NF-FF Transformation with Planar Spiral Scan - An Effective Source Modeling for Quasi-Planar Antennas
Authors: F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi, C. Rizzo
A new probe compensated near-field – far-field trans-formation technique with planar spiral scanning is here proposed. It is tailored for quasi planar antennas, since an oblate ellipsoid instead of a sphere is consid-ered as surface enclosing the antenna under test. Such an ellipsoidal modelling is quite general (containing the spherical one as particular case) and allows one to consider measurement planes at a distance smaller than one half the maximum source size, thus reducing the error related to the truncation of the scanning sur-face. Moreover, it reduces significantly the number of the needed near-field data when dealing with quasi planar antennas. Numerical tests are reported for demonstrating the accuracy of the far-field reconstruc-tion process and its stability with respect to random errors affecting the data.