Agence Spatiale Europeenne

Piero Angeletti

Giovanni Toso

Gianfranco Ruggerini

Riccardo De Gaudenzi

Marco Lisi

Giancarlo Bellaveglia

Emiliano Re

Nicolas Jeannin

Juan Lizarraga Cubillos

Alfredo Vernucci

Daniele Petrolati

Juan Camilo Lizarraga Cubillos

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. The design phase comprises the steps of: defining a continuous reference aperture; subdividing said continuous reference aperture into a plurality of elementary cells with assigned power levels; determining, within each said elementary cell, a position for at least one maximum efficiency radiating element; determining a size and an aperture field amplitude of each said maximum efficiency radiating element, such that a variation of a cumulative field distribution of the resulting array antenna aperture over each said elementary cell is substantially equal to a variation of a cumulative field distribution of said reference aperture over the same elementary cell, subject to size constraints.

Array antenna with optimized elements positions and dimensions

A digital beam-forming network for an array antenna having N&#x3e;1 antenna ports, to be associated to respective antenna elements, and M&#x2267;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, Nof which are arranged according to an array pattern having a symmetry axis, Nbeing an even integer different from zero.

Digital beam-forming network having a reduced complexity and array antenna comprising the same

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&#x3e;1 non-overlapping cells (V-V, V); 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&#x3e;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.

Method and a system of providing multi-beam coverage of a region of interest in multi-beam satellite communication

A beam-forming network for an emitting array antenna having at least Ninput ports connected to respective beam ports of the beam-forming network and at least N&#x3e;1 output ports, for associating to each output port a linear combination of input signals from respective input ports; a set of at least Nlossless single-mode networks, each having an input port connected to a respective output port of multi-beam network and at least N&#x3e;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 N&#x2267;Nlossless multi-mode networks, each having at least NNinput ports, each one connected to an output port of a respective single-mode network, and at least N&#x3e;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.

Beam-forming network for an array antenna and array antenna comprising the same

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, Ngateway 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.

Multibeam satellite communication system and method, and satellite payload for carrying out such a method

A beam-forming network having: a plurality (N) of input signal ports (IP); a plurality (N) 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 (SW, SW) 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.

Reconfigurable beam-forming-network architecture

A multibeam antenna comprising: a plurality of primary radiating elements, each associated to a respective beam; and an active radiating structure comprising a first planar array of radiating elements, a second planar array composed by a same number of radiating elements, a set of connections between each radiating element of the first planar array and one corresponding element of the second planar array, and a set of power amplifiers for amplifying signals transmitted through said connections; wherein: the relative positions of the radiating elements of the first and second planar arrays and phase delays introduced by said connections are such that the radiating structure forms an active discrete converging lens; and said primary radiating elements are clustered on a focal surface of said lens, facing the first planar array; characterized in that said first and second planar arrays are both aperiodic. A method of manufacturing such an antenna.

Multibeam active discrete lens antenna

A method of manufacturing an array antenna including a designing step which comprises: determining a one-dimensional reference radiation pattern and an associated reference aperture; computing the cumulative phasorial summation of the field distribution of said reference aperture in a reference direction and representing it as a reference curve in the complex plane; determining a polygonal curve optimally approximating said reference curve, subject to predetermined constraints; and determining, from said polygonal curve, an antenna array pattern, each side of said polygonal curve being associated to a particular antenna element of the array.

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Lisse, Netherlands

Piero Angeletti