Innovative Techniques for Amplitude-Only Near-Field Measurements

An innovative hybrid approach is proposed for Far-Field reconstruction from phaseless Near-Field data. A measurement strategy based on the use of two co-planar probes is used to obtain amplitude data which are subsequently processed by an interferometric procedure to retrieve the Near-Field phase information. Depending on the distance between the probes, a certain number of unknown phase shifts are also determined by a suitable minimization algorithm. Experimental validations are presented on a cylindrical scanning surface. The application of the integrated probe to the helicoidal geometry is also investigated and a direct Near- Field to Far-Field transformation is developed by an efficient use of the Fast Fourier Transform and the related shift property.