Compact K/Ka 4-port feed subsystem for dual circular polarisation

A compact four-port dual circular polarization feed antenna system for satellite communication is described. It consists of a septum Polarizer and two identical duplexers formed by an E-plane T-junction and of two iris filters, along with two electric field rotators since the vectors of the electric field in the rectangular ports must be vertical. This 4-ports system transmits and receives radio frequency signals in double track in which the transmission Tx is made through two ports having as access the standard rectangular waveguide WR42 and the reception RX is made also through two ports having as access the standard rectangular waveguide WR28. To separate the two ways at the circular common port (or rather at the antenna level) RHCP and LHCP was used.