An effective solution to microwave arrays synthesis with null field constraints in the near-field region

This work addresses the problem of the power synthesis with null field constraints in near-field region for a large array working at microwave frequencies. It is solved as an intersection finding problem between the set of all far-field patterns which can be radiated by the considered array and the set of all functions fulfilling the pattern requirements. An alternating projection method, based on the concept of projection operator, is used to this end. The number of null field constraints is remarkably reduced by applying the recent results on the 3-D sampling representations of electromagnetic fields. Numerical tests assessing the effectiveness of the proposed technique are presented.