A partially dielectric loaded divided horn waveguide device for a dual-polarized antenna is described. The partially dielectric loaded divided horn waveguide device may include a polarizer, a waveguide horn, multiple individual waveguides dividing a horn port of the waveguide horn, and multiple dielectric elements partially filling the individual waveguides. The dielectric elements may include a dielectric member extending along a corresponding individual waveguide and one or more matching features for matching signal propagation between the partially dielectric loaded individual waveguides and free space. Various components of the partially dielectric loaded divided horn waveguide device may be tuned for enhanced signal propagation between the waveguide horn and the individual waveguides, and between the individual waveguides and free space.