Multi-Mode Dual-Polarized Cavity Backed Patch Antenna Array for 5G Mobile Devices

This paper proposes a dual-polarised cavity backed patch antenna for next generation phased arrays for mobile handsets. The antenna exhibits multi-band performance, allowing to cover the 5G bands n257 (26.5–29.5 GHz), n258 (24.25–27.5 GHz), n261 (27.5–28.35 GHz) and a portion of band n260 (37–40 GHz). Two orthogonal modes are excited in the substrate integrated waveguide (SIW) cavity and show similar impedance matching and symmetric radiation patterns. A parasitic element is introduced on top of the cavity and shifted off-centre to improve the port-to-port isolation and guide the main beam. A parametric study of the antenna dimensions is conducted to verify the multi-resonance operating mechanism. The design is validated by the measurements of the fabricated four-element array. The array scanning angle is from −35° to 38° for V-pol and from −29° to 31° for H-pol at 28 GHz, where the realised gain raises from 8 to 12 dBi.