitter comprising a High-Power Amplifier (HPA), a control means (PROC) for adjusting an operating point of said High-Power Amplifier by carrying out such a method.

Abstract: An electrical power conditioning for an electrical power conditioning system comprises a first terminal for connecting either an electrical power generator or a battery; a second terminal for connecting either a battery or an electrical power generator, respectively; a third terminal for connecting a power bus; characterized in that it further comprises: a reactive structure connected between said second terminal and the ground, formed by a serial connection of a first inductor, a capacitor and a second inductor, first and second nodes being provided between the first inductor and the capacitor, and between the capacitor and the second inductor, respectively; at least one output switching structure for connecting the third terminal to the first and second nodes through respective first and second switches and a third in-series inductor; and at least one input switching structure for connecting the first terminal to at least the first node through a third switch.

Abstract: A radio-frequency power amplifier with envelope tracking, having a power RF amplifying device for amplifying a RF signal and a switching DC/DC converter for providing the power RF amplifying device with a DC power supply at a voltage level (VSUPP) proportional to an envelope of the RF signal, wherein the switching DC/DC converter has a reversed buck topology. Advantageously the switching device is a N-type GaN Field Effect Transistor having its drain connected to the ground.

Abstract: A re-entry broadcasting alert apparatus having a housing provided with a heat shielda connector for attaching the housing to a space system and releasing it during atmospheric re-entry thereof; a geolocalisation receiver, for determining the position of the apparatus; a processor programmed to determine a hazard area on ground and/or in airspace, where debris from the space system are expected to fall, taking the position of the apparatus as input data; and a transmitter for broadcasting a signal carrying information defining the hazard area; the geolocalisation receiver, processor and transmitter being located within the housing. A re-entry alert receiving device, cooperating with the re-entry broadcasting alert apparatus. A re-entry broadcasting alert system having a re-entry broadcasting alert apparatus and at least a re-entry alert receiving device. A method of broadcasting re-entry alerts using such a system.

Abstract: An Uplink Power Control method of adjusting an operating point of a High-Power Amplifier (HPA) of a ground-to-satellite emitter (GWj, GWk, GWl) as a function of propagation attenuation, characterized in that the method includes the steps of: a) determining an optimal Output Back Off value of the High-Power Amplifier which, for an operational propagation attenuation level, maximizes a Signal over Noise plus total interference ratio at the satellite taking into account contributions from cochannel and cross-polar interferences, intermodulation interferences and thermal noise; and b) setting the operating point of the High-Power Amplifier at the optimal Output Back Off value. A ground-to-satellite emitter comprising a High-Power Amplifier (HPA), a control means (PROC) for adjusting an operating point of said High-Power Amplifier by carrying out such a method.

Abstract: A satellite communication system including a multibeam satellite for generating a plurality of feeder beams and a plurality of user beams over a region of interest, a plurality of spatially-separated gateway stations for providing feeder links to said multibeam satellite via respective feeder beams; and a control for operating said gateway stations and multibeam satellite such that: in nominal conditions, NGW gateway stations exchange data with K user beams, each of the gateway stations allocating a fraction of its bandwidth to each of the user beams; and in case of fading, data are switched from faded to unfaded gateway stations, whereby none of said user terminals experiences service outage. A method of performing satellite communication using the satellite communication system, and a multibeam communication satellite payload for carrying out the method are provided.