On Sidelobe Problem of Configured Array Antennas

A sidelobe problem that appears in some configurations of dual linear polarized patch antenna array is discussed. The properties of patch radiation patterns which cause such problem are identified and related to the asymmetry of the probe location with respect to the center of the patch antenna. The requirement of the element radiation pattern to avoid the increased sidelobe is calculated. Radiation patterns of a symmetrical crossed dipole antenna which meet the above-mentioned requirement have been utilized to form planar arrays with different configurations. The results indicate that the sidelobe issue that appears with the patch antenna will no longer exist in the proposed crossed dipole array antenna. The symmetry feature, emphasized in this paper, can be applied to any future element to attain low cross-polarization with removed sidelobe problems in their corresponding imaged array configurations.