Broadband Conjugate Matched Feed Horn-A Novel Concept

This letter presents a novel concept for designing a broadband conjugate matched feed horn to cancel the high unwanted cross-polar components generated because of offset reflector geometry having low F/D and high offset angle. A new kind of symmetrical cascaded discontinuities is proposed in circular waveguide for broadband operation of conjugate matched feed. The designed feed has been used to illuminate an offset parabolic reflector antenna, and the secondary radiation patterns have been computed. The designs of feeds have been presented for different F/D's. Significant improvement in the cross polarization is achieved over 10% frequency bandwidth at Ku-band.