Focal region field expressions for a spherical reflector backed by chiral substrate

High frequency field expression at the focal region of a spherical reflector antenna backed by isotropic and homogeneous chiral substrate is derived using Maslov's method. As Geometrical Optics (GO) solution fails at the focal point, so Maslov's method is used to overcome this problem. Field patterns are calculated numerically and the results are plotted. Analysis is done to show the effects of thickness (d) of chiral substrate, chirality parameter (β) of the chiral substrate and permittivity (ɛ) of the medium.