A 20/30GHz Dualband Dual Circularly Polarized Antenna Hybridizing Folded Refelctarray and Folded Transmitarray

A design of 20/30GHz high-gain dual circularly polarized antenna based on the folded reflectarray antenna (FRA) and folded transmitarray antenna (FTA) is presented in this paper for satellite communications systems. Left-hand circularly polarized radiation at 20GHz and right-hand circularly polarized radiation at 30GHz can be achieved by the antenna at the same time. A dualband polarization-sensitive frequency selective surface (FSS) based on antenna-filter-antenna (AFA) technology is used as the subreflector of the antenna. The 1bit phase compensation to form the broadside plane-wave radiation is done by the printed reflectarray with the FRA technique and the subreflector with the FTA technique, respectively. Simulated results show that the antenna gains are relatively stable and the antenna axial ratios are lower than 3dB at the center frequencies of the dual operating band. Moreover, compared with the reconfigurable dualband FRA and dualband FTA, simple DC biasing network should be required in this dualband hybrid antenna design, since the phase compensation at the dualband frequencies is done by the printed reflectarray by the FRA and subreflector by the FTA, respectively. Therefore, the antenna has good dualband electronic beam-steering potential with reconfigurable phase compensation elements.