Compact Wideband Wide-Angle Scanning Millimeter-Wave Planar Antenna Array With WAIM

This letter proposes a compact millimeter-wave (mmWave) planar antenna array with wideband and wide-angle scanning capabilities. The proposed design incorporates a segmented patch to extend the bandwidth and utilizes metal vias to suppress nonradiative mode. A substrate-integrated back cavity structure is introduced to suppress surface waves, improving wide-angle impedance matching (WAIM) in the E-plane. In addition, a square-ring meta-surface enhances WAIM in the H-plane. A fabricated 6 × 6 array demonstrates a bandwidth of 23.16 GHz to 29.28 GHz (23.3%) and scanning ranges of $\bm {\pm 70^\circ }$ in the E-plane and $\bm {\pm 60^\circ }$ in the H-plane, providing a viable pathway for compact mmWave systems requiring concurrent wideband and wide-angle scanning.