Millimetre wave circularly polarized holographic antenna based on artificial impedance surface

Two novelty methods to design circularly polarized holographic antenna have been proposed at millimetre wave band. The antennas designed with the optical holographic principle are structured by sources and interference plane. The interference plane is based on quasi-periodically artificial impedance surface. The antennas which radiation circularly polarized wave from linearly feed are demonstrated by two different approaches. In the first one, the modulation of the phase is provided by varying the phase of feeds which composed of four monopole antennas. In the second one, the transformation of phase is from the surface impedance modulation. As an example, two different circularly polarized holographic antennas are presented with simulation results.