X band receiver noise temperature improvement in ESA deep space antennas

ESA has deployed two 35 m deep space antennas: one in New Norcia (Australia) and one in Cebreros (Spain). Future missions will require improved G/T in order to support higher telemetry data rate (for imaging or video applications for example) and improved link budget margin. It is proposed here to show the noise temperature and G/T improvement we can achieve by optimizing the cryogenic receiver design and front end filtering. ESA has developed in collaboration with Chalmers University and Centre de Astronomico de Yebes very high performance InP (Indium Phosphide) cryogenic amplifiers in order to improve LNA noise temperature by 6K. In addition, improving cryogenic receiver filter and diplexer loss will decrease the receiver noise temperature by 3K. Longer term improvement will be to implement a cryogenic polarizer. The overall expected G/T improvements is 1.6 dB which is equivalent to a dish size increase to 42m.