Electronically-Steerable Transmitarray Antennas for SATCOM Terminals: a System Perspective

The possibility of using electronically-steerable transmitarrays for future SATCOM-on-the-Move ground terminals operating at K-/Ka-bands is investigated here. Starting from realistic antenna specifications, the trade-offs between antenna architecture complexity, phase-control resolution over the radiating aperture, aperture efficiency, side lobe levels, and beam scanning performance are discussed at the antenna system level and evaluated through numerical simulations. Two designs of linearly-polarized 2-bit reconfigurable unit-cells controlled by four p-i-n diodes are proposed for downlink and uplink bands. By opportunely combining orthogonally-polarized designs based on the proposed cells, two transmitarrays achieving switchable circular polarization and fulfilling the targeted specifications are presented.