The phase center of horn antennas

The calculation of phase centers for rectangular and diagonal horns is presented. The calculation is based on a vector approach, by deriving the phase center from the expressions for the far field. Different expressions are derived for the phase center of the
E
and
H
planes. The phase center for an arbitrary plane is calculated from the
E-
and
H
-plane phase centers. Graphs are presented showing the dependence of the phase centers on horn dimensions.