Hybrid fast fourier transform-plane wave based near-field far-field transformation for “body of revolution” antenna measurement grids: The cylindrical case

Near-field antenna measurements are a common technique to characterize the radiation behavior of antennas. Due to the measurement in the radiating near field, a postprocessing near-field far-field transformation is required to finally compute the radiation pattern. For the near-field transformation a low numerical complexity as well as full probe correction capabilities are highly desirable. In this paper a hybrid near-field far-field transformation algorithm is presented which combines a Fast Fourier Transform preprocessing with the plane wave based fully probe corrected near-field transformation of low numerical complexity being suitable for “body of revolution” antenna measurement grids. The Fast Fourier Transform splits the probe signals into azimuthal Fourier modes which are processed individually by the plane wave based transformation algorithm. In this way the computation time can be reduced while the numerical complexity is unchanged. In this paper the hybrid technique is applied to cylindrical near-field measurements which are superior for the measurement of fan beam antennas.