Active reflectarray element with large reconfigurability frequency range

A varactor-loaded radial phasing line is proposed in this work to actively tuning the phase of an aperture-coupled reflectarray cell, thus allowing to enlarge the reconfigurability frequency range. The proposed approach is applied to design an X-band 0.45λ× 0.45λ reflectarray cell giving a 320° phase agility within a measured frequency range of about 8.5%, significantly greater with respect to that achievable by a simple linear phasing line.