Design of an X-band dual circularly polarized offset reflector antenna

A design of compact X-band dual circularly-polarized offset reflector antenna is described for the radar satellite system. The antenna is composed of a metallic reflector and a horn feed. By introducing the septum polarizer in the horn feed, it makes a more compact size for reduced space. Meanwhile, it is easier for the horn feed to reach the far field boundary condition. The offset reflector has obtained the circularly polarized radiation pattern of above 30dB gain, which the side lobe is less than -24dB; The axial ratio of the direction of the maximum radiation is below 1dB. And the two ports isolation is under -20dB at the center of the frequency of 8GHz. This configuration meet the reliability and consistency requirements for the space.