Design, Fabrication and Characterization of a Three-Band, Four-Port Planar Mimo Antenna

A multiple-input multiple-output (MIMO) compact planar antenna was designed, manufactured and experimentally characterized. It operates in the (1.3–5.5) GHz frequency range and presents three resonant frequencies, with bandwidths of (330-540) MHz at a voltage standing wave ratio (VSWR) of 1.5. The 4-ports isolation was improved up to -14 dB with chain-shape parasitic elements. The antenna exhibits a quasi-omnidirectional radiation pattern with well-defined co- and cross-polarizations and provides gains of (3.9-5) dBi, while its efficiency varies in the interval (63-77) %. A very good correspondence between simulated and measured results confirms the validity of the proposed design. With its wideband operation and enhanced port isolation, this MIMO antenna system provides valuable advantages for various communication applications.