Improvement of the Gerchberg–Saxton Algorithm Convergence in Phaseless Antenna Measurements via Spherical-Wave Filtering

Abstract

The phaseless characterization of antennas enables configurations with reduced measurement efforts as the phase acquisition is highly sensitive to numerous error sources. However, both the magnitude and phase information are necessary to reconstruct the 3D radiation pattern of the tested radiating system. The two scans technique allows for accurate phase retrievals from magnitude-only measurements. In this paper, the two concentric spheres setup is considered with a Gerchberg-Saxton (GS) algorithm as phase retrieval procedure. These methods are known for their convergence problems, the price to pay for the easier, magnitude-only, measurements. A filtering approach is studied to mitigate these effects and a new, more efficient, filter is proposed. A loop of GS runs coupled with filters is shown to improve the radiation pattern reconstruction without much considerations. Validations are led on simulations and experimental data acquired using a commercial system.