Accurate Reconstruction of Far-Field Polarization Beam Patterns from Planar Near-Field Measurements

Abstract

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. <br>

A Wideband Millimeter-Wave Corrugated Horn at 30–50 GHz Taking Advantage of All-Metal 3-D Printing Fabrication

“…3(b). The corresponding far-field beam patterns was carefully calculated from the near-field measurement data based on the near-field-to-far-field transformation and probe calibration method reported in [21]. The Co-polarization (CoP) and Cross-polarization (XsP) far field beam patterns for V-polarization at three different frequencies are presented in Fig.…”