Extrapolation of the Outside Near-Field Data in the Cylindrical Scanning

This article deals with an effective technique for reducing, in a significant way, the error related to the truncation of the scanning zone in the cylindrical near-field–far-field transformation. Such a reduction is obtained by extrapolating a proper number of data external to the near-field measurement region via the singular value decomposition method. The approach is based on the nonredundant representations of the electromagnetic field and on the optimal sampling expansions. Numerical examples are reported for assessing the accuracy of the technique and its stability with respect to random errors affecting the data.