An antenna radiator assembly (201) and radio communications assembly (200) comprising a circuit board (210) supporting electrical conductors (225), one of the electrical conductors (225) being coupled to a feed point (130), and the circuit board (210) having a ground plane (140) formed from at least one conductive sheet. There is a tuning plate (132), a parasitic tuning line (150), a switching unit (160) selectively electrically coupling the tuning plate (132) to the tuning line (150). There is also an antenna radiator element (107) spaced from the circuit board (210) and coupled to the feed point (130), and when viewed in plan view there is an overlapping area where an overlapping surface area of the antenna radiator element (107) overlaps an overlapping surface area of the circuit board (210) thereby forming a sandwiched dielectric region therebetween, the sandwiched dielectric region providing capacitive coupling of the tuning plate (132) and the antenna radiator element (107); and a ground connector (131) inductively coupling the antenna radiator element (107) to the ground plane (140), wherein the tuning plate (132) is disposed in the overlapping surface area of the circuit board (210).