Beam correction of a shared-arm dipole array for imaging radar applications

A 2-port shared-arm dipole array is designed and its beam pattern investigated. In designing a dipole array for near-field imaging, longitudinal arrangement of the elements may become a problem due to the antenna spacing limit for alias-free sampling. The proposed shared-arm dipole array is designed such that the two adjacent dipole elements share a single dipole arm, achieving an alias-free sampling in the aperture domain. In this paper, a simplified 2-port array is designed for a proof-of-concept. The beam pattern of the initial array with unloaded arms is shown to be tilted. The beam is corrected by resistively loading the arms.