Efficient far-field reconstruction of quasi-planar antennas from spherical spiral near-field data

An effective near-field - far-field transformation technique with spherical spiral scanning tailored for quasi-planar antennas is here proposed. Such a technique is based on the nonredundant sampling representations of the electromagnetic fields and makes use of a flexible source modelling, formed by two circular ¿bowls¿ with the same aperture diameter, but different lateral bends. Such a modelling allows one to fit very well a lot of this kind of antennas by properly setting its geometric parameters. It is so possible to remarkably lower the number of data to be acquired, thus reducing in a significant way the required measurement time. Some numerical tests, assessing the accuracy of the technique and its stability with respect to random errors affecting the data, are reported.