An efficient near–field to far–field transformation using the planar wide–mesh scanning

An effective procedure is here proposed for evaluating the antenna far field from the knowledge of near-field data collected on a planar wide-mesh grid. The choice of the corresponding sampling law on the considered planar surface is based on the theoretical results relevant to the nonredundant sampling representations of the radiated electromagnetic field. Then, the data needed by the standard probe-compensated near-field-far-field transformation with plane-rectangular scanning can be efficiently reconstructed by using an optimal sampling interpolation expansion of central type. The benefit of using this particular and innovative approach is that it allows one to reduce the number of near-field data with respect to the classical plane-rectangular scan, while maintaining the accuracy of the far-field reconstruction. Last but not least, the implementation of the planar wide-mesh scanning does not require to change the planerectangular positioning systems, but only the software for controlling them. Numerical tests are reported for assessing the effectiveness of the approach and its stability with respect to random errors affecting the data.