Compact Broadband Four-Port MIMO Antenna for UAV to Assist Automotive Communication

A compact broadband four-port multiple-input multipleoutput (MIMO) antenna for UAV to assist automotive communication is proposed. By utilizing a 3D ground dielectric layer, the microstrip patch elements are vertically placed on each side of the cube to achieve omnidirectional coverage. Grounding branches are introduced on both sides of the radiating patch to realize short circuit, significantly improves impedance matching, resulting in a broadband of 4.16 GHz. 8.84 GHz and a compact size of 70 mm × 70 mm × 10 mm. Additionally, parasitic ground structures are incorporated inside the 3D ground dielectric layer, effectively enhancing port isolation. Measurements show that the port coupling coefficient is better than.18 dB in the entire frequency band, and it is even superior to.25 dB in the V2X frequency band. The envelope correlation coefficient remains below 0.0048 throughout the operating band. Furthermore, the diversity gain achieves 9.992 dB, while the channel capacity loss is maintained below 0.4 bits/s/Hz. This design provides an efficient and stable signal transmission solution for drone-assisted automotive communication systems