Abstract: Disclosed herein is a double-reflector antenna (1) for use on board a satellite or space platform for data downlink or for telemetry, tracking and command. Said double-reflector antenna (1) comprises a main reflector (11) and a sub-reflector (12) arranged coaxially with, and in front of, one another. Additionally, the double-reflector antenna (1) further comprises a coaxial feeder, that is arranged coaxially with the main reflector (11) and the sub-reflector (12), and that includes inner (14) and outer (13) 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 (1), and to radiate said downlink microwave signals through a feed aperture (15), that is located centrally with respect to the main reflector (11) and that gives onto the sub-reflector (12).

Abstract: Disclosed herein is a double-reflector antenna (1) for use on board a satellite or space platform for data downlink or for telemetry, tracking and command. Said double-reflector antenna (1) comprises a main reflector (11) and a sub-reflector (12) arranged coaxially with, and in front of, one another. Additionally, the double-reflector antenna (1) further comprises a coaxial feeder, that is arranged coaxially with the main reflector (11) and the sub-reflector (12), and that includes inner (14) and outer (13) 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 (1), and to radiate said downlink microwave signals through a feed aperture (15), that is located centrally with respect to the main reflector (11) and that gives onto the sub-reflector (12).

Abstract: The present invention regards an antenna system comprising a reflection system that comprises a reflector having a rotational symmetry with respect to an axis of symmetry. Moreover, the antenna system also comprises an electronically steerable planar radiating array that is arranged in a focal region of the reflection system, has a rotational symmetry with respect to the axis of symmetry and is operable to radiate a primary radiofrequency beam oriented in a predefined direction of illumination with respect to the axis of symmetry in such a way as to cause a specific region of the reflector to be illuminated by said primary radiofrequency beam. Said specific region of the reflector is designed, when illuminated by said primary radiofrequency beam, to generate by reflection a secondary radiofrequency beam oriented in at least one predefined direction of transmission with respect to the axis of symmetry.

Abstract: The present invention regards an antenna system comprising a reflection system that comprises a reflector having a rotational symmetry with respect to an axis of symmetry. Moreover, the antenna system also comprises an electronically steerable planar radiating array that is arranged in a focal region of the reflection system, has a rotational symmetry with respect to the axis of symmetry and is operable to radiate a primary radiofrequency beam oriented in a predefined direction of illumination with respect to the axis of symmetry in such a way as to cause a specific region of the reflector to be illuminated by said primary radiofrequency beam. Said specific region of the reflector is designed, when illuminated by said primary radiofrequency beam, to generate by reflection a secondary radiofrequency beam oriented in at least one predefined direction of transmission with respect to the axis of symmetry.

Abstract: A double-reflector microwave antenna of the Gregorian optics family and capable of providing an elliptical beam with a major axis that may be oriented in any desired direction of space by rotation of the sub-reflector about an axis. By adding an additional degree of freedom, that is, an independent translation of the sub-reflector and/or the main reflector along respective axes, a considerable degree of reconfigurability of the shape of the beam may be realized. In particular, the axes of the beam may be widened to vary the ratio between the axes of the elliptical beam for any orientation of the major axis or to obtain a circular beam. The inventive antenna is particularly suitable for use as on board satellites with frequency re-use in an operational environment with one or more simultaneously active beams.

Abstract: 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.