Improved analysis of antenna radiation from a circular aperture covered bya dielectric hemispherical radome shell

A novel full-wave analysis of the antenna radiation due to an aperture flus h-mounted on a ground plane and excited by a circular waveguide TE11 wave i s presented. The aperture is further covered by a dielectric hemispherical radome. Huygens' equivalence principle and image theory are utilised to sim plify the problem, and magnetic dyadic Green's functions are employed to fo rmulate both the reactional magnetic current distribution around the apertu re and the inner near-zone and outer far-zone electromagnetic fields. The i dea of reactional iteration is implemented in this work, and, hence, the fi nal equivalent source is obtained in quite a compact form. Comparison betwe en the results obtained and those published elsewhere in the literature sho ws the additional contributions to the equivalent magnetic source distribut ion and the near- and far-zone field patterns from the feedback of the elec tromagnetic fields reflected from the dielectric radome, Although applied o nly for a simple-layer dielectric radome, the method itself is not restrict ed by the number of layers and can easily be extended to a multi-layered ra dome or dielectric inhomogeneous radome.