In this paper, we demonstrate a single layer X-band (8-12 GHz) metamaterials substrate antenna for generating orbital angular momentum (OAM) beam. The proposed design consists of a series of phase-shift unit cells to control the emergent phase, whose function is same as spiral phase plate (SPP). The SPP uses the concept of reflectarray antenna having a double circular ring type unit cell to control the reflection phase for generating beams carrying OAM wave. The results of phase patterns simulation verify that the vortex radio waves can be generated by using sub-wavelength reflective metamaterials substrate antenna. From the perspective of the electromagnetic calculation, we can use high performance computing to reduce the computation time.
One-dimensional range profile is known as a simple radar imaging technology. Based on the imaging mechanism, the laser range profiles (LRPS) of the convex rotators in three different methods, which named as the Beam Scattering Method (BS method), Radar Cross Section Method (RCS method) and Surface Elements Method (SE method),were studied. In detail, BS method, which combined the laser beam pulse scattering theory and radar equation, is the very model that can be applied to the convex quadric rotary bodies, however, it may produce singular solutions in certain incident directions. The RCS method is just an extension of the theory of radar cross section theory and radar equation. According to the definition, the simplest forms of RCS which were then substituted into the radar equation were obtained, finally the one-dimensional range profiles were analytically resolved. The SE Method is a much more comprehensive theory to get the laser range profiles of arbitrary objects. The object should be first divided into numerous small triangle facets, and sum the backscattering power of these facets in the same distance, and in this way the final LRPS were deduced. In the meanwhile, the SE method is the most convenient way to evolve into the three-dimensional range profile. In the paper, the LRPS of a cone based on the three models above were simulated, it was found that the features and shape of each profiles were similar basically, but theoretical correction to SE method was still needed.