Y.V. Korotetskiy, A.M. Shitikov, V.V. Denisenko
As a rule, calibration of PAA is preformed with a calibration probe in a far field of antenna under test. It is reasonable to assume wave that reached PAA aperture as plane, with constant phase and amplitude. But in some cases PAA calibration is performed by calibration probe located in near field of PAA. Recalculation of initial complex weights to the far field is commit with taking into account calibration probe coordinates relative to the PAA. In this paper, errors of probe coordinates determination influences on calibration results and beam shape are considered. Distortion influences along the PAA aperture and parallel to vertical axis of it are separately discussed.
Equations for aperture phase errors are obtained. Shown, that phase errors because of distortions along the aperture are described by cubic function, and phase errors because of distortions parallel to vertical axis of the aperture are described by quadratic function. Proved, that distortions of probe location along the aperture leads to further degradation of beam pointing than distortions parallel to vertical axis of the aperture. On the other hand, distortions of probe location parallel to aperture vertical axis leads to degradation of beam shape.