The reflector-optics and feed system of an 11 m diameter earth-station antenna that operates in circular polarization at X-band is described. The reflector-optics are required to have high G/T, sidelobes that satisfy the CCIR recommendation and low mismatch at the feed due to the subreflector. The feed system is required to have high isolation between the transmit and receive ports (> 40 dB) at the centre of the band. This isolation is achieved by minimizing reflections from all components forward of the polarizer. As well as meeting the high-isolation requirement, the feed system has an insertion loss < 0.15 dB and an axial ratio < 0.5 dB. A feed system was constructed and tested and some results are described.
|Number of pages||4|
|Journal||National Conference Publication - Institution of Engineers, Australia|
|Issue number||94 /7|
|Publication status||Published - 1994|