A Low-Profile and High-Gain Circularly Polarized Antenna Based on Holographic Principle

This paper presents a low-profile and high-gain right circularly polarized antenna based on holographic artificial impedance surface. The holographic antenna (HA) is comprised of around 2000 various elements printed on grounded dielectric substrate, excited by a horizontally omnidirectional ring-slot antenna. By using anisotropic rectangle patch as unit cell, the cross polarization is suppressed and the cross-polar level is of −37.8 dB in broadside. The −10 dB impedance bandwith covers 9 GHz to 11 GHz and the 3-dB axial ratio bandwith covers 9.12 GHz to 11 GHz. The maximum right circularly polarized gain is 20.8 dB and the 3-dB beamwidth is 6.08° at 20 GHz. The simulated results show the proposed antenna possesses low-profile, high-gain, and narrow pencil beam in the operating band.