Degree of freedom architectures for large adaptive arrays

Large phased array radars possess thousands of elements, but practically it is only possible to process a few tens of adaptive degrees of freedom (DOFs). However, with the use of element-level digitization and digital beamforming the next generation of phased array radars will have great flexibility in their choice of DOF architecture. This paper shows that to achieve the best performance the radar's DOF architecture must adapt to both the radar's operating mode (e.g. volume search, horizon search, track and wideband discrimination) and the interference environment (e.g. direct path jamming, multi-path jamming and clutter). The best performing DOF architectures for different combinations of radar mode and interference environment are described.