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.