NF – FF transformation with helicoidal scan for long antennas: positioning errors compensation

An iterative technique is proposed in this communication for compensating the probe positioning errors in a near-field - far-field transformation with helicoidal scanning for long antennas. It relies on a very effective source modelling wherein the surface enclosing the antenna under test is a cylinder ended in two half-spheres and uses an optimal sampling interpolation algorithm for reconstructing the data needed by a standard near-field - far-field transformation technique with cylindrical scanning from the acquired irregularly spaced ones. Numerical tests confirm the effectiveness and the robustness of the approach.