Far-field reconstruction from phaseless near-field data on a cylindrical helix

An efficient procedure is developed for far-field reconstruction from phaseless near-field data on a circular helix. The application of an integrated probe is considered for collecting amplitude data to be used in the near-field phase retrieval. This is performed along the single line given by the helicoidal curve, thus reducing computation time as compared with planar and plane-polar geometries. Antenna far-field pattern is directly evaluated from complex near-field helicoidal data by a Fast Fourier Transform based algorithm, so any intermediate interpolation on a cylindrical surface is avoided. Numerical simulations on arrays of Huyghens sources are presented for assessing the effectiveness of the proposed approach.