Reconfigurable Circularly Polarized Folded Reflectarray Antenna

A novel reconfigurable circularly polarized folded reflectarray antenna (RCPFRA) based on the circularly polarized selective surface (CPSS) is presented in this paper. The proposed RCPFRA mainly includes three parts, one upper CPSS, a lower reflectarray with electronically reconfigurable ability and a planar miniaturization broadband CP feed. The CPSS can reflect one CP wave, while it can transmit its orthogonal CP wave. Firstly, a single layer microstrip patch reflectarray element loading with one PIN diode is proposed. Through changing the on-off state of the PIN diode, this unit cell can provide 0º and 180º phase shifts with 1-bit phase quantization. Then, a RCPFRA in the X-band is designed and simulated. The simulation results indicate that the beam scanning angle of the RCPFRA achieves within the range of ±40º. Its peak radiation efficiency is about 15%, which demonstrates effectiveness of the RCPFRA design method.