Date Added: Dec 2010
This invited contribution reviews recent and on-going activity in the field of Reconfigurable ReflectArrays (RRA). The authors discuss different areas of investigation related to the modeling, optimization and design, achievement of state-of-the-art performance, or novel polarization capabilities of RRA unit cells. In terms of technology and frequencies, the different contributions are based either on semiconductor diodes or MicroElectroMechanical System (MEMS) and operate from lower X-band to Ka band. In recent years the RRA has become a popular topic of investigation in the antenna community, supported both by public agencies and by the industry.