Study of a flexible payload for S-band mobile broadcasting to multiple shaped beams

A feasibility study for a satellite multimedia broadcasting mobile system (S-MBMS) operating in S-band (2170-2200 MHz) was recently performed by the European Space Agency (ESA). The target coverage was defined to consist of multiple-shaped-beams coinciding with European countries or language homogeneous areas. Considering the noticeable effective aperture required in S-band from the geostationary orbit, the most promising antenna architecture is based on large-size deployable-reflectors fed by complex arrays (array fed reflector - AFR). The key payload element is the high power section which provides RF power generation and distribution to feeds with appropriate amplitude and phase to realize differently shaped beams. Several configurations with different amplitude and phase beamforming constraints can be considered as suitable candidates. The outcome of the undertaken design and optimization activity is a promising architectural solution showing a high degree of coverage reconfigurability as well as an almost full freedom in power-to-beam allocation.