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: 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 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: 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 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: 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: 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 Automatic Identification System—AIS—receiver comprising at least one processing section (PS1, PS2) for synchronizing, demodulating and detecting AIS messages contained in a received signal, said processing steps being carried out separately for a plurality of frequency sub-bands (SB1, SB2, SB3) spanning an AIS channel (CH1, CH2); the receiver being characterized in that: said sub-bands overlap with each others; and said or each processing section is adapted for synchronizing, demodulating and detecting said AIS messages within each sub-band on the basis of timing error and carrier frequency estimations obtained from filtered replicas of said received signal, propagating along respective auxiliary signal paths.

Abstract: A solar array system includes at least one solar array and at least one solar array regulator. The solar array regulator has an input port to be connected to the solar array, and an output port to be connected to a power bus. The solar array comprises a switching voltage converter comprising a step-down (PC1) and a step-up (PC2) power cell connected in cascade; and a control circuit for driving said voltage converter in a step-up, a step-down or a direct energy transfer mode, depending on an input control signal and on at least one feedback signal (SILF) indicative of an operating condition of said switching voltage converter; characterized in that said at least one feedback signal (SILF) is indicative of an intensity of an electrical current (IL) flowing between said step-down and said step-up power cells, whereby the control circuit implements an internal current feedback control.

Abstract: A configurable Turbo-LDPC decoder having A set of P>1 Soft-Input-Soft-Output decoding units (DP0-DPP-1; DPi) for iteratively decoding both Turbo- and LDPC-encoded input data, each of the decoding units having first (I1i) and second (I2i) input ports and first (O1i) and second (O2i) output ports for intermediate data; First and second memories (M1, M2) for storing the intermediate data, each of the first and second memories comprising P independently readable and writable memory blocks having respective input and output ports; and A configurable switching network (SN) for connecting the first input and output ports of the decoding units to the output and input ports of the first memory, and the second input and output ports of the decoding units to the output and input ports of the second memory.

Abstract: A reconfigurable reflector for electromagnetic waves, comprising: a rigid support element (10) having a front surface (13); an elastically deformable reflective membrane (30) lying over the front surface of said rigid support element; and a plurality of linear actuators (20) for deforming said reflective membrane by operating on predetermined points thereof; wherein said linear actuators are embedded within said rigid support element, and have shafts (22) protruding by the front surface thereof for operating on predetermined points of said elastically deformable reflective membrane. Preferably, the rigid support element comprises a reflector dish having a sandwich structure having a honeycomb core (11) made of CFRP or aluminum, in which the linear actuators are embedded by conventional potting techniques. Antenna system comprising such a reconfigurable reflector, possibly operating as a subreflector (SR), and spacecraft telecommunication.

Abstract: A radio-frequency power amplifier with envelope tracking, comprising: a power RF amplifying device for amplifying a RF signal; and a switching DC/DC converter, comprising a switching device and a rectifying device, for providing said power RF amplifying device with a DC power supply at a voltage level proportional to an envelope of said RF signal; wherein said switching device is a RF power transistor; characterized in that said rectifying device, and preferably also said power RF amplifying device, is also a transistor of a same technology, connected as a two-terminal device. Preferably, said power RF amplifying device is also a transistor of said same technology. A low-pass filter can also be provided for reducing the bandwidth of the envelope signal on which the PWM signal driving the DC/DC converter depends.

Abstract: The invention concerns a waveguide filter (200NP) for microwaves, characterized in that it has, at least on part of its length, a cross-section having two mutually non-parallel opposite sides (111, 111?), for example trapezoid. The use of such a shape enables the power threshold for forming self-maintained electron avalanche discharges to substantially increased and satisfactory filtering properties to be obtained. The invention also concerns the use of such a filter in a high-power microwave transmitter operating in X and Ka bands, in particular for space applications.

Abstract: A sequential switching shunt regulator cell comprising: a power line (PL) for connecting a power source (SA) to a power bus (PB); a shunting (SSW) switch for shunting said power line; and driving means (DM) for opening or closing said shunting switch depending on an error signal (MEA) indicative of a voltage level of said power bus; characterized in that it also comprises: a non-redundant rectifier (D3) connected in series to said power line for disconnecting the power bus from the shunting switch when the latter is closed; and a fault detector (FD) for detecting a short-circuit fault condition of said non-redundant rectifier, and for opening the shunting switch in reply to said condition. Advantageously, the rectifier can be a synchronous rectifier. A solar power regulator comprising a plurality of solar arrays connected to a power bus through respective sequential switching shunt regulator cells of the kind described above.

Abstract: A beam-forming network having: a plurality (NI) of input signal ports (IP); a plurality (NO) of output signal ports (OP); a weighting and interconnecting network (WIN) comprising a plurality of signal dividers (SD), phase and amplitude weighting elements (WE), switches (SW1, SW2) and signal combiners (SC), for associating each input port to output ports through respective weighting units; wherein either input (IP) or output (OP) ports, or both, are partitioned into disjoint equivalence classes (IEC, OEC), at least a majority of said equivalence classes having more than one port; and in that the network is either configured in order to associate each input port to at most one output port for each output equivalence class, or to associate each output port to at most one input port for each input equivalence class, or both. Also provide is a multibeam antenna comprising having such a beam-forming network, and an electronic circuit for implementing such a beam-forming network.