Method for Surface-Waves Suppression in Millimeter-Wave PUMA

In this paper, a method is proposed to suppress the surface waves guided by the wide-angle impedance matching (WAIM) layer in millimeter-wave planar ultrawideband modular antennas. Based on the analysis of the magnetic-fields and Poynting-vector distributions, a novel metallic structure is proposed, which suppresses the surface-wave mode effectively. By adding the metallic structures at the critical positions within the WAIM layer, the surface waves are suppressed while maintaining good radiation. Consequently, the proposed antenna array can scan to ±60° in E/H planes with active VSWRs < 3 in 21–69GHz.