A Novel Approach for Low Mutual Coupling and Ultra-Compact Two Port Mimo Antenna Development for UWB Wireless Applications

In this paper, a novel MIMO antenna operating in the UWB frequency band is presented. The proposed new antenna shape is derived from the conventional circular ring patch antenna having a partial ground plane. An array of three Quad-G Shaped Metamaterial structure was used between the antenna elements of the two port MIMO antenna to expand the bandwidth in lower frequency band of UWB application (below 5.567GHz) and reduces the mutual coupling in such expanded band. The proposed MIMO antenna operates over a bandwidth of 8GHz from 4GHz to 12GHz. Over the entire bandwidth, the mutual coupling between antenna element is less than -19.0dB with an inter-element separation  of mm. The overall optimized dimensions of the proposed antenna is   for a free-space wavelength, λ, calculated at 4GHz. The radiation pattern of the proposed MIMO antenna was analyzed using Combined Results Technique (CRT) integrated in CST microwave studio. The obtained peak radiation efficiency and gain is 83.0% and 5.57 dB respectively.  The MIMO Performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), Mean Effective Gain (MEG), and multiplexing efficiency are evaluated and compared to the standard values. The proposed antenna was compared to other antennas in literature. It has found that the key benefit of the present method was observed in achieving the highly miniaturized overall antenna dimension having good MIMO system performance metrics and better radiation characteristic. The proposed antenna was fabricated and measure. The measured and simulated values are found to be in good agreement.