Phaseless Near-Field Antenna Measurements From Two Surface Scans — Numerical and Experimental Investigations

Phaseless near-field (NF) measurements are an attractive solution to characterize antennas at reasonable costs, especially at high frequencies. The source reconstruction method is applied to compute the equivalent currents representing the antenna under test using two phaseless surface scans. The reconstruction of these equivalent currents uses recently proposed phase-retrieval algorithms that mitigate some of the shortcomings of existing techniques with an automatic settings of the initial guess. In addition to be readily available and easy to be plugged in electromagnetic modeling tools, these routines exhibit good phase recovery performances and robustness with respect to noise, separation between scanning planes, and NF sampling step. The proposed procedure is applied to determine the far-field radiated by various types of antennas operating in different frequency bands from phaseless NF scans. Experimental validations of two radiating structures show its potentialities and interest.