Reduction of Truncation Error in Near-Field to Near-Field Transformation

A new technique to rapidly evaluate the near-field and the safety perimeter of a base station antenna is reported in this paper. It consists in the reconstruction of the near-field in a volume surrounding the antenna from a standard near-field measurement on a cylindrical surface. The truncation error in near-field reconstruction, due to the finite size of the measurement cylinder, is analysed. An extrapolation technique, which takes into account the a-priori information on the geometry of the antenna, is shown to reduce the truncation error.