Study on the theory and method of vortex-electromagnetic-wave-based radar imaging

Helical phase fronts and orbital angular momentum of the vortex electromagnetic ( EM) wave are applied to radar imaging at microwave frequencies and comprehensive simulations are conducted. Results demonstrate that an incrementally phased uniform circular array can be exploited to generate vortex EM wave at microwave frequencies. The imaging model based on the linear frequency modulation signal is established and the pulse-compression and fast Fourier transform methods are used to image the target in both range and azimuth dimensions. Furthermore, antenna pattern optimisation methods for imaging are studied to enhance the directivity of the emitting signal. The work can promote the significant development of novel information-rich radar imaging technology and provide staring imaging with substantial technical supports.