Sparse planar array synthesis technique for satellite applications

This paper will give an overview of the recent advances on an innovative sparse array synthesis technique for the design of satellite antenna arrays. The equi-power sub-arrays constituting the aperiodic array are placed on a lattice reproducing the positions of the sunflower seeds, opportunely adjusted according to a desired tapering law. This particular non-uniform lattice is selected, essentially, because it guarantees a favourable radial and azimuthal spreading of the element positions. In this way the pattern in the sidelobes and grating lobes region tends towards a plateau-like shape, avoiding the presence of high, narrow peaks. Moreover, by manipulating the element positions with the presented technique, the beamwidth can be adjusted and the sidelobe level SLL kept under an assigned value without any amplitude tapering of subarray excitations; the latter is replaced by ´space tapering´, as the inter-element spacing increases from the centre to the array periphery, while all the elements are fed with the same power. This planar array can be considered in the design of a transmit direct radiating array for a communication antenna deployed on a geostationary satellite.