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Microwave lenses harnessed for multi-beam forming. This highly compact beam forming network has been designed for multi-beam satellite payload antennas. Generating a total of 64 signal beams outputted from a single antenna, this novel design could cover the entire Earth with multiple spot beams from geostationary orbit. ?'The traditional solution for a multibeam telecommunications satellite payload would be a single feed per signal beam, but only a limited number of feeds are able to be accommodated in front of the satellite antenna, with each feed requiring a dedicated amplifier,?" explains Petar Jankovic of ESA?.s Radio Frequency Equipment and Technology section. ?'This is a highly integrated, lower mass alternative, developed with Airbus in Italy.?" What looks like a sunburst design is actually a ?"Rotman?. lens, laid down on a printed circuit board, used to direct and focus microwaves. These are commonly employed in terrestrial radar systems, for instance aboard high-end drones or in-car radar, and are also being looked at for future 5G base stations. A single flat Rotman lens allows beam scanning along a single axis. For this design, eight of these Rotman lenses are stacked horizontally, and eight more are arranged vertically. The result is a two-dimensional array of 64 pencil-shaped signal beams ?? and this architecture can be leveraged up as desired. ?'Testing of our prototype demonstrator shows high performance, demonstrating low insertion loss and with the measured worst-case return loss for the beam ports and array ports always better than 15 decibels throughout the full Ka- operative band,?" adds Petar. ?'For all our measured beams very regular pointing has been achieved.?" Almost perfect alignment between simulation and measurement results have been achieved, guided by ESA in-house software that converts mathematical models of the lenses into geometric structures, combined with commercial software used to simulate the prototype in advance of its