Design of a compact wearable ultrawideband MIMO antenna with improved port isolation

Abstract

This study presents a compact dual element wearable ultrawideband (UWB) multi-in multi-out (MIMO) antenna with increased port isolation. The suggested design consists of a jeans substrate in which a tree-fashioned stub comprising of eight branches is introduced in the middle position of the partially etched antenna ground for improving the characteristics of port isolation. The proposed design occupies the frequency spectrum operating from 1.71 to 12.63 GHz (impedance bandwidth of around 152.3 % ) and satisfies the bandwidth demands for WiMAX (3.2–3.8 GHz), WLAN (5.15–5.35/5.72–4.85 GHz), the C Downlink-uplink bands (3.7–4.2/5.9–6.425GHz), ITU bands (8–8.5GHz) and the downlink defense band (7.2–7.5GHz). The antenna is able to maintain isolation between the ports > 22dB across the entire UWB frequency spectrum. The coefficient of the envelope correlation for the whole operating band was observed to be 9.9. The channel power loss of the proposed wearable UWB MIMO antenna is found to be < 0.27 bit/s/Hz. The suggested UWB MIMO antenna, fascinated with optimization, covers an area of 35 × 35 mm 2 . The suggested design is also able to perform satisfactorily when attached on-body. Simulation and testing fairly identified the performance of the antenna and rendered it to be an upstanding choice for wearable UWB applications