DOA and polarization accuracy study for an imperfect dual-polarized antenna array

In this paper, a realistic array model for dual-polarized elements that includes the cross polarization ratio is introduced. This parameter reveals element imperfections due to polarization impurity. For the introduced array model, the Cramér-Rao bound on the direction of arrival (DOA) and polarization accuracy is derived. This asymptotic estimation accuracy can be descriptively interpreted. In simulations, we investigated how the estimation accuracy is affected by the array and source parameters. It turns out that especially the polarization accuracy depends significantly on the polarization purity.