Dual Linearly Polarized 2-bit Programmable Metasurface With High Cross-Polarization Discrimination

This article presents a novel dual linearly polarized shared-aperture 2-bit programmable metasurface (PMS) with high cross-polarization discrimination (XPD). Two orthogonally placed asymmetric dipoles, each equipped with two p-i-n diodes, are used to realize the 2-bit phase resolution in the respective polarization direction. A crossover structure is introduced into the element to ensure high XPD. The design and implementation of the polarization-tilted reflection metasurface element are described, with the simulated results provided. A prototype with $12\times12$ elements has been simulated, fabricated, and measured. Multifunctional wave manipulations of the 2-bit dual linearly polarized PMS are analyzed, and the beam scanning up to ±40° at 3.5 GHz is verified. The measured results are in good agreement with the simulation analysis. The measured maximum gain is 16.9 dBi, with the corresponding aperture efficiency of 23.5%. The co-polarization radiation characteristics of both channels are proved to be excellent, maintaining XPD above 22 dB when scanning the beam. Besides, the beam keeps its stationarity in the 3.47–3.65-GHz frequency band. The proposed PMS is promised to be a competitive candidate in future wireless communication systems.