Examination of the effectiveness of FF MARS in a CATR through electromagnetic simulation

Abstract

For more than a decade now, a measurement and post-processing technique involving modal filtering, named mathematical absorber reflection suppression (MARS), has been used very successfully to identify and subsequently extract range reflections in spherical, cylindrical and planar near-field antenna test systems and far-field (FF) and compact antenna test ranges (CATRs). Much of the early work concentrated on verification through experimental testing; however, some additional validation was performed using computational electromagnetic (EM) simulations. These considered first FF and subsequently near-field cases. The recent development of an accurate, flexible EM simulation tool that enables the simulation of `measured' FF pattern data as obtained from using a CATR has, for the first time, permitted the careful verification of the FF-MARS technique for a specified antenna under test (AUT) and CATR combination. This study presents simulated `measured' FF antenna pattern data in the presence of a large scatterer and then verifies the successful extraction of the scattering artefacts. In addition to considering range reflections, feed spill-over is also treated. Results are presented and discussed.