Design of reconfigurable coplanar waveguide-fed planar antenna for multiband multi-input-multi-output applications

A new design of frequency reconfigurable planar coplanar waveguide-fed array antenna for multiband MIMO (multi-input-multi-output) applications is presented in this study. The proposed two elements MIMO array antenna consists of two identical basic reconfigurable antenna elements. Each basic antenna structure consists of two quarterwave-length resonators and is capable of operating in WLAN (wireless area network) and WiMAX frequency bands. The centre frequencies of the operating bands are controllable independently by tuning the length of the corresponding resonators. Employing switches on the proposed structure has led to three different switchable operations [WiMAX (3.36-3.7 GHz), WLAN (5-5.8 GHz) and WiMAX and WLAN (3.17-3.77 and 5.13-5.88 GHz) simultaneously]. Moreover, by arranging the antenna elements in an orthogonal alignment in space and using polarisation diversity technique, the multipath performance of the presented MIMO antenna is improved. The fabricated reconfigurable MIMO antenna has a compact size of 48.5 x 25 mm(2) while having more than 16 dB isolation level between its ports for all its various switchable performances. The measured results reveal that the proposed antenna can be a good candidate for modern multiband MIMO applications.