Edge diffractions impact on the cross polarization performance of active phased array antennas

Abstract

This paper examines the impact of diffracted fields on the cross-polarization performance of finite array antennas. The investigation included the calculation, simulation and measurement of several antenna prototypes with different element positions and different ground planes sizes. Characterization of the induced cross-polarization in a finite array with discontinusities in the ground plane was also performed. Excellent agreement between simulations and the actual measurements of eight antenna prototypes were obtained. The results demonstrated that the cross-polarization of the antenna elements in the array can be significantly impacted by the diffracted fields of the external and internal edges or discontinuities.