Design of shared-arm dipole array for imaging radar applications

A shared-arm dipole array (SADA) is designed and its radiation pattern analysed. When using a 2D physical array to image a target, arranging the antenna elements in a longitudinal direction becomes problematic owing to the limited element spacing for alias-free sampling. Therefore, the proposed structure is designed such that two dipoles share a single arm, achieving proper space for antenna elements. As a proof-of-concept, a two-port SADA is designed. The initial array shows radiation pattern distortion, which may negatively affect the radar imaging performance. To correct this distortion, antenna arms are resistively loaded. The results show that resistive loading effectively corrects the tilted beam, allowing the proposed structure to be more suitable for imaging radar applications.