An antenna (100) enables improved multi-band operation for a portable communication device, such as a portable two-way radio. The antenna structure is formed of a first radiator element (104) fed through a single radio frequency (RF) feed port (118) and terminated on the input of a transmission line (108). The transmission line (108) is routed along a ground plane reference mass (102) towards a second radiator element (106). Applying the antenna structure to a radio embodiment, the first radiator element (104) is placed at a bottom side of a portable radio device, the first radiator element being fed through the single RF feed port and terminated on the input of the transmission line. The transmission line is routed along the ground plane reference mass towards the second radiator element placed on a top side of the portable radio.