Design of Dual-Band 4-Port Flexible MIMO Antenna for mm-Wave Technologies and Wearable Electronics

In this paper, a dual-band 4-port Multiple Input Multiple Output (MIMO) antenna with very small footprints of $16 \times 12 \times 0.25$ mm3 is proposed for mm-wave applications. The proposed antenna operates in dual frequency bands at 28 GHz and 41.69 GHz. The isolation of the MIMO antenna is achieved >20dB at both the operating frequency bands by etching the slot at optimized position in the ground plane. The calculated diversity parameters of the antenna are acceptable for MIMO applications. The realized peak gain, Envelope Correlation Coefficient (ECC) and Diversity Gain (DG) are found to be 6.05 dBi, $\le 0.10$ , and 9.89 dB, respectively. Moreover, the Mean Effective Gain (MEG), Channel Capacity Loss (CCL) and Total Active Reflection Coefficient (TARC) are evaluated to verify the proposed antenna performance in MIMO technology. The channel capacity is evaluated to demonstrate the superiority of the MIMO antenna over single port antenna. Bending analysis of the antenna is also done to check the feasibility of this antenna for high data rate mm-wave wearable applications. In addition to that, antenna reflection coefficient is measured on chest and hand of human body for wireless body area network. Finally, to ensure the electromagnetic radiation safety, the specific absorption ratio (SAR) is evaluated at 28/41.69 GHz for input power of 500mW and found within the acceptable range.