HIGH ISOLATION FOUR-PORT WRENCH SHAPED COMPACT UWB MIMO ANTENNA FOR 3.1-10.6 GHZ BAND
Gayatri Tangirala, Garikipati Srinivasu, Durbhakula Manikya Krishna Krishna Chaitanya, Virendra Kumar Sharma
Abstract
This present article reports a high isolation four-port Wrench shaped compact UWB MIMO antenna with a novel decoupling network in the ground plane, and its step-by-step evolution is presented for 3.1-10.6 GHz. The proposed four-port MIMO antenna is fabricated on an FR4 substrate of size 44 44 mm 2 (0.342 0 0.342 0 ), where 0 is a free space wavelength at 2.33 GHz, with 7 mm edgeto-edge spacing between the radiating elements. It consists of four orthogonal symmetrically placed identical radiating elements each of which has a Wrench-shaped circular patch with a rectangular slot cut in the partial ground. The performance characteristics of this MIMO antenna are reflection coefficients S 11 -10 dB in the range from 2.33 GHz to 11.7 GHz, mutual coupling coefficients S 21 -28.24 dB, and S 31 -22.35 dB. The maximum peak gain is 5.15 dBi at 9.2 GHz, and minimum is 1.27 dBi at 3.1 GHz. The maximum efficiency is 98% at 4.66 GHz, and the minimum is 93% at 6 GHz. The diversity parameters of proposed four-port MIMO antenna are reported as ECC 0.2, DG 10, TARC -10 dB, the ratio of MEG between any two elements is near unity, and CCL < 0.38 bits/s/Hz in the band of interest. The design is fabricated and measured. The measured and simulated results are in good agreement and are within the permissible limits.