X-band downlink antenna characterised by isoflux gain mask

This paper presents development and measurement results of a X-band isoflux downlink antenna. Isoflux antennas have to fulfil strict requirements concerning pattern mask, cross polarisation and backlobes. To satisfy these requirements and simultaneously providing circularly polarised waves, a compact polariser was matched and combined with a specific horn geometry. The antenna was manufactured, tested and delivered as flight model to enlarge time slots for transmitting big data between Earth observation satellites and ground stations. This paper discusses pros and cons of isoflux antennas and summarises the manufactured hardware as well as corresponding measurement results.