Analysis of a dual-reflect array antenna

A modular technique for the analysis of a dual-reflectarray antenna (DRA) configuration is presented. The proposed analysis method has been used to design a DRA that emulates previous dual-reflector antennas in Ku- and W-bands including a reflectarray as a sub-reflector. The results for the DRA compare very well with those of the parabolic reflector and reflectarray sub-reflector; radiation patterns, antenna gain and efficiency are practically the same when the main parabolic reflector is substituted by a flat reflectarray, the gain being reduced by a few tenths of a dB as a result of the ohmic losses in the reflectarray. The phase adjustment on two surfaces provided by the dual-reflectarray configuration can be used to improve the antenna performance in some applications requiring multiple beams, beam scanning or shaped beams.