Waveform Analysis and Digital Predistortion for Modulation-Based Radar Target Simulators

With the help of radar target simulators radar systems can be tested and validated. Modulation-based radar target simulators offer a cost-effective simulation capability, but suffer from nonlinearities. This paper analyzes the waveform that is employed in typical radar scenarios by the radar target simulator. The signal statistics are used to define a required back-off in order to remain in the linear region of the radar target simulator. A digital predistortion scheme is presented that allows to increase the power of the modulation signal without increasing the nonlinearities. The predistortion scheme can be implemented fully in software, without additional hardware or measurement equipment. Measurements with a 77 GHz radar sensor are presented to verify the derived signal theory and digital predistortion scheme.