Agence Spatiale Europeenne

Agence Spatiale Europeene

Emmanuel Rammos

Antoine G Roederer

Peter Balling

A receive and/or transmit microwave planar array antenna is of the multiplate stack type comprising a plurality of slot radiating elements disposed along the rows and the columns of a matrix. The basic stack comprises three ground plates incorporating openings and two independent excitation circuit planes, enabling transmission or reception of two inclined beams. At least two other excitation circuit planes are provided so that each beam can additionally have dual polarization. The excitation circuits are microstrips, coplanar waveguides, dipole lines, of the loop or slot type, or a combination of such lines. Two consecutive lines are oriented at 90.degree. to each other. Applications include individual reception from two geostationary television satellites.

Planar microwave receive and/or transmit array antenna and application

A duplexing circularly polarized composite antenna comprises at least one pair of radiator elements supportings orthogonal (vertical and horizontal) linear polarization. One radiator element is fed with a signal with a phase difference of 90.degree. relative to the signal fed to the other radiator element. Each radiator element transmits and/or receives signals at two different frequencies having orthogonal polarization. One radiator element operates at a first frequency with vertical polarization and a second frequency with horizontal polarization. The other radiator element operates at the first frequency with horizontal polarization and at the second frequency with vertical polarization.

Duplexing circularly polarized composite

A planar antenna of the kind comprising feed lines disposed in a flat circuit and cooperating by hyperfrequency coupling with a metal ground plane plate pierced by apertures has the feed lines presenting a termination juxtaposed with each aperture. A lower ground plane plate is disposed at a distance of approximately a quarter wavelength from the apertured metal plate. The apertured metal plate comprises a metal coating deposited on a dielectric substrate. The feed line comprise central conductors disposed in channels which open into the apertures. The array of apertures, channels and conductors can be produced on the dielectric substate by single face printed circuit techniques. The antenna may be used for the reception of direct broadcasts from satellites.

Planar array antenna, comprising coplanar waveguide printed feed lines

A large scan antenna, particularly for embarked use on board a satellite and for operation in the ultrahigh frequency range, of the type formed of a feed and a main fixed secondary reflector, the antenna being readily foldable into a launching configuration with a minimum of component elements, and comprising at least one guide G each formed of a first and a second parabolic secondary reflectors (12, 13) aligned optically along the axis of the wave guide G between the feed (10) and the main reflector (15), said wave guide G being on the one hand variable in length by moving at least one (13) of said secondary reflectors with respect to the other (12) along the axis (14) of the wave guide G, and on the other hand, rotatable about the axis (11) of the feed (10).

Large scan antenna with fixed main reflector and fixed feed,

Inside a parallelepipedic guide section there is provided at least one partition located so as to divide the inner volume of the guide section into a main waveguide portion capable of supporting an orthogonally polarized signal and two secondary waveguide portions extending in the same direction as the main waveguide portion. The secondary waveguide portions are so dimensioned such that one of these waveguide portions is capable of supporting a horizontally polarized signal and that the second waveguide portion is capable of supporting a vertically polarized signal.

Compact orthomode transducer

A rectilinear waveguide junction apparatus in which the input and output guides are parallel to the longitudinal axis of the apparatus. This apparatus is characterized in that it takes the form of a parallelipiped guide the internal volume of which is divided up by metal partitions which form two parallel input guides, two parallel output guides and a main intermediate guide of same section as the parallelipiped guide. This apparatus is used in very high frequency circuits, for example the supply circuits for satellite or radar antennae.

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Oegstgeest, Netherlands

Emmanuel Rammos