Emulating Variable Spherical Wave by Compact Zoom Range

Abstract

The aims of this work are to propose a fast and efficient spherical wave synthesis (SWS) approach and demonstrate the physical feasibility of emulating desired spherical wave in a compact range by a reflector compact zoom range (CZR). The intersection approach (IA) and near-field (NF) transmission in the spatial and angular spectrum domain is fundamental theory of the SWS approach. The goal of the SWS approach is calculating the aperture source plane field that can generate a required spherical wave in test quiet zone (QZ). To find the intersection of achieved aperture source plane field and desired aperture source plane field, alternating projection (AP) correction is applied in the SWS approach. A Fourier transform pair relates the near field between the spatial and the angular spectrum domain, so Fast Fourier Transform (FFT) is utilized to accelerate AP correction between the aperture source plane and spherical wave field plane. The aperture source field calculated by the SWS approach is mathematical foundation of generating variable spherical wave in a compact range. For validating the physical feasibility of synthesizing a variable spherical wave environment, a reflector CZR is designed and simulated a high-performance spherical wave whose virtual source is 200 m away from QZ by full wave tool.