Various radio frequency (RF) antenna devices include an array of waveguide radiating located at the antenna aperture. The antenna can be suitable for transmitting and/or receiving a signal. RF antennas may often comprise polarizers, such as a waveguide polarizer or a septum polarizer. Polarizers are useful, for example, to convert a signal between dual circular polarization states in a common waveguide and two signal components in individual waveguides that correspond to orthogonal circular polarization signals. However, in an antenna with an array of radiating elements that are closely packed, conventional waveguide polarizers are unsuitable because they are too large/bulky. A septum polarizer is more compact, however, the septum polarizer is typically unsuitable for a wide bandwidth (e.g., arrays having wide frequency range spanning a range of 1.75:1), and that have a grating sidelobe restriction on the array lattice at the high end of the frequency range. Thus, a need exists, for an antenna array of waveguide radiating elements, for compact, wide-bandwidth, high performance solutions.