A compact OAM antenna with high isolation based on half-mode SIW

In this paper, a compact array design for generating vortex electromagnetic waves with orbital angular momenta is proposed. The proposed array has a high isolation between individual elements because of the decoupling based on a gap structure and separated half-mode SIW cavities. The orbital angular momentum antenna based on a uniform rotation array comprises four identical half-mode structures, which are halves of the mode TM110 of rectangular cavities with their side PEC walls approximated by series of metalized vias along the diagonal. These uniformly distributed metalized vias are located along with two waists of isosceles triangular cells. Apart from the merit of easy integration, the design is also of a wide bandwidth and great isolations, which is validated by the simulation and measurement results.