3-D Probe Positioning Errors Correction in Plane-Polar Near-Field Measurements

This work proposes an effective procedure for compensating known 3-D probe positioning errors in the near-to-far-field (NTFF) transformation with plane-polar (PP) scanning. Firstly, the k-correction is applied to correct positioning errors caused by displacements from the nominal acquisition plane. The NF data at the positions defined by the non-redundant sampling representation are then retrieved from those calculated in the previous step and now affected by 2-D positioning errors, using an iterative strategy. Finally, after properly recovering the correctly distributed PP samples, the data required to perform the conventional plane-rectangular NTFF transformation can be accurately obtained by using a 2-D optimal sampling (OSI) interpolation scheme. The non-redundant sampling representation, as well as the OSI interpolation scheme, have been achieved by adopting a double bowl modeling of the antenna. This is a surface made up of two circular bowls with the same aperture radius but different lateral bends to better fit the antenna shape. As it will be shown, a wide range of numerical results proves the effectiveness of the proposed technique.