The RSR 650/RSR 655 family is available in two architectural configurations optimised for different operational needs. The RSR 650 uses a single digital array antenna face on a precision rotator, combining electronic beam steering with mechanical rotation to provide full azimuth surveillance. This configuration supports high-performance forward-sector operation with look-back capability, aligned with traditional rotating AESA concepts while retaining the benefits of fully digital beamforming and adaptive multi-function scheduling. The RSR 655 employs a four-face fixed digital array, with each face covering at least 90° in azimuth, delivering continuous 360° electronic coverage without mechanical rotation. This enables simultaneous, uninterrupted surveillance and tracking, longer dwell times, deterministic revisit rates, and coherent processing for improved clutter cancellation and low-SNR target detection in demanding environments.