Precision phase center measurements of horn antennas

In many applications such as precision direction finding systems, high-resolution monopulse systems, and interferometers it has become necessary to determine the phase patterns of the radiating element to a high degree of accuracy. A precision phase measurement technique for determining the phase centers of horn antennas at band is presented. The results indicate that an apparent phase center of radiation can be determined to within electrical degrees for horn apertures as large as five inches.