Signal-to-Noise Ratio Improvement by Vortex Wave Detection With a Rotational Antenna

This article investigates whether a vortex wave detection method with a rotational antenna can improve the receiving signal-to-noise ratio (SNR) of stealth targets. To be specific, a vortex wave detection system with a rotational antenna is established. Considering both bistatic and monostatic models, it demonstrates that the vortex wave can be efficiently synthesized by applying the fast Fourier transformation algorithm to all receiving pulses. The SNR of synthetic orbital angular momentum (OAM) is compared with that of circular synthetic aperture radar (SAR) because the synthetic OAM and circular SAR systems have similar architectures and are described by similar mathematical models. Experiments confirm that the synthetic OAM method can improve the receiving SNR of a specific complex target with different polarizations. The SNR improvement by OAM for general complex targets is then demonstrated in simulations. Furthermore, the detection probability and the quality of 2-D detection results can also be improved by the proposed synthetic OAM method.