Dual Circularly Polarized High Gain Impedance Modulated Metasurface Based Leaky-wave Antenna for Dual Azimuthal Plane Radiation

Abstract

This article presents the design and comprehensive characterization of a dual-beam, dual-planar, dual-polarized scalar holographic metasurface leaky-wave antenna (HMSLWA) using surface impedance (Zsurf ) mapping techniques. The proposed HMSLWA supports orthogonal circular polarizations-left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP)-radiated in two spatially separated planes. A novel phase correction factor (φext ) is introduced to mitigate polarization-dependent nulls and enhance beam symmetry. The metasurface (MTS) consists of 3600(60×60) scalar unit cells occupying an aperture of 14.5λ0×14.5λ0, optimized for 15.5 GHz operation. The first beam, radiating at (θ1,φ1)=(−25∘,0∘), exhibits high-purity LHCP, while the second beam at (θ2,φ2)=(25∘,45∘) achieves clean RHCP with an excellent axial ratio performance. Both beams demonstrate strong polarization isolation and high crosspolar isolation. The simulated peak gain reaches 25.21 dBic, with good agreement to MTS aperture, confirming the effectiveness of the dual-planar, dual-polarized HMSLWA architecture for advanced beamforming and polarization diversity applications.