An Improved Dovetail Shape Circular Polarizer

An improved dovetail shape left-handed circular polarizer (LHCP) is proposed in this paper. The circularly polarized wave is obtained by adjusting the parameters of the improved dovetail shape dielectric plate inside the circular waveguide. The impedance bandwidth with
$\vert \mathrm{S}_{11}\vert \leqslant-20\text{dB}$
for the LHCP is 61.7% (17.57-33.25 GHz), as shown in the simulated results.