A Series fed Planar Array-based 4-port MIMO Antenna for 5G mmWave IoT Applications

This paper presents the design of a series fed planar array-based 4-port multiple-input-multiple-output (MIMO) antenna for 28 GHz Internet of Things (IoT) applications. The unit element comprises a conventional rectangular patch-shaped series array antenna offering high gain along with loaded patches to suppress the side lobe level. The unit element of the MIMO antenna is designed using a 0.787mm thick Rogers RT5880 having an overall compact size of 16mm × 16 mm. Afterward, to meet the requirements of modern 5G systems a MIMO antenna is constructed by utilizing unit elements in such a way that each element is rotated 90° with reference to the previous element. The MIMO antenna also offers a compact size of
$\boldsymbol{32}\mathbf{mm}\times \boldsymbol{32}\ \mathbf{mm}$
having an impedance bandwidth ranging from 27.66 GHz to 29.14 GHz, which refers to 5.21 % of the central frequency. The MIMO performance parameters show that the proposed antenna offers a peak gain of 10.6 dBi along with low mutual coupling and envelope correlation coefficient (ECC) of
$< -40$
dB and
$<$
0.0001, respectively. The strong performance parameter of the single element as well as the MIMO antenna makes the proposed work a strong candidate for mm-wave IoT applications.