Substrate-integrated ultra-wideband low-profile wide-scanning phased array antenna

To meet the requirements of bandwidth, profile and scanning performance for modern multifunctional radar systems, an ultra-wideband phased array antenna operating in 2−6 GHz is proposed in this paper. The array element consists of dual-polarized printed dipole patches, unbalanced feeding baluns, the wide-angle impedance matching layer based on metasurface (MS-WAIM) and a metal plate. The introduction of MS-WAIM layer not only improves the scanning performance, but also reduces profile. In addition, periodic square holes are cut in each dielectric layer to suppress common-mode resonance and surface waves. The simulated results indicate that the proposed element can achieve ±60° scanning in E/H-planes with an active voltage standing wave ratio (VSWR) below 2.3 and an isolation between orthogonal ports better than 20 dB within 2−6 GHz. To verify the validity of this design, a prototype is manufactured and measured by using multi-layer printed circuit board (PCB) technology, and the measured results are in good agreement with the simulated ones. This antenna has the characteristics of ultra wideband, low profile, wide-angle scanning coverage, and substrate-integration, providing a novel antenna structure for multifunctional radar systems.