Vortex Beam Sidelobe Suppression via Bayliss Synthesis from a Rectangular Phased Array

Abstract

We demonstrate the application of the Bayliss synthesis method for suppression of sidelobes in an OAM vortex beam, when generated by a commercial-of-the-shelf, rectangular phased array. The method is optimized for the current application and simulated for a 26.5 GHz signal in CST Microwave Studio. Sidelobes are notably reduced by 16.9 dB, with minimal reduction in gain and increase in beamwidth, as compared to a uniformed stimulated phased array. Further, the OAM modes are found to have greater purity that that of the uniformly stimulated array, as well as for other amplitude tapering methods. The Bayliss synthesis is then applied to a phased array in a test range, verifying the simulation results that demonstrate sidelobe suppression. These results indicate that OAM may be applied to existing phased arrays with minimal effort.