High gain dual-band circularly polarized two-port MIMO antenna with equivalent circuit for WiMAX/5G/C- and X-bands applications

A compact two-port novel geometry with microstrip fed wide slot equivalent circuit based dual-band MIMO antenna system of low specific absorption rate is presented. The proposed structure has two horizontal slotted patch with symmetrical chamfered at both corners, which are responsible for improving impedance bandwidth (IBW) and achieving wide axial ratio. The different cutting slots from the ground plane and vertical slot in MIMO antenna elements are responsible for enhancing isolation. The proposed antenna design covers -10 dB IBW ranging from 3.25 to 4.39 GHz and 6.74-8.41 GHz. This antenna radiates at 3.5 and 7.2 GHz with corresponding radiation efficiencies of 86.2 % and 92.32 %, isolation < -20.05 and < -29.71 dB, excellent peak gain 8.02 and 9.32 dB, while bandwidth of 1.14 GHz (29.84 %) and 1.67 GHz (22.05 %). Different diversity parameters for the proposed MIMO antenna have been obtained such as, envelope correlation coefficient < 0.0121 and < 0.0009, diversity gain nearly 9.87 and 9.99 dB, channel capacity loss < 0.0028 bits/s/Hz, and mean effective gain < -3 dB. The proposed work is printed on FR-4 epoxy substrate with overall electrical size of 0.29 lambda (0) x 0.61 lambda (0) x 0.018 lambda (0) at 3.5 GHz. Moreover, the suggested work also exhibits circular polarization ranging from 3.24-4.38, 5.27-7.2, 7.6-8.1 and 8.2-8.41 GHz. Finally, experimental analysis was done and the tested results exhibit good agreement with simulated results. The proposed structure is a suitable candidate for WiMAX/C-band, satellite for X-band and 5G LTE band applications.