Multifunctional Folded Reflectarray Antenna for Circular Polarization and High-Gain Filtering

In this letter, a circular polarization antenna and a high-gain filtering antenna based on multifunctional folded reflectarray antenna (FRA) are designed. A polarization-sensitive linear-to-circular polarization (LP-CP) serves as a dual-function structure to replace a polarization grid (PG) and LP-CP convertor in traditional circularly-polarized folded reflectarray antennas (CPFRAs). A filtering antenna can be realized by using polarization-sensitive frequency selective surface (FSS) instead of PG. To demonstrate, a circular polarization FRA and a high-gain filtering FRA designed at X-band are presented as design examples.