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

Antenna system (2,3,4) for use on board a satellite or space platform for data downlink and for telemetry, tracking and command, comprising a first antenna (21,31,41) and a second antenna (22, 32, 42), wherein said second antenna (22, 32, 42) is coaxially aligned with, and is arranged on top of, the first antenna (21,31,41);

• wherein the first antenna (21,31,41) is a first double-reflector antenna comprising a first main reflector (211,311,411) and a first sub-reflector (212, 312) arranged coaxially with, and in front of, one another;
• the first antenna (21,31,41) further comprising a first coaxial feeder, that is arranged coaxially with the first main reflector (211,311,411), the first sub-reflector (212, 312) and the second antenna (22, 32, 42), and that includes an outer conductor (23, 33) and a first inner conductor (24, 34) which are arranged coaxially with, and spaced apart from, one another;
• wherein the first coaxial feeder is designed to be fed with first downlink microwave signals to be transmitted by the first antenna (21,31,41), and to radiate said first downlink microwave signals through a first feed aperture (232,332), that is located centrally with respect to the first main reflector (211,311,411) and that gives onto the first sub-reflector (212, 312);
• wherein the first inner conductor (24, 34) protrudes coaxially and outwardly from the first feed aperture (232, 332) up to the first sub-reflector (212, 312) and is rigidly coupled to said first sub-reflector (212, 312) thereby supporting said first sub-reflector (212, 312);
• and wherein a transmission line is provided in the first inner conductor (24, 34) to feed the second antenna (22, 32, 42) with second downlink microwave signals to be transmitted by said second antenna (22,32,42).