Secondary Surveillance Radar Enhanced by OAM Wave with Azimuth Estimation Capability

Secondary Surveillance Radar (SSR) is the most widely deployed radar-communication integration system. Moreover, the vortex electromagnetic (EM) wave carrying orbital angular momentum (OAM) presents its advantages in both communication and radar performance. Due to the special vortex wave front, the OAM wave is able to measure the azimuth angle. In this paper, a novel OAM modulation based azimuth angle estimation method is proposed for SSR. Particularly, a Bessel compensation procedure and OAM number selection algorithm are utilized to improve the azimuth angle estimation performance. Furthermore, the system scheme for this OAM based SSR is designed, including the pulse sequence format of interrogation pulse.