Circularly polarized multi-beam lens antenna system. Comparison between 2 polarizers

Two Ka-Band circularly polarized multi-beam antenna systems are compared. In both cases, the antenna system is composed of a dielectric lens fed by circular waveguides terminated with small horns, but the circular polarization is achieved either by integrating a polarizer in the waveguide feed or by positioning a meander-line polarizer outside the lens. For this second case, an analytical model to design meander-line polarizers is proposed. The two antenna systems have been analyzed, realized, measured and compared. For both systems, an axial ratio lower than 3 dB is achieved within a bandwidth of 19%.