A general and effective clutter filtering strategy in near-field antenna measurements

A general strategy to reduce the effect of the clutter noise in near-field measurements is presented. The approach exploits the band-limitation properties of the radiated field in order to filter the noise in the near-field data before far-field pattern evaluation. The method requires a simple lowpass filtering of the data, collected at suitably chosen sampling positions, after the extraction of a proper phase function. It holds for general scanning and source geometries, and is robust with respect to truncation of measured data owing to the finite dimensions of the scanning area. Numerical and experimental results confirm the effectiveness of the technique.