Electronically reconfigurable reflectarrays with nematic liquid crystals

The realisation and characterisation of an electronically reconfigurable 35 GHz reflectarray, which is able to steer the main beam continuously between −20 and +20°, is reported. The tunable unit cells of the reflectarray are filled with nematic liquid crystal, a material that is able to change its effective permittivity as a result of an applied control voltage of up to 15 V. First, the unit cell and its performance, and then the setup of the reconfigurable reflectarray and its measured far-field patterns, are described.