Liquid Crystal-Based Reconfigurable Reflectarray Cells for 5G Systems

A reconfigurable aperture-coupled reflectarray cell, based on the use of a liquid crystal substrate, is investigated to operate within the Ka-band, for 5G applications. A liquid crystal cavity is tilled between the phasing line and the ground plane, to implement the proposed phase tuning mechanism. A new highly anisotropic liquid crystal material for high-frequency applications is adopted, offering improved phase ranges (congruent to 350 degrees) and low losses (< -3dB) at the central operating frequency f(0)=27 GHz. The potentialities of the adopted aperture-coupled configuration are properly exploited to achieve a good phase-reconfigurability within a quite large frequency band of about 17%.