UWB Connected Ground Transparent 4-Port Flexible MIMO Antenna for IoT Applications

A 4-port MIMO antenna, featuring transparency and flexibility with a low profile of
$0.47\lambda \times 0.58\lambda \times 0.010\lambda $
(at 3.19 GHz) is proposed. Transparency and flexibility of the antenna are achieved by utilizing materials like PET and silver oxide. The fundamental antenna comprises a semi-hollow circular structure with notches on the upper side and a lower side consisting of a partial ground to attain an ultrawideband response. To enable MIMO capability, four identical elements are strategically positioned in a sequential rotational arrangement, effectively realizing the diversity performance. A centrally positioned circular slotted structure, linked by vertical lines, establishes the ground connection between the elements. By upholding a shared reference, the isolation surpasses 20 dB. The antenna exhibits a peak gain of 2.49 dBi and maintains an efficiency greater than 40%. It also achieves an impressive 10-dB impedance bandwidth (IBW) spanning (97.83%) from 3.19 to 9.30 GHz, while maintaining an envelope correlation coefficient (ECC) of under 0.1. The decent results of S-parameters and ECC assessments under bending conditions, as well as a comprehensive time-domain analysis, all of which underscore its outstanding performance. The UWB flexible transparent MIMO antenna fulfills crucial criteria for IoT applications, offering high data rates, spectrum efficiency, adaptability, and easy integration. This technology holds significant promise for the rapidly growing IoT ecosystem.