A multi-beam antenna comprises an array of feeds illuminating a reflector, the feeds being associated in a plurality of groups. Each feed comprises a polarizer, two diplexers and four ports operating in four different colours. All the feeds belonging to the same group comprise first ports having the same first colour, or second ports having the same second colour, linked together to form a first beam and third ports having the same third colour, or fourth ports having the same fourth colour, linked together to form a second beam.