A novel circular patch antenna of generating vortex beams based on complex transformation optics

Generation of vortex beam carrying orbital angular momentum (OAM) is a popular field of research in recent years. Based on the theory of complex transformation optics, a standing-wave current distribution along the circumference of a conventional circular patch is transformed into a uniform traveling current distribution instead, thus leading to the generation of vortex beams. Compared to the other designs of generating vortex beams, our design takes a patch antenna as a single radiator, thus, it has incomparable advantage in the compact structure.