Wideband circularly polarized waveguide antenna using L-shaped probe with low cross-polarization

This paper reviews a couple of structures of circularly polarized waveguide antennas using L-shaped probe. In such antennas, the cross polarization gets increased with an increase in frequency at off-boresight direction. To avoid this effect, an effect of a parabolic short wall is discussed and is compared with the short wall with four poles.