Wideband 32-Element 3D-MIMO antenna for vehicular applications

A wideband 32-element vehicular 3D-MIMO system is proposed by utilizing eight-element MIMO antenna for Internet-of-Vehicle/Vehicle-to-Everything. The eight-element MIMO antenna consists of four sets of two identical antenna elements are arranged 90⁰ symmetrically on an octagon-shaped substrate cross-section area of 0.4374 ${\lambda }_0^2$. A combination of ground stubs between two same oriented antennas is loaded with shared ground at the bottom of the same substrate for better matching and low correlation, which are fed through the tapered microstrip line. Similarly, dual I-shaped stubs interconnected with shared ground for high isolation between a pair of corner elements. The proposed antenna achieved measured impedance bandwidth range (S_ij ∈ i = j <  − 10 dB) of 3.03–15.33 GHz with a maximum mutual coupling (S_ij ∈ i ≠ j) value of − 15.5 dB. Furthermore, a set of eight-element MIMO antenna with extended ground is vertically orthogonally symmetrically rotated around the central axis, forming a 32-element 3D-MIMO antenna and its found results are almost close to eight-element antenna with an enhanced peak gain value of 12.1 dBi. The performances of the 3D-MIMO antenna with radome and large metallic sheet are also examined. The satisfactory results observed in the 3D system-in-package highlight its capability for advanced vehicular communication.