Thales Alenia Space Italia S.p.a. Con Unico Socio

Alenia Spazio S.p.a.

Rodolfo Ravanelli

Roberto Mizzoni

Paolo Campana

The invention relates to a microwave circular polarizer including: a first outer conductor; a second outer conductor connected to the first outer conductor forming a first step discontinuity therewith; and a third outer conductor connected to the second outer conductor forming a second step discontinuity therewith. An inner conductor is provided which extends inside and is spaced apart from the first, second and third outer conductors. The first and second outer conductors are axially asymmetric with respect to the inner conductor, and the third outer conductor is axially symmetric with respect to the inner conductor. The microwave circular polarizer includes first and second rectangular waveguide ports in signal communication with an internal cavity through, respectively, a first rectangular aperture and a second rectangular aperture formed through the first outer conductor. The microwave circular polarizer further includes a first septum and a second septum.

Microwave circular polarizer

Disclosed herein is a double-reflector antenna () for use on board a satellite or space platform for data downlink or for telemetry, tracking and command. Said double-reflector antenna () comprises a main reflector () and a sub-reflector () arranged coaxially with, and in front of, one another. Additionally, the double-reflector antenna () further comprises a coaxial feeder, that is arranged coaxially with the main reflector () and the sub-reflector (), and that includes inner () and outer () conductors arranged coaxially with, and spaced apart from, one another. The coaxial feeder is designed to be fed with downlink microwave signals to be transmitted by the double-reflector antenna (), and to radiate said downlink microwave signals through a feed aperture (), that is located centrally with respect to the main reflector () and that gives onto the sub-reflector (). The inner conductor () protrudes axially and outwardly from the feed aperture () up to the sub-reflector () and is rigidly coupled to said sub-reflector () thereby supporting said sub-reflector ().

Double-reflector antenna and related antenna system for use on board low-earth-orbit satellites for high-throughput data downlink and/or for telemetry, tracking and command

A novel planar variable power divider, using waveguide technology, includes two hybrids and two variable phase shifters. The variable power divider includes a variable phase shifter based on a 3 dB hybrid circuit terminated by two sliding non-contacting moveable short circuits. The differential phase spreading of the phase shifter has been reduced to less than one-sixth of typical transmission line dispersion by the compensating short terminations. As a consequence, electrical performance achievable over a 16% bandwidth is significantly improved with respect to heretofore-known variable power dividers. The variable power divider also provides for planar integration, wideband performance, medium-high power handling capabilities and low loss.

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Rome, Italy

Rodolfo Ravanelli