Investigations on 77 GHz tunable reflectarray unit cells with liquid crystal

This paper presents investigations conducted with tunable reflectarray unit cells based on nematic liquid crystals (LC), at frequencies around 77 GHz. The structure of the cells is presented, as well as their performance as measured in a waveguide simulator setup. Encouraging results with tunable phase ranges as high as 280° with tuning voltages of up to 15V have been achieved. The investigated tunable unit cells will be used in electronically reconfigurable reflectarrays.