Compact UWB MIMO Antenna With a Modified Back Reflector and Supported by Characteristic Mode Analysis for Wireless Communication Applications

This research presents a modified back reflector to increase isolation for a small ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna. The rectangular patch and narrow line strip on the bottom side of the substrate, arranged diagonally, make up this modified back reflector. The characteristic mode analysis provides a physical comprehension of the operating events that occur during the antenna’s evolution. The suggested antenna maintains an isolation level of more than 20.7 dB and has an operating bandwidth from 2.74 GHz to 14 GHz with a small dimension of 28.5 mm $\times 28.5$ mm $\times 1.6$ mm. Important factors that assess the effectiveness of the antenna are looked into, including radiation patterns, peak gain of 4.2 dB, radiation efficiency >85%, and MIMO diversity parameters. The suggested MIMO antenna is a feasible choice for UWB applications, as evidenced by the strong agreement between the measured and simulated results.