LAUSR

This article presents a dual-band and dual-polarized microstrip antenna array with broadside beam scanning ability for millimeter-wave applications. Within a compact multilayer structure, wide bandwidth and high port isolation are achieved by using double-layer gridded patches with three groups of metallic via-fences. For beam scanning purpose, a prototype of $2 \times 2$ array is designed, fabricated, and tested. The experimental results agree well with the simulations. For both orthogonal polarizations, the −10 dB bandwidth covers 23.3–31.7 and 42.5–46.5 GHz with average gains of 12 and 13.1 dBi, respectively. A 3 dB beam scanning angle from −51° to 43° at 27 GHz and −28° to 30° at 45 GHz is obtained. The proposed array provides dual-band and wideband properties for dual orthogonal polarizations with competitive beam steering range and compact dimensions, as a feasible solution for fifth-generation (5G) millimeter-wave mobile communications.