Optimum use of fully populated, over populated and sparsely filled antenna apertures

The applications of uniform and tapered weighting and of null steering in fully populated arrays are discussed. Super directivity is introduced as the deployment of `supernumery¿ antenna elements in order to provide additional degrees of freedom for further nulls ¿ at a price in sensitivity. Weighting of elements in proportion to their distance from the centre of the array is then shown to be best for maximum angular information. Finally, sparsely filled arrays are discussed, and it is suggested that a desirable disposition of elements, for maximum angular information, may be achieved with standard spacings for the outermost segments, together with spacings increasing exponentially towards the centre, in the central region.