A slotted frustum-shaped 4 x 4 MIMO dielectric resonator antenna with enhanced isolation for 5G Wi-Fi applications

In this paper, a slotted frustum-shaped 4 x 4 multiple-input multipleoutput (MIMO) dielectric resonator antenna (DRA) is designed and developed for portable 5G Wi-Fi (5.15-5.85 GHz) applications. The DRA is excited by HEM11 delta and HEM21 delta modes. A slotted right-angle frustum-shaped (SRFS) structure of alumina material as a dielectric resonator (DR) is positioned on the ground plane of the FR4 substrate to design a DRA. Based on the designed DRA, a compact (2.57 lambda(g) x 2.57 lambda(g), where lambda(g) is guided wavelength and calculated at a lower cutoff frequency, 5.0 GHz, for epsilon(f) of 4.4) 4 x 4 MIMO antenna with high isolation of greater than 27.13 dB (from 5.0 to 6.1 GHz) and 24.3 dB (from 6.1 to 6.25 GHz) is proposed. The developed MIMO antenna's measured working frequency ranges from 5.0 to 6.25 GHz, with an impedance bandwidth, BWi of 22.22%, peak gain, G(P) of 5.85 dBi and an average peak gain, G(av) of 5.25 dBi. The calculated MIMO antenna's diversity performance parameters, channel capacity loss (C-CL(ij)), diversity gain (D-G(ij)), envelop correlation coefficient (E-CC(ij)), mean effective gain (M-EG(i)), total active reflection coefficient (T-ARC), and channel capacity (C-C) are obtained as <0.17 bits/sec/Hz, >9.99 dB, <0.0301, < - 6.06 dB, < - 12.5 dB, and <21.6 bits/sec/Hz, respectively. The agreement between the simulation and measurement results is found to be remarkably consistent.