Design of a compact wearable ultrawideband MIMO antenna with improved portisolation


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 stubcomprising of eight branches is introduced in the middle position of the partially etched antenna ground for improvingthe characteristics of port isolation. The proposed design occupies the frequency spectrum operating from 1.71 to12.63 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) andthe downlink defense band (7.2-7.5GHz). The antenna is able to maintain isolation between the ports>22dB across theentire UWB frequency spectrum. The coe?icient of the envelope correlation for the whole operating band was observedto be<0.012 along with a very high diversity gain>9.9. The channel power loss of the proposed wearable UWB MIMOantenna is found to be<0.27 bit/s/Hz. The suggested UWB MIMO antenna, fascinated with optimization, covers anarea of 35 × 35 mm2. The suggested design is also able to perform satisfactorily when attached on-body. Simulationand testing fairly identified the performance of the antenna and rendered it to be an upstanding choice for wearableUWB applications.

Keywords: Wearable antennas, diversity gain, multi-in-multi-out, total active reflection coefficient, ultrawidebandspectrum

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