Analysis of omnidirectional dual-reflector antennas with radomes

We investigate the influence of dielectric radomes on the electromagnetic performance of dual-reflector antennas suited for omnidirectional coverages. The dual-reflector systems are fed by a TEM coaxial horn. Accurate analyses are provided by surface integral equations numerically evaluated by the method of moments, taking into account all electromagnetic couplings among the several antenna elements. The analyses demostrate that λ/2-window radomes do not significantly influence the antenna behavior across the operation band. But the way the radome is attached to the dual-reflector structure may significantly influence the sidelobe levels of the radiation pattern.