Polarizer and Waveguide Antenna Apparatus Using the Same

A waveguide antenna apparatus, comprising:

• a feed horn;
• and
• a polarizer coupled to the feed horn, the polarizer comprising:
• a waveguide channel including a substantially square cross section;
• and
• a septum disposed within the waveguide channel, the septum comprising a stepped edge and two opposite stepped surfaces, the two stepped surfaces sectionally recessed toward each other along a direction pointing toward the interior of the waveguide channel, wherein the number of steps of the stepped surface is greater than two, but smaller than the number of steps of the stepped edge.

A waveguide antenna apparatus, comprising:

• a feed horn;
• and
• a polarizer coupled to the feed horn, the polarizer comprising:
• a waveguide channel including a substantially square cross section, wherein the cross section of the waveguide channel includes a plurality of rounded corners and a plurality of edges correspondingly extending between the rounded corners, wherein the ratio of the radius of the corner to the distance between two opposite ones of the edges is in a range of from 0.05 to 0.3;
• and
• a septum disposed within the waveguide channel, configured for conversion between circularly polarized waves and linearly polarized waves.