A compact tri-band flexible mimo antenna based on liquid crystal polymer for wearable applications

In this paper, a compact tri-band flexible MIMO antenna based on liquid crystal polymer (LCP) is designed to operate in WLAN and WiMAX bands. The antenna consists of two identical antenna elements. The isolation structure includes a ground slot, two I-shaped branches, and a parasitic strip. The measured results show that the impedance bandwidth (S11 < −10 dB) covers three frequency bands of 2.38–2.55 GHz, 3.37–3.60 GHz, and 4.92–5.37 GHz, and the S21 of working bands is basically better than −19 dB. Moreover, the flexibility of the MIMO antenna is analyzed at different bent cases. The specific absorption ratio (SAR) values are obtained by simulating the model of antenna approaching human body. The simulated results show that the SAR value of the antenna meets the European Union (EU) standard. The proposed antenna demonstrates the characteristics of satisfactory radiation, high isolation, sound gain in working bands and flexibility, which has good application prospects in the wearable field. © 2021, Electromagnetics Academy. All rights reserved.