A High-Gain Multibeam Bifocal Reflector Antenna With 40° Field of View for Satellite Ground Station Applications

A theoretical design of a Ku-band multibeam offset bifocal dual-reflector antenna (BFRA) with 40° field of view (FoV) suitable for satellite ground station applications is presented and discussed. The BFRA has a nearly square aperture with a dimension of about 4.5 m (191 wavelengths at a frequency of 12.75 GHz) and was designed for the required scan angle α = 18°. The antenna has a Gregorian conhguration in the offset vertical plane and a Cassegranian conhguration in the scanning horizontal plane. This BFRA was designed for a special application for which providing the maximum aperture efhciency (AE) (i.e., the maximum gain) is required and relatively high sidelobes are allowed. The calculated AE is greater than 52% and a directivity is about 54 dBi at 12.75 GHz within the whole FoV of 40° (which is equal to 100 beamwidths) in the scanning plane.