Comparison for 4-Port C-Band and Ku-Band Receive Only Feed System design

In order to get high purity 4-Port C-Band and Ku-Band Receive Only Feed Polarization, except the high performance primary feed, one importance factor is to design waveguide network which can satisfy dual Polarization operation, and the most important work is to design high-qualified two bands simultaneously with C-band and Ku-band circular Polarizer. Normally in order to get low axis ratio, waveguide network often adopt the solution with “single frequency area”, in 4-Port C-Band and Ku-Band Receive Only Feed network the circular Polarizer often adopt multi-screw adjustable type, after fine debug in single frequency area, it can make the circular Polarizer better than 0.35dB, and thus it supply reliable guarantee for making the whole antenna satisfy CCIR regulation.

For the small earth station, this is not necessary to get access in international network, due to the specification requirements are not high, no need to use the above complex two bands simultaneously with C-band and Ku-band feed waveguide network, and adopt simple the operational solution with “dual frequency area”, please refer to below drawing.At this time, 4/ 6GHz circular Polarizer adopt cavate type dielectric sheet circular Polarization, in dual frequency area, after fine debug, it can make circular Pol. Axis ratio is better than 1dB. If the antenna works only on single polarization, in the solution with “dual frequency area”, remove the two frequency-division OMT.