UWB CPW fed 4-port connected ground MIMO antenna for sub-millimeter-wave 5G applications

This paper embodies the design and development of a compact Coplanar Waveguide
(CPW) fed connected ground Multiple- Input-Multiple-Output (MIMO) antennas operating in
the sub-millimeter-wave 5G New Radio (NR) n257/n258/n261 bands. The planar geometry leads
to a small and compact structure while achieving a wide operating bandwidth, high gain, and better
radiation efficiency. The top surface of the antenna comprises a modified CPW in the form of two
circular structures that feeds the centrally slotted circular patch. The single antenna structure is
arranged in a rotational orthogonal manner forming a 4-port structure. The ground plane on the
bottom of a 4-port structure is connected using a circular ring which is carefully optimized for
achieving isolation levels>20 dB across the band of interest. The sub-mm-wave resonating 4-
port antenna achieves a compact size of 24 24 mm2
, a wide bandwidth of 24.8–44.45 GHz
(79.35%), the maximum gain of 8.6dBi, and minimum efficiency of 85% across the bands of
interest. The proposed antenna element is fabricated over Rogers 5880 substrate and experimental
tests are carried out, where a good correlation between the scattering parameters, transmission