Radiation Properties of Spherical Arrays

The array formed by elements placed on the surface of a sphere is studied by means of numerical calculations. The elements are assumed to be ideal and the mutual couplings can thus be neglected. By using a uniform element distribution and an active region moving with the main beam, the radiation properties can be kept unchanged within a scan coverage of more than a hemisphere. The grating lobes still remain small even if the element spacings are of the magnitude of a wavelength. Variations in the element field pattern have less influence than in a planar array. In some cases the spherical array can be thinned.