A radio antenna is designed for use on a circuit board having a slot. The antenna is shaped such that one radiator segment is located in the slot while the other segment is located outside the slot. As such, the total thickness of the circuit board and the disposed antenna can be reduced. The antenna can be a chip antenna having a support block for disposing the radiator segments on opposite sides of the support block. The support block can have steps so that one or more different radiator segments can be disposed on the step surfaces, and the circuit board has a plurality of electrically conductive strips separately connected to the radiator segments on the step surfaces to provide grounding and feed to the antenna.