Dual-mode quadruple ridge waveguide feed for broadband satellite communications

A novel and compact dual-channel multimode waveguide system is described, which permits two distinct frequency channels, such as C-band and Ku-band, to be propagated simultaneously. The system is also dual-moded at both the lower and the upper frequencies, thus enabling polarisation switching between orthogonal linear signals or between left and right hand circularly polarised transmissions. The development is primarily motivated by the desire to provide extended range and global coverage, for a maritime satellite communications system, employing a single antenna platform.