Isolation enhancement of the F-shaped four-port MIMO antenna for WiMAX, Wi-Fi, WLAN and ISM band applications using dielectric material

In this article, an F-shaped four-port multiple-input multiple-output (MIMO) antenna is designed and analyzed. In the designed antenna for achieving high isolation, we introduced a novel isolation technique that appears like plus-shaped wall placed in between the antenna elements. The antenna is designed on a low-cost FR-4 epoxy substrate with total dimensions of 0.61λ0×0.61λ0×0.03λ0 (31 mm × 31 mm × 1.58 mm) where λ0 is the free space wavelength at 5.8 GHz and experimentally verified. This MIMO antenna design covers operating the range of frequencies 5.47–6.20 GHz (|S11|<−10 dB) which provides a bandwidth of 730 MHz. In terms of performance, the proposed antenna achieves high isolation of <−45.52 dB with an improved reflection coefficient of −30.44 dB, a peak gain of 3.77 dBi and a radiation efficiency more than 82% across the entire operating band. Moreover, the achieved MIMO diversity parameters of the proposed antenna are envelope correlation coefficient < 0.005, diversity gain <9.99 dB, mean effective gain <−3 dB and total active reflection coefficient <−10 dB in the operating band of frequency. The simulated and measured results show a good agreement between them. Finally, after analyzing the performance of the proposed MIMO configuration, we can say that this antenna is suitable for C-band, WiMAX, Wireless-Fidelity (Wi-Fi), Wireless Local-Area Network (WLAN), Bluetooth and Industrial, Scientific, & Medical (ISM) bands applications.