Accurate Reconstruction of Far-Field Polarization Beam Patterns from
Planar Near-Field Measurements
Planar near-field measurements are a common method to characterize
antenna performance at millimeter and submillimeter wavelengths.
Far-field beam patterns are then calculated from those measurements.
However, different approximations have been traditionally used for this
calculation without careful analysis. In this paper, we derive a
Near-field-to-Far-field Transformation (NFT) based on diffraction theory
and the full components of electrical fields based on the boundary
condition in the far-field region. We analyze the systematic errors
introduced by Fourier Transformation (FT) and the probe antenna by
comparison with simulations. We further apply our data analysis
procedures in the near-field measurement of a corrugated horn.
Measurement and simulation results suggest that when all the procedures
are conducted accurately, we are able to reconstruct far-field beam
patterns from planar near-field measurements with high accuracy.