Millimeter wave metamaterial for high-order orbital angular momentum generation

We propose a millimeter wave metamaterial for high-order OAM generation. The concept uses a reflecting metasurface irradiated by a small antenna (e.g., on-chip antenna) that emits linearly polarized millimeter waves at an operating frequency of 61 GHz. We present the numerical proof of principle using finite element simulations. Results show that OAM generation of the order of ten is feasible by varying one geometrical parameter of the metamaterial unit cell. Subsequent work is to further optimize the OAM generation by combining variations of multiple parameters to minimize the amplitude response variation and experimentally analyze the concept.