ABSTRACT
The synthesis problem consists of finding the “sources” which produce a desired effect: for instance prescribed boundary values. We could keep, as a typical example, the antenna synthesis: to determine the current density which produces a prescribed (within a certain degree of approximation) radiation pattern. This problem, as we shall see below, can be solved by the use of a Fredholm integral equation of first kind; therefore, it presents the typical pathology of ill-posed problems: widely different sources can produce almost the same radiation pattern. Furthermore, if we take into account that the data must be discretized, handled by a computer, and can be specified only within a certain degree of approximation (related to the sensitivity of the apparatus) then we clearly see that the antenna synthesis problem must be regularized [1].
