Patch antenna generating structured fields with a Moebius polarization state

The term «structured light» has been recently introduced to indicate a whole series of studies related to the shaping of the amplitude and phase distributions of an optical beam, in order to obtain unusual properties. This concept has, then, found applications at microwave frequencies but limited to the generation of electromagnetic fields with a non-zero orbital angular momentum (OAM). In this letter, inspired by the recent realization of an optical beam with a Möbius strip polarization state, we investigate about the possibility of generating an electromagnetic field with such a peculiar behavior, by using standard microwave structures. In particular, in order to obtain the required amplitude and phase patterns, we propose to use a single multi-mode patch antenna and, through analytical and full-wave numerical results, we prove the effectiveness of our approach.