Upgrade to the K-band uplink channel for the ESA Deep Space Antennas: Analysis of the optics and preliminary dichroic mirror design

The incoming planned missions to the Moon and beyond would require an uplink channel significantly larger in frequency than the ones normally used in S and X band. This paper presents a preliminary study for the upgrade of the European Space Agency (ESA) Deep Space Antennas (DSAs) optical configuration in order to implement the new K band uplink channel (22.55-23.15 GHz). Among the different possible Beam Waveguide (BWG) layouts, one of the many aspect to be investigated is the design of new Frequency Selective Surfaces (FSSs), which are employed to merge/separate the different frequency bands. Preliminary designs and results, for both the BWG optics and the dichroic mirrors, are presented, with a particular focus on the advantages and disadvantages of the different solutions.