Cavity‐backed substrate integrated waveguide MIMO element with enhanced isolation for 5G communication.

Summary: This article communicates a novel compact four‐element orthogonal cavity‐backed antenna for 5G applications with enhanced isolation. The proposed dumbbell‐shaped substrate integrated waveguide–multiple input/multiple output (SIW‐MIMO) antenna resonate at 5.25 GHz (sub‐6 GHz) based on vias and resonate at 27 GHz (mm‐wave) with copper filling vias using FR‐4 substrate. Both prototypes are separately designed, fabricated, and tested using same dimension (40 mm × 40 mm × 1.6 mm) as well as same radiating structure. Moreover, SIW MIMO antenna design performances are compared between FR‐4 and Rogers RT/Duroid substrate. Deployment of SIW technique in MIMO antenna minimizes the antenna footprint and mutual coupling without involving any decoupling structure. The antenna simulation characteristics of both operating bands are compared and validated with the measurement results. Furthermore, the MIMO diversity parameters are examined. [ABSTRACT FROM AUTHOR]