Alcatel Espace

Thales

Alcatel

Alcatel N.v.

Das Photonics S.l

Gerard Caille

Michel Sotom

Philippe Voisin

Michel Gomez-Henry

Thierry Dusseux

Olivier Remondiere

Yann Cailloce

Frederic Magnin

Jean-Louis Cazaux

Cyril Mangenot

Eric Labiole

Claude Argagnon

Miguel Angel Piqueras Ruiperez

Teresa Mengual Chulia

Christian Feat

Herve Legay

Daniele Bresciani

Cecile Guiraud

A distributed feeding device for antenna beamforming comprises a first distributed feeding circuit comprising P inputs and N outputs, for producing a signal on each of its outputs with a phase shift which is substantially constant between two adjacent outputs, at least one frequency multiplexer connected to at least one input of the said first circuit, a number N of frequency demultiplexers each connected, by their input, to an output of the first circuit and a second distributed feeding means comprising a plurality of inputs, each connected to an output of one of the frequency demultiplexers, and a plurality of outputs, the second distributed feeding means comprising at least one second distributed feeding circuit comprising Q inputs and M outputs, for producing a signal on each output with a phase shift which is substantially constant between two adjacent outputs, the integers P, N, Q and M being equal or distinct.

Distributed feeding device for antenna beamforming

A distributed feeding circuit for antenna beamforming array comprises a plurality N of inputs and a plurality N of outputs, wherein the said circuit is adapted for receiving, on at least one input, an electrical signal at a microwave frequency, modulated on at least one optical carrier, the circuit comprising at least one assembly of at least two optical dividers, two delay lines of length zero or substantially equal to a fraction of the wavelength of the signal at its microwave frequency and two means for combining two optical signals, the assembly being arranged and the delay lines being configured so that the theoretical transfer function of the circuit is an orthogonal matrix.

Distributed feeding circuit for antenna beamforming array

A transmission relay system includes a receive antenna with first radiating elements, a transmit antenna with second radiating elements, and processing devices through which the first radiating elements and the second radiating elements are connected. The processing devices are in the form of processing systems all of which induce the same propagation time-delay. Each system connects a given first radiating element to a corresponding given second radiating element defined firstly by an angular position relative to a second axis of symmetry specific to the transmit antenna offset substantially 180.degree. relative to an angular position of the given first radiating element relative to a first axis of symmetry specific to the receive antenna and parallel to the second axis of symmetry and secondly by an eccentricity in the transmit antenna which is a function of an eccentricity of the given first radiating element in the receive antenna.

Transmission relay system

The invention concerns a microwave transmit/receive (T/R) circuit for a polarization synthesizer array antenna, especially a radar antenna. According to the invention the required polarization is obtained by applying two signals to an array element on two orthogonal feed paths with a variable phase difference between the two paths, both of which function simultaneously. In a preferred embodiment both transmit channels are provided with two power amplifiers which each amplify a signal from an in-phase power divider or a hybrid coupler, with a one-bit or two-bit controllable phase-shifter adding a phase-shift of 0.degree., 90.degree. or 180.degree. to synthesize orthogonal linear or circular polarizations. In a preferred embodiment the circuit according to the invention is partly or entirely implemented in monolithic (MMIC) technology. The invention also concerns an antenna including a T/R circuit as specified hereinabove.

Variable synthesized polarization active antenna

An electronically-scanned two-beam antenna designed for being installed on board a moving platform, and in particular a satellite. The antenna of the invention comprises a single, complex reflector whose reflectivity is responsive to the polarization with which it is illuminated, and associated with two arrays of orthogonally-polarized sources that illuminate the complex reflector using an offset configuration. The complex reflector is made up of two reflectors placed one in front of the other in the beam propagation direction. The first reflector is transparent to a first linear polarization and reflective to an orthogonal polarization, while the second reflector is reflective at least for the first polarization. The two resulting beams thus propagate in different directions, both parallel to the trajectory of the platform. Electronic scanning is provided in a plane perpendicular to the orbit plane. The invention is applicable to stereoscopic radars for observing the earth from a satellite, and also to radiometry.

Electronically-scanned two-beam antenna

In a method of calibrating an active antenna the active elements of a transfer function matrix are measured using a near field probe for each radiating source of the antenna. The probe is placed in front of each source in succession and each source is excited in turn with the opposite phase and with all the other sources of the array excited normally. In the case of linear superposition of radiated fields, the measurements obtained by this method yield the elements of the transfer function matrix directly. This allows for phase and amplitude errors due to the components of the active antenna and for the effects of coupling between adjacent sources which modify the theoretical characteristics of the antenna. In the non-linear case the measurements are repeated and the matrix is obtained by iteration based on a comparison of the theoretical values used to control the antenna and the measured fields actually obtained. Measurements carried out on individual active modules prior to assembly of the antenna can be used in one variant of the method.

Active antenna near field calibration method

A microwave array antenna comprises a plurality of like unit sources whose width increases progressively from the center of the array towards its ends and which are disposed relative to each other in such a way that substantially no illumination gaps are created in the array.

Microwave array antenna having sources of different widths

A high-efficiency active printed-circuit antenna system for pulsed frequency-hopping space radar electronically scanned in two planes encompasses in its timing diagram the transmission of a horizontal polarization pulse, the reception of echoes from a previous horizontal polarization pulse, the transmission of a vertical polarization pulse and the reception of echoes from a previous vertical polarization pulse. The system comprises several thousand MMIC modules distributed over the antenna and each connected to a printed-circuit radiating element comprising a plurality of dual polarized square patches connected by microstrip lines which excite them with the same amplitude and the same phase at two perpendicular ports. Switching between the two ports procures transmission or reception with horizontal or vertical polarization.

High-yield active printed-circuit antenna system for frequency-hopping

A method of forming the radiation pattern of a high efficiency active antenna for electronically-scanned radar, wherein its illumination laws, and thus its radiation patterns are dissociated in transmission and in reception; and equal amplitude illumination is provided in transmission in order to maximize the efficiency of the transmit amplifiers which are all identical, thereby minimizing their DC energy consumption and their dissipation. The invention is particularly suitable for use in space radars.

Growing community of inventors

Tournefeuille, France

Gerard Caille