A Compact Low-Profile Vehicular 5G MIMO Antenna System

This paper proposes a compact low-profile 5G Multiple-input multiple-output (MIMO) antenna system. The system comprises four antenna elements: two main antennas, and two diversity antennas. The two main antennas are symmetrical to each other, and both cover the identical frequency bands of 700 - 960 MHz and 1710 - 6000 MHz, while the two diversity antennas are also symmetrical to each other and cover the 1710-6000 MHz band. The proposed main antenna exhibits polarization orientation differences at different frequencies; thus, arranging four antennas enables adjacent antennas to have mutually orthogonal polarizations, thereby achieving low mutual coupling. Moreover, the overall size of the MIMO antenna system is only 74 mm × 74 mm × 11 mm, and the isolation between each antenna exceeds 10 dB. Experimental test results indicate that the MIMO antenna system performs excellently, meeting the requirements for practical engineering applications, and particularly demonstrates significant size advantages in MIMO antenna applications.