A Novel High-Isolation Positive-and-Negative-45-Degree Dual-Polarization 5G mmWave Micro Base Station Antenna

In this paper, a slot-coupled dual-polarization micro base station antenna based on a vertical feed structure is proposed. The structural design of the double-layer patch allows the antenna to have two resonance points. When the resonance points are close to each other, the bandwidth of the antenna is increased. Four circular metal through-holes (or via holes) are used to improve the impedance matching of the antenna, resulting in an operating bandwidth of 24.14-29.08 GHz with voltage standing wave ratio (VSWR) of less than 1.5. The antenna also has a high isolation of less than -30 dB. In addition, the cross-polarization performance of the antenna exceeds 15 dB, which meets the standards of base station antennas. At the same time, the antenna has a low profile feature, with a thickness of 1.3 mm (about 0.11λ at 26 GHz) and a compact size of 6 mm × 6 mm ( about 0.52λ × 0.52λ at 26 GHz ). This antenna has the potential for large-scale multiple-input multiple-output (MIMO) applications.