Frequency Reconfigurable MIMO Antenna Design for Sub 6 GHz Smartphone Applications

The attractive features of reconfigurable antennas have made them widely popular in the field of wireless communications. Here is an innovative design for reconfigurable MIMO antennas applicable to future smartphones. Eight reconfigurable open-ended slot radiators are etched onto the corners of the handsets and have miniaturized sizes. The antenna elements of the introduced MIMO design have been fed using rectangular microstrip lines from another side of the substrate. It has a simple configuration with ease of fabrication. By switching the ON/OFF states of the embedded PIN diodes in the slots, the frequency reconfigurability characteristic can be achieved to switch the antenna operation between 2.6 and 3.6 GHz. For S11 ≤ -10 dB, the antenna resonators provide good impedance bandwidths of 200 and 350 MHz for the OFF/ON states of the embedded diodes, respectively. The antenna elements exhibit quasi-end-fire radiations supporting half-space coverage. Its critical properties are studied in detail. It has been determined that the optimal S-parameters, patterns, and gain are all achievable with the planned 8×8 MIMO array design and meet the needs of future handheld smartphones for sub-6 GHz 5G applications.