Impact of a Purina fractal array geometry on beamforming performance and complexity

This paper investigates the possible benefits of using a Purina fractal array for beamforming, since this particular fractal has recently been suggested as the flight formation for a fractionated space craft. We analyse the beam pattern created by this, and define power concentration as measure of focussing the main beam of a multi-dimensional array. Using this performance metric and the computation cost of the array, a comparison to full lattice arrays is made. We quantify the significant benefits of the Purina array offered over a full lattice array of same complexity particularly at lower frequencies, and the complexity advantages over full lattice arrays of same aperture, particularly if energy is to be concentrated within a small angular spread.