Optimization of the parameters of focusing antennas

An analytical solution is obtained to the problem of synthesizing a focusing antenna for the case of arbitrary geometry of the source and under the constraint that the focus is located outside the region of field sources. Optimal distributions of amplitude and phase are determined along with orientations of bulk, surface, and linear currents with arbitrary spatial distribution; it is assumed that these latter conditions ensure maximum field strength at the focal point without constraints on the distance of this point from the field sources.