Ka-band Active Sparse Array for SatCom Applications: Implementation Design Issues

For future satellite antennas Active Direct Radiating Arrays exhibit good characteristics in terms of coverage re-configurability and power flexibility. Unfortunately canonical array antenna configurations present drawbacks due to the high number of active radiating elements with a consequent high complexity and costs. On the basis of the results obtained in the frame of previous ESA activities, sparse array configurations represent a promising solution because they permit minimizing the number of radiating elements and keeping all the power amplifiers at the same operative level still satisfying stringent pattern requirements in term of sidelobe level and isolation. The paper presents the first results obtained in the framework of a new ESA activity dedicated to the implementation of sparse active arrays. The problem areas are presented together with possible solutions. In particular, it appears important to exploit some geometrical modularity in the element positions in order to keep quite simple the beam forming network while implementing the required cooling devices (e.g. heatpipe).