Polarization correction in dual-polarized phased arrays of flared notches

Though flared-notch radiators are capable of achieving very large bandwidths (10:1 or more) as radiating array elements, they are known to suffer from poor polarization purity when scanning in the diagonal plane (D-plane). This paper examines the polarization properties of dual-polarized arrays of flared notches as a function of frequency and the length/width ratio of the elements. Further, it is demonstrated through a combination of simulation and measurements that polarization degradation can largely be corrected for elements that have orthogonal feed ports. Though correctable, due to the nature of the polarization degradation that occurs in the D-plane, it is also shown that there is a limitation to the extent of correction that can be achieved.