We target VHTS/UHTS systems able to flexibly allocate the resource worldwide according to traffic demands.  Digitally controlled phased arrays are an obvious candidate for the user link of these systems. However, full digital control of large number of radiating elements across bandwidths of a few GHz gives rise to unaffordable power consumption.  Hybrid analogue/digital beamforming can reduce the computational demands with some penalties on the coverage characteristics (due to e.g. grating lobes), which are ultimately reflected to compromised SNIR. In this project, we investigate the co-design of active antenna architectures with the associated signal processing and resource allocation strategies that will optimise the end-to-end system performance.