Unique steering vector design of cross-dipole array with two pairs

To obtain a unique steering vector (SV) in the whole spherical space, the linear relationship of SVs in a cross-dipole array with two pairs (CAT) is studied. Unparallel plane CATs are proved to have the same linear-dependent steering vectors distribution area (LDSVA) as corresponding two-tripole arrays. Finally, a switched CAT with unique SVs (null LDSVA) is achieved.