  This paper presents the combination of aperture field estimation (AFE)
technique and adiabatic Floquet-wave (AFW) expansion method for the analysis of
leaky-wave holograms capable of generating orbital angular momentum (OAM)
vortex waves. In these formulations the propagation and leakage constants are
theoretically estimated and as a result the aperture field and far-zone field
are calculated. This theoretical approach significantly reduces the
computational complexity in such a way that the analysis of holograms with
large dimensions is possible with low memory requirements. Isotropic and
anisotropic unit cells are used to realize the holograms, which anisotropic
structures show better performance in the control of wave polarization. The
holograms are designed to generate vortex beams with topological charge of m=2
and circular polarization states in the microwave regime. To evaluate the
accuracy of the proposed method, the results of theoretical model and full-wave
simulations are compared, with good agreement.
