A CPW-fed dual band four-port MIMO antenna based on liquid crystal polymer for flexible IoT applications

A 2 x 2 dual band MIMO flexible antenna with a low profile and CPW feeding is designed for Internet of Things (IoT) domains, operating in 5G (3.3-3.6/4.8-5.0 GHz), WiMAX (5.25-5.85 GHz) and WLAN (5.15-5.35/5.725-5.825 GHz) bands. Two resonant frequencies are generated by L-shaped branches and a rectangular monopole. The mentioned MIMO antenna comprises four elements arranged vertically. With the addition of an orthogonal branch, significant isolation is attained, which exceeds 21 dB in the entire bands. The four-element MIMO antenna is fabricated and experimented to analyze the performance. According to the measurement, the antenna can operate bandwidth covering 3.156-3.84 GHz (19.55%) and 4.638-6.348 GHz (31.13%). Furthermore, the provided four-element MIMO antenna possesses a number of advantageous properties, such as ECC, DG, and TARC, indicating its suitability for 5G/WiMAX/WLAN applications. In accordance with the results of bending measurement and human body influence, it is evident that the presented liquid crystal polymer antenna could be an ideal candidate for integrating into wearable 5G/WiMAX/WLAN devices.