Integration of two dual-port substrate integrated waveguide based MIMO antennas on a common substrate for 5G millimeter wave applications

This paper presents method for integrating two dual port multiple input multiple output (MIMO) antennas on a common substrate based on substrate integrated waveguide (SIW) technology. One of the dual port MIMO antennas (MIMO_1) resonates at 31.2 GHz with an impedance bandwidth of 1 GHz while the other dual port MIMO antenna (MIMO_2) exhibits an impedance bandwidth of 925 MHz and resonates at 36 GHz. The radiators etched on the SIW cavities are complementary slotted annular rings (CSAR). Isolation between the ports is more than 20 dB which is inherently achieved by SIW cavity backed structures. The MIMO antenna realized at 31.2 GHz exhibit a peak realized gain of 8.5 dBi while the MIMO antenna realized at 36 GHz displays a peak gain of 9.8 dBi. The diversity gain of both the MIMO antennas is around 9.9 dB and the envelope correlation coefficient (ECC) of the MIMO antenna realized at 31 GHz is below 0.004 while the ECC of MIMO antenna at 36 GHz is below 0.006. It is also confirmed that simulated results closely correlate with the measurement results.