Adjustable High Impedance Surface for active reflectarray applications: Performances optimisation of the unit cell

In this paper, the latest developments concerning the design of the unit cell of one adjustable high impedance surface (HIS) using varactor diodes are presented. The HIS obtained with this new unit cell is used in the design of a centred reflectarray antenna able to generate various types of radiation pattern beam (focalised, scanned, shaped...).