The DD-R31 medium-range X-band phased array radar 1, Product Overview The DD - R31 medium - range X - band phased array radar is outfitted with a comprehensive system that is fully solid - state, fully coherent, and incorporates a pulse Doppler mechanism. This particular configuration endows the radar with a significant set of capabilities. Firstly, it enables the radar to carry out all - weather detection and early warning functions specifically focused on "low, small, slow"