The objective of the activity is to design, manufacture and test a dual-polarised waveguide rotary joint for Q- and V-band steerable feeder link antennas.Targeted Improvements:Enabling technology for dual-polarised and dual-frequency Q- and V-band mechanical steerable antennas for future low/medium Earth orbit telecommunication satellite constellations and geostationary satellite gateway linksDescription:Waveguide RF rotary joints are essential parts for the implementation of steerable antennas. Existing broadband rotary joints are only capable of limited steering angles. However, to support future low Earth orbit satellite constellations and medium Earth orbit applications potentially targeting mobile user links, the rotary joint is required to have a large steering angle to allow tracking of the ground stations. Mechanically-steerable antennas are also commonly found in the gateway feeder links of geostationary Earth orbit satellites in order to cope with late or changing ground station deployment. There is an already demonstrated benefit of implementing dual-polarisation rotary joints, which is a simplification of the mechanism. This concept has been further extended with the integration of two frequency bands (e.g. K/Ka-band) and two polarisations per band. In addition, a large scan angle(+/-200 degrees) needs to be implemented to allow the pointing mechanism to move with minimum variation of the RF performance (VSWR,isolation, etc.). When moving to higher frequencies (Q, V and beyond), the cross-section of the waveguide becomes very small (in the order of a few millimetres) and the implementation of the simple dual-polarisation concepts used at lower frequencies is not straight forward.This activity aims to develop a high power, Q/V-band, dual-polarisation rotary joint. Mechanical and thermal aspects shall be considered. An extensive test campaign, including thermal and high-power aspects, shall be carried out in order to demonstrate the concept feasibility.