Design and analysis of tetra-port MIMO antenna for next generation vehicular communication

The demand for advanced automotive applications necessitated the development of 5G/6G multiple-input-multiple-output (MIMO) antennas. This work presents a low-profile antenna resonating at 5.9 GHz, suitable for vehicle-to-vehicle communication applications. The resonance is achieved through the use of a defected ground structure and geometric modifications to the radiator. The single element antenna is converted into a MIMO antenna by employing the elements perpendicular to each other. The unit cell antenna has dimensions of 12 mm × 11 mm, and the MIMO antenna measures 42.44 mm × 43.56 mm. The antenna reflection coefficient has been evaluated and is found to be less than -10 dB across the operating band. The tetra-port MIMO antenna achieves greater than 20 dB isolation without the use of any isolation structures. The proposed antenna shows the gain of 3.8 dBi, and efficiency of 87% at the operating frequency. Diversity parameters are evaluated to better understand the performance of the suggested MIMO antenna. The proposed MIMO antenna exhibits an envelope correlation coefficient below 0.1, a diversity gain above 9.9 dB, a total active reflection coefficient below -10 dB, channel capacity loss below 0.4 bits/s/Hz and MEG ratio is close to unity. When installed in the vehicle, the antenna is unaffected by interference from nearby radiators and the metal body of the car.