Study of bifocal dual reflectarray configurations for multi-beam antennas in ka-band

This paper describes the design of multi-beam dual reflectarray antennas for operation in the Ka-band satellite transmission band (around 20 GHz), using the bifocal design concept to improve antenna performance. This technique has been first applied to obtain beam compression with adjacent feeds, resulting in low radiation efficiency. Then it has been used without beam compression to correct beam aberration, showing better results than an equivalent single-focus reference reflector. The simulated radiation patterns in the elevation plane and the amplitude distributions of the incident field on each reflectarray have been calculated for different antenna configurations.