Performance Analysis of a Dielectric Dome in Circular Polarization for Beam Scanning at Low Elevation

The use of phase-correcting domes above planar phased arrays allows to increase their field of view. However, such a dome may behave differently depending on the polarization of the incident wave. A different behavior for the transverse electric (TE) and transverse magnetic (TM) components of the incident field would prevent the use of such a dome for a circularly -polarized beam. The influence of a fully -dielectric dome is analyzed when placed above a linear array of printed patches. The dome is made of non-resonant sub-wavelength unit-cells. The impact of the dome on the polarization purity of the transmitted wave is estimated by considering the transmission behavior of the unit-cell for TE and TM polarizations. These results are confirmed by full wave simulations. They validate the capability of such a dome to enhance the antenna field of view with a limited impact on the axial ratio of the radiated beam.