A selectively coupled two-piece antenna for use in a mobile phone having a casing (102) and radio frequency (RF) communications circuitry (112) includes a composite radiator (206) that is selectively extendable from and retractable into the casing and a communications interface that is connected to the RF communications circuitry. The composite radiator has first and second radiating elements (208, 212), and a connecting element (210). When the composite radiator is extended, the connecting element connects the first and second radiating elements. In this position, the communications interface connects the RF communications circuitry to the first and second radiating elements. Thus, the RF communications circuitry transmits and/or receives RF signals through both the first and second radiating elements as a top loaded antenna. However, when the composite radiator is retracted, the connecting element electrically isolates the first and second radiating elements. In this position, the composite radiator electrically connects with the communications interface so that the first radiating element is electrically connected to the RF communications circuitry.