Echo reduction properties of fast non-redundant planar NF sampling methodologies

The optimal sampling interpolation expansion is employed in near field measurements to reconstruct the field at any point of the observation surface starting from a non- redundant scanning scheme [1]-[3]. Such schemes allow faster measurements than classical Nyquist-compliant acquisitions. The methodology has no accuracy loss and has been validated at different bands and with different antennas [5], [6]. As the metrology restricts the source region to a surface conformal to the measured antenna, it intrinsically acts as low-pass spatial filter and thus possess echo reduction properties [7].
In this paper, the echo reduction benefits of the optimal sampling interpolation expansion applied to Planar Near Field measurements is investigated for the first time. A standard gain horn, MVG SGH4000 has been measured at V-band in an environment with controlled echoes. The results obtained with non-redundant methodology are compared against classical measurements post-processed with standard echo reduction techniques [8].