Design and Implementation of Reconfigurable MIMO Antenna Based on Diodes for 5G Mid/High Frequencies

This paper presents a reconfigurable quad-element frequency-MIMO antenna designed to work at sub-6 GHz and 38 GHz of the fifth generation (5G) spectrum. The proposed design uses orthogonal radiating elements to provide more isolation (>15 dB) and pattern diversity. The antenna is fabricated on a Rogers RT/Duroid 5880 substrate with dimensions of , a loss tangent of 0.0009, and a dielectric constant of 2.2. Switching between the far diverse bands of 5G communications using a MIMO reconfigurable antenna is a significant way of this work aims to perform. The RLC equivalent circuit's ON/OFF response determines two types of PIN diodes used that perform differently. Diodes used in mid/high-frequency 5G bands are evaluated to choose the best of the target frequencies. According to CST simulations, SMPPSC79 diodes function best at 5.15 GHz with (4.58-6.45) GHz bandwidth running, and MACOM MADP-000907-14020 diodes perform best at 38 GHz with (36.2-39.6) GHz operation bandwidth. High performance is obtained with a diversity gain of 9.8 and an envelope correlation coefficient of less than 0.04. Additionally, the Antenna peaks at a gain of 6.14dB and a total efficiency of 87% in the two frequency bands. These results suggest that the frequency-reconfigurable MIMO antenna is suitable for 5G applications.