Cavity-Backed Slot-Coupled Patch Antenna Array With Dual Slant Polarization for Millimeter-Wave Base Station Applications

This paper presents a novel dual slant polarized antenna for millimeter-wave (mmWave) base stations. Compared with the traditional slant polarized mmWave antennas, the proposed antenna offers the advantages of high cross-polarization discrimination (XPD), good aperture efficiency, simple structure, and low profile. The corner-fed substrate integrated waveguide (SIW) cavity is adopted to improve the port isolation and XPD of this slot-coupled antenna. Four corner-truncated patches connected by a thin cross strip are placed over the SIW cavity to increase the operation bandwidth. Then, a 2×8 antenna array is designed to exemplify the antenna element performance. To improve impedance matching, a shorted patch is introduced in designing the series feeding network and the power divider. The experimental results show that the 2-dB-down gain bandwidth of the proposed antenna array reaches 6.0% and the port isolation is better than 20 dB. The gain and XPD of the antenna array measure 16.7 dBi and 25 dB at the center frequency, respectively