Computation of the antenna directivity from bi-polar near-field data

An effective procedure for the computation of the antenna directivity from a nonredundant number of voltage data acquired via a bi-polar scanning in the near-field region is developed in this work. It can be applied whenever the power radiated by the antenna in the backward half-space is negligible and the total radiated power coincides practically with that radiated in the forward one. It makes use of a closed form formula for computing the total radiated power from the knowledge of the radiation intensity samples on the far-field sphere. These samples are determined via a probe compensated near-field -far-field transformation from the nonredundant bi-polar data. An optimal sampling interpolation formula is properly used for their evaluation. Numerical simulations assessing the effectiveness of the procedure are reported