Measurement of an active radar module in a compact antenna test range

Due to their reciprocal nature, passive antennas can be completely characterized in transmit or receive mode. This is in contrast with active antennas where characterization is performed in one of two modes, with the other deemed not suitable due to non-reciprocity. This requires an antenna measurement facility be able to perform measurements in both transmit and receive modes. This article describes a measurement setup used to characterize an active radar module (ARM) in transmit mode and presents the results of these measurements, which were performed in the compact antenna test range at the Institute of High-Frequency Technology at the University of Aachen (RWTH), Aachen, Germany.