Parabolic Reflectarray Antenna To Generate Multiple Beams In Dual-Frequency And Dual-Circular Polarization

This contribution presents the design and simulations of a 1.8-m parabolic reflectarray to generate a multi-spot coverage from a geostationary satellite. The antenna has been designed to generate two spaced beams per feed in orthogonal circular polarizations (CP) simultaneously at transmission and reception frequencies in Ka-band. The parabolic reflectarray operates by the variable rotation technique independently applied at 19.7 GHz and 29.5 GHz to split the orthogonal CP beams focused by the parabolic surface. The proposed design technique and the simulated results have been experimentally validated by the manufacturing and testing of a 0.9-m parabolic reflectarray with the same operating principle. The proposed antenna technology can be used to provide multispot coverages in Ka-band from geostationary satellites, with the advantage of reducing to one-half the number of antennas and feed-chains commonly required using conventional reflectors.