In this paper, a compact multiple-input-multiple-output (MIMO) antenna is proposed for ultra wideband (UWB) communication. The UWB MIMO antenna consists of two identical monopole antenna elements with a comb-line structure on the ground plane to improve impedance matching and enhance isolation. Simulation and measurement have been analysed in terms of reflection coefficient, mutual coupling, dispersion diagram, radiation pattern, peak gain, efficiencyand envelope correlation coefficient. Results show that the antenna has an impedance bandwidth larger than 3.1-10.6 GHz, mutual coupling between the two ports lower than -25 dB and envelope correlation coefficient less than 0.001 across the UWB band. The proposed antenna has a compact size of 26×31 mm2. All the measured and calculated results show that the proposed UWB MIMO antenna is a good candidate for UWB MIMO systems.
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