A Method to Improve Bandwidth of Circularly Polarized Asymmetric Beam Horns

A design method is presented to improve the bandwidth of a circularly polarized horn with asymmetric beam (50° × 30°) coverage. This paper reports that by integrating the phase shifting section in an asymmetric dual mode horn, the over all length of circularly polarized horn can be reduced by about 23%. The phase dispersion characteristics of dual mode asymmetric beam horns with different axial lengths and dielectric phase-shifters with different thicknesses is analysed. The authors suggest that by proper selection of horn and dielectric phase shifter, broadband quadrature phase requirement for circularly polarized horns can be obtained. A circularly polarized broadband asymmetric beam ridged horn has been developed and the results are presented.