Effect of different truncation angles in spherical near-field measurements

In all antenna measurement scenarios the complete radiation pattern is not available or not measurable and this is mainly due to montage reasons, where the tower on which the antenna is mounted shadows the antenna´s back side; causing loss of information. Other scenarios might be that the operator is not interested in the complete radiation pattern of the antenna but in some specific solid angle or area. In this paper truncation effect will be investigated, in which the missing field range will simply be filled with zeros. It will be shown that the location at which one truncates has a direct effect on the accuracy of the reconstructed antenna pattern in the valid region.